Principles of Biology Lecture Notes



Principles of Biology Lecture Notes Fall, 2006

FROM GENE TO PROTEIN

From Gene to Protein- Outline

The Central Dogma:

DNA RNA PROTEIN

TRANSCRIPTION TRANSLATION

Transcription

Initiation

Promoter

Transcription Factors

Elongation

Termination

Product:

Prokaryote: mRNA

Eukaryote: Transcript

Transcript Processing

Capping

Splicing Gene Exon = Protein Domain

Translation: Nucleotide Sequence to AA Sequence

Genetic Code

Initiation

Elongation

Termination

Post-Translation Modification of Polypeptide

Targeting

Folding

Mutation

Types

Effects

[pic]

Basic Principles of Transcription and Translation

Transcription

Translation

In prokaryotes

In eukaryotes

Transcription: Synthesis of an RNA Transcript

Stages:

1.Initiation

2.Elongation:

RNA pol

pries the DNA strands apart

hooks together the RNA nucleotides

3. Termination

RNA Polymerase Binding and Initiation of Transcription

Promoters

Transcription factors

Elongation of the RNA Strand

Termination of Transcription

RNA Processing

Modify Transcript to form mRNA

Cap & polyA Tail

Splicing Remove introns & join exons

Proteins often have a modular architecture: Different exons => different domains

Splicing: Evolutionary Significance

Consisting of discrete structural and functional regions called domains

in a protein

Translation

The basic concept

Three phases:

Initiation

Elongation

Termination

Translation: Nucleotide Sequence to Amino Acid Sequence

Transcription

Translation

The Genetic Code

mRNAcodon

tRNA

specific amino acid

specific anticodon

Ribosomes

tRNA anticodons with mRNA codons Form peptide bond between amino acids

3 Binding sites for tRNA: A, P & E

Building a Polypeptide

Translation three stages Initiation Elongation Termination

Ribosome Association and Initiation of Translation

Elongation of the Polypeptide Chain

Termination of Translation

Completing and Targeting the Functional Protein

Two populations of ribosomes in cells

Free ribosomes in the cytosol

Ribosomes bound to ER membrane

Mutations

Point mutations

Two general categories

Spontaneous mutations: Can occur during DNA replication, recombination, or repair

Mutagens: physical or chemical agents that can cause mutations

................
................

In order to avoid copyright disputes, this page is only a partial summary.

Google Online Preview   Download