Biomolecules

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Comparison of Elements in Non-living & Living Matter

Element

% Weight

Earth’s crust

Human body

Hydrogen (H)

O.14

0.5

Carbon (C)

0.03

18.5

Oxygen (O)

46.6

65.0

Nitrogen (N)

Very little

3.3

Sulphur (S)

0.03

0.3

Sodium (Na)

2.8

0.2

Calcium (Ca)

3.6

1.5

Magnesium (Mg)

2.1

0.1

Silicon (Si)

27.7

Negligible

KNOWLEDGE CORNER

Molecular weight of micromolecules found in the acid

soluble pool ranges from 18 to 800 Dalton (Da). The acid

soluble pool represents the cytoplasmic composition. They

include amino acids, sugars, nitrogen bases etc.

1. ÅMÏÑØ ÅÇÏDS

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A typical amino acid is formed of

an amino group (-NH2), an acid

group (-COOH), hydrogen & a

variable group (R). The groups –

NH2 & –COOH are attached to the

same carbon atom (α-carbon).

Hence they are called α-amino

acids.

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They are substituted methanes.

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Based on the nature of R group, there are many amino acids. However,

those which occur in proteins are only of 20 types.