34 Apoptosis Programmed cell death is vital to the health and development of multicellular organisms.
|
|
- Christina Gibson
- 5 years ago
- Views:
Transcription
1 Principles of Biology contents 34 Apoptosis Programmed cell death is vital to the health and development of multicellular organisms. Apoptosis is the reason we have separate fingers and toes. During embryonic development, the cells between the fingers and toes go through apoptosis, or programmed cell death. Picture Partners/Science Source. Topics Covered in this Module Programmed Cell Death Major Objectives of this Module Explain the adaptive value of programmed cell death. Give examples of intrinsic and extrinsic triggers for apoptosis. Describe how apoptosis proceeds. page 180 of pages left in this module of biology / /1
2 Principles of Biology contents 34 Apoptosis What is the difference between a duck's foot and a chicken's foot? A duck's foot is webbed and the chicken's foot is not the difference is due to apoptosis. The spaces between the toes of a chicken's foot (and the fingers and toes of other vertebrates) form during early development because the cells that exist between the digits die. Apoptosis is a form of programmed cell death. This type of cell death is the result of a cellular "self destruct" mechanism that is initiated when the cell responds to specific signals, leading to the activation of cell destroying enzymes within the cell. Ducks have webbed feet because the cells between their toes do not undergo apoptosis. A protein called bone morphogenetic protein 4 (BMP4) is the signal for the excess cells around the toes to undergo apoptosis. Both chicken and duck embryos express BMP4 in the space between the toes. However, duck embryos also express the protein Gremlin between their toes, whereas chicken embryos do not. Gremlin binds to BMP4, inhibiting its apoptosis inducing action, ensuring that ducks have webbed feet. Programmed Cell Death Apoptosis is critically important during development. But apoptosis also continues to be essential throughout the life of an organism. By some estimates, a million cells die in the human body every second. Many of these cells are parts of tissues and organs deep within the body. Yet these dead and dying cells do not induce inflammatory responses or other triggers that would damage the surrounding healthy tissue. This is due, at least in part, to apoptosis. Apoptosis also serves as a means of removing abnormal cells. It is important that the process of cell death be tightly controlled since clearly problems will arise if there is too little or too much cell death. Understanding apoptosis could improve cancer treatment because some tumor cells manage to escape the apoptotic process. Why do cells need to self destruct? Programmed cell death is adaptive for an organism for the following reasons: A cell may no longer be needed by an organism. For instance the webbing between the toes of a chicken, and the tail of a tadpole undergoing metamorphosis into a frog, are cells that are no longer needed. Programmed cell death is how animals regulate the size and structure of the developing nervous system. As cells age they may be exposed to more pathogens or have sustained damage or injury. New cells will take their place, but the old cells must be removed. A cell may be killed to play a non living structural role. An example of this would be the death of the skin cells that become the keratinized top layer of skin of an animal or the water conducting xylem cells of a plant that consist of strong structural cell walls only. In plants, pathogen infected cells "seal themselves off" from the surrounding tissue and then undergo apoptosis, as a means of preventing the spread of the pathogen to the rest of the plant. This is called the hypersensitive response. The term apoptosis was coined to distinguish it from necrosis, which is cell death due to external factors such as toxins, lack of oxygen, lack of nutrients, or some pathological reason. In contrast with apoptosis, necrosis does not involve gene expression or the activation of a controlled, predictable cellular process. Necrosis is the catastrophic loss of cellular homeostasis. A necrotic cell loses membrane integrity and organization, resulting in cellular rupture and death. Cells undergoing apoptosis appear very different from cells undergoing necrosis. As apoptosis begins in animals, the cell detaches itself from the surrounding cells. The chromatin aggregates and components of the nucleus and cytosol condense. The DNA is hydrolyzed by DNases, and parts of the nucleus and cytoplasm partition off into small membrane bound vesicles called apoptotic bodies. The cell membrane fragments by forming blebs, which are membranous lobes. Apoptotic cells and cell fragments are typically taken up by neighboring cells or phagocytes. However, there is no activation of the immune response. Observation of many kinds of multicellular animals has revealed a type of apoptosis with a common morphological appearance, suggesting a common programmed cell death pathway. The hypothesis that the mechanism of programmed cell death was evolutionarily conserved is supported by recent molecular evidence of homologous elements of the apoptosis pathway in animals as different as nematodes, insects and humans. Single celled fungi (yeasts) have several molecular mechanisms of apoptosis that are homologous to those in animals, suggesting that these pathways arose many millions of years ago, before animals evolved as a distinct lineage. Apoptosis signals can arise from many factors. Since the concept of apoptosis was firmly established in 1972, researchers have identified hundreds of genes whose products control and conduct apoptosis. There are two main pathways that lead to the apoptosis of a cell: one is through death receptors on the cell surface (extrinsic pathway), and the other is through the mitochondria (intrinsic pathway) (Figure 1). of biology / /1 1/6
