Unit 2 Review

Which biomolecule has sugars and starches?

• Lipids
• Proteins
• Carbohydrates
• Nucleic Acid

Which biomolecule is made of nucleotides and include your DNA? (Hint: they carry genetic information)

• Carbohydrate
• Lipids
• Protein
• Nucleic Acid

Which biomolecule is responsible for insulation and energy storage?

• Protein
• Nucleic Acid
• Lipid
• Carbohydrate

What is the function of nucleic acids?

• Stores energy
• Stores genetic information
• Movement
• Physical structure

Nucleic acids, proteins, and other large biological molecules are known as polymers because

• They all contain only ionic bonds.

• they contain many small, repeating subunits bonded together.

• They all have the capability of functioning as enzymes.

• They are the base units used in the formation of plastics.

Enzymes are proteins that help increase the rate of chemical reactions inside cells. These proteins are composed of many simpler molecules called amino acids. Which of the following suggests that the shape of an enzyme determines the enzyme's function?

• Enzymes are specific to a substrate.

• Enzymes can operate in a wide range of conditions

• Enzymes are activated by neighboring molecules.

• Enzymes can be found in all life-forms

Which of the following statements about enzymes is NOT true?

• Enzymes are almost always proteins.

• Enzymes activity is affected by changes in pH.

• Enzymes increase the rate of a reaction.

• Enzymes increase the activation energy.

The enzyme amylase will affect the breakdown of carbohydrates, but it will not affect the breakdown of proteins. The ability of an enzyme molecule to interact with specific molecules is most directly determined by the

• shapes of the molecules involved

• number of molecules involved

• temperature of the solution containing the enzyme

• amount of energy present in the cell

Taq polymerase is an enzyme used in the polymerase chain reaction (PCR) to replicate fragments of DNA. A study published in 1976 examined the properties of Taq polymerase after the enzyme was isolated from Thermus aquaticus, a thermophilic bacterium that lives in the hot springs of Yellowstone National Park. The graph shows one of the results of the study.

Which statement about enzyme activity is best supported by this graph?

• An enzyme must be composed of multiple polypeptides, or subunits, to be active.

• An enzyme's rate of activity increases with time until it becomes inactive.

• An enzyme functions best under specific temperature conditions.

• An enzyme works equally well in bacteria that are adapted to high temperatures and in eukaryotic cells such as human cells.

Adenine, thymine, guanine, and cytosine are the _________ that make up the nucleotides of DNA.

• nitrogenous bases

• nucleic acids

• phosphate groups

• 5-carbon sugars