2. OBJECTIVES
After accomplishing this
module, you should be
able to:
Explain how protein is
made using information
from DNA.
Discuss the changes in a
DNA molecule that may
cause changes in its
product.
Explain how mutation
mutations may cause
changes in the structure
and function of a protein.
4. DNA and Its Structure
DNA stores instructions for making
other large molecules, called proteins.
These instructions are stored inside each of
your cells, distributed among 46 long
structures called chromosomes.
CHROMOSOMES
These chromosomes are made up of
thousands of shorter segments of DNA, called
genes. Each gene stores the directions for
making protein fragments, whole proteins, or
multiple specific proteins.
GENES
5. Nucleic Acids: DNA and RNA
Nucleic acid- is a large
molecule composed of
carbon, hydrogen, nitrogen,
oxygen, and phosphorus.
The building blocks of
nucleic acid are
nucleotides.
The nucleotide
consists of:
Phosphate group
Sugar
Nitrogenous bases
Types of
Nucleotide
• DNA-
Deoxyribonucleic
acid
• RNA-Ribonucleic
acid
10. Chargaff’s Rule of Base Pairing
The rules of base pairing (or
nucleotide pairing) are:
A with T: the purine adenine
(A) always pairs with the
pyrimidine thymine (T)
C with G: the pyrimidine
cytosine (C) always pairs with
the purine guanine (G)
13. 2. mRNA
nucleus and
cytoplasm
brings instructions
from DNA in nucleus to
ribosomes in the cytoplasm
is the RNA transcript or RNA copy of the
DNA message produced during DNA
transcription. Messenger RNA is translated
to form proteins.
14. 3. tRNA
nucleus and
cytoplasm
brings amino acids
to ribosome to build
polypeptides (proteins)
has a three-dimensional shape and is
necessary for the translation of mRNA
in protein synthesis.
15.
16. Amino acids are the building block of proteins, which are
made up of long chains of chemical units. There are 20
different amino acids.
17. Amino acids are the building block of proteins, which are
made up of long chains of chemical units. There are 20
different amino acids.
Non-essential
• Gly
• Cys
• Tyr
• Glu
• Arg
• Asp
• Asn
• Pro
• Ala
• Gln
• Ser
Essential
• His
• Ile
• Leu
• Lys
• Met
• Phe
• Thr
• Trp
• Val
19. IMPORTANCE OF PROTEINS
1.Protein hormones regulate many physiological processes like insulin,
which affect glucose transport into cells.
2. Proteins in the blood help as a blood clotting factor and transport
molecule. For instance, hemoglobin transport oxygen in the blood.
3. Protein acts as ion channels, carriers, and receptor molecules in the
cell membrane.
20. PROCESSES OF PRODUCING PROTEIN SYNTHESIS
How does protein synthesis happen?
This is known as
the
Central
Dogma of
Biology.
21. How are proteins made?
Step 1: Transcription – RNA polymerase splits open DNA
and copies it to form a strand of mRNA. mRNA leaves the
nucleus.
Transcription takes place in three steps: initiation,
elongation, and termination.
22. How are proteins made?
Step 2: Translation – mRNA in the cytoplasm binds to a
ribosome. Ribosome reads it 3 bases at a time, and matches these
with bases on tRNA attached to an amino acid. An amino acid
chain is formed from many peptide bonds.
Translation of the codons in mRNA to a chain of amino acids occurs at a
ribosome.
23. Step 3: Protein folding – polypeptide is folded and combined
with other polypeptides to form a protein.
How are proteins made?
Start codon
AUG(Methionine)
Stop codon
UAA, UAG, and UGA
