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