BSCI 330 Study Guide - Midterm Guide: Electrochemical Gradient, Calcium Atpase, Atp Hydrolysis

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.

(c) Direction of passive transport of molecules across membrane is controlled by osmosis and electrochemical gradient.

(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⁺

(c) Ca²⁺

(d) Cl^–

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.

(c) positive diffusion.

(d) passive transport.

1. Which of the following pairings are/is correct?

Cholesterol: has a hydrophilic and hydrophobic end
Cholesterol: does not have a hydrophilic end since it is a lipid
Cholesterol: is often times wedged in between the phospholipids
1st and 2nd choices only
1st and 3rd choices only
2nd and 3rd choices only
All of the above
None of the above

2. Which of the following pairing/s is/are correct?

Cholesterol: helps maintain the integrity of the cell membrane
Cholesterol: the rigid four carbon rings prevent lipid tails from packing too closely
Cholesterol: the rigid four carbon rings also prevent the membrane from being too fluid
1st and 2nd choices only
1st and 3rd choices only
2nd and 3rd choices only
All of the above
None of the above

3. Which of the following pairing/s is/are correct?

Membrane proteins: help maintain concentration gradients
Concentration gradient: the difference of amounts of solutes on two sides of a solution
Solutes: are the substances dissolved in a solution
1st and 2nd choices only
1st and 3rd choices only
2nd and 3rd choices only
All of the above
None of the above

4. Which of the following pairing/s is/are correct?

Molecules: move around randomly on their own
Molecules: when concentrated create an unstable environment due to increased collisions of molecules
Diffusion: is the movement of molecules from a region of low concentration to a region of high concentration
1st and 2nd choices only
1st and 3rd choices only
2nd and 3rd choices only
All of the above
None of the above

5. Which of the following pairing/s is/are correct?

Passive movement: movement of molecules that is energetically favorable b/c free energy is released in the process
Passive movement: requires energy from outside of the system
Passive movement: occurs as molecules move up their concentration gradients
1st and 2nd choices only
1st and 3rd choices only
2nd and 3rd choices only
All of the above
None of the above

6. Which of the following pairings/s is/are correct?

Active movement: is a passive process
Active movement: is an energetically unfavorable process
Active movement: releases free energy
1st and 2nd choices only
1st and 3rd choices only
2nd and 3rd choices only
All of the above
None of the above

7. Which of the following pairing/s is/are correct?

Transport channels: allow movement of all ions through
Transport carriers: allow movement of all ions through
Channels : passive movement
Carriers: active movement
1st and 2nd choices only
1st and 3rd choices only
1st, 2nd, and 3rd choices only
2nd and 3rd choices only
All of the above
None of the above

8. Which of the following paring/s is/are correct?

Active transporters: movement of molecules up their concentration gradients
Active transporters: require energy
Active transporters: ATP dependent pumps, antiporters, symporters
1st and 2nd choices only
1st and 3rd choices only
2nd and 3rd choices only
All of the above
None of the above

Question 1

Plasma membranes are selectively permeable. This means that

Question 2

Oxygen molecules O₂ crosse a plasma membrane by

Question 3

Facilitated diffusion across a biological membrane requires ________ and moves a substance ________ its concentration gradient.

Question 4

When two aqueous solutions that differ in solute concentration are placed on either side of a semipermeable membrane and osmosis is allowed to take place, the water will

Question 5

Kinetic energy differs from chemical energy in that

Question 6

When a cell uses chemical energy to perform work, it uses the energy released from a(n) ________ reaction to drive a(n) ________ reaction.

Question 7

When an enzyme catalyzes a reaction

Question 8

Which of the following statements regarding enzyme function is false?