Unit 2 Study Guide

Which atoms are in carbohydrates

• carbon, nitrogen, oxygen

• carbon, phosphorus, oxygen

• carbon, hydrogen, nitrogen

• carbon, hydrogen, oxygen

Which type of macromolecule is the sugar fructose?

• protein

• lipid

• carbohydrate

• nucleic acid

Which statement best explains how the structure of a starch molecule relates to its function?

• A branching structure provides many points where enzyme digestion can take place and release glucose molecules.

• A branching structure makes the molecule stronger.

• A branching structure has more chemical bonds than an unbranched structure.

• A branching structure contains bonds that are harder to break.

Which characteristic do glycogen and starch share?

• Both are storage forms of glucose.

• They are the most energy-rich organic molecules.

• They are proteins.

• Both are difficult to digest.

Most lipids contain long chains of which two atoms?

• water and phosphorus

• carbon and hydrogen

• carbon and oxygen

• water and carbon

Which statement best relates to how the structure of a lipid influences the lipid’s function?

• A phospholipid has a charged head and an uncharged tail.

• A lipid is made up of a long chain of phosphorus molecules.

• The ends of the lipid are attached to each other.

• Lipids contain fatty acids and glycerol.

All amino acids have a central carbon with four components attached to it. One of these components is called the R group. Which statement best describes the R group?

• The R group stabilizes the amino acid.

• The R group helps the amino acid replicate.

• The R group gives the amino acid unique characteristics.

• The R group is the same in all amino acids.

Chitinase is an enzyme that breaks down the chitin molecules in the insect exoskeleton.

The sequence of amino acids in the chitinase is an example of which level of protein structure?

• primary

• secondary

• tertiary

• quaternary

The amount of energy needed for a reaction to take place is the activation energy. Enzymes can lower the activation energy of a chemical reaction.

Which statement describes a way that this could happen?

• Molecules can be brought together so they will bond more easily.

• The enzyme distributes ATP to cells and then is destroyed.

• More substrate is added by the enzyme.

• The enzyme separates molecules from each other.

What is one way that RNA differs from DNA?

• It is not soluble in water.

• It has no nucleus.

• It is single-stranded.

• It forms a double helix.