Also, how substances are transported throughout the cell.

Transcription

1 Also, how substances are transported throughout the cell.

2 Why Study Cells? Cells are as fundamental to Biology as the atom is to chemistry. All organisms are made of cells. The cell is the simplest collection of living matter that can live. Everything an organism does occurs fundamentally at the cellular level

3 The Order of Things: Organism Organ system Organs Tissue Cells Organelles Macromole cules atoms

4 Cells are about 90% water, the rest (other 10%) is about 50% protein 15% carbohydrate 15% nucleic acid 10% lipid 10% other

5 Contributors to the Cell Theory Anton Van Leeuwenhoek developed the first microscope (observed organisms in pond water) Robert Hooke discovered the cell in 1655 (looked at wood, stems, & thought that compartments looked like cells in a monastery (small rooms)

6 Cork Cells

7 Other Contributors Robert Brown 1833 observed that many cells have dark structure near the center now known to be the nucleus. Mathias Schleiden stated that all plants are made of cells Theodore Schawn Stated that animals are made up of cells Rudolf Virchow stated that all cells come from pre existing cells

8 The Three Parts of the Cell Theory 1-All living things are made of cells 2-Cells are the basic units of structure and function in living thing 3-All cells come from preexisting cells

9 All cells can be classified as Prokaryotes (no true nucleus) (Think pro=no)

10 All cells can be classified as Eukaryotes ( has True nucleus) (Think Eu (you)=true)

11 Prokaryotic Cells Eukaryotic Cells Has No true nucleus NO membrane bound organelles Have a simple structure and are smaller in size. Mostly Unicellular (1 cell) All are Bacteria Eubacteria & Archeabacteria Has a true Nucleus Has Membrane bound Organelles Are more complex and are larger in size Protists, Fungi, Plants, and Animals are all eukaryotes

12 Prokaryotic Cells Locomotion Some use flagella Some use a slime layer Some don t move at all Click on the link below and read about 5 fun facts about bacteria (prokaryotes) BACTERIA FUN FACTS Rotary motor Bacterial cell wall Flagellum Sheath

13 How did cells change, make the transition from prokaryotic (NO nucleus) to eukaryotic (TRUE nucleus) cells?

14 Endosymbiotic Theory Endosymbiotic theory suggests that eukaryotes arose from a symbiotic relationship between various prokaryotes. Heterotrophic bacteria became mitochondria. Cyanobacteria (autotrophic bacteria) became chloroplasts. Host cell was a larger prokaryotic cell. Evidence for this theory is that mitochondria, centrioles and chloroplasts have their OWN DNA

15 Endosymbiosis Prokaryotic cell is engulfed Host cell CLICK for More on endosymbiosis Smaller Prokaryotic cell Symbiosis-Increases survival of both!

16 Eukaryotes Eukaryotes arose from prokaryotes and developed into larger more complex organisms. Eukaryotes are cells that contain a nucleus and organelles surrounded by a membrane, such as the ER, mitochondria and chloroplasts.

17 The Nucleus All eukaryotic cells have a nucleus at some point. This is a membranebound structure that contains the DNA (organism's genome). The nuclear membrane has pores or holes in it. The nucleolus is also in the nucleus where ribosome units are made.

18 Cytoplasm The cytoplasm is the AREA between the nucleus and the cell membrane. (the cytosol is the jellylike substance filling the space) Many chemical reactions occur here.

19 Cell membrane Structure & Function Separates cells from their environment Controls what goes in & out of cells Aids in the protection & support of the cells Aids in inter cell communication (BETWEEN cells)

20 Cell membrane Structure & Function Separates cells from their environment Controls what goes in & out of cells Aids in the protection & support of the cells Aids in inter cell communication (BETWEEN cells)

21 Cell Membrane Structure & Function Mostly phospholipid bi-layer with the outer part being hydrophilic (phosphate head) and the inner portion very hydrophobic (2 fatty acids) The hydrophilic heads allow interaction with watery environment inside and out The hydrophobic inner layers squeeze together and are both stable and fluid Proteins either move freely w/in the layer & act as channels thru which molecules can OR act like a pump pushing molecules from one side of the membrane to another. Carbohydrates are attached to proteins, and help cells recognize & interact w/ each other

22 Cell Wall Found in plants, algae, bacteria,& fungi Lies OUTSIDE of the cell membrane Helps protect & support the cell In plants the primary cell wall is made up of cellulose, makes it elastic so that plant can grow. In plants with woody stems, a secondary cell wall develops made up of cellulose & lignin which makes it rigid.

