An Overview of Biological Basics - Bioprocess Engineering: Kinetics, Biosystems, Sustainability and Reactor Design - page 74

C

G

A G

T

T

A

Sugar
Phosphate
Backbone

C

G

T

A
A

T

Cytosine

C

G

G C

T

A

Base pair

Thymine

T

A

Adenine

A

T

Guanine

G

C

FIGURE 2.33 Double-helical structure of DNA.

FIGURE 2.34 Overall process of replication by complementary base pairing.

are small particles made of protein and RNA. Ribosomes are cytoplasmic organelles (usually
attached to the inner surfaces of endoplasmic reticulum in eukaryotes) and are the sites of
protein synthesis.
RNA is a long, unbranched macromolecule consisting of nucleotides joined by 5-3 phos-
phodiester bonds. An RNA molecule may contain from 70 to several thousand nucleotides.