3 Figure 1: Apoptosis can be initiated by two pathways. Apoptosis can be activated through death receptors on the cell surface (also known as the extrinsic pathway) or through mitochondria (also known as the intrinsic pathway). The intrinsic pathway is activated in response to a variety of internal damage signals such as UV radiation damage or the improper folding of proteins Nature Education All rights reserved. Figure Detail The extrinsic pathway is controlled by the signaling molecules that bind to the cell surface death receptors (DRs). The intrinsic pathway is controlled by the Bcl 2 family of proteins and involves the disruption of mitochondrial membranes in response to internal signals of damage. Both pathways eventually activate an enzyme called an initiator caspase. Caspases (cysteine proteases that cleave after an aspartate) are proteolytic enzymes that carry out the cell death response. The initiator caspase activates one or more executioner caspases. Executioner caspases cleave death substrates, which eventually results in apoptosis (see Figure 1). Points of crossover of the two pathways allows for crosstalk between elements of each pathway. For instance, after apoptosis induction through death receptors, the cleavage of one particular Bcl 2 protein (BID) by caspase 8 can activate the intrinsic mitochondrial pathway, amplifying the apoptotic response (see Figure 1). How does apoptosis proceed? Apoptosis starts with a condition that signals the cell to "commit suicide." Such triggers may be a decline in the local concentration of a growth factor, damage to DNA or the cytoskeleton, or infection. These signals, acting through the intrinsic or extrinsic pathways, activate the caspase cascade. The executioner caspases target various cellular proteins, leading to the characteristic morphological events of apoptosis. The cell detaches itself from the surrounding cells. The chromatin aggregates and components of the nucleus and cytosol condense (Figure 2). The DNA is hydrolyzed by DNases, which digest the DNA in regions unprotected by the nucleosomes. Evidence of DNA hydrolysis is seen as a ladder of evenly spaced fragments in gel electrophoresis analysis of DNA extracted from cells at this stage. Parts of the nucleus and cytoplasm partition off into small membranebound vesicles called apoptotic bodies. The cell membrane fragments by forming membranous lobes called blebs. Apoptotic cells and cell fragments are typically taken up by neighboring cells or phagocytes. of biology / /1 2/6
4 Figure 2: How does apoptosis look compared to necrosis? Images of DNA labeled cells in culture showing: a) normal control cells (live cells show green nuclei); b) cells undergoing necrosis after treatment with a toxin (dead cells show non condensed orange nuclei); and c) cells undergoing apoptosis; the white arrowheads point to cells with nuclei that display chromatin aggregation in the early stages of apoptosis, while the yellow arrowheads point to dead cells that display the chromatin clumping typical of apoptosis Nature Publishing Group Bezabeh, T. et al. Detection of drug induced apoptosis and necrosis in human cervical carcinoma cells using 1H NMR spectroscopy. Cell Death and Differentiation 8, (2001) doi: /sj.cdd Used with permission. Figure Detail Apoptotic cells are removed by phagocytosis by either neighboring cells or phagocytic cells like macrophages. Cells undergoing necrosis are engulfed by macrophages, which triggers the inflammatory response of innate immunity. Why does phagocytosis of apoptotic cells by macrophages not result in an immune response? The apoptotic cells attract macrophages with "eat me" signals that are different from the signals that characterize necrotic cells. After phagocytosis of apoptotic cells, instead of up regulating the immune response, these macrophages appear to "calm" the immune response. This calming is likely accomplished by suppression of chemical signals that promote inflammation and cell killing and regulation of immune system activation by inducing changes in how the immune system signals are presented to the rest of the immune system (Figure 3). of biology / /1 3/6
5 Figure 3: Phagocytic clearance of apoptotic cells. Apoptotic cells express proteins that serve as "eat me" flags that promote their phagocytosis by macrophages. Besides serving as waste disposal, this process has acquired new meaning as an immune system modulating process Nature Education All rights reserved. Figure Detail There is a delicate balance of cell death and cell division required for maintaining health. Excessive apoptosis contributes to many pathological conditions, including Alzheimer's disease and Huntington's disease. Deficient apoptosis is linked to many pathological conditions, such as autoimmune diseases and cancer. Therapeutic approaches that affect the apoptotic pathway are currently very active areas of research. Future perspectives. Ongoing work in apoptosis signaling is an avenue for cancer therapies. One of the many proteins that play a role in the development of cancer, the p53 protein is a key player in the cell's response to cellular stresses, such as DNA damage. Following DNA damage, p53 regulates the expression and activity of genes to mediate DNA repair, cell cycle arrest, senescence or apoptosis (Figure 4). Loss of p53 activity is often found in cancerous cells. This enables them to escape apoptosis. Figure 4: The p53 pathway and its role in apoptosis and cancer. The p53 protein is a tumor suppressor protein that regulates the cell cycle and is involved in preventing cancer. Following cellular stress, p53 mediates apoptosis and senescence, which lead to cancer cell clearance. As an adjunct treatment for cancer, reactivation of p53 in cancer cells could help clear cancer cells Nature Publishing Group Vazquez, A., et al. The genetics of the p53 pathway, apoptosis and cancer therapy. Nature Reviews Drug Discovery 7, (2008) doi: /nrd2656. Used with permission. Traditional cancer therapies work by inducing cellular stress, and p53 helps to remove the cancer cells. Enhancement or reactivation of p53 activity in cancer cells has the potential to improve the response to cancer therapies. Other approaches in cancer therapy are the development of pro apoptotic therapies. One promising approach under study is pro apoptotic receptor agonists (PARAs) that target the extrinsic apoptosis pathway. BIOSKILL Interpret a Signaling Pathway Problems with apoptosis underlie many human diseases, such as stroke, heart failure, Alzheimer's disease, Parkinson's disease, cancer and the development of autoimmune diseases. Consequently, ways to enhance or interrupt the pathways identified in apoptosis are actively being sought by researchers. Some of the biochemical targets that are being investigated include Bcl 2, FLIP (a caspase inhibitor) and the caspases. One of the challenges is how to induce apoptosis in one target cell type without affecting non target cells or organs. Figure 5 shows just a small fraction of what is known about apoptotic pathways with potential therapeutic approaches for each drug target (for which potential drug leads are being pursued) highlighted in blue. Ligands, such as the cytokine tumor necrosis factor (TNF), bind to pro apoptotic "death" receptors on the surface of the target cell, inducing the formation of a death inducing signaling complex. Caspase 8/10 is activated, and the intrinsic pathway is also activated via the Bcl 2 family protein BID. Caspase 8/10 is negatively regulated by FLIP, which is of biology / /1 4/6
