Cells and Metabolism

Question 1

NADH becomes ___ when it becomes NAD+ because it ___ electrons.

Answer 1

oxidized; loses

Question 2

Classify the following macromolecule: four-ring structure with HO- on bottom left

Answer 2

Lipid

Question 3

A culture of yeast is grown in the absence of oxygen. Under these conditions, ATP is
generated by ___, which takes place in the ____.

Answer 3

glycolysis; cytoplasm

Question 4

Enzymes act as biological catalysts by
A) making the ΔG negative
B) increasing the rate of a specific reaction
C) lowering the activation energy of a specific reaction
D) A and B
E) B and C
F) A, B, and C

Answer 4

B and C

Question 5

Simple diffusion and facilitated diffusion differ in that

Answer 5

facilitated diffusion requires an integral membrane protein

Question 6

What is an example of a catabolic reaction?

Answer 6

Glycolysis

Question 7

The Calvin Cycle takes place in the ___ and reduces carbon dioxide into ___.

Answer 7

Stroma; carbohydrates

Question 8

The following carbohydrate is classified as:
CH2OH
|
C=O
|
HO-C-H
|
H-C-OH
|
H-C-OH
|
CH2OH

Answer 8

Hexose and/or Ketose

Question 9

Which of the following are components of the Cell Theory (all that apply)
A) Cells are the most basic unit of life.
B) All cells need to have a nucleus.
C) Cells arise from preexisting cells.
D) All living things are composed of one or more cells.
E) Cells must be able to join with other cells or attach to solid surfaces.

Answer 9

A) Cells are the most basic unit of life.
C) Cells arise from preexisting cells.
D) All living things are composed of one or more cells.

Question 10

Valine is

Answer 10

Neutral, Non-Polar, Hydrophobic

Question 11

Glutamic Acid is

Answer 11

Negative Charge, Polar, Hydrophilic

Question 12

Serine is

Answer 12

Neutral, Polar, Hydrophilic

Question 13

How do you determine the polarity of an amino acid?

Answer 13

Polar: R-group will terminate with OH, SH, or NH2
Non-Polar: R-group terminates with CH

Question 14

Which amino acids are negatively charged?

Answer 14

Aspartic Acid (Asp)
Glutamic Acid (Glu)

Question 15

Which amino acids are positively charged?

Answer 15

Arginine (Arg)
Histidine (His)
Lysine (Lys)

Question 16

Potassium cyanide is incredibly toxic and even low doses acts as a lethal poison in humans. In
initial experiments, you find that cyanide localizes to the mitochondria and specifically acts as an
electron acceptor in a redox reaction with cytochrome C. Explain why cyanide poisoning leads to decreased ATP synthesis

Answer 16

• Electrons are stopped/inhibited from transport to complex 4
• Loss of proton/ less efficient proton gradient established which leads to less ATP synthesis

Question 17

Aquaporins are proteins that aid in transporting water into/out of the cell. Based on their function,
are aquaporins peripheral or integral membrane proteins? Explain your answer.

Answer 17

Integral membrane proteins because if they aid in the transport of water they must act as a carrier or channel protein and span the entire membrane to pass through the hydrophobic barrier

Question 18

Your lab has engineered a novel protein, aquapumpin, that pumps water out of a cell using active transport. Cells that overexpress aquapumpin are placed in a hypotonic solution, and you will measure ATP consumption. Will the rate of ATP consumption be very high or very low? Explain your answer.

Answer 18

• Very high
• Water will attempt to fill the cell in a hypotonic solution, so aquapumpin must work harder to pump out the excess water.

Question 19

Explain how photosynthetic cells maintain the correct ratio of ATP:NADPH needed for the
Calvin cycle

Answer 19

Cells utilize both non-cyclic and cyclic electron transport in the light reactions to make up the
deficiency of ATP needed in the Calvin Cycle