Study Guide: transcription, translation and gene regulation

Here is a long list of questions and topics that we have covered since the last exam. These questions may help you refresh your memory on what we covered.

To practice applying these concepts, do some of the extra problems from the book that were not assigned.

Transcription

Remind yourself of the general structure of RNA

Know the four types of RNA

Be able to identify the template strand and the coding strand. Which matches the RNA? Which is copied? Which way does synthesis go?

Understand the initiation signals used by prokaryotes and eukaryotes

How do they help initiate transcription?

Understand the basic mechanism of elongation ("transcription bubble")

Know the various ways prokaryotes and eukaryotes terminate transcription

RNA processing (in eukaryotes only)

Capping, splicing, polyadenylation

What is an intron vs an exon?

How are introns spliced out?

What is alternative splicing?

Translation

What is a ribosome and how does it work?

In which direction is the RNA copied?

You should know the basic structure of a polypeptide

What do we mean by a charged tRNA? How does a tRNA recognize its correct amino acid?

How is translation initiated? Terminated?

Genetic code:

How does the code work? How can you tell it consists of triplets?

What is redundancy? wobble?

How is the DNA code translated to amino acids?

You don't need to memorize all of the codons, but you should recognize start and stop codons and be able to use the codon table to translate a strand of mRNA.

Regulation in prokarykotes:

What is an operon?

You should understand the various units of the lac and trp operons and how those units work together.

Why aren't lac genes transcribed when lactose is absent?

Why aren't lac genes transcribed when glucsose is present?

What are partial diploids? How are they used to determine the interactions among parts of the lac operon?

You should be able to predict the phenotypes of various partial diploid genotypes.

You should understand the difference between cis and trans effects of genes

What is attenuation in the trp operon? How does is work?

Regulation in Phage Lambda:
You should know the broad outline for how the cell determines whether to enter the lytic or lysogenic life cycle (i.e. the principles involved and a couple of examples)

(It may be the simplest example of genetics of development)

Gene regulation in eukaryotes:

You should know the general similarities and differences in gene regulation between prokaryotes and eukaryotes

What are enhancers? Promoters? transcription factors?

What is combinatorial control?

How does the structure of chromatin affect transcription?

How is that controlled?

How do steroid homones vs polypeptide hormones control gene expression?

Drosophila development

Concentrate on the general principles: formation of gradients, signaling cascades, feedback loops and combinatorial control of expression

Understand the various genes as examples of those principles

Major developmental genes are usually transcription factors, the control the expresson of genes later in development

Have some familiarity with the major classes of Drosophila development genes: maternal effects, gap genes, pair-rule genes, and how they interact

Be familiar with homeotic genes and some of the specific examples.