Unit 2 Review - Chemistry of Life

Which elements are present in all carbohydrates?

• carbon

• hydrogen

• oxygen

• nitrogen

• phosphorus

Which type of macromolecule is glucose?

• protein

• lipid

• carbohydrate

• nucleic acid

How does the branched structure of a starch molecule aid in its function?

• More points available for enzyme digestion.

• Stronger structure.

• More chemical bonds.

• Stronger chemical bonds.

What characteristic does glycogen and starch share?

• Both are storage for glucose.

• Both are the most energy-rich organic molecules.

• Both are proteins.

• Both are difficult to digest.

Which two elements are the long chains of lipids made out of?

• carbon

• phosphorus

• hydrogen

• oxygen

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 chitin in insect exoskeletons.

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 can occur?

• 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.

How does DNA differ from RNA?

• It is not soluble in water.

• It has no nucleus.

• It is single-stranded.

• It forms a double helix.