1. CHAPTER 10 Protein Synthesis

2. The flow of genetic information in the cell is DNARNAprotein
The Central Dogma: Transcription and Translation
Bozeman Science
The sequence of codons in DNA spells out the primary structure of a polypeptide
Polypeptides form proteins that cells and organisms use

3. Review/Preview-control of Gene expression in Eukaryotes
DNA molecule
Review/Preview-control of Gene expression in Eukaryotes
Gene 2
DNA strand
TRANSCRIPTION
RNA
Codon
TRANSLATION
Polypeptide
Amino acid
Figure 10.7

4. Summary of transcription and translation
DNA
Stage mRNA is transcribed from a DNA template. 1
mRNA
RNA polymerase
Amino acid
TRANSLATION
Stage Each amino acid attaches to its proper tRNA with the help of a specific enzyme and ATP. 2
Enzyme
tRNA
Initiator
tRNA
Anticodon
Stage Initiation of polypeptide synthesis 3
Large ribosomal subunit
The mRNA, the first tRNA, and the ribosomal subunits come together.
Start Codon
Small ribosomal subunit
mRNA
Figure 10.15

5. Modification of the polypeptide
Endoplasmic reticulum
Collects proteins made by the ribosomes
Packages them into vesicles which move to the Golgi apparatus
Golgi apparatus
Proteins are altered, packaged into vesicles, and transported to different parts of the cell or exported out of the cell

6. Mutations can change the meaning of genes
Mutations are changes in the DNA base sequence
These are caused by errors in DNA replication or by mutagens
The change of a single DNA nucleotide causes sickle-cell disease

7. Sickle-cell hemoglobin
Normal hemoglobin DNA
Mutant hemoglobin DNA
mRNA
mRNA
Normal hemoglobin
Sickle-cell hemoglobin
Glu
Val
Figure 10.16A

8. The genetic code is the Rosetta stone of life
Virtually all organisms share the same genetic code
Figure 10.8A

9. Types of mutations NORMAL GENE mRNA Protein Met Lys Phe Gly Ala
BASE SUBSTITUTION
Met
Lys
Phe
Ser
Ala
BASE DELETION
Missing
Met
Lys
Leu
Ala
His
Figure 10.16B

10. There are 2 general categories of mutations: Base substitution
Types of Mutations
There are 2 general categories of mutations:
Base substitution
The replacement of one nucleotide with another
Can result in no change in the protein
An insignificant change
The altered amino acid has no effect on the function of the protein

11. A change that is crucial to life of the organism
Types of Mutations
A change that is crucial to life of the organism
The altered amino acid has an effect on the function of the protein
Base insertions or deletions
One or more bases are added or deleted from the DNA
Often have disastrous effects
The nucleotide sequence following the change alters the genetic message (reading frame)

12. Mutations are useful because they
Provide diversity that allows evolution by natural selection to occur
Essential tool for geneticists
Create different alleles needed for genetic research