Q: Which of the following is a function of the mitochondrion?

Production of ATP through cellular respiration $$\text{C}_6\text{H}_{12}\text{O}_6 + 6\text{O}_2 \rightarrow 6\text{CO}_2 + 6\text{H}_2\text{O} + \text{ATP}$$

Question 1

Which of the following best explains why cells are typically small in size?

Accepted Answer

Smaller cells have a higher surface area-to-volume ratio, which facilitates efficient exchange of materials with the environment. $$	ext{Surface Area-to-Volume Ratio} = \frac{	ext{Surface Area}}{	ext{Volume}}$$

Question 2

Which structure is present in both prokaryotic and eukaryotic cells?

Accepted Answer

Plasma membrane

Question 3

A red blood cell is placed in distilled water. What will happen to the cell, and why?

Accepted Answer

Water will move into the cell by osmosis, causing it to swell and potentially burst, because the solution is hypotonic to the cell. $$	ext{Osmosis: Water moves from low solute to high solute concentration}$$

Question 4

Which of the following organelles is NOT part of the endomembrane system?

Accepted Answer

Mitochondrion

Question 5

Which statement correctly describes the role of cholesterol in the plasma membrane?

Accepted Answer

Cholesterol stabilizes membrane fluidity by preventing extremes in fluidity at different temperatures.

Question 6

Which of the following best describes the difference between passive and active transport across cell membranes?

Accepted Answer

Passive transport does not require energy and moves substances down their concentration gradient, while active transport requires energy (usually ATP) and moves substances against their concentration gradient. $$	ext{Active Transport:} 	ext{ATP} ightarrow 	ext{ADP} + 	ext{P}$$

Question 7

Which of the following is a function of the mitochondrion?

Accepted Answer

Production of ATP through cellular respiration $$	ext{C}_6	ext{H}_{12}	ext{O}_6 + 6	ext{O}_2 ightarrow 6	ext{CO}_2 + 6	ext{H}_2	ext{O} + 	ext{ATP}$$

Question 8

Which of the following statements about enzymes is correct?

Accepted Answer

Enzymes lower the activation energy of a reaction, increasing the rate without being consumed. $$	ext{Activation Energy} = E_a$$

Question 9

Which of the following would increase membrane fluidity?

Accepted Answer

Increasing the proportion of unsaturated fatty acids in phospholipids

Question 10

Which of the following is true about the first law of thermodynamics in biological systems?

Accepted Answer

Energy cannot be created or destroyed, only transformed from one form to another.

Question 11

A celery stalk is placed in salt water. What will happen to the cells?

Accepted Answer

Water will move out of the cells, causing them to shrink and the stalk to become limp, because the solution is hypertonic.

Question 12

Which of the following best describes the process of exocytosis?

Accepted Answer

A vesicle fuses with the plasma membrane to release its contents outside the cell.

Question 13

Which of the following is a correct statement about feedback inhibition in metabolic pathways?

Accepted Answer

The end product of a pathway inhibits an earlier enzyme, preventing overproduction.

Question 14

Which of the following is true about anabolic and catabolic pathways?

Accepted Answer

Anabolic pathways build complex molecules from simpler ones and require energy; catabolic pathways break down complex molecules and release energy.

Question 15

Which of the following statements about ATP is correct?

Accepted Answer

ATP couples exergonic and endergonic reactions by transferring a phosphate group.

Question 16

Which of the following would most likely decrease enzyme activity?

Accepted Answer

Increasing temperature beyond the enzyme's optimal range, causing denaturation.

Question 17

Which of the following is a property of the plasma membrane that allows it to control what enters and leaves the cell?

Accepted Answer

Selective permeability

Question 18

Which of the following is true about simple diffusion?

Accepted Answer

It does not require energy and moves molecules down their concentration gradient.

Question 19

Which of the following best describes the second law of thermodynamics in biological systems?

Accepted Answer

Every energy transfer increases the entropy (disorder) of the universe.

Question 20

If a reaction has a negative $$\Delta G$$, what does this indicate?

Accepted Answer

The reaction is spontaneous and releases free energy.

Cells, Membranes, and Metabolism: Study Guide for General Biology

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