The document provides an overview of molecular biology, detailing the structure and function of key cellular components such as DNA, RNA, and the nucleus. It outlines the central dogma of molecular biology, which describes the flow of genetic information, and includes fascinating facts about human DNA and its similarities to that of other species. Additionally, it explains essential terminology related to genetics and cellular biology, emphasizing the complexity and importance of DNA in life.

1. • Molecular Biology -branch
within biology that deals with
the composition, structure
and interactions of
cellular molecules – such as
nucleic acids and proteins
• Carry out
the biological processes
essential for the cell's
functions and maintenance
• biology and chemistry,
particularly genetics and
biochemistry

3. Cytosol
Cytoplasm refers to
the jelly-like material
with organelles in it.
If the organelles were
removed, the soluble
part that would be left
is called the cytosol.
• Nucleus- The nucleus is the
control center of the cell. It is the
largest organelle in the cell and it
contains the DNA of the cell.
• contains all the information for
cells to live, perform their
functions and reproduce.
• The nucleolus is responsible for
making ribosomes.

5. DNA- Language
A,T,G,C- Alphabets
Codon- Word
Gene- Sentence
Chromosome- Chapter
Genome- Book
DNA
DNA
The Code of Life
The Code of Life

6. 30,000
metabolite

7. AMAZING DNA FACTS…
• DNA from a single human cell
extends in a single thread for
almost 2 meters long!!!
• It contains information equal to
some 600,000 printed pages of
500 words each!!!
(a library of about 1,000 books)

8. Did you know?
• Each cell has about 2 m of
DNA.
• The average human has 75
trillion cells.
• The average human has
enough DNA to go from the
earth to the sun more than
400 times.
• DNA has a diameter of only
0.000000002 m.
The earth is 150 billion m
or 93 million miles from
the sun.
(100 trillion x 6 feet divided
by 93 million miles = 1200).

9. Amazing Facts of Human Genome
Amazing Facts of Human Genome
3 billion (3,000,000,000) letters in the DNA code in every cell in your
body.
There is 6 feet of DNA in each of our cells packed into a structure only
0.0004 inches across (it would easily fit on the head of a pin).
There are 75 trillion (75,000,000,000,000) cells in the body
If we recited the genome at one letter per second for 24 hours a day it
would take a century to recite the book of life.
The vast majority of DNA in the human genome - 97% - has no known
function.
Our DNA is 98% identical to that of chimpanzees.
Between humans, our DNA differs by only 0.2%, or 1 in 500 bases
(letters). (This takes into account that human cells have two copies of
the genome.)
The estimated number of genes in both humans and mice is 30,000-
45,000; in the round worm (C. elegans), the number is approximately
19,000.

14. protein
RNA
The “Central Dogma”
DNA
transcription translation
replication
• Flow of genetic information in a cell

15. Some Terminology
 Cell - a membrane-bound structure that is the basic unit of
life
 cell cycle - the events of cell division; includes interphase,
mitosis, and cytokinesis
 cell differentiation - the change in morphology, physiology, or
function of a cell in relation to its neighbouring cells
 Nucleus - the organelle that contains most of the DNA and
directs most of the cell’s activities

16.  nucleic acid - an organic molecule, DNA or RNA, that stores
and carries important information for cell function
 Nucleolus - the structure in which ribosomes are
synthesized and partially assembled; found in most nuclei
 Gene: Basic physical and functional units of heredity
located on the chromosomes consisting of specific
sequences of DNA bases; a segment of DNA that contains
coding for a polypeptide or protein; a unit of hereditary
information

17.  gene expression - the transcription of DNA into RNA and then
into proteins
 Genome - the complete genetic material contained in an
individual
 Genotype: The genetic makeup of an organism
 Phenotype: the physical expressed traits of an organism
 Chromatid - one of two identical parts of a chromosome
 chromatin - the DNA and proteins in the nucleus of a
nondividing cell
 Chromosome - DNA and protein in a coiled, rod-shaped form
that occurs during cell division

18.  Nucleoside - a monomer of DNA and RNA, consisting of a
nitrogen base and a sugar
 Nucleotide - a monomer of DNA and RNA, consisting of a
nitrogen base, a sugar, and a phosphate group
 codon - a group of three sequential nitrogen bases of an
mRNA molecule
 genetic code - triplets of nucleotides in mRNA that
determine the sequence of amino acids in protein
 Anticodon - a region of tRNA consisting of three bases
complementary to the codon of mRNA

19. • amino acid - a carboxylic acid with an amino group;
one of 20 monomers that form proteins
• protein - an organic compound composed of one or
more chains of polypeptides, which in turn are formed
from amino acids
• protein synthesis - the formation of proteins using
information coded on DNA and carried by RNA
• ribosome - an organelle that functions in the
synthesis of proteins

20. • ribonucleic acid (RNA) a nucleic acid composed of
a single strand and distinguished from DNA by
containing ribose and uracil
• Deoxy ribonucleic acid (DNA) a nucleic acid
composed of a double strand and distinguished
from RNA by containing deoxyribose and thymine
• ribose the five-carbon sugar in RNA
• operon a unit of DNA common in bacteria and
phages consisting of clusters of regulated genes