Cell Communication - 1

Save this PDF as:
 WORD  PNG  TXT  JPG

Size: px
Start display at page:

Download "Cell Communication - 1"

Transcription

1 Cell Communication - 1 Just as we communicate with other humans (a number of different ways), cells communicate with other cells, to interact with the external environment and to make appropriate responses within the cellular environment. Cellular communication is necessary to coordinate the myriad activities needed for any organism (unicellular or multicellular) to grow, develop and function. Fortunately for students studying biology, most groups of organisms use the same kinds of cell signals, once more affirming the uniformity of life processes. Cells typically use chemical signals for communication, but electromagnetic signals (light) and mechanical signals (pressure or touch) are not uncommon. Plants in particular respond to a host of external environmental signals. Nerve cells of animals are especially sensitive to stimuli (e.g., chemoreceptors, mechanoreceptors, photoreceptors, thermoreceptors, nocireceptors (pain), electroreceptors). However, cell-to-cell communication is most often chemical, and chemical communication is the subject of this section. Before we begin lets look at a few examples of cell signaling to give you an idea of what we mean: Cellular slime molds secrete chemicals that induce adjacent cells to aggregate into a multicellular "slug" when growth conditions are unfavorable. This slug can disassemble, migrate or form a resistant "fruiting body" depending on the conditions. Myxobacteria do a very similar aggregation forming a resistant colony "spore" when their nutrients are diminished. Many protists and other unicellular organisms are similar in dimension. Gender is determined by genetic "mating types". One individual recognizes an appropriate mate by secreting its mating factor (chemical) for which a compatible mate will have a receptor. In a similar fashion, the compatible mate will secrete its mating factor, for which the original cell has a receptor. These signals binding to the respective membrane receptors of the "mate" trigger the fusion of the two cells. Typically, once a zygote is formed, meiosis occurs and the new generation haploid cells are formed, half of each mating type. By the way, receptiveness to sexual reproduction is one of the more common uses of chemical signals. Female insects secrete pheromones that can be detected by males of the species in ppb as much as a mile distant. (Some orchids produce the same chemical signal to trick an unsuspecting male insect into pollinating the orchid.) Female pigs don't ovulate unless the appropriate male boar scent is detected. There are thousands of sexual selection examples involving chemical attractants.

2 Cell Communication - 2 Communication of Self In our discussion of membrane proteins we mentioned the recognition proteins, important to the immune system. They play a critical role in communicating to cells of our immune system and to our tissues in recognizing and determining identity. Each cell has unique surface identity markers. Many of these are glycolipds or a group of proteins called MHC (major histocompatibility complex) proteins. The markers that form the A B and O blood groups are examples of glycolipid identity markers. Most of the MHC proteins are immunoglobulins. A section of Biology 202 is devoted to discussion of the immune system and how it interacts with recognition markers. Signals and Receptor Proteins We have previously mentioned that membranes have signal transduction or receptor proteins that have attachment sites for chemical messengers, such as hormones. Receptor proteins are specific; each "fits" a specific chemical messenger molecule. The binding of the signal molecule to its protein receptor induces a conformational change in the receptor protein that ultimately leads to a response within the cell. Individual cells have different receptor proteins. This means that cells uniquely respond only to the signal molecules that are appropriate. Types of Cell Signaling There are a number of types of cell signaling mostly dependent on the distance between the signal and the responding cell. We will mention these briefly before turning to the mechanisms of signal receptors and the signal pathways involved in cell communication. Autocrine Signaling Direct Contact Signaling Paracrine Signaling Endocrine Signaling Synaptic Signaling Autocrine Signaling Cells can send intracellular signals that trigger receptors within their own membrane. Such signals often trigger differentiation in developmental processes.

3 Cell Communication - 3 Direct Contact Signaling Molecules on the surfaces of adjacent cells have direct contact with each other and specific surface molecules on plasma membranes can serve as signals. For example, cell recognition markers are important in embryo develop as they signal adjacent cells to specialize for a specific tissue type and/or inhibit specialization. Paracrine Signaling A signal molecule released by one cell travels through the extracellular environment and acts on the receptor molecule of adjacent cells in paracrine signaling. The influence of the signal molecule is short-lived, as it reacts with the receptor cell and is removed from the environment. Growth regulators are typically paracrine molecules. Endocrine Signaling We are probably most familiar with endocrine signals. Chemicals produced in one cell or tissue travel through the organism to the target cells and tissues. Many of these signal molecules are our regulatory hormones. Details of endocrine functions are discussed in both Biology 202 and 203. Synaptic Signaling The signal molecules of the nervous system of animals are chemical. Neurotransmitters, released at the axon end of one nerve cell traverse the space (called the synaptic cleft) to the target cells (receptor cells, nerve cells, or neuromuscular junction). Neurotransmitter signal molecules and nerve function are discussed in Biology 202.

4 Cell Communication - 4 Signal Pathways The mechanisms for chemical messaging that occur in yeasts, bacteria, plants and animals are remarkably similar in all groups. Receptor cells on the surface of the plasma membrane induce changes in the cell that elicit appropriate responses, generally some type of chemical reaction or series of metabolic reactions. The series of steps involved is referred to as a signal transduction pathway and there are a variety of methods for signaling. Signaling has been studied most in animals, and the emphasis in this section is on chemical messaging in animal cells. Table 7.1 in your text summarizes the signal receptor mechanisms.

5 Cell Communication - 5 Early Studies of Cell Signaling Earl Sutherland won a Nobel prize for his research on the chemical signaling. He specifically studied the role of epinephrine in promoting the conversion of glycogen to glucose-1-phosphate during stress responses, the effect of which is to mobilize fuel reserve molecules for cell respiration. He is responsible for first determining the stages of cell signaling. When you look at examples of cell signaling, what all have in common is that at some point a chemical signal attaches to a receptor molecule in a plasma membrane. This information carried by this signal molecule is changed in some way (hence the term "transduced") within the cell initiating a process that results in some kind of cellular response. The three stages of cell signaling are, therefore, reception, transduction and response. The three stages of chemical cell signaling: Reception The target cell must be able to detect that a signal is "arriving". This requires a chemical binding to a receptor molecule (protein), specialized for different functions. Most receptor molecules are found on the cell surface, but there area also intracellular receptors. Transduction - Initiating the Intracellular Signal The receptor molecule binds to the signal molecule in a method that brings about a change in the receptor molecule (often a conformational change). This change effectively translates (or transduces) the signal into a form that the target cell can respond to. This transduction may be a single step or a relay pathway of chemical reactions within the cell. Secondary messengers are important in the signal transduction. Response The cell makes an appropriate response to the signal. For example, the appropriate response to epinephrine (studied by Sutherland) in most target cells it the activation of the enzyme, glycogen phosphorylase, which catalyzes the conversion of glycogen to glucose-1-phosphate. Catalyzing a chemical reaction is just one response that can be made to an appropriate signal. A signal can activate genetic transcription, movement of cytoskeletal components, or other activities. Cell signals ensure that the right kind of activity occurs in the cell at the right time and in the proper cell conditions.