6 structurally similar to a caspase but lacks enzymatic activity. On the left of Figure 5, a caspase activated DNase (CAD) moves into the nucleus and fragments the cell's DNA in a characteristic pattern defined by the spacing of the nucleosomes. The caspase 8/10 and the Bcl 2 pathways also come together at this point via caspase 9. Figure 5: Apoptosis pathways and drug targets. A small fraction of what is known about the apoptosis pathway is shown here, potential targets for drugs are highlighted in light green Nature Education All rights reserved. Figure Detail Test Yourself Many cancers (for example, lymphoma a white blood cell cancer) over express BCL 2, a protein that inhibits apoptosis. Think of an approach that may lead to an effective therapy. Submit BIOSKILL What are other mechanisms of programmed cell death? Autophagy is another form of programmed cell death in which cells break down their own cytoplasm and organelles. The breakdown products are metabolized within the cell as a source of nutrients during times of limited resources. It is likely that future research will provide more opportunities for understanding these different forms of cell death in both animals and plants. Test Yourself How might researchers distinguish between autophagy and apoptosis? of biology / /1 5/6
7 Submit IN THIS MODULE Programmed Cell Death Summary Test Your Knowledge WHY DOES THIS TOPIC MATTER? Cancer: What's Old Is New Again Is cancer ancient, or is it largely a product of modern times? Can cutting edge research lead to prevention and treatment strategies that could make cancer obsolete? PRIMARY LITERATURE Identifying genes linked to cystic fibrosis Genome wide association and linkage identify modifier loci of lung disease severity in cystic fibrosis at 11p13 and 20q13.2. Classic paper: X rays reveal the structure of myoglobin (1958) A three dimensional model of the myoglobin molecule obtained by X ray analysis. page 181 of pages left in this module of biology / /1 6/6
8 1/20/2015 Summary of Apoptosis Principles of Biology from Nature Education Principles of Biology contents 34 Apoptosis Summary OBJECTIVE Explain the adaptive value of programmed cell death. Apoptosis is a form of programmed cell death that is used to remove cells that are no longer needed in development or to remove cells that may be damaged or irregular in some way. Defects in apoptosis play a role in many diseases. Studies on the molecular mechanisms of apoptosis regulation have provided several potential targets for future therapies. OBJECTIVE Give examples of intrinsic and extrinsic triggers for apoptosis. Apoptosis can be triggered along either the intrinsic or extrinsic pathway. There are points of convergence between the two pathways. An example of an intrinsic signal is damaged DNA, and an example of an extrinsic signal would be a ligand for the death receptors, such as tumor necrosis factor. Signals acting through the intrinsic or extrinsic pathways activate the caspase cascade. The executioner caspases process various cellular proteins, leading to the characteristic morphological events of apoptosis. OBJECTIVE Describe how apoptosis proceeds. As apoptosis begins in animals, the cell detaches itself from the surrounding cells. The chromatin aggregates, and components of the nucleus and cytosol condense. The DNA is hydrolyzed by DNases, and parts of the nucleus and cytoplasm partition off into small membrane bound vesicles called apoptotic bodies. The cell membrane fragments by forming blebs, which are membranous lobes. Apoptotic cells and cell fragments are typically taken up by neighboring cells or phagocytes. However there is no activation of the immune response. Key Terms apoptosis Programmed cell destruction or death. autophagy Process of breaking down and recycling malfunctioning or worn out cell parts. blebs Membranous lobes created as the cell membrane breaks up in apoptosis. caspase A type of proteolytic enzyme that is involved in initiating and executing programmed cell death. DNA hydrolysis Process by which DNA is broken into small fragments. hypersensitive response Infected cells are sealed off and die so as to protect the rest of the plant. necrosis Cell death caused by toxins, hypoxia, lack of nutrients, or some pathological reason. IN THIS MODULE Programmed Cell Death Summary Test Your Knowledge WHY DOES THIS TOPIC MATTER? Cancer: What's Old Is New Again Is cancer ancient, or is it largely a product of modern times? Can cutting edge research lead to prevention and treatment strategies that could make cancer obsolete? PRIMARY LITERATURE Identifying genes linked to cystic fibrosis Genome wide association and linkage identify modifier loci of lung disease severity in cystic fibrosis at 11p13 and 20q13.2. Classic paper: X rays reveal the structure of myoglobin (1958) A three dimensional model of the myoglobin molecule obtained by X ray analysis. of biology / /2 1/2
9 1/20/2015 Summary of Apoptosis Principles of Biology from Nature Education page 182 of pages left in this module of biology / /2 2/2
