20 Amino Acids

Question 1

What are the building blocks of proteins?

Answer 1

Amino acids

Question 2

How many standard amino acids are there?

Answer 2

Twenty

Question 3

Which amino acid is known as the primary amino acid with a sulfur atom?

Answer 3

Cysteine

Question 4

What is the general structure of an amino acid?

Answer 4

An amino group, a carboxyl group, a hydrogen atom, and a variable R group (side chain) attached to a central carbon.

Question 5

True or False: All amino acids are non-polar.

Answer 5

False

Question 6

Fill in the blank: The amino acid ________ is essential for protein synthesis and has a side chain that contains an indole group.

Answer 6

Tryptophan

Question 7

Which amino acid has a positively charged side chain?

Answer 7

Lysine

Question 8

What property do hydrophobic amino acids generally have?

Answer 8

They do not interact well with water.

Question 9

Name one amino acid that is classified as aromatic.

Answer 9

Phenylalanine

Question 10

Which amino acid is known for its role in the formation of disulfide bonds?

Answer 10

Cysteine

Question 11

Multiple Choice: Which of the following is not a polar amino acid? A) Serine B) Threonine C) Alanine D) Asparagine

Answer 11

C) Alanine

Question 12

What is the charge of aspartic acid at physiological pH?

Answer 12

Negatively charged

Question 13

True or False: Glycine is the simplest amino acid.

Answer 13

True

Question 14

What distinguishes the side chains of amino acids?

Answer 14

The variable R group (side chain) determines the properties of each amino acid.

Question 15

Which amino acid is known as the precursor to neurotransmitters like serotonin?

Answer 15

Tryptophan

Question 16

Fill in the blank: The amino acid ________ has a branched-chain structure and is essential for muscle metabolism.

Answer 16

Leucine

Question 17

What type of bond links amino acids together in a protein?

Answer 17

Peptide bond

Question 18

Which amino acid contains a hydroxyl group in its side chain?

Answer 18

Serine

Question 19

Multiple Choice: Which amino acid is considered essential? A) Glutamic acid B) Valine C) Aspartic acid D) Glycine

Answer 19

B) Valine

Question 20

What is the role of histidine in proteins?

Answer 20

Histidine can act as a proton donor or acceptor, playing a key role in enzyme activity.

Question 21

True or False: Methionine is a non-polar amino acid.

Answer 21

True

Question 22

Name the amino acid with a side chain that contains a carboxylic acid group.

Answer 22

Glutamic acid

Question 23

What is the significance of proline in protein structure?

Answer 23

Proline introduces kinks in polypeptide chains due to its unique cyclic structure.

Question 24

Fill in the blank: The amino acid ________ is known for its role in collagen structure.

Answer 24

Proline

Question 25

What type of amino acid is arginine and what is its charge at physiological pH?

Answer 25

Arginine is a positively charged amino acid.

Question 26

Multiple Choice: Which amino acid is not typically found in proteins? A) Selenocysteine B) Tyrosine C) Arginine D) Ornithine

Answer 26

D) Ornithine