6 Cell Communication - 6 Let's look now at some specific details and examples of cell receptors and signal pathways. The Receptors A signal molecule binds to a specific receptor site on a membrane or within the cytoplasm or the nucleus of the cell for intracellular receptors. Ligand is a term used to describe any small molecule that binds to a larger molecule. Many signal molecules behave like ligands. The signaling molecule has a shape that fits into a portion of its receptor protein, just as a key fits into a specific lock so a door can be opened. Intracellular Receptors Intracellular receptors function with small signal molecules that can readily pass through the plasma membrane. Intracellular receptors either act as enzymes or gene regulators. Gene Regulator Intracellular Receptors Many of our steroid hormones function as signals for gene regulator receptors. These receptors have specific DNA binding sites that are normally blocked by an inhibitor protein. When activated by the signal molecule, the inhibitor is released so that the receptor can bind to DNA to initiate gene activity. Gene controls of transcription will be discussed in more detail later! Enzyme Intracellular Receptors Some enzymes require signal molecules to become active. Signal molecules function much the same way that co-factors and coenzymes work. Each has a binding site on the enzyme that alters the conformation of the enzyme so that the target substrate can "fit". Similarly, many of our digestive enzymes are produced in inactive forms and must be activated in the target location of the digestive system.

7 Cell Communication - 7 Cell Surface Receptors The signaling molecule has a shape that fits into a portion of its receptor protein in the plasma membrane. The signal transduction is then initiated in the membrane when the receptor protein reacts with its signal. Sometimes the signal molecule promotes a conformational change in the receptor molecule that activates the receptor to interact with a specific cellular molecule or an aggregation of receptor proteins In some cases, the ligand (signal molecule) causes an aggregation of receptor proteins in the plasma membrane. Researchers have determined a number of different types of cell surface receptors involved in signaling in animals. Receptors include: Gated Ion-Channel Receptors G-protein (Guanine-protein) Linked Receptors Protein-Kinase Receptors Ion-Channel Receptors As discussed previously, ion channels are gated pores in the plasma membrane that open and close in response to signals. The pores are highly specific and allow the flow of just one type of molecule (typically Na +, Ca ++ or K + ). Nerve transmission and muscle contraction rely on gated ion channels which, when open, rapidly cause a change in ion concentration as the ions flow through the pore. This change in the polarity of the cytoplasm triggers a reaction or relay reactions. Ligand binds, channel opens, Ligand dissociates, Ligand released ions flow through channel closes

8 Cell Communication - 8 G-Protein Linked Receptors There are a number or receptor molecules that must work with a special group of helper proteins in membranes called G-proteins. Receptor proteins that work with G-proteins have a common structure. Each is comprised of 7 alpha-helices (a motif) within the membrane, with an attachment site for the G-protein on the cytoplasmic side and for the signal molecule on the extracellular side of the membrane. How G-Proteins Work G-proteins are intermediates in cell signal pathways. In their non-active form, G- proteins have guanine diphosphate (GDP) attached. The active form of a G-protein has guanine triphosphate (GTP). GTP is formed when ATP is used to phosphorylate GDP. A ligand attaching to the receptor molecule triggers (by inducing a conformational change in) the receptor molecule to activate its associated G-protein by causing GTP to displace the inactive GDP on the G-protein. In general, the activated G-protein then binds to a specific enzyme in the membrane, activating the enzyme which catalyzes a signal pathway in the cell resulting in a specific cell response.

9 Cell Communication - 9 This activation is short-term. The GTP is rapidly hydrolyzed back to GDP in the cell by the enzymatic activity of the G-protein. (A G-protein serves as its own enzyme to catalyze the reaction of GTP --> GDP.) This prevents chemical reactions from occurring in the absence of the appropriate signal molecule. There are over 100 G-protein linked receptors. Although each is specific in function, they are closely related in structure. They are important in: genetic-gender reproduction neurotransmitters sensory reception (vision, taste and smell) embryonic development many hormone signals Many of the medicines in use today involve the mechanisms of G-proteins and is an active area of medical research.

10 Cell Communication - 10 Protein-Kinase Receptors Protein-kinase receptors are in the group of membrane proteins that have enzymatic activity. Tyrosine kinase receptors are common in animal cells. Serinethreonine kinases are also found. Protein kinases catalyze phosphorylation (using ATP) of a region of the receptor protein on the cytoplasmic side of the membrane when the signal molecule attaches to the surface. Relay proteins are then activated to elicit the appropriate cellular responses. Tyrosine kinase receptor molecules are pairs of small α helix chains of tyrosine attached to the inactive enzyme "tail" on the cytoplasmic side of the membrane, and to signal binding sites on the extracellular side of the membrane. Growth factors are typical signals for tyrosine kinase receptors. A signal molecule (ligand) attaching to the binding site of the tryosine kinase receptor triggers two tyrosine polypeptides to aggregate, forming a dimer. The dimer conformation promotes the phosphorylation of the tyrosine molecules of the opposite polypeptide in the dimer (using ATP). Each polypeptide is catalyzing the phosphorylation of the tyrosines of the opposite dimer component. The activated receptor is recognized by a number of relay proteins within the cell that undergo conformational changes when activated by the phosphorylated tyrosines. Multiple relay proteins can be activated at once so that a number of reactions can occur simultaneously within the cell. A multiple response is one of the primary differences between G-protein receptors and protein-kinase receptors. Some cancers may be caused by tyrosine-kinase receptors that aggregate (hence get phosphorylated) without the signal molecule.

11 Cell Communication - 11 Secondary Messengers, Pathways and Relay Proteins As you can see from the brief discussion so far, the transduction process (translation of a signal) often involves relays and pathways rather than a single action. Secondary messengers are important in relaying the message from the signal receptor within the cell. Pathways can provide more opportunities to coordinate and regulate cell activities and can also serve to amplify responses. The proteins involved in these pathways are called relay proteins because they are "relaying" the information from the signal to the target response. They also frequently serve to amplify the original signal to get a greater response. Secondary Messenger Molecules Small water-soluble molecules and ions can relay messages from the membrane proteins rapidly throughout the cytoplasm by diffusion. Relay substances work with both G-protein receptors and protein kinase receptors. Two of the most important secondary messengers are calcium ions and cyclic AMP. camp To provide an example of the use of camp as a secondary messenger, let's look at Earl Sutherland's work (the discover of the signal transduction pathway) on epinephrine as a signal that activates the conversion of glycogen to glucose-1- phosphate to rapidly process fuel molecules in response to stress situations. When epinephrine binds to its receptor G-protein, the response is an elevation in the concentration of cyclic AMP in the cell's cytosol. The G-protein receptor activates the plasma membrane enzyme, adenylyl cyclase which catalyzes the conversion of ATP to camp. The rapid increase in the concentration of camp activates a protein kinase pathway that ends in the conversion of glycogen to glucose-1-phosphate in the cell. Each step in the pathway activates an increasing number of molecules in the next step for a much greater total reaction in the end product. Looking at Sutherland's epinephrine example we see that a single epinephrine molecule attaching to a receptor protein in the plasma membrane can, because of the secondary messenger camp and the relay pathway, amplify the response a millionfold, bringing greater efficiency and timeliness in cell responses. (And when we are talking stress reaction, timeliness is important.)

