Transcript Protein Synthesis

Protein Synthesis
Translation
http://www.youtub
e.com/watch?v=_
Q2Ba2cFAew
(central dogma
song)
Genes and Proteins
The coded information in DNA is put
to work through production of
proteins.
DNA > RNA > Protein
(Melanin)
> Trait
Genes and Proteins
 Some proteins:
 Muscle, skin, pigment, hair etc.
 Enzymes
 Help digest food
 Control Cellular Respiration - (break down glucose)
 Make spindle apparatus
 Enzymes control all the chemical reactions of
an organism.
 By encoding the instructions for making proteins,
DNA controls cells.
(Human Insulin)
Genes and Proteins
Proteins are polymers of amino acids.
The sequence of nucleotides in each
gene contains information for
assembling the string of amino acids
that make up a single protein.
RNA
Differs from DNA:
 DNA double
stranded: RNA
single
 DNA deoxyribose
sugar; RNA
ribose
 DNA Thymine:
RNA Uracil
Uracil
Hydrogen bonds
Adenine
Protein Synthesis
Computer Analogy
 DNA = CD for Game
 RNA = Computer and
Monitor
 Protein = Game
Building Analogy
 DNA = Printed Instructions
 RNA = Workers
 Protein = Product
Three Types of RNA:
 Messenger RNA (mRNA),
brings instructions from DNA in
the nucleus (headquarters) to
the cytoplasm (factory).
 In the factory mRNA moves to
the assembly line, a ribosome.
Three Types of RNA:
The ribosome
(assembly line),
made of ribosomal
RNA (rRNA)
 Binds to the mRNA
 Uses the
instructions to
assemble the
amino acids in the
correct order.
Amino Acid
rRNA
mRNA
Three Types of RNA:
Transfer RNA
(tRNA) is the
supplier. Delivers
amino acids (raw
materials) to the
ribosome to be
assembled into a
protein.
Amino Acid
Ribosome
tRNA
mRNA
Translation: From mRNA to Protein
 “A communication in a
second language having the
same meaning as the
communication in a first
language”
 Converting a sequence of
nitrogenous bases in mRNA
into a sequence of amino
acids.
Translation
 At ribosomes.
 Attaches to mRNA like a
clothespin clamped onto a
clothesline.
Translation
QuickTime™ and a
Cinepak decompressor
are needed to see this picture.
Click image to view movie
Translation
Amino
acid
Amino acids
brought to
ribosomes by
transfer RNA.
tRNA molecule
attaches to only
one type of
amino acid.
Chain of RNA
nucleotides
Transfer RNA
molecule
Anticondon
Translation
A ribosome attaches
to start of mRNA.
tRNA, carrying a
specific amino acid,
approaches.
tRNA anticodon
pairs with mRNA
codon.
Ribosome
mRNA codon
Translation
 First codon AUG codes
methionine.
 Signals “start”
Methionine
 Ribosome slides to next
codon.
tRNA
anticodon
Translation
 New tRNA carries an amino acid to pair with
second mRNA codon.
Alanine
Translation
 Amino acids joined
by peptide bond.
 Continues for 50 to
thousands of amino
acids to make a
protein.
Methionine
Alanine
Peptide
bond
The Genetic Code
The Messenger RNA Genetic Code
First
Letter
U
U
Phenylalanine (UUU)
A
G
Third
Letter
G
Serine (UCU)
Tyrosine (UAU)
Cysteine (UGU)
Serine (UCC)
Tyrosine (UAC)
Cysteine (UGC)
Leucine (UUA)
Leucine (UUG)
Serine (UCA)
Stop (UAA)
Stop (UGA)
Serine (UCG)
Stop (UAG)
Tryptophan (UGG)
Leucine (CUU)
Proline (CCU)
Histadine (CAU)
Arginine (CGU)
Leucine (CUC)
Proline (CCC)
Histadine (CAC)
Arginine (CGC)
Leucine (CUA)
Proline (CCA)
Glutamine (CAA)
Arginine (CGA)
Leucine (CUG)
Isoleucine (AUU)
Proline (CCG)
Glutamine (CAG)
Arginine (CGG)
Threonine (ACU)
Asparagine (AAU)
Serine (AGU)
Isoleucine (AUC)
Threonine (ACC)
Asparagine (AAC)
Serine (AGC)
Isoleucine (AUA)
Methionine;
Start (AUG)
Threonine (ACA)
Lysine (AAA)
Threonine (ACG)
Lysine (AAG)
Arginine (AGA)
Arginine (AGG)
Valine (GUU)
Alanine (GCU)
Aspartate (GAU)
Glycine (GGU)
Valine (GUC)
Alanine (GCC)
Aspartate (GAC)
Glycine (GGC)
Valine (GUA)
Valine (GUG)
Alanine (GCA)
Alanine (GCG)
Glutamate (GAA)
Glutamate (GAG)
Glycine (GGA)
Glycine (GGG)
Phenylalanine (UUC)
C
C
Second Letter
A
U
C
A
G
U
C
A
G
U
C
A
G
U
C
A
G
Translation
QuickTime™ and a
Cinepak decompressor
are needed to see this picture.
Click image to view movie
mRNA re-use
mRNA can be used
again, not “used up”
after just one.
 Can use the same
plans to build many
houses.
Codons
 DNA code is a series of 4 nucleotides, A, T, C and G.
 Each three nucleotides in a row on a gene code for a
certain amino acid in that part of the protein.
 TGG-CGC-TAC
 ACC-GCG-AUG
 Thr-Ala-Met
 Threonine, Alanine, Methionine
Summary
Diagram
http://www.youtube.
com/watch?v=d1UP
f7lXeO8 (rap
attempt)
http://www.youtube.
com/watch?v=ygpqVr7_xs
(instrumental)