10 Principles of Biology contents 34 Apoptosis IN THIS MODULE Test Your Knowledge 1. Which of the following is NOT an adaptive advantage of apoptosis? A cell may no longer be needed by an organism. A cell may be killed to play a nonliving structural role. to protect the rest of the organism from pathogens activation of the immune response to fight pathogens All answers are correct. Programmed Cell Death Summary Test Your Knowledge WHY DOES THIS TOPIC MATTER? Cancer: What's Old Is New Again Is cancer ancient, or is it largely a product of modern times? Can cutting edge research lead to prevention and treatment strategies that could make cancer obsolete? Which of the following scenarios would most likely involve apoptosis? destruction of muscle cells in the muscles (formerly used to move a caterpillar's body) during its metamorphosis to a butterfly killing of skin cells by contact with an extremely hot surface the breakdown of a cell's internal structures (mitochondria, membrane vesicles, etc.) during times of limited resources phagocytosis and killing of an invading bacterium by a macrophage All answers are correct. Which of the following is/are an example of an intrinsic trigger for apoptosis? damaged DNA mitochondrial damage a ligand binding to the death receptor All answers are correct. damaged DNA and mitochondrial damage only PRIMARY LITERATURE Identifying genes linked to cystic fibrosis Genome wide association and linkage identify modifier loci of lung disease severity in cystic fibrosis at 11p13 and 20q13.2. Classic paper: X rays reveal the structure of myoglobin (1958) A three dimensional model of the myoglobin molecule obtained by X ray analysis. 4. Which of the following is NOT a step in apoptosis in animal cells? The cytosol leaks out of the cell. The cell membrane forms blebs. The cell detaches itself from the surrounding cells. Caspases digest their target proteins. The DNA is hydrolyzed by DNAses. 5. Which step(s) occur in the apoptosis of both plant and animal cells? Macrophages engulf the cell and trigger an immune response. The DNA is hydrolyzed by DNAses. The cytosol leaks out of the cell. The cell membrane forms blebs. All answers are correct. Submit page 183 of of biology / /3 1/1
Introduction to pathology lecture 5/ Cell injury apoptosis. Dr H Awad 2017/18
Introduction to pathology lecture 5/ Cell injury apoptosis Dr H Awad 2017/18 Apoptosis = programmed cell death = cell suicide= individual cell death Apoptosis cell death induced by a tightly regulated
More informationAPOPTOSIS, NECROSIS AND CANCER. Dr. S. P. Pattanayak
APOPTOSIS, NECROSIS AND CANCER Dr. S. P. Pattanayak LEARNING OBJECTIVES At the end of the lecture, students should be able to: Know the importance of cell death. Define various modes of cell death. Identify
More informationApoptotic Pathways in Mammals Dr. Douglas R. Green
Apoptotic Pathways in Mammals Douglas R. Green 1 Apoptosis A form of cell death that is defined morphologically, and features a number of biochemical events Programmed cell death Cell death that occurs
More informationCell cycle and apoptosis
Cell cycle and apoptosis Cell cycle Definition Stages and steps Cell cycle Interphase (G1/G0, S, and G2) Mitosis (prophase, metaphase, anaphase, telophase, karyokinesis, cytokinesis) Control checkpoints
More informationshehab Moh Tarek ... ManarHajeer
3 shehab Moh Tarek... ManarHajeer In the previous lecture we discussed the accumulation of oxygen- derived free radicals as a mechanism of cell injury, we covered their production and their pathologic
More informationCell Quality Control. Peter Takizawa Department of Cell Biology
Cell Quality Control Peter Takizawa Department of Cell Biology Cellular quality control reduces production of defective proteins. Cells have many quality control systems to ensure that cell does not build
More informationApoptosis Chapter 9. Neelu Yadav PhD
Apoptosis Chapter 9 Neelu Yadav PhD Neelu.Yadav@Roswellpark.org 1 Apoptosis: Lecture outline Apoptosis a programmed cell death pathway in normal homeostasis Core Apoptosis cascade is conserved Compare
More informationLecture 14 - The cell cycle and cell death
02.17.10 Lecture 14 - The cell cycle and cell death The cell cycle: cells duplicate their contents and divide The cell cycle may be divided into 4 phases The cell cycle triggers essential processes (DNA
More informationlysosomes Ingested materials Defective cell components Degrades macromolecules of all types:
lysosomes Digests Ingested materials Defective cell components Degrades macromolecules of all types: Proteins Nucleic acids Carbohydrates Lipids Single membrane bound vesicle, contains up to 50 digestive
More informationObjectives. Abbas Chapter 11: Immunological Tolerance. Question 1. Question 2. Question 3. Definitions
Objectives Abbas Chapter 11: Immunological Tolerance Christina Ciaccio, MD Children s Mercy Hospitals and Clinics February 1, 2010 To introduce the concept of immunologic tolerance To understand what factors
More informationSmall-molecule activation of procaspase-3 to caspase-3 as a personalized anticancer strategy
Small-molecule activation of procaspase-3 to caspase-3 as a personalized anticancer strategy Paul J. Hergenrother and Co-workers Department of Chemistry Department of Biochemistry Univeristy of Illinois-Urbana
More informationCell 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 informationIdentification and characterization of genes responsive to apoptosis: Application of DNA chip technology and mrna differential display
Histol Histopathol (2000) 15: 1271-1 284 http://www.ehu.es/histol-histopathol Histology and H istopat hology Cellular and Molecular Biology Invited Revie W Identification and characterization of genes
More information#19 Apoptosis Chapter 9. Neelu Yadav PhD
#19 Apoptosis Chapter 9 Neelu Yadav PhD Neelu.Yadav@Roswellpark.org Why cells decide to die? - Stress, harmful, not needed - Completed its life span Death stimulation or Stress Cell Survival Death Functions
More informationRegulating the Cell Cycle. Lesson Overview THINK ABOUT IT. How do cells know when to divide? Review: Why do cells divide?
THINK ABOUT IT How do cells know when to divide? Review: Why do cells divide? Controls on Cell Division How is the cell cycle regulated? The cell cycle is controlled by regulatory proteins both inside
More informationMolecular biology :- Cancer genetics lecture 11
Molecular biology :- Cancer genetics lecture 11 -We have talked about 2 group of genes that is involved in cellular transformation : proto-oncogenes and tumour suppressor genes, and it isn t enough to
More informationThe Jobs of Cells. Food & water storage. Vacuoles & vesicles. Vacuoles in plants 10/5/2015. plant cells
Cells have 3 main jobs make energy need energy for all activities need to clean up waste produced while making energy make proteins proteins do all the work in a cell, so we need lots of them make more
More informationCh. 4 Cells: The Working Units of Life
Ch. 4 Cells: The Working Units of Life Originally prepared by Kim B. Foglia. Revised and adapted by Nhan A. Pham Types of cells Cell Size Why organelles? Specialized structures - specialized functions
More informationWhat are the parts of a eukaryotic cell? What is the function of each part of a eukaryotic cell?