12 Cell Communication - 12 camp works with a number of G-proteins and protein kinase receptors in cells, not just with epinephrine. In particular, camp activates a specific protein kinase, called protein-kinase A (which is a serine-threonine kinase). Protein-kinase A is an intermediate in a number of relay pathways in cells. As a feedback mechanism, camp is rapidly catalyzed to AMP, an inactive substance, in the absence of the signal molecule. The synthesis of camp can also be inhibited by a variety of molecules that block adenylyl cyclase (which prevents the synthesis of camp from ATP at the plasma membrane).

13 Cell Communication - 13 Ca ++ In animal cells, calcium ions are usually in a much higher concentration in the extracellular environment than within the cytosol. Within the cell, the ER serves as a Ca ++ reservoir. You will study the sarcoplasmic reticulum calcium reservoir needed for muscle contraction in Biology 202. Note: In humans, bone serves as a reservoir of calcium. Metabolic calcium needs take priority over structural needs. When calcium intake is low, calcium will be removed from bone to maintain appropriate blood (extracellular calcium) and cell calcium levels. Ca ++ often serves as a secondary messenger in the cytosol when its concentration is elevated by the actions of a signal molecule that results in the release of Ca ++ from the ER. As one would suspect by now, such activation requires a pathway and a number of molecules. A signal molecule binds to either a G-protein or a tyrosine-kinase receptor. The signal binding activates the membrane enzyme, phospholipase "C" which catalyzes the messenger inositol triphosphate (IP 3 ) derived from membrane phospholipids. Inositol triphosphate promotes the release of Ca ++ from the ER (by binding to a gated protein channel in the ER specific for Ca ++ ) Ca ++ then serves to activate any number of appropriate proteins to elicit cell responses, either by itself, or by binding to and activating the enzyme, calmodulin, which catalyzes or inhibits a number or relay protein kinase and protein phosphatase pathways in cells.

14 Cell Communication - 14 Relay Proteins Many signal transduction pathways use a sequence or relay to transmit the signal message within the cell. The typical mechanism for relay proteins to transmit information is phosphorylation of protein kinases. Relay proteins (which are protein kinases) catalyze the phosphorylation of two amino acids, threonine and serine, on their substrate proteins (the next relay protein in the pathway). Each phosphorylation causes a conformational change (the charged phosphate interacts with polar amino acids) in the substrate, activating it to catalyze the phosphorylation and conformational change of the next protein kinase in the pathway. Ultimately one reaches the end of the pathway, gets an active protein and appropriate cellular response. Relay Proteins Phosphorylation Cascade Although we associate the protein kinase relay pathways with a response in the cell that promotes a reaction, it is also important to note that the pathway can work to de-activate rather than activate, diminishing cell activity. That can be the appropriate response. Activity of protein kinases is also regulated by feedback mechanisms. A second set of proteins, the protein phosphatases, remove phosphates from protein kinases, stopping their activity. Protein phosphatases are active when the signal molecule for a protein kinase is absent, which shuts down that particular signal transduction pathway.

15 Cell Communication - 15 Amplification of the Response Amplification of response is common in both G-protein and Protein Kinase receptor signal transduction pathways. Using secondary messengers and relay pathways, a single signal molecule can effect a far greater response for more efficiency. Each step in the pathway triggers a greater number of molecules, for a cascading effect. Your text illustrates how signal amplification is accomplished with Rhodopsin, the G-protein-linked receptor important in vision. Each activated molecule in the relay triggers an ever increasing number of molecules so that the final relay is sufficient to send a message to the brain. Protein-kinase relays involving the cell-division promoting protein ras, are implicated in some cancers. A mutated ras becomes active all of the time, resulting in frequent, uncontrolled cell division.

16 Cell Communication - 16 Cellular Responses to Chemical Communication Signal Specificity We have seen in this discussion that chemical signaling involves 3 stages: reception, transduction and response. A number of times in discussing signal receptors and transduction we have alluded to the "appropriate response". The appropriate response may be a metabolic activity needed in the cell, a cell activity involving mechanical motion or rearrangement, active transport through a membrane via channel proteins, or regulating genetic activity by activating DNA molecules to initiate transcription and protein synthesis. Part of why chemical communication is so complex (and to some, confusing at this stage of one's education) is to ensure the appropriate responses. The specific receptor molecules in membranes and relay proteins within the cytosol determine the ultimate cellular response. This is important in many processes in organisms. Although all cells have the same DNA, not all DNA is active in any one cell. Receptor proteins in membranes have an impact on which genes ultimately get expressed in which cells, and whether a signal triggers an activation or an inhibition response. There are at least four categories of cell response to specific signals. A signal can attach to a receptor that triggers a transduction pathway leading to one response. A signal can attach to a receptor starting a pathway that branches into multiple transduction pathways leading to multiple responses In some cells, pathways interact. For example, two separate signals can trigger transduction pathways that interact with each other, either enhancing or inhibiting one response.

17 Cell Communication - 17 In different cells, the same signal molecule can elicit different responses by attaching to different receptors, each of which can activate different secondary messengers and relay pathways in different cells. For example, epinephrine does the following: Blood pressure Heart beat Insulin Blood glucose levels Oxygen consumption Release rbc from spleen reserve Blood flow to heart and skeletal network Blood flow to digestive system Dilate pupils Promote piloerection That one signal molecule can have such different effects on different cells and tissues explains the multiple symptoms of some diseases and disorders that are related to the "failure" of chemical communications. Several cancers are related to failure of chemical communication molecules to function properly. Many metabolic disorders and genetic disorders are related to the chemical communication sequences - receptor-transduction pathways and how they affect different cells and tissues. Some poisons affect signal receptors: Botulism, cholera and whooping cough involve bacterial toxins that inhibit G-protein-linked receptors. Cholera, for example, is caused by a toxin produced by the bacterium, Vibrio cholerae. The toxin prevents GTP from being hydrolyzed back to GDP on a G- protein receptor critical to maintaining water and salt balance in the intestine. The G-protein signal receptor stays active and camp levels remain high so water (and salts) flow into the intestine resulting in a serious loss of water and salts from the body. Although not emphasized in the discussion, the degradation of a signal molecule and secondary messenger molecules is just as critical to cell functioning as the signal. It is as important for cells to know when to stop as when to start a metabolic activity. Just as there are many alternatives to activation in chemical communication, there are methods of restoring the inactive molecular structures to await a new signal.

