Friday 11/14/2014
Take a notes sheet from the front
table. Get out your warm-up
sheet & answer the following:
What is the complementary
strand for the below DNA strand?
ACTGCACCTGAGCGTATTGAC
TGACGTGGACTCGCATAACTG
Blast from the Past…
1. Who makes proteins
in the cell?
2. What are proteins
made of?
Protein Synthesis
DNA vs.RNA
• Double-stranded
• Deoxyribose
• A,G, C, T
• Single stranded
• Ribose
• A, G, C, U
DNA vs.RNA
Nucleus
The office
The Boss never leaves
DNA – The Boss
mRNA – Ms. Rene
Secretary
She’s a
foreigner
In her
language
Uhere is
no “T”
Protein Synthesis
Protein synthesis is the making of
proteins, using the information that is
found in DNA.
 Proteins are long chains of small
molecules called amino acids.
Different proteins are made by using a
different sequence of amino acids.
 Pieces of information in DNA are called
genes.

Transcription: means write across


Protein synthesis begins with the
DNA molecule. The DNA of this
gene will unzip like it does in
replication. *The enzyme that
separates the DNA strand at a
specific gene is helicase.
In protein synthesis, only one
strand of the DNA will be used.
Transcription
 A single strand of mRNA forms and
transcribes (copies) the genetic
information from the DNA. This strand
of RNA is called messenger RNA or
mRNA. *The enzyme that connects
and assembles the ribonucleotides is
called RNA polymerase
 The DNA “zips” closed and remains in
the nucleus.
 The mRNA will leave the nucleus and
travel to a ribosome.
RNA which stands for
RIBONUCLEIC ACID is
single stranded,
contains a ribose sugar, and
has Uracil instead of
Thymine.
Comparing RNA and DNA
Image courtesy of Wikimedia Commons
5’DNA Helicase3’
5’
A T
G C
T A
A T
C G
G C
G C
A T
T A
C G
T A 5’
3’
Touch the
helicase!
3’
5’
3’
A
A
T
C
G
U
5’
A
G
T
A
C
G
G
A
T
C
T
3’
3’
T
C
A
T
G
C
C
T
A
G
A 5’
5’
Assemble
your
mRNA
strand!!
3’
Hit Me
when
done!
5’
A
A
3’
T
C
G
U
5’
RNA
polymerase
A
G
T
A
C
G
G
A
T
C
T
3’
3’
T
C
A
T
G
C
C
T
A
G
A 5’
3’
5’
A
G
C
C
U
A
C
U
A
G
U
5’
3’
A
A
T
C
G
U
5’
3’
A T
G C
T A
A T
C G
G C
G C
A T
T A
C G
T A 5’
3’
5’
3’
U
C
A
U
G
C
C
U
A
G
A 5’
3’
Quick Review!
Where does TRNASCRIPTION
take place?
Nucleus
The office
The Boss never leaves
Where do we get the information to
make different types of proteins?
DNA – The Boss
Who delivers the message to
the workers?
mRNA – Ms. Rene
Secretary
She’s a
foreigner
In her
language
Uhere is
no “T”
Quick Quiz
1.
2.
3.
4.
5.
What is the name of the enzyme that unwinds
DNA?
What is the process where a secret message
goes ACROSS the nuclear membrane?
What carries the sequence from the DNA out
of the nucleus?
How many strands are copied on the original
DNA molecule?
What happens to the DNA once the
messenger detaches?
Transcribe the following DNA
strand:
TCCGCGCAGAGCTAG
AGGCGCGUCUCGAUC