CHAPTER 3 SECTION 2 Cells: The Basic Units of Life Eukaryotic Cells BEFORE YOU READ After you read this section, you should be able to answer these questions: What are the parts of a eukaryotic cell? What
More informationFunctional Limitations
Regulation of the Cell Cycle Chapter 12 Pg. 228 245 Functional Limitations Various factors determine whether and when a cell divides. Two functional limitations for cell size limit growth or influence
More informationApoptosis Oncogenes. Srbová Martina
Apoptosis Oncogenes Srbová Martina Cell Cycle Control point Cyclin B Cdk1 Cyclin D Cdk4 Cdk6 Cyclin A Cdk2 Cyclin E Cdk2 Cyclin-dependent kinase (Cdk) have to bind a cyclin to become active Regulation
More informationTypes of insult - hypoxia
Introduction This presentation will be a guide to cell injury and cell death outline causes and pathogenesis of cell injury/death describe the morphological changes of cell injury/death Describe the process
More informationChapter 5: Cell Growth and Division
Chapter 5: Cell Growth and Division 1 Background Info Formation of New Cells ~2 trillion cells formed/day in human body ~25 million cells/second Cell division = cell reproduction DNA must be copied before
More informationAP Biology. Tour of the Cell 1
Tour of the Cell 1 Types of cells Prokaryote bacteria cells - no organelles - organelles Eukaryote animal cells Eukaryote plant cells Why organelles? Specialized structures specialized functions cilia
More informationCells communicate with each other via signaling ligands which interact with receptors located on the surface or inside the target cell.
BENG 100 Frontiers of Biomedical Engineering Professor Mark Saltzman Chapter 6 SUMMARY In this chapter, cell signaling was presented within the context of three physiological systems that utilize communication
More informationMechanisms of Cell Injury
Causes of Cell Injury 1- oxygen deprivation (anoxia) 2- physical agents 3- chemical agents 4- infections agents 5- immunologic reactions 6- genetic defects 7- nutritional imbalances Mechanisms of Cell
More informationChapter 12 The Cell Cycle
Chapter 12 The Cell Cycle Objectives Describe how cell reproduction contributes to repair and growth. Compare and contrast prokaryotic and eukaryotic cell division. Compare and contrast asexual and sexual
More informationChapter 1 CELL INJURY CELL DEATH CELL ADAPTATIONS. M.G.Rajanandh, Dept. of Pharmacy Practice, SRM College of Pharmacy, SRM University.
Chapter 1 CELL INJURY CELL DEATH CELL ADAPTATIONS M.G.Rajanandh, Dept. of Pharmacy Practice, SRM College of Pharmacy, SRM University. CONCEPTS IN CELL INJURY The clinical signs and symptoms are several
More informationCell Communication. Local and Long Distance Signaling
Cell Communication Cell to cell communication is essential for multicellular organisms Some universal mechanisms of cellular regulation providing more evidence for the evolutionary relatedness of all life
More informationSignaling Apoptosis. Scott André Oakes, M.D. Dept. of Pathology Univ. of Calif-San Francisco. Cyt c Release BAX/BAK. Apoptosome Formation
Signaling Apoptosis Cyt c Release BAX/BAK Apoptosome Formation Caspase Activation Scott André Oakes, M.D. Dept. of Pathology Univ. of Calif-San Francisco Why do we need cell death? Sculpt Organs Control
More informationChapter 3. Chapter 3. Bellringer. Objectives. Chapter 3. Chapter 3. Vocabulary. Cell Wall. Identify the different parts of a eukaryotic cell.
Bellringer Objectives Identify the different parts of a eukaryotic cell. Explain the function of each part of a eukaryotic cell. Plant cells and animal cells have many cell parts in common. But they also
More informationUnit 5 Section 1. Evidence 1: Why aren t all organisms made of just one cell? Why do cells divide, instead of simply growing larger?
Unit 5 Section 1 Evidence 1: Why aren t all organisms made of just one cell? Why do cells divide, instead of simply growing larger? Cell Theory states the following 1. All organisms are made of cells 2.
More information5.1. KEY CONCEPT Cells have distinct phases of growth, reproduction, and normal functions. 68 Reinforcement Unit 2 Resource Book
5.1 THE CELL CYCLE KEY CONCEPT Cells have distinct phases of growth, reproduction, and normal functions. Cells have a regular pattern of growth, DNA duplication, and division that is called the cell cycle.
More informationMitosis and the Cell Cycle
Mitosis and the Cell Cycle Chapter 12 The Cell Cycle: Cell Growth & Cell Division Where it all began You started as a cell smaller than a period at the end of a sentence Getting from there to here Cell
More informationnumber Done by Corrected by Doctor Heyam Awad
number 4 Done by Waseem Abu Obeida Corrected by Saad Al-Hayek Doctor Heyam Awad Cell injury -in the previous lectures we talked about the causes (etiology) and the mechanism (pathogenesis) of cell injury.
More informationCELL GROWTH & DIVISION
CELL GROWTH & DIVISION A- ANA- AUTO CARCIN- CHEMO- CHROMA- CYTO- DI- FERTIL- HAPLO- IMPORTANT WORD ROOTS Homo- like not, without Inter- between of each, re Karyo- nucleus self Kinet- move ulcer Meta- A
More informationCell Structure & Function. Source:
Cell Structure & Function Source: http://koning.ecsu.ctstateu.edu/cell/cell.html Definition of Cell A cell is the smallest unit that is capable of performing life functions. http://web.jjay.cuny.edu/~acarpi/nsc/images/cell.gif
More informationFig. 1. Simple columnar epithelial cells lining the small intestine.
Mitosis Prelab Reading Fig. 1. Simple columnar epithelial cells lining the small intestine. The tall cells pictured in Fig. 1 form the lining of the small intestine in humans and other animals. These cells
More informationCancer. Throughout the life of an individual, but particularly during development, every cell constantly faces decisions.
