Question 1

Which of the following best describes an isotope?

Accepted Answer

An atom with the same number of protons but a different number of neutrons.

Question 2

Which chemical bond is primarily responsible for the cohesion of water molecules?

Accepted Answer

Hydrogen bond

Question 3

A carbon atom forms four covalent bonds in methane ($$CH_4). $$What is the geometry of the molecule?

Accepted Answer

Tetrahedral

Question 4

Which functional group is present in both amino acids and proteins and is responsible for peptide bond formation?

Accepted Answer

Carboxyl group ($$-COOH)$$

Question 5

Which of the following statements about water is correct?

Accepted Answer

Water is a polar molecule, allowing it to dissolve many ionic and polar substances.

Question 6

Which of the following best explains why carbon is the backbone of organic molecules?

Accepted Answer

Carbon can form four covalent bonds, allowing for complex and diverse molecular structures.

Question 7

Which reaction is responsible for joining two monosaccharides to form a disaccharide?

Accepted Answer

Dehydration synthesis

Question 8

Which of the following is a correct example of a biologically important polysaccharide used for energy storage in animals?

Accepted Answer

Glycogen

Question 9

Which type of lipid is the main component of cell membranes?

Accepted Answer

Phospholipid

Question 10

What is the difference between saturated and unsaturated fatty acids?

Accepted Answer

Saturated fatty acids have no double bonds between carbon atoms; unsaturated fatty acids have one or more double bonds.

Question 11

Which of the following best describes a dehydration reaction?

Accepted Answer

A reaction in which two molecules are joined together by removing a molecule of water.

Question 12

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

Accepted Answer

Storing genetic information

Question 13

Which bond is responsible for the primary structure of a protein?

Accepted Answer

Peptide bond

Question 14

Which of the following statements about nucleic acids is correct?

Accepted Answer

DNA contains deoxyribose sugar, while RNA contains ribose sugar.

Question 15

Which of the following is a correct description of a hydrolysis reaction?

Accepted Answer

A reaction in which a molecule is split into two smaller molecules by the addition of water.

Question 16

Which of the following is a monomer of proteins?

Accepted Answer

Amino acid

Question 17

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

Accepted Answer

Phospholipids have hydrophilic heads and hydrophobic tails, causing them to arrange in bilayers.

Question 18

Which of the following is a correct example of a functional group found in nucleic acids?

Accepted Answer

Phosphate group ($$-PO_4$^{2-})$$

Question 19

Which of the following statements about enzymes is correct?

Accepted Answer

Enzymes are proteins that speed up chemical reactions by lowering activation energy.

Question 20

A student mixes oil and water in a beaker and observes that they do not mix. Which property of water explains this observation?

Accepted Answer

Water is polar and oil is nonpolar, so they do not mix.

General Biology Exam Study Guide: Chemistry of Life, Macromolecules, and Water

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