Plasma membranes. Plasmodesmata between plant cells. Gap junctions between animal cells Cell junctions. Cell-cell recognition

Plasma membranes. Plasmodesmata between plant cells. Gap junctions between animal cells Cell junctions. Cell-cell recognition Cell Communication Cell Signaling Cell-to-cell communication is essential for multicellular organisms Communicate by chemical messengers Animal and plant cells have cell junctions that directly connect

More information

BIOLOGY. Cell Communication CAMPBELL. Reece Urry Cain Wasserman Minorsky Jackson. Lecture Presentation by Nicole Tunbridge and Kathleen Fitzpatrick

BIOLOGY. Cell Communication CAMPBELL. Reece Urry Cain Wasserman Minorsky Jackson. Lecture Presentation by Nicole Tunbridge and Kathleen Fitzpatrick CAMPBELL BIOLOGY TENTH EDITION Reece Urry Cain Wasserman Minorsky Jackson 11 Cell Communication Lecture Presentation by Nicole Tunbridge and Kathleen Fitzpatrick Cellular Messaging Cells can signal to

More information

Chapter 11. Cell Communication

Chapter 11. Cell Communication Chapter 11 Cell Communication Overview: The Cellular Internet Cell-to-cell communication Is absolutely essential for multicellular organisms Concept 11.1: External signals are converted into responses

More information

Cell Communication. Chapter 11. PowerPoint Lectures for Biology, Seventh Edition. Lectures by Chris Romero. Neil Campbell and Jane Reece

Cell Communication. Chapter 11. PowerPoint Lectures for Biology, Seventh Edition. Lectures by Chris Romero. Neil Campbell and Jane Reece Chapter 11 Cell Communication PowerPoint Lectures for Biology, Seventh Edition Neil Campbell and Jane Reece Lectures by Chris Romero Overview: The Cellular Internet Cell-to-cell communication Is absolutely

More information

Cell Communication. Chapter 11. Biology Eighth Edition Neil Campbell and Jane Reece. PowerPoint Lecture Presentations for

Cell Communication. Chapter 11. Biology Eighth Edition Neil Campbell and Jane Reece. PowerPoint Lecture Presentations for Chapter 11 Cell Communication PowerPoint Lecture Presentations for Biology Eighth Edition Neil Campbell and Jane Reece Lectures by Chris Romero, updated by Erin Barley with contributions from Joan Sharp

More information

Cell Communication. Chapter 11. Biology. Eighth Edition Neil Campbell and Jane Reece. PowerPoint Lecture Presentations for

Cell Communication. Chapter 11. Biology. Eighth Edition Neil Campbell and Jane Reece. PowerPoint Lecture Presentations for Chapter 11 Cell Communication PowerPoint Lecture Presentations for Biology Eighth Edition Neil Campbell and Jane Reece Lectures by Chris Romero, updated by Erin Barley with contributions from Joan Sharp

More information

The plasma membrane plays a key role in most cell signaling

The plasma membrane plays a key role in most cell signaling CONCEPT 5.6 The plasma membrane plays a key role in most cell signaling In a multicellular organism, whether a human being or an oak tree, it is cell-to-cell communication that allows the trillions of

More information

Cell Communication. Chapter 11. Key Concepts in Chapter 11. Cellular Messaging. Cell-to-cell communication is essential for multicellular organisms

Cell Communication. Chapter 11. Key Concepts in Chapter 11. Cellular Messaging. Cell-to-cell communication is essential for multicellular organisms Chapter 11 Cell Communication Dr. Wendy Sera Houston Community College Biology 1406 Key Concepts in Chapter 11 1. External signals are converted to responses within the cell. 2. Reception: A signaling

More information

Cell Communication. Chapter 11. Overview: The Cellular Internet

Cell Communication. Chapter 11. Overview: The Cellular Internet Chapter 11 Cell Communication Overview: The Cellular Internet Cell-to-cell communication is essential for multicellular organisms Biologists have discovered some universal mechanisms of cellular regulation

More information

Cell Communication. Chapter 11. Biology. Eighth Edition Neil Campbell and Jane Reece. PowerPoint Lecture Presentations for

Cell Communication. Chapter 11. Biology. Eighth Edition Neil Campbell and Jane Reece. PowerPoint Lecture Presentations for Chapter 11 Cell Communication PowerPoint Lecture Presentations for Biology Eighth Edition Neil Campbell and Jane Reece Lectures by Chris Romero, updated by Erin Barley with contributions from Joan Sharp

More information

Cellular Communication

Cellular Communication Cellular Communication But before we get into that What have we learned about so far? Energy and Matter Why do living things need energy? Grow Reproduce Maintain homeostasis Cellular signaling Cells communicate

More information

Resp & Cell Comm Review

Resp & Cell Comm Review Resp & Cell Comm Review Two main catabolic processes: fermentation: partial degradation of sugars in the absence of oxygen. cellular respiration: uses oxygen to complete the breakdown of many organic molecules.

More information

Cell Communication. Cell Communication. Communication between cells requires: ligand: the signaling molecule

Cell Communication. Cell Communication. Communication between cells requires: ligand: the signaling molecule Cell Communication Cell Communication Communication between cells requires: ligand: the signaling molecule receptor protein: the molecule to which the ligand binds (may be on the plasma membrane or within

More information

G-Protein Signaling. Introduction to intracellular signaling. Dr. SARRAY Sameh, Ph.D

G-Protein Signaling. Introduction to intracellular signaling. Dr. SARRAY Sameh, Ph.D G-Protein Signaling Introduction to intracellular signaling Dr. SARRAY Sameh, Ph.D Cell signaling Cells communicate via extracellular signaling molecules (Hormones, growth factors and neurotransmitters

More information

Chapter 11: Cell Communication

Chapter 11: Cell Communication Name Period Chapter 11: Cell Communication The special challenge in Chapter 11 is not that the material is so difficult, but that most of the material will be completely new to you. Cell communication

More information

Bio 111 Study Guide Chapter 11 Cell Communication

Bio 111 Study Guide Chapter 11 Cell Communication Bio 111 Study Guide Chapter 11 Cell Communication BEFORE CLASS: Reading: Read the introduction on p. 210, and for Concept 11.1, read from the first full paragraph on p. 212. Read all of Concept 11.2. Pay

More information

GPCR. General Principles of Cell Signaling G-protein-Coupled Receptors Enzyme-Coupled Receptors Other Signaling Pathways. G-protein-Coupled Receptors

GPCR. General Principles of Cell Signaling G-protein-Coupled Receptors Enzyme-Coupled Receptors Other Signaling Pathways. G-protein-Coupled Receptors G-protein-Coupled Receptors General Principles of Cell Signaling G-protein-Coupled Receptors Enzyme-Coupled Receptors Other Signaling Pathways GPCR G-protein-coupled receptors Figure 15-30 Molecular Biology

More information

Cell Signaling (part 1)

Cell Signaling (part 1) 15 Cell Signaling (part 1) Introduction Bacteria and unicellular eukaryotes respond to environmental signals and to signaling molecules secreted by other cells for mating and other communication. In multicellular

More information

Propagation of the Signal

Propagation of the Signal OpenStax-CNX module: m44452 1 Propagation of the Signal OpenStax College This work is produced by OpenStax-CNX and licensed under the Creative Commons Attribution License 3.0 By the end of this section,

More information

Chapter 11 Cell Communication

Chapter 11 Cell Communication Chapter 11 Cell Communication Lecture Outline Overview: Cellular Messaging Cell-to-cell communication allows the trillions of cells in a multicellular organism to communicate to coordinate their activities.

