类别 全部 - ribosomes - transcription - gene - dna

作者:Aaron Gonzalez 3 年以前

144

Concept Map 3

The process of gene expression involves several intricate steps beginning with the transcription of DNA into RNA. Transcription, regulated by various elements such as promoters, enhancers, and silencers, is crucial for determining which genes are expressed and when.

Concept Map 3

Floating topic

Ribosomes ->(Ribosomes)

Phosphate group

Pentose Sugar (Deoxyribose

Structure of DNA

DNA

Nucleotides
Base

Adenine

Thymine

Guanine

Cytosine

Transcription

elements and specific transcription factors

Coordinately controlled genes
Eukaryotic form of operon model

Transcription Elements

Combinatorial control of gene expression
Variation in types of numbers of control
Control Elements
Distal

repressors are binded by silencers

decreased rate of transcription

enhancers

bind activators

increased of transcription

Promoter + TATA box

Bind General transcription factors

Change in structure of DNA (Packing)
Modification of chromatin structure

Level of Genetic Code

Gene amplification
Increase in number of copies of genes

DNA ->

Transcription ->
(RNA synthesis)->

mRNA->

Transcription level

3' poly-A-tail
5' 7 methylguasnosine cap
Recognition of mature mRNA by ribosomes
Editing of mature mRNA
Modifying of nucleotide sequences
spilcing
Enables alternative splicing of mRNA
splicing together of exons
splicing of introns
3' Pre-mRNA becomes Mature RNA
Subtopic

Stages of Transcription

RNA polymerase II- pre mRNA - EUkaryotes
RNA polymerase (RNAP)- Prokaryotes
Acomplished by RNA polymerase

Translation

Includes

Initiation
Start codon (AUG)
Elongation
Movement of tRNA from A site to P site

the polypeptide chain grows

Termination
Stop codon is reached

Involves

tRNA

anticodon

amino acid attached to 3' end

synthase

Is

clover shaped

Short

Translate multiple codons

wobble effect

Ribosomes
rRNA

Has

3 active sites

Are

P site

Growing polypeptide

E site

Exit site

A site

Amino acid

2 subunits Large and Small