Path from Gene to Protein
1. What is the one
gene - one polypeptide hypothesis?
Discuss the early experimental evidence (the work of Beadle and Tatum)
that supported this hypothesis.
2. Review the
structure of RNA. How is
it different from that of DNA?
3. How are genes
transcribed into a mRNA transcript?
- Discuss the various functions of the proteins and enzymes (transcription
factors, RNA polymerases) involved in transcription.
In
what direction does RNA transcription occur (i.e. 5’ to 3’ or 3’ to 5’
on the growing transcript)?
- How does transcription differ from DNA replication? How are
they
similar?
- What are the functions of various DNA sequences that regulate
transcription
(promoters, enhancers, terminators)?
4. What
modifications must the primary mRNA transcript
undergo before it can be translated?
- Discuss the significance of alterations to the ends of the mRNA
transcript
(capping and addition of a poly(A) tail).
- Discuss RNA splicing (intron removal and splicing
together
of exons).
- What is the function of the mature mRNA transcript?
5. Describe the nature of the genetic
code.
- What is a codon? How are codons that code for the
same
amino
acid different/similar? What is the function of codons that don’t
code for any amino acids?
- Discuss some of the classic experiments which led to an
understanding
of
the nature of the code and the "meaning" of individual codons.
- What is the significance of the nearly universal nature to the
genetic
code amongst all living organisms?
6. Describe the
process of translation.
- Describe the structure of a ribosome and tRNA as
they
relate
to translation. What is an anticodon?
- How are ribosomes, tRNA, and aminoacyl-tRNA synthetase
used to
assemble
amino acids into proteins?
- How is translation initiated? Describe chain elongation and
termination
of transcription.
- What is a polyribosome?
- How does translation of polypeptides destined for secretion from
the
cell
or for inclusion into endomembrane organelles differ from translation
of
polypeptides destined for use in the cytosol?
7. Describe the
general characteristics of mutations.
- How do point mutations occur?
- How are substitution mutations different from insertion
or deletion mutations? What is meant by a frame shift
mutation?
What are some possible effects of these mutations on the protein
product
of a gene?
- What is a mutagen?