18.1

Metabolism is generally referred to as the chemical processes that allow the body to function. How do enzymes allow metabolic chemical reactions to proceed more quickly?

• They convert carbohydrates into proteins during biochemical reactions.

• They lower the activation energy of biochemical reactions.

• They cause products of biochemical reaction to break down.

• They decrease the amount of reactants needed for biochemical reactions.

Hormones are proteins that regulate many functions in the body, such as growth and cell differentiation. Which of the following does NOT describe a function of proteins in living organisms?

• They catalyze biochemical reactions

• They provide support for connective tissues

• They serve as a short-term energy source for the body

• They carry molecules from one place to another in the body

Carbohydrates are a type of biological macromolecules required to carry out life functions. Which of the following statements regarding carbohydrates is true?

• They contain fatty acids and glycerol

• They are made of monomers called amino acids

• They are used by living things as the main source of energy

• They are not used for structural support in living organisms

Proteins are one of four classes of biological macromolecules. Which of the following statements about proteins is NOT correct?

• Enzymes are specific types of proteins.

• There are 20 different amino acids that make up proteins.

• Peptide bonds form between amino acids in a dehydration reaction, creating proteins.

• All R chains on the amino acids that make up proteins are polar and acidic

How do enzymes speed up the rate of biological reactions?

• Enzymes increase the activation energy of the reaction

• Enzymes provide a site where reactants can be brought together

• Enzymes become reactants and are used up in the chemical re

• Enzymes change the temperature of the surroundings to be suitable for the reaction

What is the optimum pH range for this enzyme?

• above 10

• between 5 and 7

• between 8 and 10

• below 5

Which molecule would most likely react with the enzyme?

• A

• B

• C

• D

What is the optimum temperature this enzyme works the best in?

• 20

• 26

• 38

• 50

What type of macromolecule are enzymes?

• Carbohydrates

• Lipids

• Proteins

• Nucleic Acids