Question 1

Which of the following best describes the process by which monomers are joined to form polymers in biological systems?

Accepted Answer

By dehydration synthesis, which removes a water molecule to form a covalent bond between monomers.

Question 2

A patient is diagnosed with atherosclerosis, a condition linked to the buildup of certain molecules in blood vessels. Which type of molecule is most directly associated with this disease, and what dietary change could help reduce risk?

Accepted Answer

Triglycerides; reducing intake of saturated and trans fats

Question 3

Which of the following statements about the structure of DNA and RNA is correct?

Accepted Answer

DNA contains deoxyribose sugar, while RNA contains ribose sugar.

Question 4

Which of the following best describes a functional group in organic chemistry?

Accepted Answer

A group of atoms that determines the chemical properties and reactions of a molecule.

Question 5

A triglyceride molecule is formed from which combination of building blocks?

Accepted Answer

Three fatty acids and one glycerol

Question 6

Which of the following is a correct match between a macromolecule and its monomer?

Accepted Answer

Carbohydrate – monosaccharide

Question 7

Which of the following best explains why cellulose cannot be digested by most animals, while starch can?

Accepted Answer

The glucose monomers in cellulose are linked by $$\beta-1$$,4-glycosidic bonds, which most animals lack enzymes to break.

Question 8

Which of the following is an example of an isomer?

Accepted Answer

Glucose and fructose, which have the same molecular formula but different structures

Question 9

Which level of protein structure is primarily stabilized by hydrogen bonds between backbone atoms, forming alpha helices and beta sheets?

Accepted Answer

Secondary structure

Question 10

A food label lists 'partially hydrogenated vegetable oil' as an ingredient. What type of fat is likely present, and why is it a health concern?

Accepted Answer

Trans fat; it increases risk of cardiovascular disease

Question 11

Which of the following best describes the process of hydrolysis?

Accepted Answer

A water molecule is added to break a covalent bond in a polymer, releasing monomers.

Question 12

Which of the following correctly lists the three components of a nucleotide?

Accepted Answer

A phosphate group, a five-carbon sugar, and a nitrogenous base

Question 13

Which of the following statements about genes is correct?

Accepted Answer

A gene is a segment of DNA that codes for a specific protein or RNA molecule.

Question 14

Which of the following best explains why unsaturated fats are typically liquid at room temperature, while saturated fats are solid?

Accepted Answer

Unsaturated fats have one or more double bonds, causing kinks that prevent tight packing.

Question 15

Which of the following is NOT a function of proteins in living organisms?

Accepted Answer

Storing genetic information

Question 16

A mutation causes a single amino acid change in the primary structure of a protein. Which levels of protein structure could potentially be affected?

Accepted Answer

Primary, secondary, tertiary, and quaternary structures

Question 17

Which of the following best describes a hydrocarbon?

Accepted Answer

A molecule consisting only of carbon and hydrogen atoms

Question 18

Which of the following pairs correctly matches a nitrogenous base with the nucleic acid in which it is found?

Accepted Answer

Uracil – RNA

Question 19

Which of the following best describes the nutritional importance of carbohydrates?

Accepted Answer

They are the primary source of energy for most cells.

Question 20

Which of the following best describes denaturation of a protein?

Accepted Answer

The loss of a protein's three-dimensional structure due to disruption of weak interactions, often caused by heat or pH changes.

Study Guide: The Molecules of Life – Key Concepts and Practice

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