Cancer Throughout the life of an individual, but particularly during development, every cell constantly faces decisions. Should it divide? Yes No--> Should it differentiate? Yes No-->Should it die? Yes-->Apoptosis
More informationProgrammed Cell Death (apoptosis)
Programmed Cell Death (apoptosis) Stereotypic death process includes: membrane blebbing nuclear fragmentation chromatin condensation and DNA framentation loss of mitochondrial integrity and release of
More information#19 Apoptosis Chapter 9. Neelu Yadav PhD
#19 Apoptosis Chapter 9 Neelu Yadav PhD Neelu.Yadav@Roswellpark.org Why cells decide to die? - Stress, harmful, not needed - Completed its life span Death stimulation or Stress Cell Survival Death Functions
More informationImmunity. Chapter 38 Part 1
Immunity Chapter 38 Part 1 Impacts, Issues Frankie s Last Wish Infection with a common, sexually transmitted virus (HPV) causes most cervical cancers including the one that killed Frankie McCullogh 38.1
More informationStudy Guide for Biology Chapter 5
Class: Date: Study Guide for Biology Chapter 5 Multiple Choice Identify the choice that best completes the statement or answers the question. 1. Which of the following led to the discovery of cells? a.
More informationWhere are we heading?
Unit 5: Where are we heading? Unit 5: Introduction Unit 1: Why should we care about infectious diseases? Unit 2: What does it mean to have an infectious disease? Unit 3: When does a microbe become a pathogen?
More informationFluid movement in capillaries. Not all fluid is reclaimed at the venous end of the capillaries; that is the job of the lymphatic system
Capillary exchange Fluid movement in capillaries Not all fluid is reclaimed at the venous end of the capillaries; that is the job of the lymphatic system Lymphatic vessels Lymphatic capillaries permeate
More informationAsexual Reproduction & Cancer
Asexual Reproduction & Cancer Asexual Reproduction Only one individual needed No new genetic material added = organism clones itself Reproduction is fast and produces many individuals Gene pool is shallow
More informationChapter 19: The Cardiovascular System: The Blood. Copyright 2009, John Wiley & Sons, Inc.
Chapter 19: The Cardiovascular System: The Blood Blood Liquid connective tissue 3 general functions 1. Transportation Gases, nutrients, hormones, waste products 2. Regulation ph, body temperature, osmotic
More informationCell Structure and Function
Cell Theory Cell Structure and Function Chapter 6 Pg. 94-124 What is a cell? The basic functional unit of all living things. The Cell Theory states All organisms are made of one or more cells. Cells are
More informationQuestion #1 Controls on cell growth and division turned on and off
Lesson Overview 10.3 Regulating the Cell Cycle Question #1 Controls on cell growth and division turned on and off When cells are grown in the laboratory, most cells will divide until they come into contact
More informationName Class Date. What are the parts of a eukaryotic cell? What is the function of each part of a eukaryotic cell?
CHAPTER 2 SECTION 2 Cells: The Basic Units of Life Eukaryotic Cells BEFORE YOU READ After you read this section, you should be able to answer these questions: What are the parts of a eukaryotic cell? What
More informationPREPARED BY P.DHARANI PRASAD II YEAR B.PHARM II SEM SUB:PATHOPHYSIOLOGY
CELL INJURY UNIT I PREPARED BY P.DHARANI PRASAD II YEAR B.PHARM II SEM SUB:PATHOPHYSIOLOGY DETECTION OF CELLULAR CHANGES AFTER INJURY BY: LIGHT MICROSCOPY OR GROSS EXAMINATION DETECT CHANGES HOURS TO DAYS
More informationCell signaling. How do cells receive and respond to signals from their surroundings?
Cell signaling How do cells receive and respond to signals from their surroundings? Prokaryotes and unicellular eukaryotes are largely independent and autonomous. In multicellular organisms there is a
More information1. The barriers of the innate immune system to infection
Section 3.qxd 16/06/05 2:11 PM Page 12 12 SECTION THREE: Fleshed out 1. The barriers of the innate immune system to infection Questions What are the three characteristics of the innate immune system? What
More informationMechanisms of Cell Death
Mechanisms of Cell Death CELL DEATH AND FORMATION OF THE SEMICIRCULAR CANALS Carol M. Troy August 25, 2008 FROM: Fekete et al., Development 124: 2451 (1997) PHENOMENOLOGY OF CELL DEATH I. DEVELOPMENT A.
More informationDetermination of the temporal pattern and importance of BALF1 expression in Epstein-Barr viral infection
Determination of the temporal pattern and importance of BALF1 expression in Epstein-Barr viral infection Melissa Mihelidakis May 6, 2004 7.340 Research Proposal Introduction Apoptosis, or programmed cell
More informationAcquired Immunity Cells are initially and require before they can work Responds to individual microbes
1 of 10 THE IMMUNE SYSTEM CHAPTER 43; PAGES 898 921 WHY DO WE NEED AN IMMUNE SYSTEM? It s a dirty, dirty world out there and we are vastly outnumbered Bacteria and parasites are everywhere The body has
More informationCellular Boundaries. Cell Organelles. The Nucleus and Cell Control. Cell Membrane. Cell Wall. Nucleus 10/11/2012. Cell Membrane Cell Wall
Cell Organelles Cellular Boundaries Protects cell Support and shape Controls what comes in and out of the cell Selectively permeable the process in which a membrane allows some molecules to pass through
More informationACTIVATION OF T LYMPHOCYTES AND CELL MEDIATED IMMUNITY
ACTIVATION OF T LYMPHOCYTES AND CELL MEDIATED IMMUNITY The recognition of specific antigen by naïve T cell induces its own activation and effector phases. T helper cells recognize peptide antigens through
More informationBlood: Functions. Liquid connective tissue 3 general functions 1. Transportation. 2. Regulation. 3. Protection
Blood Elements Lecture Objectives List blood components. Classify formed elements of blood. Discuss the scientific basis of the above classification. Describe the basic structure of erythrocytes and criteria
More informationCell 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 informationKEY CONCEPT Cells have distinct phases of growth, reproduction, and normal functions.
