Amino Acids

Question 1

What does it mean to describe an amino acid as aliphatic?

Answer 1

it means its carbons form a chain, not an aromatic ring

Question 2

Which 3 amino acids are non polar and AROMATIC?

Answer 2

Tryptophan (Trp, W)
Tyrosine (Tyr, Y)
Phenylalanine (Phe, F)

Tyrone be trippin’ and phen-aggling

Question 3

Which 3 amino acids are positively charged and polar?

Answer 3

Histidine (His, H)
Arginine (Arg, R)
Lysine (Lys, K)

Shallow ‘HAL’ had a positive message (for Our Janine)

Question 4

Which 2 amino acids are negatively charged and polar?

Answer 4

Aspartic Acid (Asp, D)
Glutamic Acid (Glu, E)

Negative aspirations are glued to my 2 acids

Question 5

Which 7 amino acids have side chains with pKas?

Answer 5

Tyrosine (Tyr)
Lysine (Lys)
Histidine (His)
Glutamic Acid (Glu)
Asparagine (Asp)
Cysteine (Cys)
Arginine (Arg)

Pkas the tyrant likes his gloomy asparagus acid from the Cystine Chapel in Argentina

Question 6

What is the pka for the side chain in Asparagine (Asp)?

Answer 6

3.9

Question 7

What is the pka for the side chain in Glutamic Acid (Glu)?

Answer 7

4.2

Question 8

What is the pka for the side chain in Histidine (His)?

Answer 8

6

Question 9

What is the pka for the side chain in Cysteine (Cys)?

Answer 9

8.3

Question 10

What is the pka for the side chain in Lysine (Lys)?

Answer 10

10.0

Question 11

What is the pka for the side chain in Tyrosine (Tyr)?

Answer 11

10.1

Question 12

What is the pka for the side chain in Arginine (Arg)?

Answer 12

12.5

Question 13

What is the pka (generally) for an amino acid’s COOH?

Answer 13

2

Question 14

What is the pka (generally) for an amino acid’s NH3+?

Answer 14

9.5

Question 15

What does it mean to say that an amino acid is amidic?

Answer 15

It means that amino acid consists of, contains, or is concerned with an amide group.

Question 16

what 7 properties can be used to compare amino acids?

Answer 16

amino acids can be compared by whether they are:

alipathic (in a chain)
aromatic (in a ring)
acidic
basic
Sulfur-containing
amidic (amide containing)
hydroxylic (hydroxyl containing)

Question 17

How can you tell if an amino acid is non-polar?

Answer 17

Its R groups is usually primarily composed of hydrogens and carbons

(but methionine is an exception because it has a sulfur, which is almost the same electronegativity as carbon)

Question 18

How can you tell if an amino acid is acidic?

Answer 18

It has COOH in its R group

and/or has ‘acid’ in the name!

Question 19

How can you tell if an amino acid is basic?

Answer 19

It has an amine in its R group

Question 20

How can you tell if a POLAR amino acid is neither acidic nor basic?

Answer 20

Its R group usually has alcohol or amide

or

it’s a cysteine

Question 21

Which amino acids have beta branches?

Answer 21

Valine
Isoleucine
Threonine

Question 22

What does it mean to say that an amino acid has beta branch?

Answer 22

It has 2 NON hydrogen atoms on the beta carbon