Lesson 3: proteins and enzymes Flashcards Preview

Biochemistry Final Exam > Lesson 3: proteins and enzymes > Flashcards

Flashcards in Lesson 3: proteins and enzymes Deck (15):
1

All amino acids are chiral. True or False?

False

2

All amino acids can be synthesised from carbon skeletons that are produced as intermediates in major metabolic pathways. True or False?

False

3

Amino acids are linked by glycosidic bonds. True or False?

False

4

An amino acid sequence is the protein’s

Select one:
a. None of these answers are correct
b. Quaternary structure
c. Primary structure
d. Tertiary structure
e. Secondary structure

c. Primary structure

5

Competitive inhibitors bind to the active site of an enzyme surface. True or False?

True

6

D-isomers of amino acids are extremely rare in nature. True or False?

True

7

Denaturation

Select one:
a. Destroys the active conformation of a protein
b. Is the synthesis of glucose from carbon skeletons
c. Covalently links two amino acids through the formation of peptide bonds
d. Is the pH at which all the molecules have equal positive and negative charges
e. Is the synthesis of amino acids from carbon skeletons

a. Destroys the active conformation of a protein

8

Enzyme activity is often dependent not just on the protein portion of the enzyme, but also on an organic nonprotein group called a(n)

Select one:
a. Isomerase
b. Allosterism
c. Coenzyme
d. Isoenzyme
e. Zymogen

c. Coenzyme

9

Enzymes

Select one:
a. Cannot make a reaction take place that would otherwise not occur without them
b. All of these answers are correct
c. Are unchanged after catalysing a chemical reaction
d. Increase the speed of a reaction by lowering the activation energy
e. Are highly specific

b. All of these answers are correct

10

How many different amino acids are commonly found in proteins in humans?

Select one:
a. 28
b. 8
c. 32
d. 23
e. 20

e. 20

11

The majority of enzymes are

Select one:
a. Alcohols
b. Carbohydrates
c. None of these answers are correct
d. Lipids
e. Proteins

e. Proteins

12

The tertiary structure of a protein can be stabilised by

Select one:
a. Hydrogen bonds
b. Metal ion coordination
c. Hydrophobic interactions
d. All of these answers are correct
e. Salt bridges

d. All of these answers are correct

13

What class of enzyme catalyses oxidation-reduction reactions?

Select one:
a. Lyases
b. Oxidoreductases
c. Transferases
d. Hydrolases
e. Ligases

b. Oxidoreductases

14

Which of the following is a secondary protein structure?

Select one:
a. β-pleated sheet
b. α-helix
c. None of these answers are correct
d. Random coil
e. All of these answers are correct

e. All of these answers are correct

15

Which of the following is NOT a basic amino acid?

Select one:
a. All of these are nonpolar amino acids
b. Arginine
c. Lysine
d. Histidine
e. Glutamic acid

e. Glutamic acid