1

PROTEIN PROTEIN SYNTHESISSYNTHESIS

2

Pathway to Making a Pathway to Making a ProteinProtein

DNADNA

mRNAmRNA

ProteinProtein

What What is is

RNA?RNA?

4

Roles of RNA and DNA

•DNA is the MASTER PLAN

•RNA is the BLUEPRINT of the

Master Plan

5

RNA Differs from DNARNA Differs from DNA

RNA:RNA: DNA:DNA:

6

Structure of RNAStructure of RNA

7

. Three Types of Three Types of RNARNA

• Messenger RNA (mRNA)Messenger RNA (mRNA)

• Ribosomal RNA (rRNA)Ribosomal RNA (rRNA)

• Transfer RNA (tRNA)Transfer RNA (tRNA)

8

Remember the Remember the Complementary Complementary

BasesBasesOn DNA: A- C-On RNA: A-U C-

TranscriptiTranscription and on and

TranslationTranslation

10

DNADNA RNARNA ProteinProtein

Nuclearmembrane

TranscriptionTranscription

RNA ProcessingRNA Processing

TranslationTranslation

DNA

Pre-mRNA

mRNA

Ribosome

Protein

EukaryotEukaryotic Cellic Cell

11

Question:Question: What would be the What would be the

complementary RNA complementary RNA strand for the following strand for the following DNA sequence?DNA sequence?

DNA 5’-DNA 5’-GCGTATGGCGTATG-3’-3’

12

Answer:Answer:

•DNA 5’-GCGTATG-DNA 5’-GCGTATG-3’3’

•RNA 3’-CGCAUAC-RNA 3’-CGCAUAC-5’5’

13

The Genetic Code

• A codon designates an amino acid

• A codon is three bases

• There are 20 amino acids, but 64 possible codons

14

The Genetic Code

•read from the center to the outside

•Example: AUG codes for Methionine

15

Name the Amino Acids

•GGG?•UCA?•CAU?•GCA?•AAA?

16

TranscriptioTranscriptionn

TranslatiTranslationon

17

OverviewOverview

methionine glycine serine isoleucine glycine alanine stopcodon

proteinprotein

A U G G G C U C C A U C G G C G C A U A AmRNAmRNA

startcodon

Primary structure of a proteinPrimary structure of a protein

aa1 aa2 aa3 aa4 aa5 aa6

peptide bonds

codon 2 codon 3 codon 4 codon 5 codon 6 codon 7codon 1