Bio 107 Practice Exam 1-Chap 5

7. Which of these statements describes what occurs in facilitated diffusion? a. Facilitated diffusion of solutes occurs through protein pores in the membrane. b. Facilitated diffusion of solutes occurs through phospholipid pores in the membrane. c. Facilitated diffusion requires energy from the cell to drive a concentration gradient. d. Facilitated diffusion is another name for osmosis.

a. Facilitated diffusion of solutes occurs through protein pores in the membrane.

12. Cellular respiration is an example of _____. a. an exergonic reaction b. thermodynamics c. bioenergetics d. an endergonic reaction

a. an exergonic reaction

5. The diffusion of water across a selectively permeable membrane is called _____. a. osmosis b. facilitated diffusion c. active transport d. exocytosis

a. osmosis

9. Which of the following terms specifically refers to the intake of very large particles by cells? a. phagocytosis b. osmosis c. exocytosis d. pinocytosis

a. phagocytosis

1. Which of the following best describes the general structure of a cell membrane? a. proteins embedded in two layers of phospholipid b. proteins sandwiched between two layers of phospholipid c. phospholipids sandwiched between two layers of protein d. a layer of protein coating a layer of phospholipid

a. proteins embedded in two layers of phospholipid

8. The transport of molecules of a particular solute from inside an animal cell across the cell membrane to the extracellular fluid always requires energy when _____. a. the concentration of the solute is lower inside the cell than outside it b. a transport protein is involved in the movement of the molecules c. the lipid bilayer is permeable to the solute d. the concentration of the solute is higher inside the cell than outside it

a. the concentration of the solute is lower inside the cell than outside it

3. Which of the following statements is true about passive transport? a. Passive transport phenomena can never reach equilibrium. b. Passive transport operates independently of diffusion. c. Passive transport requires no expenditure of cellular energy. d. Passive transport operates independently of concentration.

c. Passive transport requires no expenditure of cellular energy.

2. Phospholipids are well suited to be the main structural components of membranes because they _____. a. are completely insoluble in water b. form a structure in which the hydrophobic portion faces outward c. form a selectively permeable structure d. form a single sheet in water

c. form a selectively permeable structure

6. If the volume of a cell increases when it is placed in an aqueous solution, that solution is said to be _____ to the cell. a. osmotic b. isotonic c. hypotonic d. hypertonic

c. hypotonic

16. If the tertiary structure of an enzyme is changed, _____. a. the product of the reaction will be a different molecule b. it will be missing one of its polypeptides c. its substrate may not fit properly in the active site d. the helical coil will be stretched out

c. its substrate may not fit properly in the active site

10. Energy is _____. a. the rearrangement of chemical molecules within matter b. the amount of food eaten c. the capacity to perform work d. movement

c. the capacity to perform work

13. A reaction is designated as exergonic rather than endergonic when _____. a. no kinetic energy is released b. activation energy is necessary c. the potential energy of the products is less than the potential energy of the reactants d. activation energy exceeds net energy release

c. the potential energy of the products is less than the potential energy of the reactants

17. Which of these statements about enzyme inhibitors is true? a. A competitive inhibitor binds to the enzyme outside the active site. b. The action of competitive inhibitors may be reversible or irreversible. c. A noncompetitive inhibitor does not change the shape of the active site. d. When the product of an enzyme or an enzyme sequence acts as its inhibitor, this is known as positive feedback.

d. When the product of an enzyme or an enzyme sequence acts as its inhibitor, this is known as positive feedback.

4. The movement of atoms, ions, or molecules from a region of higher concentration to regions of lower concentration is called _____. a. crenation b. spontaneous combustion c. active transport d. diffusion

d. diffusion

14. The phosphorylation of ADP to form ATP is an _____ reaction that _____ energy. a. exergonic ... releases kinetic b. endergonic ... releases c. exergonic ... requires an input of d. endergonic ... requires an input of

d. endergonic ... requires an input of

15. The mechanism of enzyme action is to _____. a. change endergonic into exergonic reactions b. create an energy barrier between substrates c. change the direction of thermodynamic equilibrium d. lower the energy of the activation of a reaction

d. lower the energy of the activation of a reaction

11. The first law of thermodynamics _____. a. states that entropy spontaneously increases b. predicts the direction of a reaction c. deals with heat content d. states that energy is neither created nor destroyed

d. states that energy is neither created nor destroyed