Pt. 1 Nucleic Acids, Biochemical energy production, and enzymes

Enzymes are best described as

Proteins that catalyze reactions

Enzymes speed up chemical reactions by

Lowering activation energy

The substance upon which an enzyme acts is called

Substrate

Which enzyme breaks down proteins into amino acids?

Protease

Which enzyme catalyzes the breakdown of starch into sugars?

Amylase

The specific region on an enzyme where the substrate binds is called:

Active site

Which of the following is a coenzyme?

Vitamins or vitamin derivatives

The lock-and-key hypothesis explains enzyme action

Substrate fitting exactly into the enzyme’s active site

The induced-fit model differs from lock-and-key because:

Both the enzyme and substrate change shape slightly upon binding, resulting in an optimal fit.

At what temperature do most enzymes in the human body function optimally?

37C

Extreme changes in temperature or pH cause enzymes to:

Denature

Increasing substrate concentration beyond saturation leads to:

A plateau in activity

Enzyme inhibitors that bind to the active site are called:

Competitive inhibitors

Enzyme inhibitors that bind away from the active site are:

Noncompetitive inhibitors

The suffix “-ase” in enzyme names generally indicates:

The substance is an enzyme

The enzyme catalase breaks down hydrogen peroxide into

Water and oxygen

How many main classes of enzymes are there?

6 (Oxidoreductases, Transferases, Hydrolases, Lyases, Isomerases, Ligases)

Oxidoreductase enzymes primarily catalyze:

Oxidation-reduction reactions

Ligases function by

Joining two molecules

Which factor does NOT affect enzyme activity?

Color of the enzyme

The information for protein synthesis is stored in:

Nucleic acids

How many bases are found in DNA? (1 Point)

Four (Adenine, Guanine, Cytosine, Thymine)

The repeating units in DNA and RNA are called:

Nucleotides

The sugar in DNA is:

Deoxyribose

The sugar in RNA is

Ribose

DNA bases pair via:

Hydrogen bonds

The structure of DNA is:

Double helix

RNA contains which unique base?

Uracil

DNA can replicate because:

It is double-stranded (allowing one strand to serve as a template for the other)

The monomers of nucleic acids are composed of:

Phosphate, sugar, and nitrogen base

Complementary base pairing: A pairs with , G pairs with .

A–T, G–C

Which RNA carries genetic information from DNA to ribosomes?

mRNA (messenger RNA)

The anticodon is found in

tRNA (transfer RNA)

Transcription occurs in the

Nucleus (in eukaryotes)

During transcription, adenine in DNA pairs with:

Uracil

Codons are sequences of how many bases?

3

The start codon in protein synthesis is:

AUG

The end products of translation are:

Polypeptides/proteins

Which mutation involves substitution of one base?

Point mutation

A retrovirus uses what enzyme for reverse transcription?

Reverse transcriptase