amino acids

Question 1

describe the structure of an amino acid

Answer 1

• central carbon with H and R group
• NH2 on one side (amine)
• COOH on other side (carboxyl)

Question 2

define amphoteric

Answer 2

acidic and basic properties
- has an organic side chain

Question 3

define chiral

Answer 3

4 different groups around central carbon

Question 4

describe an alpha amino acid

Answer 4

NH2 and COOH attached to same carbon

Question 5

what is formed when an amino acid reacts with an acid or alkali?

Answer 5

a salt

Question 6

describe what happens when an amino acid reacts with an alkali

Answer 6

• alkali reacts with COOH group
• to form a conjugate base
• the base combines with a positive ion
• to form a salt and water
  RCH(NH2)COO- Na+ + H2O

Question 7

describe what happens when an amino acid reacts with an acid

Answer 7

• acid reacts with amino group
• to form a conjugate acid
  COOHRCHH3N+Cl-

Question 8

describe what happens when an amino acid reacts with an alcohol

Answer 8

• alcohol reacts with COOH group
• using a strong H2SO4 catalyst
  H2NRCHCOOCH3

Question 9

what is formed when an amino acid reacts with an alcohol?

Answer 9

ester and water

Question 10

what is the principle force of attraction between amino acids?

Answer 10

hydrogen bonds

Question 11

how do amino acids become dipolar?

Answer 11

COOH loses a proton and the lone pair of electrons on N forms a dative covalent bond to this H+

Question 12

why are amino acids soluble in water?

Answer 12

• OH on carboxyl forms H bonds with delta pos H in water
• NH3+ of amine forms H bonds with delta neg O in water

Question 13

what is formed when an amino acid reacts with NaOH?

Answer 13

salt and water