Question 1

Which property of carbon is most responsible for the diversity and complexity of organic molecules found in living organisms?

Accepted Answer

Its tendency to form four covalent bonds with other atoms

Question 2

A scientist is studying a molecule that contains carbon, hydrogen, and oxygen in a ratio of 1:2:1. Which class of biological molecule is she most likely investigating?

Accepted Answer

Carbohydrate

Question 3

Which process is responsible for joining two amino acids together to form a dipeptide, and what is the byproduct of this reaction?

Accepted Answer

Dehydration synthesis; water is produced

Question 4

Which of the following best describes the difference between saturated and unsaturated fats?

Accepted Answer

Unsaturated fats contain double bonds between carbon atoms, while saturated fats do not

Question 5

Which of the following is a disaccharide composed of glucose and galactose?

Accepted Answer

Lactose

Question 6

A patient is unable to digest cellulose. What is the most likely reason for this?

Accepted Answer

Humans lack the enzymes to break the specific bonds in cellulose

Question 7

Which level of protein structure is maintained primarily by peptide bonds?

Accepted Answer

Primary structure

Question 8

What is the main function of ATP in cells?

Accepted Answer

It acts as an energy carrier for cellular processes

Question 9

Which of the following statements about phospholipids is correct?

Accepted Answer

Phospholipids have hydrophilic heads and hydrophobic tails

Question 10

Which functional group is found in all amino acids and is responsible for their acidic properties?

Accepted Answer

Carboxylic acid group ($-COOH$)

Question 11

A protein loses its three-dimensional structure when exposed to high heat. What is this process called, and what is the consequence?

Accepted Answer

Denaturation; the protein loses its function

Question 12

Which of the following molecules is NOT a polymer formed by joining monomers?

Accepted Answer

Lipid

Question 13

Which of the following is a structural polysaccharide found in the exoskeletons of insects and the cell walls of fungi?

Accepted Answer

Chitin

Question 14

Which of the following best explains why waxes are water-repellent and solid at outdoor temperatures?

Accepted Answer

They are highly saturated and lack enzymes for digestion in most animals

Question 15

Which of the following is true about the structure of DNA?

Accepted Answer

It consists of two strands forming a double helix held together by hydrogen bonds

Question 16

Which of the following is a correct chemical formula for a hexose monosaccharide?

Accepted Answer

$C_6H_{12}O_6$

Question 17

Which of the following is a function of proteins in living organisms?

Accepted Answer

Catalyzing chemical reactions as enzymes

Question 18

Which of the following best describes the role of functional groups in organic molecules?

Accepted Answer

They are less stable than the carbon backbone and increase reactivity

Question 19

Which of the following molecules is used as a precursor for synthesizing steroid hormones such as estrogen and testosterone?

Accepted Answer

Cholesterol

Question 20

A mutation changes the sequence of nucleotides in a gene. Which level of protein structure is directly affected by this change?

Accepted Answer

Primary structure

Biological Molecules: Structure, Function, and Importance in Life

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