Amino Acids

Question 1

What are proteins?

Answer 1

biological macromolecules that act as enzymes, hormones, receptors, channels, transporters, antibodies, and support structures inside and outside cells

Question 2

How many amino acids are there?

Answer 2

20 amino acids

Question 3

How are amino acids classified?

Answer 3

by their unique side chains (variable R-group)

Question 4

What are the four broad categories for amino acids?

Answer 4

acidic , basic, nonpolar, polar

Question 5

What are the acidic amino acids?

Answer 5

aspartic acid, glutamic acid

Question 6

What is the functional group for aspartic acid and glutamic acid?

Answer 6

carboxylic acid functional group

Question 7

What are the basic amino acids?

Answer 7

lysine, arginine, and histidine

Question 8

Which basic amino acid can also act as an acidic amino acid due to its pKa?

Answer 8

histidine

Question 9

What are the nonpolar/hydrophobic amino acids?

Answer 9

glycine, alanine, valine, leucine, isoleucine, phenylalanine, tryptophan

Question 10

What type of side chains can hydrophobic/nonpolar amino acids have?

Answer 10

either alipathic (alkyl) or aromatic side chains

Question 11

What are the polar amino acids?

Answer 11

serine, threonine, tyrosine, aspargine, glutamine

Question 12

What are the sulfur containing amino acids?

Answer 12

cysteine, methionine

Question 13

What is unique about proline?

Answer 13

its amino group is covalently bonded to its nonpolar side chain, creating a secondary alpha-amino group and a distinctive ring structure

Question 14

What does it mean to be an essential amino acid? How many are there?

Answer 14

nine. cannot be synthesized by adult humans and must be obtained from diet

Question 15

What are the nine essential amino acids?

Answer 15

lysine, histidine, threonine, valine, leucine, isoleucine, phenylalanine, tryptophan, methionine