Presentation on theme: "Chapter 7 Membrane Structure and Function. You should be able to: 1. Define the following terms: amphipathic molecules, aquaporins, diffusion 2. Explain."— Presentation transcript:
Fig. 7-5 Lateral movement (~10 7 times per second) Flip-flop (~ once per month) (a) Movement of phospholipids (b) Membrane fluidity Fluid Viscous Unsaturated hydrocarbon tails with kinks Saturated hydro- carbon tails (c) Cholesterol within the animal cell membrane Cholesterol
Fig. 7-5a (a) Movement of phospholipids Lateral movement ( 10 7 times per second) Flip-flop ( once per month)
Fig. 7-7 Fibers of extracellular matrix (ECM) Glyco- protein Microfilaments of cytoskeleton Cholesterol Peripheral proteins Integral protein CYTOPLASMIC SIDE OF MEMBRANE Glycolipid EXTRACELLULAR SIDE OF MEMBRANE Carbohydrate
Fig Filling vacuole 50 µm (a) A contractile vacuole fills with fluid that enters from a system of canals radiating throughout the cytoplasm. Contracting vacuole (b) When full, the vacuole and canals contract, expelling fluid from the cell.
Fig. 7-20c RECEPTOR-MEDIATED ENDOCYTOSIS Receptor Coat protein Coated pit Ligand Coat protein Plasma membrane 0.25 µm Coated vesicle A coated pit and a coated vesicle formed during receptor- mediated endocytosis (TEMs)
Fig. 7-UN1 Passive transport: Facilitated diffusion Channel protein Carrier protein
Fig. 7-UN2 Active transport: ATP
Fig. 7-UN3 Environment: 0.01 M sucrose 0.01 M glucose 0.01 M fructose Cell 0.03 M sucrose 0.02 M glucose
An animal cell membrane will be more fluid at room temperature if it contains a) more cholesterol. b) longer chain fatty acids. c) more cis-unsaturated and polyunsaturated fatty acids. d) more trans-unsaturated fatty acids. e) any of the above
Osmosis If a marine algal cell is suddenly transferred from seawater to freshwater, the algal cell will initially a) lose water and decrease in volume. b) stay the same: neither absorb nor lose water. c) absorb water and increase in volume.
Transport Kinetics: Passive Diffusion Which of the curves below illustrates uptake of nitrous oxide into the cell, if nitrous oxide diffuses passively across the membrane? A B C
Transport Kinetics: Passive Diffusion Which of the curves below illustrates uptake of lactose into the cell via a passive transporter? A B C
Transport Kinetics: Passive Diffusion Which of the curves below illustrates uptake of phosphate into the cell by an active transport system? A B C