Question 1

Which of the following best describes the fluid mosaic model of the plasma membrane?

Accepted Answer

A flexible layer of phospholipids with proteins embedded throughout, allowing lateral movement.

Question 2

A red blood cell is placed in a solution and swells until it bursts. Which term best describes the solution?

Accepted Answer

Hypotonic

Question 3

Which of the following molecules can most easily diffuse across the plasma membrane without the help of transport proteins?

Accepted Answer

Oxygen ($$\mathrm{O}_2)$$

Question 4

A cell with an internal solute concentration of 0.3 M is placed in a 0.1 M solution. What will happen to the cell?

Accepted Answer

Water will move into the cell, causing it to swell.

Question 5

Which statement best explains how the sodium/potassium pump creates an electrochemical gradient?

Accepted Answer

It pumps three sodium ions out and two potassium ions in, using ATP, creating both a charge and concentration difference across the membrane.

Question 6

Which of the following is true about the 2nd law of thermodynamics as it applies to living systems?

Accepted Answer

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

Question 7

Given the equation for free energy change $$\Delta G = \Delta H - T\Delta S$$, which scenario describes an exergonic reaction?

Accepted Answer

$$\Delta G is $$negative and energy is released.

Question 8

A scientist adds a competitive inhibitor to an enzyme-catalyzed reaction. What is the most likely effect?

Accepted Answer

The inhibitor binds to the active site, increasing the substrate concentration needed to reach maximum velocity.

Question 9

Where in the mitochondrion does the citric acid cycle occur?

Accepted Answer

In the mitochondrial matrix

Question 10

Which of the following correctly lists the path of electrons during aerobic cellular respiration?

Accepted Answer

Glucose $$\rightarrow$$ NADH $$\rightarrow$$ Electron Transport Chain $$\rightarrow$$ Oxygen

Question 11

How is the proton gradient that drives ATP synthesis in mitochondria established?

Accepted Answer

By the electron transport chain pumping protons from the matrix into the intermembrane space.

Question 12

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

Accepted Answer

Alcohol fermentation releases $$\mathrm{CO}_2$$, while lactic acid fermentation does not.

Question 13

Which statement best distinguishes autotrophs from heterotrophs?

Accepted Answer

Autotrophs use light or inorganic chemicals to produce organic molecules.

Question 14

Where do the light reactions of photosynthesis take place within the chloroplast?

Accepted Answer

On the thylakoid membranes

Question 15

Which of the following is an output of the Calvin cycle?

Accepted Answer

Glucose (or G3P)

Question 16

During the light reactions, what is the path of electrons from water to NADP$$^+$$?

Accepted Answer

Water $$\rightarrow PS II$$ $$\rightarrow$$ Electron Transport Chain $$\rightarrow PS I$$ $$\rightarrow$$ NADP^+$

Question 17

A patient is given an intravenous solution with a higher solute concentration than their blood plasma. What is the most likely effect on their red blood cells?

Accepted Answer

Cells will shrink as water leaves the cells.

Question 18

Which of the following best describes the role of chemiosmosis in both cellular respiration and photosynthesis?

Accepted Answer

It uses a proton gradient to drive ATP synthesis via ATP synthase.

Question 19

If a cell's environment becomes more acidic, how might this affect enzyme activity?

Accepted Answer

Enzyme activity may decrease if the pH moves away from the enzyme's optimum.

Question 20

Which of the following is a correct comparison between aerobic respiration and fermentation?

Accepted Answer

Fermentation produces less ATP because it does not use an electron transport chain.

BIO 191 Exam II Study Guide: Membrane Structure, Metabolism, Cellular Respiration, and Photosynthesis

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