Post on 22-Dec-2015
Protein Synthesis
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
DNA RNA
Deoxyribonucleic Acid 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
http://www.princeton.edu/%7Ehos/images/rna.gif
http://images2.clinicaltools.com/images/gene/dna_versus_rna_reversed.jpg
STEP 1: TRANSCRIPTION= making RNALocation: 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
Try this example.
• Using the following DNA sequence, what would be the complementary RNA sequence?
• ATCCGTAATTATGGC
• UAGGCAUUAAUACCG
http://www.odec.ca/projects/2004/mcgo4s0/public_html/t3/mRNA%20to%20protein.gif
• 1. Messenger RNA= 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
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.obgynacademy.com/basicsciences/fetology/genetics/&usg=__4MvAO2N3sXbERXQwODVDSqtsOjM=&h=160&w=168&sz=4&hl=en&start=5&tbnid=toyuIN8drVBr4M:&tbnh=94&tbnw=99&prev=/images%3Fq%3Dcodon%26gbv%3D2%26hl%3Den
http://www.microbelibrary.org/microbelibrary/files/ccImages/Articleimages/kaiser/tRNA_arg.jpg
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
SUMMARY
• Transcription= process of making RNA from DNA
• Translation= RNA directions are used to make a protein from amino acids
• DNARNA Protein• Transcription Translation
nucleus Cytoplasm on ribosome
DNA RNA
Deoxyribonucleic Acid 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
Video Clips
• http://www.youtube.com/watch?v=KvYEqGb7XN8&feature=related
• http://www.youtube.com/watch?v=B6O6uRb1D38&feature=related
DNA Replication RNA Transcription
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.
Explain the steps in protein synthesis.
http://stemcells.nih.gov/info/scireport/images/figurea6.jpg