$$[H^+] = 1 \times 10$$^{-4}$$ \, M$$

Question 1

Which of the following best describes the role of enzymes in biological systems?

Accepted Answer

Enzymes lower the activation energy, speeding up chemical reactions.

Question 2

A student is investigating the effect of temperature on enzyme activity. Which equation would best describe the rate of an enzyme-catalyzed reaction?

Accepted Answer

$$v = \frac{V_{max} [S]}{K_m + [S]}$$

Question 3

Which statement about the structure of water is correct and explains its role in biological systems?

Accepted Answer

Water's hydrogen bonds allow it to have a high specific heat capacity.

Question 4

A patient is diagnosed with acidosis. Which buffer system in the blood helps maintain pH homeostasis?

Accepted Answer

The bicarbonate buffer system

Question 5

Which of the following is a correct application of the concept of homeostasis?

Accepted Answer

A human sweating to cool down when overheated

Question 6

Which macromolecule is primarily responsible for storing genetic information?

Accepted Answer

Nucleic acids

Question 7

A scientist discovers a new organism with cells containing a nucleus and membrane-bound organelles. What type of cell does this organism have?

Accepted Answer

Eukaryotic

Question 8

Which of the following best explains why phospholipids form bilayers in water?

Accepted Answer

Phospholipids have hydrophilic heads and hydrophobic tails.

Question 9

Which equation correctly represents the dissociation of water?

Accepted Answer

$$H_2O \rightleftharpoons H^+ + OH^-$$

Question 10

A solution has a pH of 4. What is the concentration of hydrogen ions in the solution?

Accepted Answer

$$[H^+] = 1 	imes 10$$^{-4}$$ \, M$$

Question 11

Which of the following is NOT a property of water that is important for life?

Accepted Answer

Low surface tension

Question 12

Which of the following best describes the function of carbohydrates in living organisms?

Accepted Answer

Carbohydrates provide energy and structural support.

Question 13

Which of the following is a correct example of a dehydration synthesis reaction?

Accepted Answer

Glucose + Fructose $$\rightarrow$$ Sucrose + $$H_2O$$

Question 14

A cell placed in a hypertonic solution will:

Accepted Answer

Lose water and shrink

Question 15

Which of the following is a correct statement about the pH scale?

Accepted Answer

A solution with pH 7 is neutral.

Question 16

Which of the following molecules is most likely to pass through a cell membrane by simple diffusion?

Accepted Answer

Oxygen ($$O_2)$$

Question 17

Which of the following is a correct example of negative feedback in biological systems?

Accepted Answer

Release of insulin to lower blood glucose levels

Question 18

Which of the following best explains why ice floats on water?

Accepted Answer

Hydrogen bonds in ice create an open lattice structure.

Question 19

Which of the following is a correct statement about the relationship between structure and function in biological molecules?

Accepted Answer

The sequence of amino acids in a protein determines its function.

Question 20

A researcher adds a strong acid to a solution containing a buffer. What will happen to the pH of the solution?

Accepted Answer

The pH will remain relatively stable.

Cell Structure and Function: An Overview

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