Question 1

Which of the following best explains why water is less dense as a solid (ice) than as a liquid?

Accepted Answer

Hydrogen bonds in ice cause water molecules to be spaced farther apart than in liquid water.

Question 2

A solution has a pH of 4. What is the concentration of hydrogen ions $$[H^+] in $$this solution?

Accepted Answer

$$[H^+] = 10$$^{-4}$$ \ \mathrm{M}$$

Question 3

Which of the following molecules would most likely dissolve well in water?

Accepted Answer

A molecule with several polar covalent bonds

Question 4

Which of the following statements about the sodium-potassium pump ($$\mathrm{Na^+/K^+}-$$ATPase) is correct?

Accepted Answer

It moves three sodium ions out of the cell and two potassium ions into the cell, using ATP.

Question 5

Which functional group acts as a weak acid and is commonly found in amino acids?

Accepted Answer

Carboxyl group ($$-\mathrm{COOH})$$

Question 6

A patient is given an intravenous solution that is hypertonic relative to their blood cells. What is the most likely outcome for the patient’s red blood cells?

Accepted Answer

Water will leave the cells, causing them to shrink.

Question 7

Which of the following best describes the primary structure of a protein?

Accepted Answer

The unique sequence of amino acids in a polypeptide chain

Question 8

Which of the following is a property of enzymes that allows them to speed up chemical reactions?

Accepted Answer

They lower the activation energy required for the reaction.

Question 9

Which of the following is true about facilitated diffusion?

Accepted Answer

It requires a membrane protein and moves substances down their concentration gradient.

Question 10

Which of the following best explains why fats are hydrophobic?

Accepted Answer

They are composed mostly of nonpolar hydrocarbon chains.

Question 11

Which of the following is a correct statement about the flow of genetic information in cells (the central dogma)?

Accepted Answer

DNA is transcribed into RNA, which is translated into protein.

Question 12

Which of the following is a real-life example of negative feedback in homeostasis?

Accepted Answer

Regulation of blood calcium levels by parathyroid hormone and calcitonin

Question 13

Which of the following statements about phospholipids is correct?

Accepted Answer

They are amphipathic, with hydrophilic heads and hydrophobic tails.

Question 14

Which of the following best describes the role of the Golgi apparatus in the cell?

Accepted Answer

It modifies, sorts, and packages proteins for secretion or delivery to other organelles.

Question 15

Which of the following is a property of water that allows trees to transport water from roots to leaves?

Accepted Answer

Cohesion between water molecules due to hydrogen bonding

Question 16

Which of the following is true about the secondary structure of proteins?

Accepted Answer

It is stabilized by hydrogen bonds between backbone atoms.

Question 17

Which of the following best describes an amphipathic molecule?

Accepted Answer

A molecule with both hydrophilic and hydrophobic regions

Question 18

Which of the following is a correct description of an ionic bond?

Accepted Answer

An attraction between oppositely charged ions after electron transfer

Question 19

Which of the following is a function of the cytoskeleton in eukaryotic cells?

Accepted Answer

Providing structural support and facilitating cell movement

Fundamentals of Biology: Chemistry of Life, Cell Structure, and Communication

Guida di studio - Domande di pratica

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