More information

2013 W. H. Freeman and Company. 12 Signal Transduction

2013 W. H. Freeman and Company. 12 Signal Transduction 2013 W. H. Freeman and Company 12 Signal Transduction CHAPTER 12 Signal Transduction Key topics: General features of signal transduction Structure and function of G protein coupled receptors Structure

More information

Physiology Unit 1 CELL SIGNALING: CHEMICAL MESSENGERS AND SIGNAL TRANSDUCTION PATHWAYS

Physiology Unit 1 CELL SIGNALING: CHEMICAL MESSENGERS AND SIGNAL TRANSDUCTION PATHWAYS Physiology Unit 1 CELL SIGNALING: CHEMICAL MESSENGERS AND SIGNAL TRANSDUCTION PATHWAYS In Physiology Today Cell Communication Homeostatic mechanisms maintain a normal balance of the body s internal environment

More information

BIOLOGY. Cell Communication. Outline. Evolution of Signaling. Overview: Cellular Messaging. Local and Long-Distance Signaling

BIOLOGY. Cell Communication. Outline. Evolution of Signaling. Overview: Cellular Messaging. Local and Long-Distance Signaling 11 CAMBELL BIOLOGY TENTH EDITION Reece Urry Cain Wasserman Minorsky Jackson Cell Communication Lecture resentation by Dr Burns NVC Biol 120 Outline I. Cell Signaling II. Forms of cell signaling III. Quick

More information

Chapter 20. Cell - Cell Signaling: Hormones and Receptors. Three general types of extracellular signaling. endocrine signaling. paracrine signaling

Chapter 20. Cell - Cell Signaling: Hormones and Receptors. Three general types of extracellular signaling. endocrine signaling. paracrine signaling Chapter 20 Cell - Cell Signaling: Hormones and Receptors Three general types of extracellular signaling endocrine signaling paracrine signaling autocrine signaling Endocrine Signaling - signaling molecules

More information

Signal Transduction Cascades

Signal Transduction Cascades Signal Transduction Cascades Contents of this page: Kinases & phosphatases Protein Kinase A (camp-dependent protein kinase) G-protein signal cascade Structure of G-proteins Small GTP-binding proteins,

More information

Cell Biology Lecture 9 Notes Basic Principles of cell signaling and GPCR system

Cell Biology Lecture 9 Notes Basic Principles of cell signaling and GPCR system Cell Biology Lecture 9 Notes Basic Principles of cell signaling and GPCR system Basic Elements of cell signaling: Signal or signaling molecule (ligand, first messenger) o Small molecules (epinephrine,

More information

Reading Packet 2- Cells Unit. Chapter 6: A Tour of the Cell 1. What is resolving power?

Reading Packet 2- Cells Unit. Chapter 6: A Tour of the Cell 1. What is resolving power? AP Biology Reading Packet 2- Cells Unit Name Chapter 6: A Tour of the Cell 1. What is resolving power? 2. How is an electron microscope different from a light microscope and what is the difference between

More information

Enzymes Part III: regulation II. Dr. Mamoun Ahram Summer, 2017

Enzymes Part III: regulation II. Dr. Mamoun Ahram Summer, 2017 Enzymes Part III: regulation II Dr. Mamoun Ahram Summer, 2017 Advantage This is a major mechanism for rapid and transient regulation of enzyme activity. A most common mechanism is enzyme phosphorylation

More information

LQB383 Testbank. Week 8 Cell Communication and Signaling Mechanisms

LQB383 Testbank. Week 8 Cell Communication and Signaling Mechanisms LQB383 Testbank Week 8 Cell Communication and Signaling Mechanisms Terms to learn match the terms to the definitions --------------------------------------------------------------------------------------------------------------------------

More information

Chapter 15: Signal transduction

Chapter 15: Signal transduction Chapter 15: Signal transduction Know the terminology: Enzyme-linked receptor, G-protein linked receptor, nuclear hormone receptor, G-protein, adaptor protein, scaffolding protein, SH2 domain, MAPK, Ras,

More information

Cellular Communication

Cellular Communication (a) Communicating cell junctions. by direct cell-cell contact lasma membranes 1. Direct cell contact. Vesicle-mediated 3. Chemical messengers (b) Cell-cell recognition. Gap junctions between animal cells

More information

Close to site of release (at synapse); binds to receptors in

Close to site of release (at synapse); binds to receptors in Chapter 18: The Endocrine System Chemical Messengers 1. Neural 2. Endocrine 3. Neuroendocrine 4. Paracrine 5. Autocrine Endocrine System --Endocrine and nervous systems work together --Endocrine vs. Nervous

More information

Cellular Signaling Pathways. Signaling Overview

Cellular Signaling Pathways. Signaling Overview Cellular Signaling Pathways Signaling Overview Signaling steps Synthesis and release of signaling molecules (ligands) by the signaling cell. Transport of the signal to the target cell Detection of the

More information

Hormones and Signal Transduction. Dr. Kevin Ahern

Hormones and Signal Transduction. Dr. Kevin Ahern Dr. Kevin Ahern Signaling Outline Signaling Outline Background Signaling Outline Background Membranes Signaling Outline Background Membranes Hormones & Receptors Signaling Outline Background Membranes

More information

Cellular Messengers. Intracellular Communication

Cellular Messengers. Intracellular Communication Cellular Messengers Intracellular Communication Most common cellular communication is done through extracellular chemical messengers: Ligands Specific in function 1. Paracrines Local messengers (neighboring

More information

Signal Transduction Pathways

Signal Transduction Pathways Why? Signal Transduction athways What happens inside of a cell when a signal has been received? When cells release signal molecules (ligands) to send a message, and the message is received, a whole host

More information

Molecular Bioscience 401: Lecture 11.1 Cell Signaling. Slide #1

Molecular Bioscience 401: Lecture 11.1 Cell Signaling. Slide #1 Molecular Bioscience 401: Lecture 11.1 Cell Signaling Slide #1 Cell Communication Necessary for multicellular organisms Unlike unicellular organisms, multicellular Organisms require elaborate cell communication

More information

Name: Class: Date: Unit 1 Test: Cells. Multiple Choice Identify the choice that best completes the statement or answers the question.

Name: Class: Date: Unit 1 Test: Cells. Multiple Choice Identify the choice that best completes the statement or answers the question. Class: _ Date: _ Unit 1 Test: Cells Multiple Choice Identify the choice that best completes the statement or answers the question. 1) Which of the following is true of integral membrane proteins? A) They

More information

HORMONES (Biomedical Importance)

HORMONES (Biomedical Importance) hormones HORMONES (Biomedical Importance) Hormones are the chemical messengers of the body. They are defined as organic substances secreted into blood stream to control the metabolic and biological activities.

