Final exam review -- cells

1. Final exam review -- cells Structure and tranport

2. Discovering the Cell • Robert Hooke – named cell; looked at cork • Anton Van Leeuwenhoek – saw first living cells • Robert Brown – saw and named nucleus • Matthias Schleiden & Theodor Schwann plants and animals made of cells • Rudolph Virchow – physician, healing of wounds in humans, cells coming from cells

3. The Modern Cell Theory 1. All known living things are made up of 1 or more cells. 2. The cell is structural & functional unit of all living things 3. All cells come from pre-existing cells by division.             (Spontaneous Generation does not occur). 4. Cells contain hereditary information which is passed from cell to cell during cell division. 5. All cells are basically the same in chemical composition. 6. All energy flow (metabolism & biochemistry) of life occurs within cells.    

4. Prokaryotic vs. Eukaryotic • Prokaryotic *NO NUCLEUS, but do have nucleiod region with DNA present *Small and Simple – few organelles *Have cell membranes and cytoplasm Ex. Bacteria • Eukaryotic: *Contain nuclei *Contains organelles that perform specialized functions *Uni-or multicellular Ex. Plant and animal cells

5. Surface Area to Volume Ratio • Surface area acts as limiting factor in size of cell because is a two dimensional unit SA = Length x width • Volume is three dimensional, so increases more quickly than the surface area can accommodate Vol = length x width x height

6. Figure 7.5 Geometric relationships explain why most cells are microscopic

7. Plant and animal cells to label -- interactive

10. Organelles -- functions • Control: *Nucleus (plant and animal); DNA is here, contains all directions for carrying on activities • Assembly, Transport, and Storage: *Nucleolus (plant and animal) makes ribosomes *Endoplasretic (plant and animal) “highway” system for transport *Ribosomes (plant and animal) protein assembly sites *Golgi bodies (plant and animal) packaging site for materials *Vacuoles (plant – one big and animal – many small ones) vacuoles are for storage *Lysosomes (plant and animal) digestive enzymes in these – break down materials • Energy transformations: *Chloroplasts(plant only) make sugars -- photosynthesis *Mitochondria (plant and animal) produce ATP – cellular respiration • Cell division *centrioles – ONLY in animal cells help chromosomes divide correctly

11. Cell membrane • Fluid Mosaic Model made up of MANY different structures working together in a flexible manner (parts are NOT bonded together) Major components are: Phospholipids, arranged in a bilayer Proteins embedded in the membrane

13. Fig. 7-7 Fibers of extracellular matrix (ECM) Carbohydrate Glyco- protein Glycolipid EXTRACELLULAR SIDE OF MEMBRANE Receptor protein Gated channel protein Cholesterol Microfilaments of cytoskeleton Peripheral proteins Channel protein Integral protein CYTOPLASMIC SIDE OF MEMBRANE

14. 3 types of proteins found associated with cell membrane… • Channel Proteins – form physical pathway through phospholipid bilayer • Receptor Proteins – change shape as other molecules bind to them and pass INFO into the cell (nothing physically passes through) • Marker Proteins – identify the specific type of cell (so when organism needs to repair/replace cells, can do so with correct type)

15. Two types of transport… • Passive transport – requires no input of energy; follows concentration gradient Ex. Diffusion • Active transport – DOES need energy to occur; moves against the concentration gradient Ex. Pumps Ex. Endocytosis and Exocytosis

16. Diffusion • Movement of a substance from where there is a large amount of that substance to where there is a small amount of that substance (from an area of high concentration to an area of low concentration) • Like a canoe in a stream – go with the flow • No energy needed • 2 types: dialysis and osmosis

17. Osmosis • Movement of WATER from an area of high water concentration to an area of low water concentration Ex. Flood of water into sinking ship… *This type of diffusion is more common in cells because water molecules are smaller and easier to move than particles… • Water molecules can pass directly through the TINY spaces between phospholipid molecules and don’t need to use channel proteins…

18. Terms that describe the conditions of mixtures – will only use these terms when are comparing substances • Hypertonic – concentration of dissolved substances is higher than in what it is being compared to Ex. Syrup vs. tap water – syrup is hypertonic • Hypotonic – concentration of dissolved substances is lower than in what it is being compared to From above, now tap water is the answer! • Isotonic – concentration of dissolved substances is equivalent to the solution to which it is being compared to Syrup compared to syrup, tap water compared to tap water….

19. The differences in concentration affect the movement of water and particles… • Water moves from where there is a great deal of it (hypo) to where there is less of it (hyper) • Particles move from where there are many of them (hyper) to where there are less of then (hypo) • tonicity animation

20. Figure 8.12 The water balance of living cells

21. Active Transport • Requires energy input to do this – ATP *moving materials from low concentration to a high concentration – stockpiling… • Pumps: see pages 89-90 in your textbook Ex. Na-K Pump (keeps nerves functioning) See pages 90-91 in your textbook • Exocytosis – releases large particles out of the cell through the membrane using vesicles • Endocytosis – brings large particles in to cell through the membrane using vesicles

22. Fig. 7-17 __________ – 3 types A review... ______________ ___________ _____ _______________ ____________ __________ _________________________

23. Fig. 7-17 Endocytosis – 3 types A review... Active Transport Phagocytosis Pump Passive transport Pinocytosis Exocytosis Receptor-Mediated endocytosis Osmosis and dialysis are passive