BSC 1010 Chapter Notes - Chapter 9: Electrochemical Gradient, Electrochemical Potential, Facilitated Diffusion

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yellowcricket154

27 Aug 2020

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Solutes cross membranes by simple diffusion, facilitated diffusion, and active transport. A few molecules cross membranes by simple diffusion. The direct unaided movement dictated by differences in concentration of the solute on the two sides of the membrane. Transport proteins assist most solutes across membranes. Some move via facilitated diffusion (passive transport: movement of solutes down their free energy gradient, no energy required. Transport proteins can also move solutes against their free energy gradient: active transport. Requires energy (atp hydrolysis, simultaneous transport of another solute down an energy gradient) The movement of uncharged molecules is determined by their concentration gradient: simple or facilitated diffusion: exergonic, down a molecule"s concentration gradient, active transport: endergonic, against a molecule"s concentration gradient. The movement of a solute across a membrane is determined by its concentration gradient or its electrochemical potential. The movement of an ion is determined by its electrochemical potential (or electrochemical gradient)

Related Questions

11. Synthesis of ATP using the energy released as a proton diffuses down a concentration gradient involves the conversion of concentration gradient energy into chemical energyâTrue or false?

12. In the absence of active transport of a molecule, a simple or facilitated diffusion of the molecule will result in an equilibrium of the molecule across the membraneâTrue or false?

13. In the absence of an active transport of a molecule, a simple or facilitated diffusion of the molecule across a membrane will result in zero energy available to do workâTrue or false?

14. If biological membranes were permeable to all solutes osmosis could not occur because the concentration of water will be same on both sides of the membraneâTrue or false?

ceruleanfox820

Read the following scenarios and indicate which of the following processes they describe.

11. Sodium molecules move randomly around a solution of sodium chloride in water, frequently colliding with other sodium ions and chloride ions. secondary active transport diffusion osmosis facilitated diffusion primary active transport

12. Sodium ions (Na+) move through sodium channels in a synthetic membrane. primary active transport secondary active transport facilitated diffusion osmosis

13. Water molecules move into the cytosol of a cell placed in a hypotonic solution. primary active transport secondary active transport facilitated diffusion osmosis

14. Water molecules move into the cytosol of a cell placed in pure water. facilitated diffusion osmosis secondary active transport primary active transport

15. Water molecules move out of a cell placed in a hypertonic solution. facilitated diffusion primary active transport secondary active transport osmosis

16. The action of sodium-potassium pumps moves sodium ions (Na+) out of a cell and potassium ions (K+) into a cell. facilitated diffusion secondary active transport osmosis primary active transport

17. Glucose molecules move into cells lining the intestine against their concentration gradient driven by the movement of sodium ions (Na+) into the cells down their concentration gradient. osmosis secondary active transport primary active transport facilitated diffusion

18. A beaker of water is separated by a selectively permeable membrane that allows the passage of water but not ions. A solution of 4% sodium chloride (NaCl) is placed on one side of the membrane and pure water is placed on the other side of the membrane. The solutions are allowed to equilibrate. At this point, which process is going on? facilitated diffusion osmosis secondary active transport primary active transport

amaranthelk944

1 Which of the following statements is false?

(a) CO₂ and O₂ can diffuse freely across the cell membranes.

(b) The differences in permeability between artificial lipid bilayers and cell membranes arise from variations in phospholipid content.

(d) Cells expend energy in the form of ATP hydrolysis to maintain ion concentrations that differ from those found outside the cell.

2 Cells use membranes to help maintain set ranges of ion concentrations inside and outside the cell. Which of the following ions is the most abundant inside a typical mammalian cell?

(a) Na⁺

(b) K⁺

(d) Cl^â

3 Pumps are transporters that are able to harness energy provided by other components in the cells and drive the movement of solutes across membranes, against their concentration gradient. This type of transport is called _____________.

(a) active transport.

(b) free diffusion.

(d) passive transport.

harlequinbuffalo618

BSC 1010 Chapter Notes - Chapter 9: Electrochemical Gradient, Electrochemical Potential, Facilitated Diffusion

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