More information

Signaling Molecules and Cellular Receptors

Signaling Molecules and Cellular Receptors Signaling Molecules and Cellular Receptors Bởi: OpenStaxCollege There are two kinds of communication in the world of living cells. Communication between cells is called intercellular signaling, and communication

More information

What is the function (purpose) of this system? (clue: one word)

What is the function (purpose) of this system? (clue: one word) Endocrine System: Overview What is the function (purpose) of this system? (clue: one word) Communication! The role of hormones is to provide communication between cells (tissues and organs). There are

More information

Cell Communication External signals are converted to responses within the cell

Cell Communication External signals are converted to responses within the cell 11 Cell Communication KEY COCETS Figure 11.1 How does cell signaling trigger the desperate flight of this gazelle? 11.1 External signals are converted to responses within the cell 11.2 Reception: A signaling

More information

Basics of Signal Transduction. Ebaa M Alzayadneh, PhD

Basics of Signal Transduction. Ebaa M Alzayadneh, PhD Basics of Signal Transduction Ebaa M Alzayadneh, PhD What is signal transduction? Cell signaling The science of understanding how individual cells sense their environments and respond to stimuli... how

More information

Cell responses to environment-- Signals

Cell responses to environment-- Signals Cell responses to environment-- Signals Signal transduction can coordinate: Development Formation of tissues Timing of cell division Direction of cell enlargement Size and shape of organs Responses to

More information

The Endocrine System. PowerPoint Lecture Presentations prepared by Jason LaPres. Lone Star College North Harris

The Endocrine System. PowerPoint Lecture Presentations prepared by Jason LaPres. Lone Star College North Harris 18 The Endocrine System PowerPoint Lecture Presentations prepared by Jason LaPres Lone Star College North Harris NOTE: Presentations extensively modified for use in MCB 244 & 246 at the University of Illinois

More information

Organization of lectures: Cell Signaling I: Sex, Drugs and Violence. Cell signaling is central to modern medicine. Forms of Cell Signaling

Organization of lectures: Cell Signaling I: Sex, Drugs and Violence. Cell signaling is central to modern medicine. Forms of Cell Signaling Cell Signaling I: Sex, Drugs and Violence Joe W. Ramos jramos@crch.hawaii.edu www.crch.org/profiles/jramos Organization of lectures: General Principles of signaling cascades Hormone Signaling Signaling

More information

AP Biology Cells: Chapters 4 & 5

AP Biology Cells: Chapters 4 & 5 AP Biology Cells: Chapters 4 & 5 Multiple Choice Identify the choice that best completes the statement or answers the question. 1. The was the first unifying principle of biology. a. spontaneous generation

More information

Endocrine Notes Mrs. Laux AP Biology I. Endocrine System consists of endocrine glands (ductless), cells, tissues secrete hormones

Endocrine Notes Mrs. Laux AP Biology I. Endocrine System consists of endocrine glands (ductless), cells, tissues secrete hormones I. Endocrine System consists of endocrine glands (ductless), cells, tissues secrete hormones regulates metabolism, fluid balance, growth, reproduction A. Hormones 1. chemical signals-cell to cell communication

More information

Pharmacodynamics. OUTLINE Definition. Mechanisms of drug action. Receptors. Agonists. Types. Types Locations Effects. Definition

Pharmacodynamics. OUTLINE Definition. Mechanisms of drug action. Receptors. Agonists. Types. Types Locations Effects. Definition Pharmacodynamics OUTLINE Definition. Mechanisms of drug action. Receptors Types Locations Effects Agonists Definition Types Outlines of Pharmacodynamics Antagonists Definition Types Therapeutic Index Definition

More information

Review II: Cell Biology

Review II: Cell Biology Review II: Cell Biology Rajan Munshi BBSI @ Pitt 2006 Department of Computational Biology University of Pittsburgh School of Medicine May 24, 2006 Outline Cell Cycle Signal Transduction 1 Cell Cycle Four

More information

I. Fluid Mosaic Model A. Biological membranes are lipid bilayers with associated proteins

I. Fluid Mosaic Model A. Biological membranes are lipid bilayers with associated proteins Lecture 6: Membranes and Cell Transport Biological Membranes I. Fluid Mosaic Model A. Biological membranes are lipid bilayers with associated proteins 1. Characteristics a. Phospholipids form bilayers

More information

Principles of cell signaling Lecture 4

Principles of cell signaling Lecture 4 Principles of cell signaling Lecture 4 Johan Lennartsson Molecular Cell Biology (1BG320), 2014 Johan.Lennartsson@licr.uu.se 1 Receptor tyrosine kinase-induced signal transduction Erk MAP kinase pathway

More information

target effector enzyme is Phospholipase C A. target protein adenylate cyclase camp-> PKA B. target protein phospholipase C two 2nd Messengers:

target effector enzyme is Phospholipase C A. target protein adenylate cyclase camp-> PKA B. target protein phospholipase C two 2nd Messengers: COR 011 Cell Communication II Lect 19 Lecture Outline Signal molecule Activated Ras-GT A G-rotein And they tell friends And they tell friends And they tell friends 1. Finish Trimeric G-rotein: hospholipase

More information

Hormones. Prof. Dr. Volker Haucke Institut für Chemie-Biochemie Takustrasse 6

Hormones. Prof. Dr. Volker Haucke Institut für Chemie-Biochemie Takustrasse 6 Hormones Prof. Dr. Volker Haucke Institut für Chemie-Biochemie Takustrasse 6 Tel. 030-8385-6920 (Sekret.) 030-8385-6922 (direkt) e-mail: vhaucke@chemie.fu-berlin.de http://userpage.chemie.fu-berlin.de/biochemie/aghaucke/teaching.html

More information

Biol220 Cell Signalling Cyclic AMP the classical secondary messenger

Biol220 Cell Signalling Cyclic AMP the classical secondary messenger Biol220 Cell Signalling Cyclic AMP the classical secondary messenger The classical secondary messenger model of intracellular signalling A cell surface receptor binds the signal molecule (the primary

More information

Lecture 36: Review of membrane function

Lecture 36: Review of membrane function Chem*3560 Lecture 36: Review of membrane function Membrane: Lipid bilayer with embedded or associated proteins. Bilayers: 40-70% neutral phospholipid 10-20% negative phospholipid 10-30% cholesterol 10-30%

More information

AP Biology. Regulation. Chapter 45. Endocrine System Hormones. Regulation & Communication. Regulation by chemical messengers. Classes of Hormones

AP Biology. Regulation. Chapter 45. Endocrine System Hormones. Regulation & Communication. Regulation by chemical messengers. Classes of Hormones Chapter 5. Endocrine ystem Hormones Regulation Why are s needed? chemical messages from one body part to another communication needed to coordinate whole body homeostasis & regulation metabolism growth

More information

Biochemie 4. Cell communication - GPCR

Biochemie 4. Cell communication - GPCR Biochemie 4 Cell communication - GPCR 1 Lecture outline General principles - local and long-distance signaling - classes of receptors - molecular switches and second messengers Receptor tyrosine kinases

