Every cell in a specific
organism (body) has the
same DNA
DNA to RNA to Protein
Transcription & Translation
Facts

Every body has
 200
major types of cells
 Total number of cells: trillions (10¹²)

Each cell contains
10 billion (billion = 10⁹) proteins
 2,000+ different varieties of proteins

DNA → RNA → Proteins

How is the DNA coded to make proteins?

Do all cells produce the same proteins?

How do the different cells “know” what
proteins to make?
 “Gene
expression”
The structure of the
DNA provides the its
function.
How does the structure
of the DNA provide
instructions for the
working of the cells?
Biotech course:

Overview: Transcription and Translation
 Additional

The Code for Gene Expression
 Say


information about DNA
it with DNA
What controls the code?
Proteins
 Structure &
 Enzymes

Function
Using biotechnology to produce proteins needed
for medicine or products
Video segment
How are proteins made?
DNA Contains Genes
DNA
Genes
Gene 1
Gene 2
Genes Provide Instructions
for Making Proteins
DNA
Genes
Proteins
Gene 1
Gene 2
Protein 1
Protein 2
Proteins Have Functions
DNA
Genes
Proteins
Function
Gene 1
Gene 2
Protein 1
Protein 2
Blue eye
color
Blood clotting
factor
During replication,
each
Original strand
acts as a template
for a new
complementary
strand
DNA polymerase

See HHMI video
Using The New Genetics to help your
understanding:




Getting the Message
Pp. 11 – 14.
Transcription
RNA splicing
 Introns


and Exons
Pp. 18 – 21
Translation
Gene Expression

DNA only carries the
instructions, in the form of genes

Proteins do the work
mRNA
DNA
Transcription
Translation
Differences between DNA and RNA
DNA
RNA
Sugar
deoxyribose
ribose
Strand
Double
Single
Bases
A,T,C,G
A,C,G,U
Carries
instructions*
Intermediary
between DNA and
proteins
Function
* Exception - RNA viruses
A little more about RNA

3 types
 mRNA

Messenger RNA, works between
DNA and protein
 tRNA

Transfers RNA, converts RNA to
amino acids (the smallest part of
a protein)
 rRNA

Ribosomal RNA- part of the
ribosome
Differences between DNA and RNA
Transcription
 DNA is converted to mRNA
 Requires
protein called RNA Polymerase
 Complimentary bases (A-U) and (G-C)

RNA polymerase
 Green

DNA strand
 Blue

RNA
 Pink
DNA Interactive: Code (copying the code)
www.dnai.org

Finding the DNA Structure, Copying,
Reading, & Controlling DNA Code
Starting & stopping the RNase

www.DNAi.org
 Controlling

the code
Genetics.utah.edu
 Epigenetics

Inside the Cell:
 p.23

RNA’s many talents; p.32 Tags
New Genetics
 P.
14-16 RNA splicing; p.30-31 epigenetics &
chromatins
How does it start?

DNA contains promoters
 Think
“promote transcription”
RNA polymerase
Gene A
promoter

Without a promoter RNA polymerase
doesn’t know where to start
Transcription

Once initiated RNA P adds
complimentary nucleotides

How does it stop?
 Stop
signal
 When RNA P encounters this
signal it stops
Eukaryotic Example
Promoter
Examples
Negative system
Repressor prevents
transcription
If a specific protein
is in the cell, then it
will bind with the
repressor & stop the
repressor from
working.
Then, transcription
can take place.
Why is there a negative system to
control transcription?