Page 175 - MNU microbiology theoritical 2025

General Microbiology & Immunology (PM 401) Second level Semester 4 2024/2025

Chromatin, Chromosomes, genes

Genes

Are part of DNA that carry the information for a phenotypic character
⮚ Eukaryotic genes are characterized by the presence of
▪ Introns (noncoding sequences)
▪ Exons (coding sequences)

Chromosome
- It is a single DNA molecule In bacteria there is a single
chromosome,
- while in Human there are 46 chromosomes (23 x 2)

Chromatin

The DNA and associated proteins (e.g. histones) in the
nucleus of eukaryotes.

Structure and Function of RNA

RNA Structure

• RNA is typically single stranded and is made

of ribonucleotides that are linked

by phosphodiester bonds.

• A ribonucleotide in the RNA chain contains

ribose (the pentose sugar), one of the four

nitrogenous bases (A, U, G, and C), and a

phosphate group.

• The RNA-specific pyrimidine uracil forms a complementary base pair

with adenine and is used instead of the thymine used in DNA

General Microbiology & Immunology (PM 401) theoretical handbook Page 164