Ch. 2 Flashcards
1
Q
- Which of the following is not part of a cell membrane?
a. Cholesterol
b. Phospholipid
c. Ubiquitin
d. Integral proteins
e. Glycolipids
A
c
2
Q
- A molecule that consists of a polar portion and a nonpolar portion is said to be
a. hydrophilic.
b. an emergent property.
c. hydrophobic.
d. an integral protein.
e. amphipathic.
A
e
3
Q
- A saturated hydrocarbon tends to
a. contain no double bonds.
b. be more solid at colder temperatures compared to an unsaturated hydrocarbon.
c. contain many double bonds.
d. Both a and b
e. Both b and c
A
d
4
Q
- Compared to fish found in lower temperature habitats, fish that inhabit higher temperatures tend to have
a. more saturated phospholipids in their brain synaptic membranes.
b. more saturated phospholipids in their brain proteins.
c. more unsaturated phospholipids in their brain synaptic membranes.
d. more unsaturated phospholipids in their brain proteins.
e. equal amounts of saturated and unsaturated brain proteins.
A
a
5
Q
- Which of the following membrane proteins is responsible for the passive movement of K+ across the typical animal cell membrane?
a. Channel
b. Enzyme
c. Transporter
d. Receptor
e. Structural protein
A
a
6
Q
- When a protein is denatured, which of the following structures is disrupted first?
a. Primary
b. Secondary
c. Tertiary
d. Quarternary
e. Amino acid
A
c
7
Q
- Which of the following is not a type of functional membrane protein?
a. An aqueous pore
b. Cholesterol
c. The Na+‒K+ pump
d. A receptor protein
e. Cytoskeletal filaments
A
b
8
Q
- A ring of _______ demarcates the apical surface of the cell from its lateral and basal surfaces.
a. tight junctions
b. septate junctions
c. gap junctions
d. epithelia
e. microvilli
A
a
9
Q
- Which of the following is not an occluding junction?
a. Gap junction
b. Tight junction
c. Septate junction
d. Both a and b
e. Both b and c
A
a
10
Q
- _______ is (are) the specific set of processes by which complex chemical compounds are broken down to release energy, create smaller chemical building blocks, or prepare chemical constituents for elimination.
a. Metabolism
b. Catabolism
c. Anabolism
d. Nitrogen metabolism
e. Biochemical reactions
A
b
11
Q
- Per gram, the leopard frog can jump farther per jump compared to the western toad because the leopard frog
a. is insensitive to lactic acid.
b. tends to live in warmer climates.
c. has a higher aerobic capacity.
d. creates more lactic acid per unit time.
e. is much larger.
A
d
12
Q
- Which of the following statements regarding enzymes is false?
a. All enzymes are catalysts.
b. Enzymes have substrates and products.
c. Enzymes speed chemical reactions.
d. All catalysts are enzymes.
e. Enzymes often regulate reactions.
A
d
13
Q
- Which of the following reactions is catalyzed by LDH?
a. Pyruvic acid + NADH2 → lactic acid + NAD
b. Lactic acid + NAD → pyruvic acid + NADH2
c. Pyruvic acid + NAD → lactic acid + NADH2
d. Lactic acid + NADH2 → pyruvic acid + NAD
e. Both a and b
A
e
14
Q
- The amount of substrate converted to product per unit of time is called the
a. turnover number.
b. saturated speed.
c. Vmax.
d. enzyme affinity.
e. reaction velocity.
A
e
15
Q
- Turnover number (kcat) describes what property of an enzymatic reaction?
a. Activation energy
b. Half the maximum reaction velocity
c. Catalytic effectiveness
d. Enzyme‒substrate affinity
e. The transition state
A
c
16
Q
- The likelihood that an enzyme will form a complex with the substrate during a collision is called the
a. catalytic effectiveness.
b. maximum reaction velocity.
c. activation energy.
d. enzyme‒substrate affinity.
e. transition state.
A
d
17
Q
- An enzymatic reaction is proceeding at subsaturation. Which of the following is not a means by which the enzymatic reaction can be increased?
a. Adding more substrate
b. Adding more enzyme
c. Increasing the catalytic effectiveness
d. Increasing the enzyme‒substrate affinity
e. Increasing the temperature
A
b
18
Q
- An interaction in which the binding of nonsubstrate ligands to the enzyme decreases its affinity for the substrate is called
a. allosteric inhibition.
b. negative cooperativity.
c. heterotropic cooperativity.
d. allosteric activation.
e. competitive inhibition.
A
a
19
Q
- Human LDH-B4 and rat LDH-B4 are examples of
a. isozymes.
b. analogous enzymes.
c. isoenzymes.
d. intraspecific enzyme homologs.
e. interspecific enzyme homologs.
A
e
20
Q
- An enzyme-encoding gene is considered to be_______ within a cell if the gene results in the synthesis of the encoded enzyme within that same cell.
a. promoted
b. expressed
c. induced
d. enhanced
e. constituted
A
b
21
Q
- _______ enzymes are present in a tissue in relatively high and steady amounts regardless of conditions, whereas _______ enzymes are present at low levels (or not at all) in a tissue unless their synthesis is activated.
a. Inducible; constitutive
b. Promotable; inducible
c. Constitutive; expressed
d. Constitutive; inducible
e. Expressed; promotable
A
d
22
Q
- Which of the following statements regarding allosteric modulation is false?
a. The binding of an allosteric modulator follows the law of mass action.
b. The binding of an allosteric modulator is reversible.
c. An allosteric modulator, when present, will always bind to the enzyme it modulates.
d. The binding of an allosteric modulator can increase the catalytic activity of the enzyme.
e. The binding of an allosteric modulator can decrease the catalytic activity of the enzyme.
A
c
23
Q
- Citrate combines with phosphofructokinase at the _______ site, ultimately _______ catalytic activity and thus regulating glycolysis.
a. allosteric; increasing
b. allosteric; decreasing
c. active; increasing
d. active; decreasing
e. covalent; increasing
A
b