More information

BL 424 Chapter 15: Cell Signaling; Signal Transduction

BL 424 Chapter 15: Cell Signaling; Signal Transduction BL 424 Chapter 15: Cell Signaling; Signal Transduction All cells receive and respond to signals from their environments. The behavior of each individual cell in multicellular plants and animals must be

More information

Protein kinases are enzymes that add a phosphate group to proteins according to the. ATP + protein OH > Protein OPO 3 + ADP

Protein kinases are enzymes that add a phosphate group to proteins according to the. ATP + protein OH > Protein OPO 3 + ADP Protein kinase Protein kinases are enzymes that add a phosphate group to proteins according to the following equation: 2 ATP + protein OH > Protein OPO 3 + ADP ATP represents adenosine trisphosphate, ADP

More information

Membrane Transport and Cell Signaling

Membrane Transport and Cell Signaling CAMPBELL BIOLOGY IN FOCUS URRY CAIN WASSERMAN MINORSKY REECE 5 Membrane Transport and Cell Signaling Lecture Presentations by Kathleen Fitzpatrick and Nicole Tunbridge, Simon Fraser University SECOND EDITION

More information

Regulation of glycogen degradation

Regulation of glycogen degradation Paper : 04 Metabolism of carbohydrates Module : 26 Principal Investigator Paper Coordinator Content Reviewer Content Writer Dr.S.K.Khare,Professor IIT Delhi. Dr. Ramesh Kothari,Professor UGC-CAS Department

More information

MCB*4010 Midterm Exam / Winter 2008

MCB*4010 Midterm Exam / Winter 2008 MCB*4010 Midterm Exam / Winter 2008 Name: ID: Instructions: Answer all 4 questions. The number of marks for each question indicates how many points you need to provide. Write your answers in point form,

More information

Neurotransmitters. Chemical transmission of a nerve signal by neurotransmitters at a synapse

Neurotransmitters. Chemical transmission of a nerve signal by neurotransmitters at a synapse Neurotransmitters A chemical released by one neuron that affects another neuron or an effector organ (e.g., muscle, gland, blood vessel). Neurotransmitters are small molecules that serve as messengers

More information

Chapter 5: Cell Membranes and Signaling

Chapter 5: Cell Membranes and Signaling Chapter Review 1. For the diagram below, explain what information you would use to determine which side of the membrane faces the inside of the cell and which side faces the extracellular environment.

More information

Homeostatic Control Systems

Homeostatic Control Systems Homeostatic Control Systems In order to maintain homeostasis, control system must be able to Detect deviations from normal in the internal environment that need to be held within narrow limits Integrate

More information

Cell Membranes Valencia college

Cell Membranes Valencia college 6 Cell Membranes Valencia college 6 Cell Membranes Chapter objectives: The Structure of a Biological Membrane The Plasma Membrane Involved in Cell Adhesion and Recognition Passive Processes of Membrane

More information

KEY CONCEPT QUESTIONS IN SIGNAL TRANSDUCTION

KEY CONCEPT QUESTIONS IN SIGNAL TRANSDUCTION Signal Transduction - Part 2 Key Concepts - Receptor tyrosine kinases control cell metabolism and proliferation Growth factor signaling through Ras Mutated cell signaling genes in cancer cells are called

More information

The Endocrine System. The Endocrine System

The Endocrine System. The Endocrine System The Endocrine System Like nervous system, endocrine system provides communication and control. Messages are relayed from one cell to another via chemical messengers (hormones). Unlike nervous system which

More information

Cell Cell Communication

Cell Cell Communication IBS 8102 Cell, Molecular, and Developmental Biology Cell Cell Communication January 29, 2008 Communicate What? Why do cells communicate? To govern or modify each other for the benefit of the organism differentiate

More information

Bio 100 Guide 24.

Bio 100 Guide 24. Bio 100 Guide 24 http://www.offthemarkcartoons.com/cartoons/2006-05-03.gif Chemical signals coordinate body functions Hormones are chemical signals that communicate regulatory messages throughout the body

More information

Neurotransmitter Systems II Receptors. Reading: BCP Chapter 6

Neurotransmitter Systems II Receptors. Reading: BCP Chapter 6 Neurotransmitter Systems II Receptors Reading: BCP Chapter 6 Neurotransmitter Systems Normal function of the human brain requires an orderly set of chemical reactions. Some of the most important chemical

More information

CHAPTER. Movement Across Plasma Membrane. Chapter 6 Outline. Diffusion Osmosis. Membrane Potential Cell Signaling

CHAPTER. Movement Across Plasma Membrane. Chapter 6 Outline. Diffusion Osmosis. Membrane Potential Cell Signaling CHAPTER 6 Interaction Between Cells and the Extracellular Environment Chapter 6 Outline Extracellular Environment Diffusion Osmosis Carrier-Mediated Carrier Mediated Transport Membrane Potential Cell Signaling

More information

Cell Biology (BIOL 4374 and BCHS 4313) Third Exam 4/24/01

Cell Biology (BIOL 4374 and BCHS 4313) Third Exam 4/24/01 Cell Biology (BIOL 4374 and BCHS 4313) Third Exam 4/24/01 Name SS# This exam is worth a total of 100 points. The number of points each question is worth is shown in parentheses. For multiple choice questions,

More information

Chapter 20 Endocrine System

Chapter 20 Endocrine System Chapter 20 Endocrine System The endocrine system consists of glands and tissues that secrete Hormones are chemicals that affect other glands or tissues, many times far away from the site of hormone production

More information

Chapter 10. Introduction to Nutrition and Metabolism, 3 rd edition David A Bender Taylor & Francis Ltd, London 2002

Chapter 10. Introduction to Nutrition and Metabolism, 3 rd edition David A Bender Taylor & Francis Ltd, London 2002 Chapter 10 Introduction to Nutrition and Metabolism, 3 rd edition David A Bender Taylor & Francis Ltd, London 2002 Chapter 10: Integration and Control of Metabolism Press the space bar or click the mouse

More information

Chapter 9. The Endocrine System. Lecture Presentation by Patty Bostwick-Taylor Florence-Darlington Technical College Pearson Education, Inc.

Chapter 9. The Endocrine System. Lecture Presentation by Patty Bostwick-Taylor Florence-Darlington Technical College Pearson Education, Inc. Chapter 9 The Endocrine System Lecture Presentation by Patty Bostwick-Taylor Florence-Darlington Technical College Intro to the Endocrine System Chief Complaint:8-year-old girl with excessive thirst, frequent

More information

11/8/16. Cell Signaling Mechanisms. Dr. Abercrombie 11/8/2016. Principal Parts of Neurons A Signal Processing Computer

11/8/16. Cell Signaling Mechanisms. Dr. Abercrombie 11/8/2016. Principal Parts of Neurons A Signal Processing Computer Cell Signaling Mechanisms Dr. Abercrombie 11/8/2016 Principal Parts of Neurons A Signal Processing Computer A Multitude of Synapses and Synaptic Actions Summation/Synaptic Integration 1 The Synapse Signal

More information

Chapter 50: Sensory and Motor Mechanisms

Chapter 50: Sensory and Motor Mechanisms Name Period As in Chapter 49, there are several topics in this chapter that we will emphasize only lightly. If your teacher stresses human anatomy and physiology, you may be expected to go into more depth.