23 Ribosomes Structure & function Site of protein synthesis (place where proteins are made) Cells that have high rates of protein synthesis like the liver have a larger # Ribosomes. Free Ribosomes are suspended in the Cytosol Bound Ribosomes are attached to the rough ER.

24 More about Ribosomes Made of TWO sub-units that are 60% protein and 40% ribosomal RNA Free Ribosomes make different proteins than Bound ribosomes (on ER) They can switch places as needed depending on metabolic needs of the cell

25 The endoplasmic reticulum (ER) is where lipids of the cell membrane, along with proteins and other materials are assembled. Rough ER has ribosomes & Smooth ER has no ribosomes The ER usually surrounds the nucleus and may reach the cell membrane

26 Function of the Smooth ER Functions in many different metabolic processes: Makes Lipid (fats) Including phospholipids & steroids Detoxification (lots of smooth ER in liver cells)

27 Function of the Rough ER Ribosomes are attached to it Major site of protein synthesis Makes secretary proteins called glycoproteins because they are bound to carbohydrates (glyco part) It is also involved in membrane production Click on link THE MAKING OF A PROTEIN

28 Golgi apparatus collection of Golgi bodies Stacked flattened sacks Site where cell products are packaged for export Proteins are modified by being combined with fats or carbohydrates

29 Golgi apparatus Vesicles then pinch off from the Golgi body to be secreted (outside the cell) Involved in the production of lysosomes

30 Golgi apparatus Close to cell membrane Has Vesicles

31 Golgi apparatus

32 Function of the Mitochondria Site of Cellular Respiration which Converts Glucose molecules into ATP energy which the cell can use- C 6 H 12 O 6 + O 2 H 2 O + CO 2 + ATP (energy) Membrane bound organelle It is called the power house of the cell because it is the site of cell respiration.

33 Function of the Mitochondria Found in ONLY in ALL Eukaryotic cells & has its own DNA (remember endosymbiosis)

34 Chloroplasts are organelles that capture sunlight energy and convert it into chemical energy in a process known as photosynthesis. Sunlight + H 2 O + CO 2 C 6 H 12 O 6 + O 2

35 Vacuoles Found in PLANT and ANIMAL cells The vacuole acts a container, storing water and dissolved particles Plants have a large central vacuole for water storage and to maintain turgor pressure Unicellular organisms can use contractile vacuoles for movement and to maintain homeostasis (water balance) video

36 High Turgor- Full vacuoles Low Turgorempty vacuoles

37 Lysosomes Are membrane bound sacs of hydrolytic enzymes Are used by the cell to digest (lyse=breakdown) Macromolecules-like proteins, polysaccharides, fats, & nucleic acids. If the cell releases too many Lysosomes it will die because it will eat itself (autolysis).

38 More about Lysosomes Involved in Phagocytosis is when a large molecule engulfs a smaller molecule. Are often found in white blood cells, used as a immune defense mechanism to eat pathogens like viruses and bacteria. Tay Sach s, a fatal genetic disease occurs when a lipid eating enzyme is missing so the fat accumulates in the cells preventing the brain from working.

39 The cytoskeleton is a network of protein filaments that helps the cell maintain its shape. It is also involved in movement.

40 Centrioles Centrioles are cylindrical bundles of microtubules that function during cell reproduction in animal cells.

41 Cilia and Flagella Some eukaryotes have cilia or flagella for locomotion or as tissue to help move stuff along. Flagella are long whiplike structures. Cilia are more numerous and are short flagella. Eukaryotic differ from prokaryotic cillia/ flagella

42 Plant vs. Animal Cells Turn to page 8 PLANT of packet and click on link and complete sheet! When done CELL return to the notes ;-) HAVE: Cell Wall LARGE vacuoles Chloroplasts cell part QUIZ! DO NOT HAVE: Centrioles ANIMAL Cell membrane CELL Mitochondria Golgi apparatus Nucleus Cytoskeleton Ribosomes Endoplasmic reticulum Lysosomes HAVE: Centrioles DO NOT HAVE: Cell Wall LARGE vacuoles Chloroplasts

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44 The Cell Membrane As previously mentioned, The cell membrane is the edge of life, the boundary that separates the living cell from its environment. It s almost like the bouncer in the club that is in charge of regulating who goes in and out of the party.

