Exam 1 Questions

Question 1

Mitochondria are thought to have evolved from _____ bacteria that was engulfed by an early _____ eukaryotic cells.

• aerobic; anaerobic
• anaerobic; aerobic
• photosynthetic; anaerobic
• photosynthetic; aerobic

Answer 1

aerobic; anaerobic

Question 2

Which of the following is a structural polysaccharide?

• glycogen
• fructose
• cellulose
• starch
• all of the above are structural polysaccharides

Answer 2

Cellulose

Question 3

The difference between an acid and a base is that an acid _____, whereas a base ______.

• undergoes a reversible reaction; does not
• releases OH- ions in solution; accepts OH- ions
• releases H+ ions in solution; accepts H- ions
• releases H+ ions in solution; accepts H+ ions
• releases OH- ions in solution; releases H+ ions

Answer 3

Releases H+ ions in solution; accepts H+ ions

Question 4

All of the following are common functional groups found in biological molecules except…

• phosphoryl groups
• carbonyl groups
• amino groups
• sulfhydryl groups
• butyl groups

Answer 4

Butyl groups

Question 5

Chemical reactions carried out by living systems depend on the ability of some organisms to capture and use atoms from nonliving sources in the environment. The specific subset of these reactions that break down nutrients in food can be described as

• metabolic
• catabolic
• anabolic
• biosynthetic

Answer 5

Catablolic

Question 6

Two or three alpha helices can sometimes wrap around each other to form coiled-coils. The stable wrapping of one helix around another is typically driven by ____ interactions.

• hydrophilic
• hydophobic
• van der Waals
• ionic

Answer 6

Hydrophobic

Question 7

Refer to the polymer below. First determine what type of macromolecule this represents. Which of the following bonds is broken during hydrolysis reactions that release the molecule’s monomers as products?

• Bond A
• Bond B
• Bond C
• Bond D
• Bond E

Answer 7

Bond D

Question 8

You have just sequenced a new protein isolated from mice and observed that sulfur-containing cysteine residues occur at regular intervals. This finding is most consistent with which of the following claims about proteins?

• Cysteine residues are required for the formation of alpha-helices​ and beta-pleated sheets
• It will be important to include cysteine in the diet of the mice
• Cysteine residues are involved in disulfide bridges that help form the tertiary structure
• Cysteine causes bends, or angles, to occur in the tertiary structure of proteins.

Answer 8

Cysteine residues are involved in disulfide bridges that help form the tertiary structure

Question 9

Motor proteins use the energy in ATP to transport organelles, rearrange elements of the cytoskeleton during cell migration, and move chromosomes during cell division. Which of the following mechanisms is sufficient to ensure the unidirectional movement of a motor protein along its substrate?

• a conformational change is coupled to the release of a phosphate (Pi)
• the substrate on which the motor moves has conformational polarity
• a conformational change is coupled to the binding of ADP
• a conformational change is coupled to ATP hydrolysis

Answer 9

A conformational change is coupled to ATP hydrolysis.