Protein synthesis involves two main steps - transcription and translation. In transcription, RNA polymerase uses DNA as a template to make messenger RNA (mRNA) in the nucleus. This mRNA is then transported to the cytoplasm for translation, where transfer RNA (tRNA) and ribosomes work together to assemble amino acids in the sequence specified by the mRNA codons to produce a protein.
Protein Synthesis
•Synthesis= the process of building or
making
• DNA= (deoxyribonucleic acid) the genetic
code or instructions for the cell
• RNA= ribonucleic acid
• Amino Acids= building blocks of proteins
3.
DNA RNA
DeoxyribonucleicAcid Ribonucleic Acid
Sugar=deoxyribose Sugar= ribose
Contains 1 more H atom
than deoxyribose
Double stranded Single stranded- a single
strand of nucleotides
Nitrogen bases: ATCG Nitrogen bases: AUCG
U=Uracil
STEP 1: TRANSCRIPTION=making RNA
Location: Eukaryotes-nucleus
Prokaryotes-cytoplasm
• 1. RNA polymerase binds to the gene’s
promoter
• 2. The two DNA strands unwind and
separate.
• 3. Complementary nucleotides are added
using the base pairing rules EXCEPT:
• A=U
• The rest are the same C=G, T=A, G=C
6.
Try this example.
• Using the following DNA sequence, what
would be the complementary RNA
sequence?
• ATCCGTAATTATGGC
• UAGGCAUUAAUACCG
• 1. MessengerRNA= mRNA is a form of RNA
that carries the instructions for making the protein
from a gene and delivers it to the site of
translation.
• Codon= three nucleotide sequence
• Transfer RNA= tRNA single strands of RNA
that temporarily carry a specific amino acid on one
end and has an anticodon
• Anticodon-a 3 nucleotide sequence that is
complementary to an mRNA codon
• Ribosomal RNA= rRNA- a part of the structure
of ribosomes
9.
Codon and Anticodon
• Codon-found on mRNA Anticodon-found on tRNA
http://images.google.com/imgres?
imgurl=http://www.obgynacademy.com/basicsciences/fetology/
genetics/images/codon_GCA.gif&imgrefurl=http://www.obgyna
cademy.com/basicsciences/fetology/genetics/&usg=__4MvAO2
N3sXbERXQwODVDSqtsOjM=&h=160&w=168&sz=4&hl=e
n&start=5&tbnid=toyuIN8drVBr4M:&tbnh=94&tbnw=99&pre
v=/images%3Fq%3Dcodon%26gbv%3D2%26hl%3Den
http://www.microbelibrary.org/microbelibrary/files/ccImages/Articleimages
/kaiser/tRNA_arg.jpg
10.
STEP 2-TRANSLATION-Assembling
proteins-in the cytoplasm
• mRNA leaves nucleus and enters cytoplasm
• tRNA molecules with the complementary
anticodon and a specific amino acid arrives at the
ribosome where the mRNA is waiting.
• Peptide bond forms between amino acids
• tRNA molecule leaves and a new one comes with
another amino acid.
• Amino acids continue to attach together until the
stop codon and a protein is formed
11.
SUMMARY
• Transcription=process of making RNA
from DNA
• Translation= RNA directions are used to
make a protein from amino acids
•DNA®RNA ®Protein
• Transcription Translation
nucleus Cytoplasm on
ribosome
12.
DNA RNA
DeoxyribonucleicAcid Ribonucleic Acid
Sugar=deoxyribose Sugar= ribose
Contains 1 more H atom
than deoxyribose
Double stranded Single stranded- a single
strand of nucleotides
Nitrogen bases: ATCG Nitrogen bases: AUCG
U=Uracil
13.
Video Clips
•http://www.youtube.com/watch?v=KvYEqGb7XN8&• http://www.youtube.com/watch?v=B6O6uRb1D38&
14.
DNA Replication RNATranscription
DNA polymerase is used. RNA polymerase is used.
DNA nucleotides are
linked.
RNA nucleotides are
linked.
A DNA molecule is
made.
An RNA molecule is
made.
Both DNA strands serve
as templates.
Only one part of one
strand of DNA ( a gene)
is used as a template.
15.
Explain the stepsin protein
synthesis.
http://stemcells.nih.gov/i
nfo/scireport/images/figu
rea6.jpg