Chem Lec (Dash 3)

Question 1

Building units of proteins

Answer 1

Amino Acids

Question 2

There are about — amino acids occur in nature.
and only – of them enter in proteins synthesis.

Answer 2

300

20

Question 3

Structure of amino acids:

Four different groups are attached to α- carbon:

Answer 3

Amino Group
COOH Group
Hydrogen atom
And Side Chain (R)

Question 4

At physiological pH (7.4), -COOH group is
dissociated forming a negatively charged —– and amino group is protonated forming positively charged ion forming ——-

Answer 4

Carboxylate ion (COO-)

Zwitter Ion

Question 5

Proline is an —— —- not amino acid.

Answer 5

Imino Acid

Question 6

Classification according to polarity of side chain (R):

In Polar amino acids: in which R contains —— ——- —— so can forms hydrogen bond with H2O.

Answer 6

polar hydrophilic group

Question 7

Classification according to polarity of side
chain (R):

OH Group: as in —-, ——, and ——-
- SH Group: as in ——
Amide group: as in ——, and ——-
NH2 group or nitrogen act as a base (basic amino acids): as ——, ——, and ——
COOH group (acidic amino acids): as —— and ——-

Answer 7

OH group : as in serine, threonine and tyrosine
- SH group : as in cysteine
amide group: as in glutamine and aspargine
NH2 group or nitrogen act as a base (basic amino
acids ): as lysine, arginine and histidine
COOH group (acidic amino acids): as aspartic and
glutamic .

Question 8

Polar, uncharged R groups

Answer 8

Serine, Threonine, Cysteine, Asparagine, and Glutamine

Question 9

Positively Charged R groups

Answer 9

Lysine, Arginine, and Histidine

Question 10

Negatively charged R groups

Answer 10

Aspartate and Glutamate

Question 11

In Non polar amino acids: R is —– ——- group which can’t enter in hydrogen bond formation.

Answer 11

Alkyl hydrophobic group

Question 12

9 amino acids are non polar

Answer 12

glycine, alanine,
valine, leucine, isoleucine, phenyl alanine,
tryptophan, proline and methionine).

Question 13

Nonpolar, Aliphatic

Answer 13

Glycine, Alanine, Valine, Proline Lecuine, Isoleucine

Question 14

Aromatic R Groups

Answer 14

Phenylalanine
Tyrosine and Trptophan

Question 15

Can’t be synthesized in the body, essential to be taken in
diet. Their deficiency affects growth, health and
protein synthesis

Answer 15

Essential Amino Acids

Question 16

How many Essential amino acids can’t be synthesized by our body

Answer 16

10

Question 17

formed in the body but not in
sufficient amount for body requirements especially in children.

Answer 17

Semi Essential

Question 18

What are the 2 examples of Semi essential amino acids?

Answer 18

Arginine and histidine

Question 19

This amino acid can be synthesized by our body

Answer 19

Non essential amino acid

Question 20

How many non standard amino acids have been detected in living organisms. Many are metabolic intermediates.

Answer 20

700

Question 21

are intermediates in urea biosynthesis

Answer 21

ornithine and
citrulline

Question 22

Chemical derivatives of amino acids also have i m p o r t a n t b i o l o g i c a l f u n c t i o n s , e g .
————- lack the a-carboxylate
of amino acids

Answer 22

Catecholamines

Question 23

——— and ——- are neurotransmitters.
——– mediates parts of the immune
response.

Answer 23

GABA & Dopamine

Histamine

Question 24

Functions of Amino Acids
Apart from being the monomeric constituents
of proteins and peptides, amino acids serve
variety of functions.
(a) Some amino acids are converted to carbohydrates and are called as

Answer 24

Glucogenic amino acids

Question 25

Specific amino acids give rise to specialised products, e.g.

• Tyrosine forms hormones such as —– hormones, (T3, T4), ———- and ——– and a pigment called ——.

Answer 25

Thyroid
epinephrine and
norepinephrine
Melanin

Question 26

Tryptophan can synthesise a vitamin called

Answer 26

Niacin

Question 27

• Glycine, arginine and methionine synthesise

Answer 27

Creatine

Question 28

help in synthesis of Bile
salts.

Answer 28

Glycine and cysteine

Question 29

•Glutamate, cysteine and glycine synthesis

Answer 29

Glutathione

Question 30

Histidine changes to ——- on
decarboxylation.

Answer 30

Histamine

Question 31

Is formed from tryptophan

Answer 31

Serotonin

Question 32

Glycine is used for the synthesis of

Answer 32

Haem

Question 33

Pyrimidines and purines use several amino acids for their synthesis such as ——–, ——– for pyrimidines and glycine,

——-, ——-, ——- for purine synthesis

Answer 33

aspartate and
glutamine

aspartic
acid, Glutamine and serine

Question 34

Some amino acids such as —— and —– are used as detoxicants of specific substances.

Answer 34

glycine and cysteine

Question 35

Are sources or sulphur

Answer 35

Cystine and methionine

Question 36

Methionine acts as “active” methionine (S-adenosylmethionine) and transfers methyl group to various substances by : ——-

Answer 36

transmethylation