Question 1

Which of the following best describes the main structural difference between prokaryotic and eukaryotic cells?

Accepted Answer

Eukaryotic cells contain membrane-bound organelles, including a nucleus, while prokaryotic cells do not.

Question 2

A scientist observes a cell with a well-defined nucleus, rough endoplasmic reticulum, and mitochondria. Which type of cell is being observed?

Accepted Answer

Eukaryotic cell

Question 3

Which of the following best explains why the plasma membrane is described as 'selectively permeable'?

Accepted Answer

It allows some substances to cross more easily than others due to the structure of its phospholipid bilayer and embedded proteins.

Question 4

Which of the following statements about facilitated diffusion is correct?

Accepted Answer

Facilitated diffusion requires channel or carrier proteins but does not require energy input from the cell.

Question 5

A red blood cell is placed in a hypotonic solution. What will most likely happen to the cell?

Accepted Answer

Water will enter the cell, causing it to swell and possibly burst.

Question 6

Which of the following best describes the function of lysosomes in animal cells?

Accepted Answer

They contain hydrolytic enzymes that break down macromolecules, damaged organelles, and foreign substances.

Question 7

Which of the following equations correctly represents the free energy change ($$\Delta G) of a $$reaction?

Accepted Answer

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

Question 8

Which of the following best explains why enzymes are able to speed up chemical reactions?

Accepted Answer

They lower the activation energy ($$E_a) $$required for the reaction to proceed.

Question 9

A cell is observed to engulf large particles by wrapping its plasma membrane around them and forming a vesicle. Which process is being described?

Accepted Answer

Phagocytosis

Question 10

Which of the following statements about ATP is correct?

Accepted Answer

ATP hydrolysis releases energy that can be coupled to endergonic cellular reactions.

Question 11

Which of the following best describes the role of cholesterol in the plasma membrane?

Accepted Answer

It helps maintain membrane fluidity at different temperatures.

Question 12

A mutation causes a cell to lack peroxisomes. Which of the following processes would be most directly affected?

Accepted Answer

Breakdown of fatty acids and detoxification of hydrogen peroxide.

Question 13

Which of the following is a correct statement about the sodium-potassium pump?

Accepted Answer

It moves 3 Na$$^+$$ ions out of the cell and 2 K$$^+$$ ions into the cell, using ATP.

Question 14

Which of the following best describes the difference between channel proteins and carrier proteins in the plasma membrane?

Accepted Answer

Channel proteins form hydrophilic pores for specific molecules to pass through, while carrier proteins undergo conformational changes to transport substances.

Question 15

Which of the following is an example of secondary active transport?

Accepted Answer

A glucose symporter that uses the Na$$^+$$ gradient established by the sodium-potassium pump to transport glucose into the cell.

Question 16

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

Accepted Answer

A membrane is a fluid bilayer of phospholipids with proteins embedded or attached, allowing lateral movement of components.

Question 17

Which of the following best explains why hydrophobic substances can pass through the plasma membrane more easily than hydrophilic substances?

Accepted Answer

The interior of the membrane is hydrophobic due to the fatty acid tails of phospholipids.

Question 18

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

Accepted Answer

Living systems increase the entropy of their surroundings as they maintain order internally.

Question 19

Which of the following statements about enzyme regulation is correct?

Accepted Answer

Allosteric regulation involves the binding of a molecule at a site other than the active site, changing the enzyme's activity.

General Biology: Cell Structure, Membrane Function, Transport, and Enzymes Study Guide

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