RNA and Protein Synthesis

I. Introduction and Review

protein?

DNA?

location?

A. Fundamental Questions

II. The Role of RNA

A. What are the types of RNA? (snRNA-small nuclear)

1. mRNA

-long polymer of ribonucleotides (chemical linking bond?)

-single-stranded

-copy of single DNA strand

-uracil (U) for thymine (T)

from: http://images2.clinicaltools.com/images/gene/dna_versus_rna_reversed.jpg

How is RNA copied from DNA?

-process called transcription

-specific part of DNA is copied called a transcription unit (TU) (analogous to a gene)

-beginning point (promoter) and ending point (terminator sequence)

-RNA polymerase

Not all information in a TU copied in transcription codes for a protein

     -introns and exons

exon shuffling; How can 30,000 genes (TU's) in the human genome code for 100,000 different types of RNA?

animation

How does the mRNA get from the nucleus to the cytoplasm?

-covalent modifications

-5' end is 'capped'

-3' end is 'tailed' with polyA

-linear form becomes a curved fiber that exits through a nuclear pore

How is information stored in RNA?

from: http://www.blc.arizona.edu/INTERACTIVE/DNA3/code.html

 

DNA sequence

TAC

ATG

CAC

GTG

GTG

CAC

GAC

CTG

TGA

ACT

GGA

CCT

CTC

GAG

CTC

GAG

ACT

TGA

mRNA sequence

AUG

GUG

CAC

CUG

ACU

CCU

GAG

GAG

UGA

Amino acid sequence

met

val

his

leu

thr

pro

glu

glu

stop

 

2. tRNA

3. rRNA

from: http://www.csu.edu.au/faculty/health/biomed/subjects/molbol/images/7_25.jpg

III. Protein Synthesis (Translation)

A. What are the "players" in translation?

B.   translation translation1 translation2

from: http://library.thinkquest.org/C0123260/basic%20knowledge/images/basic%20knowledge/RNA/translation%20steps.jpg

1. Initiation

2. Elongation

3. Termination

C. Is energy (ATP) required for protein synthesis?

IV. Summary