Question 1

Which of the following best explains why a molecule with many C-H bonds has more potential energy than a molecule with many O-H bonds?

Accepted Answer

C-H bonds are less stable and release more energy when broken compared to O-H bonds.

Question 2

During a chemical reaction, what does the 'transition state' refer to?

Accepted Answer

The high-energy, unstable arrangement of atoms that occurs as reactants are converted to products.

Question 3

Which of the following statements about enzymes is correct?

Accepted Answer

Enzymes lower the activation energy by stabilizing the transition state.

Question 4

A competitive inhibitor differs from a non-competitive inhibitor in that:

Accepted Answer

A competitive inhibitor binds to the active site, while a non-competitive inhibitor binds to a different site on the enzyme.

Question 5

Which of the following best describes the process of phosphorylation?

Accepted Answer

The addition of a phosphate group to a molecule, often using ATP as the phosphate donor.

Question 6

Which of the following is a function of the extracellular matrix (ECM) in animal cells?

Accepted Answer

Providing structural support and helping cells stick together.

Question 7

Gap junctions and plasmodesmata are similar in that they both:

Accepted Answer

Allow direct communication between adjacent cells by permitting the passage of small molecules.

Question 8

Which property allows some hormones to diffuse directly through cell membranes?

Accepted Answer

Being nonpolar and lipid-soluble.

Question 9

Which of the following correctly lists the four basic events of signal transduction in order?

Accepted Answer

Signal reception, signal processing, signal response, signal deactivation.

Question 10

During glycolysis, which of the following occurs?

Accepted Answer

Glucose is split into two molecules of pyruvate, producing ATP and NADH.

Question 11

Which of the following best describes the role of NADH and FADH$$_2 in $$cellular respiration?

Accepted Answer

They carry high-energy electrons to the electron transport chain.

Question 12

In eukaryotic cells, where does the citric acid cycle take place?

Accepted Answer

In the mitochondrial matrix.

Question 13

What is the main function of oxygen (O$$_2) in $$the electron transport chain of aerobic cells?

Accepted Answer

It acts as the final electron acceptor, forming water.

Question 14

Why is it important for fermenting cells to regenerate NAD$$^+$$?

Accepted Answer

NAD$$^+ is $$required for glycolysis to continue producing ATP.

Question 15

Which of the following is a key difference between lactic acid fermentation and ethanol fermentation?

Accepted Answer

Lactic acid fermentation produces lactate, while ethanol fermentation produces ethanol and CO$$_2.$$

Question 16

What is the overall goal of photosynthesis, and where does the energy for this process come from?

Accepted Answer

To make glucose, using energy from sunlight.

Question 17

Which of the following is produced by the light reactions of photosynthesis and used by the Calvin cycle?

Accepted Answer

NADPH

Question 18

What is the main adaptation that allows C$$_4$$ plants to thrive in hot, dry environments?

Accepted Answer

They spatially separate carbon fixation and the Calvin cycle, using PEP carboxylase in mesophyll cells and Rubisco in bundle sheath cells.

Question 19

Which of the following best describes the role of ATP synthase in the electron transport chain?

Accepted Answer

It uses the proton gradient to synthesize ATP from ADP and inorganic phosphate: $$ \mathrm{ADP} + \mathrm{P_i} \rightarrow \mathrm{ATP} $$

Question 20

Which of the following is a function of protein kinases in cell communication?

Accepted Answer

They transfer phosphate groups to proteins, altering protein activity.

Comprehensive Study Guidance for General Biology Exam II Topics

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