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?
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
1. Initiation
2. Elongation
3. Termination
C. Is energy (ATP) required for protein synthesis?
IV. Summary
