Transcription and Translation

1
Transcription and Translation Recall that we
previously covered the final section on the RNA
world
Questions in this chapter you should be able to
answer Chapter 7- s 2, 3, 4, 5, 7, 8, 9, 10,
13, 14, 16A,C,D, 17
Virtual Cell Animation
2
What is the pathway from DNA to Protein?
3
What are the key events during transcription?
Question 7-2 In what direction are the RNA
polymerases moving in this image? Explain how
you can tell.
RNA polymerase Jmol model
7.2 transcription.mov video
4
What are promoters and terminators?
TATA binding protein Jmol model
Virtual Cell Animation
5
Which strand carries the coding sequence?
Question From an evolutionary perspective, why
dont overlapping genes occur?
6
What happens to mRNA after (as) it is transcribed?
7
What is the nature of 5 capping and poly-A
adenylation?
(250)
Poly-A tail protects against RNAse (function is
sort of like a telomere)
8
How does RNA processing occur? snRNPs and
spliceosomes
7.3 RNA splicing mechanism
Virtual Cell Animation
9
Is an mRNA always processed in the same way? --
alternative splicing
Question Will counting the number of promoters
yield the number of genes in the human genome?
10
How do mRNAs get to the cytosol?
Why do eukaryotes have DNA within a membrane
bound compartment and prokaryotes do not? Could
eukaryotes function without it?
Figure 15-8
11
How is RNA used to produce a protein? --
translation
7.5 Translation 1.mov
A polysome
7.7 polyribosome.mov
12
What is the structure of tRNAs? How many tRNAs
are needed to translate all the codons? -- 48
in humans -- wobble allows some to fit 2 or
more codons How is the correct reading frame
identified?
tRNA Jmol model
AGGCAAGCAUGCACGC
13
How is an amino acid coupled to a tRNA? --
charging of a tRNA
Question? When does translation of the genetic
code actually occur, during the charging of the
tRNA synthetases or during the binding of tRNAs
to the ribosome?
14
What is the structure of the ribosome? What
are the functions of the A, P E sites?
Ribosome Jmol model
15
How is translation initiated? In which
orientation does translation occur? What are
roles of the initiator factors initiator
tRNA What triggers binding of the large
subunit?
16
How does elongation proceed? Which end of the
protein is produced first?
7.8 Ribosome elongation
17
How is translation terminated?