amino acid

Question 1

what is an amino acid?

Answer 1

amino acids are organic compounds with both amino group(-NH20 and carboxyl group(cooh) attached to the same carbon. they are substituted methanes as there are four substituent groups attached to the same carbon.

Question 2

what are the properties of amino acids?

Answer 2

amino acid never exists uncharged no matter the ph. at the isoelectric point, amino acids are zwitterions. hence in a solution of different ph , the structure of amino acid changes.

Question 3

what are zwitterions?

Answer 3

it is a compound with a negative atom and a non-adjecent positive atom . the molecule shows both positive and negative charges.

Question 4

what are the types of amino acids, based on the number of carboxyl and amino groups?

Answer 4

1) neutral amino acid: they contain a single nh2 and COOH group. e.g. glycine, alanine, valine

2) acidic amino acids; contain single NH2 and two COOH, group
e. g. glutamic acid , aspartic acid

3) basic amino acids: they contain two NH2 and single COOH group.
e. g. lysine, arginine

4) aromatic amino acid: the variable group in these amino acids contains aromatic rings. e.g. phenylalanine, tyrosine

5) heterocyclic amino acids: they contain heterocyclic aromatic rings.
e. g. proline, tryptophan

6) sulfur-containing amino acid: e.g.. Methionine, cysteine, homocysteine, and taurine

Question 5

types of amino acid based on involvement in protein formation.

Answer 5

1) coded: a) involved in protein synthesis
b) there are totally 20 coding amino acids
eg: glycine, alanine, glutamic acid, methionine, aspartic acid and serine, valine

2) non-coding: non involved in protein synthesis.
eg: GABA ( neurotransmitter) : gamma amino
butyric acid
othanine citrulline(helps in urea formation)

Question 6

types of amino acids based on production in the body/requirement in the diet.

Answer 6

1)essential amino acid: not produced in our body thus required in our diet .
   P: PHENYLALANINE
   V- VALINE
   T- TRYPTOPHAN
   T- THREONINE
    I- ISOLEUCINE
   M-METHIONINE
   H-HISTIDINE
   A-ARGININE
    L-LYSINE
   L- LEUCINE

2) non-essential protein: sufficiently produced in our body and not required in the diet.
eg: aspartic acid, glutamic acid, alanine, serine,
glycine

Question 7

explain peptide bond.

Answer 7

when two amino acids join through an amino group of one and carboxyl group of the other by loss of water it is called a peptide bond. the structure of multiple amino acids joined by peptide bond are called oligopeptide and the product is called a polypeptide.

Question 8

what are peptides? give examples.

Answer 8

A peptide is a short chain of amino acids. The amino acids in a peptide are connected to one another in a sequence by bonds called peptide bonds.

eg: 1)short peptides called enkephalin are formed in the CNS binds receptors of certain cells and induces analgesia(absence of pain sensation)
2) some extremely toxic mushrooms such as amanitin are peptides are well as many antibiotics.

Question 9

function of glycine

Answer 9

glycine required in the synthesis of haem

Question 10

function of tryptophan

Answer 10

precursors of :

1) melatonin
2) indole 3 acetic acid in plants
3) serontine (vasoconstrictor)
4) nicotinamide

Question 11

functions of tyrosine.

Answer 11

tyrosine is converted to adrenaline and thyroxine, as well as melanin(skin pigment).

Question 12

the function of histidine.

Answer 12

precursor of histamine

Question 13

function of alanine

Answer 13

precursor of vitamin B5

Question 14

what are the two semi-essential amino acids?

Answer 14

arginine and histidine.

Question 15

some other functions of amino acids.

Answer 15

1) amino acids form organic acids which form glucose by glucogenesis
2) ornithine and citrulline are compounds of the urea cycle
3) antibiotics have non-protein amino acids
4) glutamate and cysteine are used for glutathione
5) after removal of the amino group the carbon chain of amino acid is converted to glucose