Question 1

Which of the following best explains why phospholipids form a bilayer in biological membranes?

Accepted Answer

Phospholipids have hydrophilic heads and hydrophobic tails, causing them to arrange with heads facing water and tails facing inward.

Question 2

Which of the following factors would increase the fluidity of a cell membrane?

Accepted Answer

Increasing the proportion of unsaturated fatty acids in phospholipids.

Question 3

A cell is placed in a hypertonic solution. What will happen to the cell?

Accepted Answer

Water will leave the cell, causing it to shrink.

Question 4

Which equation correctly represents the free energy change ($$\Delta G) in a $$chemical reaction?

Accepted Answer

$$\Delta G = \Delta H - T\Delta S$$

Question 5

Which of the following statements about enzymes is TRUE?

Accepted Answer

Enzymes lower the activation energy, speeding up the reaction.

Question 6

Which of the following is a function of membrane proteins?

Accepted Answer

They facilitate cell signaling, transport, and cell recognition.

Question 7

What are the three conditions that determine the direction ions will travel through gated channels?

Accepted Answer

Concentration gradient, voltage difference, and the state of the gate (open/closed).

Question 8

Which statement best describes competitive inhibition of an enzyme?

Accepted Answer

An inhibitor binds to the active site, preventing substrate binding.

Question 9

During aerobic respiration, what is the final electron acceptor?

Accepted Answer

Oxygen ($$O_2)$$

Question 10

Which of the following is the correct summary equation for photosynthesis?

Accepted Answer

$$6CO_2 + 6H_2O \rightarrow C_6H_{12}O_6$ + 6O_2$$

Question 11

Which process directly generates the most ATP during cellular respiration?

Accepted Answer

Electron transport chain and chemiosmosis

Question 12

Which of the following statements about NAD+ and NADH is correct?

Accepted Answer

NAD+ is the oxidized form and NADH is the reduced form.

Question 13

Which of the following best describes the role of rubisco in the Calvin cycle?

Accepted Answer

It fixes carbon dioxide by catalyzing its attachment to ribulose bisphosphate.

Question 14

Which statement about binary fission in bacteria is TRUE?

Accepted Answer

It produces two genetically identical daughter cells.

Question 15

Which of the following is a tumor suppressor gene that helps prevent cancer by inducing cell cycle arrest or apoptosis?

Accepted Answer

p53

Question 16

How many copies of a tumor suppressor gene must be damaged for cancer to develop?

Accepted Answer

Both copies

Question 17

Which of the following best describes feedback inhibition in metabolic pathways?

Accepted Answer

The end product of a pathway inhibits an enzyme involved early in the pathway.

Question 18

Which of the following is NOT a factor that affects enzyme function?

Accepted Answer

The color of the enzyme

Question 19

Which of the following statements about the structure of ATP is correct?

Accepted Answer

ATP consists of adenine, ribose, and three phosphate groups; energy is stored in the bonds between the phosphate groups.

Question 20

Which of the following best describes the difference between anabolism and catabolism?

Accepted Answer

Anabolism builds complex molecules from simpler ones using energy; catabolism breaks down complex molecules to release energy.

BIOL161 Exam 2 Study Guide: Cell Membranes, Energy, Enzymes, and Cellular Processes

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