protein synthesis introduction and overview
DESCRIPTION
PROTEIN SYNTHESIS Introduction and Overview. Protein Synthesis. How DNA directs how proteins are made. The variety of life on earth is due to different proteins. Protein Synthesis. You are different from the people around you because your proteins are different. Protein Synthesis. - PowerPoint PPT PresentationTRANSCRIPT
PROTEIN PROTEIN
SYNTHESISSYNTHESIS Introduction and Introduction and
OverviewOverview
Protein SynthesisProtein SynthesisHow DNA directs how proteins are How DNA directs how proteins are
mademade
The variety of The variety of life on earth is life on earth is
due to due to different different proteins.proteins.
Protein SynthesisProtein Synthesis
You are different You are different from the people from the people
around you around you because your because your proteins are proteins are different.different.
Protein SynthesisProtein Synthesis
Your hair, Your hair, muscles fibres in muscles fibres in your skin are all your skin are all
made of proteins.made of proteins.
Protein SynthesisProtein Synthesis
If you have If you have straight hair, straight hair,
your protein is your protein is slightly different slightly different to someone who to someone who
has curly hairhas curly hair
Protein SynthesisProtein Synthesis
Proteins are made up of units Proteins are made up of units called amino acidscalled amino acids
In our examples we will use a few In our examples we will use a few amino acids to represent a amino acids to represent a protein protein
Proteins are much larger and Proteins are much larger and have more that 50 amino acidshave more that 50 amino acids
Protein SynthesisProtein Synthesis
Proteins are made up of units called Proteins are made up of units called amino acids.amino acids.
Amino acids join together to make Amino acids join together to make proteins.proteins.
Protein SynthesisProtein SynthesisProteins differ from each other by the Proteins differ from each other by the type (different shapes) and sequence type (different shapes) and sequence (the order in which the shapes occur) of (the order in which the shapes occur) of amino acids.amino acids.
If this is the If this is the protein for protein for straight hairstraight hair
A single A single amino acid amino acid change change results in results in curly haircurly hair
Protein SynthesisProtein Synthesis
The proteins are different because The proteins are different because the DNA for curly and straight hair the DNA for curly and straight hair is different.is different.
There is a THREE letter DNA code There is a THREE letter DNA code (codon) for each amino acid.(codon) for each amino acid.
Eg. TGG codes forEg. TGG codes for
Protein SynthesisProtein Synthesis
In this example:In this example:
TAC codes for aTAC codes for a
AAA codes for aAAA codes for a
AGC codes for AGC codes for aa
GGT codes for GGT codes for aa
The code for this aminoThe code for this aminoacid sequence is :acid sequence is :
What is the DNA What is the DNA codecodefor this sequence?for this sequence?
AAA GGT GGTAAA GGT GGT TAC TAC AGC AGC GGT GGT
G
G
C
A
U
U
U
A
A
CC
C
G
T
A
A
A
T
T
GG
G
C
A
T
T
T
A
A
C
Protein Synthesis: Overview of the Protein Synthesis: Overview of the ProcessProcess
DNADNA ProteinProteinRNARNA
makesmakes makesmakes
Protein Synthesis: A closer Protein Synthesis: A closer looklook
Firstly, part of Firstly, part of the DNA is the DNA is copied into copied into
messenger RNA messenger RNA (mRNA)(mRNA)
This is calledThis is calledTRANSCRIPTIONTRANSCRIPTION
The The mRNA mRNA carries carries the message to the message to
make the protein make the protein to the cytoplasm to the cytoplasm and attaches to and attaches to the ribosomethe ribosome
Protein Synthesis: A closer Protein Synthesis: A closer looklook
tRNAtRNA collects collects amino acids in the amino acids in the
cytoplasmcytoplasm
Protein Synthesis: A closer Protein Synthesis: A closer looklook
TRANSLATION: TRANSLATION: tRNAtRNA brings amino brings amino
acids to the acids to the ribosome which ribosome which link and form link and form
proteinsproteins
Protein Synthesis: A closer Protein Synthesis: A closer looklook
Protein SynthesisProtein SynthesisThe Detailed ProcessThe Detailed Process
TRANSCRIPTIONA piece of DNA that codes for a protein is copied into
mRNA
Part of the Part of the DNA DNA
molecule molecule is is
unzipped unzipped by an by an
enzymeenzyme
TTRRAANNSSCCRRIIPPTTIIOONN
DNA DNA separatesseparates
TTRRAANNSSCCRRIIPPTTIIOONN
TA
AC
A
AA
G
GC
GT A
C
A
CGCUUUUGU A piece of A piece of
DNA from DNA from one side is one side is copied intocopied into
mRNA
TTRRAANNSSCCRRIIPPTTIIOONN
TA
AC
A
AA
G
GC
GT A
C
A
CGCUUUUGU
A U AG U U U U C G C C
mRNAmRNA separates separates from DNAfrom DNA
TTRRAANNSSCCRRIIPPTTIIOONN
TA
AC
A
AA
G
GC
GT
A U AG U U U U C G C C
TA
AC
A
AA
G
GC
GT
A U AG U U U U C G C C
mRNAmRNA moves moves out of the out of the
nucleus to a nucleus to a ribosome in ribosome in
the the cytoplasmcytoplasm
ribosome
A U AG U U U U C G C CAC G C C
mRNAmRNA attaches to a attaches to a ribosome ribosome
TRANSLATION
The ribosome encodes mRNA to form a new
protein
A U AG U U U U C G C CU A C
tRNA brings a specific amino acid which links mRNA
mRNA
tRNA
Amino Acid
A U AG U U U U C G C CU A C
mRNA
tRNA
Amino Acid
mRNA three letter code (codon)
Corresponding tRNA code (anticodon)
The tRNA with its specific amino links to mRNA according to its
specific three letter code
U A CA U AG U U U U C G C C
A A A
tRNA brings in the next amino
acid according to the next mRNA
codon
The amino acids combine
The ribosome moves along the mRNA molecule
exposing the next codon
tRNA moves into the cytoplasm to collect another
amino acid
U A C
A U AG U U U U C G C CA A A A G CA G C
tRNAs bring in another amino acids to extend the protein chain
The process continues as the ribosome moves along mRNA exposing the next codon
A U AG U U U U C G C CA G C G G U
The process continues as the ribosome moves along mRNA exposing the next codon
tRNAs bring in another amino acids to extend the protein chain
A U AG U U U U C G C CG G U
TERMINATION: Ribosome and mRNA separate
NEW “Protein” is formed
In Summary …
T A TC A A A A G C G GDNAmakes
A U AG U U U U C G C CRNA
ProteinProtein
makes