Amino Acids

Question 1

What is a protein made of

Answer 1

Protein is a polypeptide
Macromolecules made up of amino acids
Amino acids joined covalently to give the sequence of the protein

Question 2

What are the amino acids called in a polypeptide

Answer 2

Monomers

Question 3

How is the amino acids sequence coded

Answer 3

The amino acid sequence of a protein is encoded by a gene
(The nucleotide sequence of a gene determines the amino acid sequence of a protein)

Question 4

What does the folding of a protein depend on

Answer 4

The folding of proteins depends on the chemical and physical properties of the amino acids

Question 5

What is the central carbon in an amino acid called

Answer 5

The (a-carbon) Alpha Carbon

Question 6

What are the four groups attached to the central carbon in an amino acid
and with what bond

Answer 6

covalently bonded to:
* an amino group (-NH2)
* a carboxyl group (-COOH)
* a hydrogen atom (-H)
* a distinctive R group (side chain)

Question 7

What happens to the ionization of amino acids below PH 5

Answer 7

The amino group and the Carboxyl group both get Hydrogenated (given an H+).

Question 8

What happens to the ionisation of amino acids from PH 0-12

Answer 8

Zwitterionic form
Amino-group gains an H+ making it positive
The Carboxyl group loses Hydrogen making it negatively charged.

Question 8

What happens to the ionisation of amino acids from PH 0-12

Answer 8

Zwitterionic form
Amino group

Question 9

What happens to the ionisation of amino acids from Ph 7 and above

Answer 9

Both groups
amino group and the Carboxyl group get deprotonated
They both lose an H+

Question 10

How do you classify an amino acid

Answer 10

Classified according to the chemical and physical properties of the R groups

Question 11

What is an amino acid residue

Answer 11

An amino acid residue is what remains of an amino acid after it has been joined by a peptide bond to form a protein

Question 12

What are the classifications of amino acids

Answer 12

Chemical properties
Hydrophobic / Hydrophilic
Polar / Non-polar
Acidic / Basic

Physical properties
Aliphatic / Aromatic

Question 13

How can you tell if an amino acid is Hydrophobic / Hydrophilic

Answer 13

Hydrophobic amino acids have little or no polarity in their side chains.
(no charge on their side chains)

Question 14

How can you tell if an amino acid is polar

Answer 14

C-N
C-F
C-O

Polar bonds

Question 15

how can you tell if an amino acid is an Acid or Base?

Answer 15

Look at how many H+ are ready to dissociate

Question 16

how can you tell if an amino acid is Aliphatic / Aromatic?

Answer 16

An aromatic amino acid is an amino acid that includes an aromatic ring.

Question 17

Henderson Hesselbalch equation

Answer 17

Ph= pKa + Log((A-)/(HA))

Ka = X
PKa = -logKa
PKA = -log X

A- = base conc
HA = Acid Conc