45 Selectively-Permeable Cell membranes are always selectively-permeable, meaning that some molecules are allowed to pass freely (diffuse) through the membrane while others are not. Made of a phospholipid bilayer, Also called the Fluid Mosaic Model

46 Phospholipid bilayer or phosphodigyceride Head Polar (charged) Phosphate (PO 4 ) Hydrophilic (water-loving) Pointed toward inside & outside of cell Tails (2) Nonpolar (no charge) Fatty acid chains Hydrophobic (water-hating) Pointed toward middle of membrane

47 Permeability Vocabulary: Semi-permeable Some things can enter the while others can not Think of the Bouncer at the club that lets the pretty and the popular students in. But leaves the crazy science teachers outside staring at the door. Complete Permeable Everything can enter the cell. An open door Impermeable Nothing can enter the cell. Closed and locked door

48 Types of Transport diagram Types of Transport Passive Transport Active Transport Osmosis Diffusion Facilitated Diffusion Endocytosis & Exocytosis Protein pumps

49 Passive Transport Active Transport Requires No ATP (energy) Requires ATP energy Goes with (down)the concentration gradient (from highlow concentration) Goes against (up) the concentration gradient (from lowhigh) examples: Osmosis, diffusion & facilitated diffusion examples: Endocystosis, exocytosis & protein pumps.

50 Osmosis and Diffusion Diffusion- movement of materials from an area of high concentration to an area of low concentration. In cells O2 and CO2 diffuses in and out Click on link diffusion Osmosis diffusion of water which moves from a high to low concentration. Click on link (be sure to add salt!) osmosis Dynamic Equilibrium Particles move in and out at the same rate, so there is no overall change and the cell remains in balance

51 Diffusion

52 Concentration gradient The difference in concentration of molecules across a distance in a solution or in and out of cells.

53 Hypertonic, Hypotonic, and Isotonic Solutions (The Power of Osmosis) The concentration of solute in the solution can be less than the concentration of solute in the cells. The cell is in an hypotonic solution. (hypo = less than normal) The concentration of solute in the solution can be greater than the concentration of solute in the cells. The cell is in an hypertonic solution. (hyper = more than normal) The concentration of solute in the solution can be equal to the concentration of solute in the cells. The cell is in an isotonic solution. (iso = same as normal)

54 Osmosis Hypotonic Solutions Solution has less solute (salt) than the cell Water enter the cell Cell swells Hypertonic Solutions Solution has more solute than the cell Water leaves the cell. Cell shrinks Isotonic solution Solute concentration of the solution is equal to that of the cell. No net movement of water Cell stays the same

55 Osmosis Diffusion of water through a selectively permeable membrane. From high water concentration to low water concentration Click on link below and take the quiz OSMOSIS

56 Osmosis- animal cells (RBC)

57 Osmosis- Plant cells

58 Facilitated Diffusion Movement of specific molecules across cell membranes through protein channels or doorways from a high to low concentrations Is fast and specific, but does not require cell energy. Glucose moves through cell membranes this way

59 Active Transport A material moves from an area of lower concentration to an area of higher concentration. REQUIRES the input of cell energy. THREE main types 1-Protein Pumps-cell membrane protein that pumps ions into cell, Na + K + pumps enable nerve impulses to move from cell to cell click on link protein pump

60 more Active Transport 2-Endocytosis: the process of taking material into the cell by means of pockets of the membrane. TWO KINDS Phagocytosis: type of endocytosis where the cytoplasm surrounds and engulfs large particles cell eating Pinocytosis: cell drinking 3-Exocytosis: the removal of cell contents that consists of the membrane fusing with the membrane of the object and forcing the content out the cell. Exiting the cell cell pooping

61 Endocytosis stuff coming into the cell against the gradient Phagocytosis cell eating Pinocytosis Cell drinking Active Transport (Requires energy) Exocytosis Stuff leaving the cell against the gradient Opposite of endocytosis getting rid of waste Protein pumps Ex. Sodium- Potasium pumps

62 Phagocytosis Exocytosis Protein Pump (Na+ K+)

63 Phagocytosis (taking place in cells under a microscope)

64 Review ALL Cell Transport Click on link below and review all the forms of cell transport have fun! review! Ready for a quiz??????