5.1 The Cell Cycle KEY CONCEPT Cells have distinct phases of growth, reproduction, and normal functions. Objective: Cells have distinct phases of growth, reproduction and normal functions. APK: Why do
More informationAll animals have innate immunity, a defense active immediately upon infection Vertebrates also have adaptive immunity
1 2 3 4 5 6 7 8 9 The Immune System All animals have innate immunity, a defense active immediately upon infection Vertebrates also have adaptive immunity Figure 43.2 In innate immunity, recognition and
More informationFunctions of Blood. Transport. Transport. Defense. Regulation. Unit 6 Cardiovascular System: Blood
Unit 6 Cardiovascular System: Blood Functions of Blood With each beat of the heart, approximately 75 ml of blood is pumped On average, the heart beats 70 times per minute Every minute, the heart pumps
More informationBlood and Defense. Chapter 11
Blood and Defense Chapter 11 Functions of Blood 1. Carry nutrients from the small intestine and oxygen from the lung to tissues in the body 2. Transport wastes from tissues to the kidneys and carbon dioxide
More informationAP Biology. Overview. Endoplasmic Reticulum (ER) Types of ER. Smooth ER function. Rough ER function
The Cell: Endomembrane System Endoplasmic Reticulum,, Lysosomes, Peroxisomes, Vacuoles, Vesicles Overview Play key role in synthesis (& hydrolysis) of macromolecules in cell Various players modify macromolecules
More informationCELL BIOLOGY - CLUTCH CH THE IMMUNE SYSTEM.
!! www.clutchprep.com CONCEPT: OVERVIEW OF HOST DEFENSES The human body contains three lines of against infectious agents (pathogens) 1. Mechanical and chemical boundaries (part of the innate immune system)
More informationChemical and Biochemical Mechanism Of Cell Injury.
Chemical and Biochemical Mechanism Of Cell Injury. Professor Dr. M. Tariq Javed Dept. of Pathology Faculty of Vet. Science The University Of Agriculture Faisalabad Cell Injury When the cell is exposed
More informationBio10 Cell Structure SRJC
3.) Cell Structure and Function Structure of Cell Membranes Fluid mosaic model Mixed composition: Phospholipid bilayer Glycolipids Sterols Proteins Fluid Mosaic Model Phospholipids are not packed tightly
More informationJourney to the World of Cells
Journey to the World of Cells Starting Point for Life All living organisms on Earth are divided into pieces called cells. Formed from Proteins Organelles Make larger pieces called Tissues and systems Main
More informationLIVING SYSTEMS APPEAR COMPLEX BUT THERE IS AN UNDERLYING SIMPLICITY AND ELEGANCE:
CHM333 LECTURE 1: 8/26/09 FALL 2009 Professor Christine Hrycyna What is Biochemistry? Simplest definition: Chemistry of the living cell Uses basic laws of chemistry, biology and physics to explain processes
More informationEukaryotic Cell Structure
Eukaryotic Cell Structure Vocabulary listed for Chapter 7.3: cell wall, chromatin, nucleolus, ribosome, cytoplasm, endoplasmic reticulum, Golgi apparatus, vacuole, lysosome, chloroplast, plastid, chlorophyll,
More informationCampbell Biology in Focus (Urry) Chapter 9 The Cell Cycle. 9.1 Multiple-Choice Questions
Campbell Biology in Focus (Urry) Chapter 9 The Cell Cycle 9.1 Multiple-Choice Questions 1) Starting with a fertilized egg (zygote), a series of five cell divisions would produce an early embryo with how
More informationScience 8 - Cells & Cell Organization Notes
Science 8 - Cells & Cell Organization Notes 1.1 - Characteristics of Living Things Composed of cells Reproduce, grow & repair themselves Require energy o Plants usually from sun o Animals from plants or
More information7/9/2008. Hypoxic cell injury. Consequences of hypoxia depend on cell type. Significance of hypoxia depends on:
Cellular Adaptation and Cell Injury CLDavis Foundation On the Beach Lecture 2 Hypoxia, reperfusion, free radicals, and apoptosis R K Myers 2008 Hypoxic cell injury Hypoxia: any state of reduction of O
More informationCellular Reproduction, Part 1: Mitosis Lecture 10 Fall 2008
Cell Theory 1 Cellular Reproduction, Part 1: Mitosis Lecture 10 Fall 2008 Cell theory: All organisms are made of cells All cells arise from preexisting cells How do new cells arise? Cell division the reproduction
More informationCell Cycle Notes chromatin, somatic cells gametes mitosis sister chromatids, centromere cytokinesis binary fission,
Cell Cycle Notes 1. Importance of Cell Division a. For single celled organisms, cell division increases the number of individuals. b. In a multicellular organism, cell division functions to repair and
More informationTypes of ER. Chapter 6 The Cell: Endomembrane System Endoplasmic Reticulum, Golgi Apparatus, Lysosomes, Peroxisomes, Vacuoles, Vesicles.
