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Anatomy & Physiology: Cell Membrane Transport and Cellular Respiration

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Terms in this set (31)

  • What is a concentration gradient?

    A concentration gradient is the difference in the concentration of a substance between two areas, driving movement from higher to lower concentration.

  • Compare passive transport and active transport.

    Passive transport moves substances down their concentration gradient without energy, while active transport moves substances against the gradient using energy (ATP).

  • Name the three types of passive transport processes.

    Simple diffusion, channel-mediated facilitated diffusion, and carrier-mediated facilitated diffusion.

  • Define diffusion and its driving force.

    Diffusion is the movement of molecules from high to low concentration down the concentration gradient, driven by kinetic energy of molecules.

  • What conditions allow diffusion across a membrane?

    Diffusion occurs when there is a concentration gradient and the membrane is permeable to the substance.

  • Compare simple diffusion and facilitated diffusion.

    Simple diffusion moves small, nonpolar molecules directly through the membrane; facilitated diffusion uses proteins to transport larger or polar molecules.

  • What determines if a substance crosses a plasma membrane?

    Size and polarity of the substance determine membrane crossing: small nonpolar cross easily; large or polar require facilitation.

  • Compare carrier-mediated and channel-mediated facilitated diffusion.

    Carrier-mediated uses proteins that change shape to transport molecules; channel-mediated uses protein channels forming pores for ions or water.

  • Give an example of substances transported by each passive transport type.

    Simple diffusion: oxygen; channel-mediated: ions like Na+; carrier-mediated: glucose.

  • Is diffusion effective over long distances in the body?

    No, diffusion is only effective over short distances due to slow rate over large distances.

  • Name three factors affecting the rate of diffusion.

    Concentration gradient size, temperature, and membrane permeability.

  • Define isotonic, hypertonic, and hypotonic solutions.

    Isotonic: equal solute concentration; hypertonic: higher solute outside; hypotonic: lower solute outside compared to inside the cell.

  • Define osmosis without using the term diffusion.

    Osmosis is the movement of water molecules across a selectively permeable membrane toward a higher solute concentration.

  • What drives osmosis and does it require ATP?

    Osmosis is driven by solute concentration differences and does not require ATP; it is a passive process.

  • How can water molecules pass through a membrane?

    Water passes directly through the lipid bilayer or via aquaporin channels.

  • How do solute concentration differences affect water pressure in cells?

    Water moves to balance solute concentrations, causing cells to swell (hypotonic) or shrink (hypertonic) due to changes in water pressure.

  • What energy source powers active transport?

    ATP provides energy for active transport moving substances against their concentration gradient.

  • Describe primary active transport using the sodium-potassium pump.

    The pump uses ATP to move 3 Na+ out and 2 K+ into the cell via a carrier protein, maintaining ion gradients.

  • Which ion is not pumped correctly in cystic fibrosis and its effect?

    Chloride ions (Cl-) are not pumped correctly, causing thick mucus buildup in airways.

  • Explain secondary active transport with glucose as example.

    Uses energy from Na+ moving down its gradient to co-transport glucose against its gradient into the cell.

  • Define specificity and saturation in carrier molecules and channels.

    Specificity means carriers transport specific substances; saturation means carriers have a maximum transport rate. Both affect facilitated transport.

  • What is transcytosis?

    Transcytosis is the transport of molecules across a cell by endocytosis on one side and exocytosis on the other.

  • Compare endocytosis and exocytosis.

    Endocytosis brings substances into the cell; exocytosis expels substances out of the cell.

  • Name and describe the three types of endocytosis.

    Phagocytosis (cell eating), pinocytosis (cell drinking), receptor-mediated endocytosis (specific uptake via receptors).

  • Describe the exocytosis process and give an example.

    Vesicles fuse with the plasma membrane to release contents outside the cell; example: neurotransmitter release.

  • Define anabolism and catabolism.

    Anabolism builds complex molecules; catabolism breaks down molecules releasing energy.

  • What are aerobic and anaerobic respiration?

    Aerobic requires oxygen; anaerobic does not require oxygen.

  • Name the three main stages of cellular respiration.

    Glycolysis, Krebs cycle (citric acid cycle), and electron transport chain.

  • Where does glycolysis occur and is it aerobic or anaerobic?

    Occurs in the cytoplasm and is anaerobic.

  • What is the role of oxygen and carbon dioxide in cellular respiration?

    Oxygen is the final electron acceptor; carbon dioxide is a waste product from breakdown of glucose.

  • What vitamins are essential for NAD and FAD production?

    Vitamin B3 (niacin) for NAD and vitamin B2 (riboflavin) for FAD.