More information

Lojayn Salah. Razan Aburumman. Faisal Muhammad

Lojayn Salah. Razan Aburumman. Faisal Muhammad 20 Lojayn Salah Razan Aburumman Faisal Muhammad Note: I tried to include everything that's important from the doctor's slides but you can refer back to them after studying this sheet.. After you read this

More information

The Nobel Prize in Physiology or Medicine 2000

The Nobel Prize in Physiology or Medicine 2000 The Nobel Prize in Physiology or Medicine 2000 Press Release NOBELFÖRSAMLINGEN KAROLINSKA INSTITUTET THE NOBEL ASSEMBLY AT THE KAROLINSKA INSTITUTE 9 October 2000 The Nobel Assembly at Karolinska Institutet

More information

Autonomic Nervous System. Lanny Shulman, O.D., Ph.D. University of Houston College of Optometry

Autonomic Nervous System. Lanny Shulman, O.D., Ph.D. University of Houston College of Optometry Autonomic Nervous System Lanny Shulman, O.D., Ph.D. University of Houston College of Optometry Peripheral Nervous System A. Sensory Somatic Nervous System B. Autonomic Nervous System 1. Sympathetic Nervous

More information

REGULATION OF ENZYME ACTIVITY. Medical Biochemistry, Lecture 25

REGULATION OF ENZYME ACTIVITY. Medical Biochemistry, Lecture 25 REGULATION OF ENZYME ACTIVITY Medical Biochemistry, Lecture 25 Lecture 25, Outline General properties of enzyme regulation Regulation of enzyme concentrations Allosteric enzymes and feedback inhibition

More information

2401 : Anatomy/Physiology

2401 : Anatomy/Physiology Dr. Chris Doumen Week 11 2401 : Anatomy/Physiology Autonomic Nervous System TextBook Readings Pages 533 through 552 Make use of the figures in your textbook ; a picture is worth a thousand words! Work

More information

Figure 1 Original Advantages of biological reactions being catalyzed by enzymes:

Figure 1 Original Advantages of biological reactions being catalyzed by enzymes: Enzyme basic concepts, Enzyme Regulation I III Carmen Sato Bigbee, Ph.D. Objectives: 1) To understand the bases of enzyme catalysis and the mechanisms of enzyme regulation. 2) To understand the role of

More information

Copyright Mark Brandt, Ph.D. 128

Copyright Mark Brandt, Ph.D. 128 Signal transduction In order to interact properly with their environment, cells need to allow information as well as molecules to cross their cell membranes. Information in many single-celled and all multicellular

More information

Ch. 3: Cells & Their Environment

Ch. 3: Cells & Their Environment Ch. 3: Cells & Their Environment OBJECTIVES: 1. To distinguish different cellular (fluid) compartments 2. Understand movement of substances across cell membranes (passive vs active) 3. To recognize different

More information

Cell Injury MECHANISMS OF CELL INJURY

Cell Injury MECHANISMS OF CELL INJURY Cell Injury MECHANISMS OF CELL INJURY The cellular response to injurious stimuli depends on the following factors: Type of injury, Its duration, and Its severity. Thus, low doses of toxins or a brief duration

More information

The Brain & Homeostasis. The Brain & Technology. CAT, PET, and MRI Scans

The Brain & Homeostasis. The Brain & Technology. CAT, PET, and MRI Scans The Brain & Homeostasis Today, scientists have a lot of information about what happens in the different parts of the brain; however they are still trying to understand how the brain functions. We know

More information

Muscle and Neuromuscular Junction. Peter Takizawa Department of Cell Biology

Muscle and Neuromuscular Junction. Peter Takizawa Department of Cell Biology Muscle and Neuromuscular Junction Peter Takizawa Department of Cell Biology Types and structure of muscle cells Structural basis of contraction Triggering muscle contraction Skeletal muscle consists of

More information

Axon Nerve impulse. Axoplasm Receptor. Axomembrane Stimuli. Schwann cell Effector. Myelin Cell body

Axon Nerve impulse. Axoplasm Receptor. Axomembrane Stimuli. Schwann cell Effector. Myelin Cell body Nervous System Review 1. Explain a reflex arc. 2. Know the structure, function and location of a sensory neuron, interneuron, and motor neuron 3. What is (a) Neuron Axon Nerve impulse Axoplasm Receptor

More information

Zool 3200: Cell Biology Exam 4 Part I 2/3/15

Zool 3200: Cell Biology Exam 4 Part I 2/3/15 Name: Trask Zool 3200: Cell Biology Exam 4 Part I 2/3/15 Answer each of the following questions in the space provided, explaining your answers when asked to do so; circle the correct answer or answers

More information

Cell Respiration - 1

Cell Respiration - 1 Cell Respiration - 1 All cells must do work to stay alive and maintain their cellular environment. The energy needed for cell work comes from the bonds of ATP. Cells obtain their ATP by oxidizing organic

More information

3- Cell Structure and Function How do things move in and out of cells? A Quick Review Taft College Human Physiology

3- Cell Structure and Function How do things move in and out of cells? A Quick Review Taft College Human Physiology 3- Cell Structure and Function How do things move in and out of cells? A Quick Review Taft College Human Physiology How do things move in and out of cells? Things may move through cell membranes by Passive

More information

Campbell's Biology: Concepts and Connections, 7e (Reece et al.) Chapter 26 Hormones and the Endocrine System Multiple-Choice Questions

Campbell's Biology: Concepts and Connections, 7e (Reece et al.) Chapter 26 Hormones and the Endocrine System Multiple-Choice Questions Campbell's Biology: Concepts and Connections, 7e (Reece et al.) Chapter 26 Hormones and the Endocrine System 26.1 Multiple-Choice Questions 1) Hormones are chemicals produced by the endocrine system that

More information

NOTES: ENDOCRINE SYSTEM (CH 9)

NOTES: ENDOCRINE SYSTEM (CH 9) NOTES: ENDOCRINE SYSTEM (CH 9) Endocrine System *The endocrine system consists of a range of glands and tissues throughout the body Functions of the Endocrine System: 1) Maintain balance within body (homeostasis)

More information

Art labeling Activity: Figure 16.1

Art labeling Activity: Figure 16.1 ANP 1105D Winter 2013 Assignment 6 part I: The Endocrine Sy... Assignment 6 part I: The Endocrine System, Chapter 16 Due: 11:59pm on Monday, March 4, 2013 Note: To understand how points are awarded, read

More information

6 functions of membrane proteins integral & peripheral proteins Membrane Junctions

6 functions of membrane proteins integral & peripheral proteins Membrane Junctions Cells Cells are the structural units of all living organisms ranging from unicellular to multicellular organisms. Biochemical activities of cells are dictated by cell shape and specific subcellular structures.

More information