Question 1

Which of the following statements best explains why water is considered a 'universal solvent' in biological systems?

Accepted Answer

Water's polarity allows it to dissolve many ionic and polar substances by surrounding and separating their ions or molecules.

Question 2

A patient is diagnosed with acidosis, meaning their blood pH has dropped below the normal range. Which buffer system in the blood helps to minimize this change in pH?

Accepted Answer

The carbonic acid-bicarbonate buffer system: $$\mathrm{H_2CO_3 \rightleftharpoons $$HCO_3$$^- + H^+}$$

Question 3

Which of the following best describes the difference between a saturated and an unsaturated fatty acid?

Accepted Answer

Saturated fatty acids contain only single bonds between carbon atoms, while unsaturated fatty acids contain at least one double bond between carbon atoms.

Question 4

A molecule of glucose ($$\mathrm{C_6H_{12}O_6$}) $$and a molecule of fructose ($$\mathrm{C_6H_{12}O_6$}) $$have the same molecular formula but different structures. What is the term for this relationship?

Accepted Answer

Isomers

Question 5

Which of the following best explains why enzymes are highly specific to their substrates?

Accepted Answer

The three-dimensional shape of the enzyme's active site fits only specific substrate molecules, similar to a lock and key.

Question 6

A radioactive isotope of carbon, $$^{14}\mathrm{C}$$, is used in medical imaging. What makes $$^{14}\mathrm{C}$$ different from the most common carbon isotope, $$^{12}\mathrm{C}$$?

Accepted Answer

$$^{14}\mathrm{C}$$ has more neutrons than $$^{12}\mathrm{C}.$$

Question 7

Which of the following best describes the role of hydrogen bonds in the properties of water?

Accepted Answer

Hydrogen bonds are responsible for water's high surface tension and its ability to moderate temperature changes.

Question 8

A solution has a pH of 4. How many times greater is the concentration of hydrogen ions ($$\mathrm{[H^+]}) $$compared to a solution with a pH of 6?

Accepted Answer

100 times greater

Question 9

Which of the following is a correct description of a phospholipid's structure and its role in the plasma membrane?

Accepted Answer

Phospholipids have a hydrophilic head and hydrophobic tails, forming a bilayer with tails facing inward and heads facing outward toward water.

Question 10

Which of the following best explains why proteins can lose their function when exposed to high temperatures or extreme pH?

Accepted Answer

High temperatures or extreme pH disrupt hydrogen bonds and other interactions, causing the protein to denature and lose its three-dimensional shape.

Question 11

Which of the following best describes the process of dehydration synthesis in the formation of biological macromolecules?

Accepted Answer

Dehydration synthesis removes water to join monomers into polymers.

Question 12

A patient is found to have a genetic disorder that prevents the production of molecular chaperones. Which of the following cellular processes would most likely be directly affected?

Accepted Answer

The ability to properly fold newly synthesized proteins.

Question 13

Which of the following best explains the difference between ionic and covalent bonds?

Accepted Answer

Ionic bonds involve the transfer of electrons from one atom to another, resulting in oppositely charged ions that attract each other; covalent bonds involve the sharing of electrons between atoms.

Question 14

Which of the following is a function of cholesterol in animal cell membranes?

Accepted Answer

Cholesterol increases membrane rigidity and helps maintain fluidity at various temperatures.

Question 15

Which of the following best describes the structure of DNA?

Accepted Answer

A double helix composed of two polynucleotide strands held together by hydrogen bonds between complementary bases.

Question 16

Which of the following best explains why ATP is considered the energy currency of the cell?

Accepted Answer

ATP stores energy in the bonds between its phosphate groups, which can be released by hydrolysis: $$\mathrm{ATP + H_2O \rightarrow ADP + P_i + energy}.$$

Question 17

A patient is given a solution with a pH of 8. Which of the following best describes this solution?

Accepted Answer

It is basic (alkaline), with a higher concentration of $$\mathrm{OH^-}$$ ions than $$\mathrm{H^+}$$ ions.

Question 18

Which of the following best describes the relationship between monomers and polymers in biological macromolecules?

Accepted Answer

Polymers are large molecules made by joining together many monomers through covalent bonds.

Question 19

Which of the following best explains why cellulose cannot be digested by humans, even though it is made of glucose monomers?

Accepted Answer

Humans lack the enzyme needed to break the specific type of glycosidic bonds found in cellulose.

Chapter 2: Chemistry Comes Alive – Study Notes for Anatomy & Physiology

Guida di studio - Domande di pratica

Study guide - Flashcard