WH Chapter 6 The Cell: Endomembrane System Endoplasmic Reticulum, Golgi Apparatus, Lysosomes, Peroxisomes, Vacuoles, Vesicles Types of ER Overview Play key role in synthesis (& hydrolysis) of macromolecules
More informationStudy Guide A. Answer Key. Cell Structure and Function
Cell Structure and Function Answer Key SECTION 1. CELL THEORY 1. b 2. e 3. d 4. a 5. c 6. i. cells; ii. living; iii. cell 7. biology 8. Surrounded by a cell membrane = Both; Contains cytoplasm = Both;
More informationIntrinsic cellular defenses against virus infection
Intrinsic cellular defenses against virus infection Detection of virus infection Host cell response to virus infection Interferons: structure and synthesis Induction of antiviral activity Viral defenses
More informationChapter 22: The Lymphatic System and Immunity
Bio40C schedule Lecture Immune system Lab Quiz 2 this week; bring a scantron! Study guide on my website (see lab assignments) Extra credit Critical thinking questions at end of chapters 5 pts/chapter Due
More informationUnit 2 - Characteristics of Living Things
Living Environment Answer Key to Practice Exam- Parts A and B-1 1. A fully functioning enzyme molecule is arranged in a complex three-dimensional shape. This shape determines the A) specific type of molecule
More informationTest Review Worksheet 1 Name: Per:
Test Review Worksheet 1 Name: Per: 1. Put the following in order according to blood flow through the body, starting with the lungs: Lungs, right atrium, left atrium, right ventricle, left ventricle, aorta,
More informationDefense mechanism against pathogens
Defense mechanism against pathogens Immune System What is immune system? Cells and organs within an animal s body that contribute to immune defenses against pathogens ( ) Bacteria -Major entry points ;open
More informationCell Communication CHAPTER 11
Cell Communication CHAPTER 11 What you should know: The 3 stages of cell communication: reception, transduction, and response. How a receptor protein recognizes signal molecules and starts transduction.
More informationThe Immune System All animals have innate immunity, a defense active immediately
The Immune System All animals have innate immunity, a defense active immediately upon infection Vertebrates also have adaptive immunity Figure 43.2 INNATE IMMUNITY (all animals) Recognition of traits shared
More information4/12/17. Cells. Cell Structure. Ch. 2 Cell Structure and Func.on. Range of Cell Sizes BIOL 100
Ch. 2 Cell Structure and Func.on BIOL 100 Cells Fundamental units of life Cell theory All living things are composed of one or more cells. The cell is the most basic unit of life. All cells come from pre-existing
More information11/25/2017. THE IMMUNE SYSTEM Chapter 43 IMMUNITY INNATE IMMUNITY EXAMPLE IN INSECTS BARRIER DEFENSES INNATE IMMUNITY OF VERTEBRATES
THE IMMUNE SYSTEM Chapter 43 IMMUNITY INNATE IMMUNITY EXAMPLE IN INSECTS Exoskeleton made of chitin forms the first barrier to pathogens Digestive system is protected by a chitin-based barrier and lysozyme,
More informationBreaking Up is Hard to Do (At Least in Eukaryotes) Mitosis
Breaking Up is Hard to Do (At Least in Eukaryotes) Mitosis Prokaryotes Have a Simpler Cell Cycle Cell division in prokaryotes takes place in two stages, which together make up a simple cell cycle 1. Copy
More informationANATOMY OF THE IMMUNE SYSTEM
Immunity Learning objectives Explain what triggers an immune response and where in the body the immune response occurs. Understand how the immune system handles exogenous and endogenous antigen differently.
More informationCell 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 informationGMS 6644: Apoptosis. Introduction
GMS 6644: Apoptosis Introduction (Feb. 15, 2006) Lei Xiao, Ph.D. Department of Anatomy & Cell Biology UF Shands Cancer Center ARB Rm R4-250, 846-1199, lxiao@ufl.edu Outline of the Lecture Different types
More informationBreaking Up is Hard to Do (At Least in Eukaryotes) Mitosis
Breaking Up is Hard to Do (At Least in Eukaryotes) Mitosis Chromosomes Chromosomes were first observed by the German embryologist Walther Fleming in 1882. Chromosome number varies among organisms most
More information4 A Tour of the Cell CAMPBELL BIOLOGY IN FOCUS. Urry Cain Wasserman Minorsky Jackson Reece
CAMPBELL BIOLOGY IN FOCUS Urry Cain Wasserman Minorsky Jackson Reece 4 A Tour of the Cell Lecture Presentations by Kathleen Fitzpatrick and Nicole Tunbridge Overview: The Fundamental Units of Life All
More informationA Tour of the Cell. Chapter 6. Biology Eighth Edition Neil Campbell and Jane Reece. PowerPoint Lecture Presentations for
Chapter 6 A Tour of the Cell 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 informationCell Structure and Function
Cell Structure and Function Agre and cells in the news Cells Smallest living unit Most are microscopic Discovery of Cells Robert Hooke (mid-1600s) Observed sliver of cork Saw row of empty boxes Coined
More informationNOTES: CH 43, part 2 Immunity; Immune Disruptions ( )
NOTES: CH 43, part 2 Immunity; Immune Disruptions (43.3-43.4) Activated B & T Lymphocytes produce: CELL-MEDIATED IMMUNE RESPONSE: involves specialized T cells destroying infected host cells HUMORAL IMMUNE
More informationCell Structure and Function Chapter 3, Day 1 Notes
Review: Characteristics of Living Things Cell Structure and Function Chapter 3, Day 1 Notes 1. Made of 2. Require 3. (species) 4. Maintain 5. 6. to environment 7. 8. materials with surroundings (water,
More informationChapter 7: Modes of Cell Death
Chapter 7: Modes of Cell Death 7.1. Background Cell death can follow one of two distinct pathways, apoptosis or necrosis, and can occur in response to severe stress conditions or after exposure to toxic
More informationUnit 2:The Cell. Section 3: Organelle Structure and Function Mrs. McNamara Biology
Unit 2:The Cell Section 3: Organelle Structure and Function Mrs. McNamara Biology Organelle-cell part that performs a specific function for the cell Most are surrounded by a membrane Each helps to maintain
More informationOrganelles. copyright cmassengale 1
Organelles copyright cmassengale 1 Organelles Very small (Microscopic) Perform various functions for a cell Found in the cytoplasm May or may not be membrane-bound 2 Animal Cell Organelles Nucleolus Nucleus
More information