Question 1

Which property of carbon allows it to form a wide variety of organic molecules with different shapes and functions?

Accepted Answer

It has four valence electrons, allowing it to form up to four covalent bonds.

Question 2

A molecule of glucose ($$C_6H_{12}O_6$) and a molecule of fructose (C_6H$$_{12}$$O_6) $$have the same chemical formula but different structures. What term best describes this relationship?

Accepted Answer

Isomers

Question 3

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

Accepted Answer

Carboxyl group ($$-COOH)$$

Question 4

During the formation of a peptide bond between two amino acids, what type of reaction occurs and what is released?

Accepted Answer

Condensation (dehydration synthesis); water is released

Question 5

Which of the following best describes the structure of a triglyceride?

Accepted Answer

Three fatty acids bonded to a glycerol molecule

Question 6

What is the main function of carbohydrates in living organisms?

Accepted Answer

Main energy source

Question 7

Which of the following statements about enzymes is correct?

Accepted Answer

Enzymes lower the activation energy of a reaction, speeding it up.

Question 8

A phospholipid differs from a triglyceride in that a phospholipid:

Accepted Answer

Contains two fatty acids and a phosphate group

Question 9

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

Accepted Answer

Saturated fats have no double bonds, allowing molecules to pack closely together.

Question 10

Which macromolecule is primarily responsible for storing and transmitting genetic information?

Accepted Answer

Nucleic acids

Question 11

A student adds a drop of acid to a solution containing an enzyme and observes that the enzyme no longer functions. What is the most likely explanation?

Accepted Answer

The acid denatured the enzyme by altering its shape.

Question 12

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

Accepted Answer

Carbohydrate – Monosaccharide

Question 13

Which functional group is found in both DNA and ATP and is important for energy transfer?

Accepted Answer

Phosphate group ($$-PO_4$)

Question 14

Which level of protein structure is directly determined by the sequence of amino acids?

Accepted Answer

Primary structure

Question 15

A hydrolysis reaction is required to:

Accepted Answer

Break a polymer into monomers, consuming water

Question 16

Which of the following best describes the 'lock and key' model of enzyme function?

Accepted Answer

Each enzyme has a specific shape that fits only a particular substrate.

Question 17

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

Accepted Answer

Energy storage

Question 18

Which of the following best explains why phospholipids are essential for cell membrane structure?

Accepted Answer

They have both hydrophilic and hydrophobic regions, allowing them to form bilayers.

Question 19

Which of the following is a correct description of a condensation (dehydration synthesis) reaction?

Accepted Answer

A reaction that links monomers together, releasing a molecule of water

Question 20

Which of the following best describes the difference between DNA and RNA nucleotides?

Accepted Answer

DNA contains deoxyribose sugar, while RNA contains ribose sugar.

Biochemistry: Molecules of Cells and Macromolecules

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