Daily Newsletter April 2, 2012
Today's Topic: Gene Regulation
Suggested Reading - Operons and Prokaryotic Gene Regulation
Do we express all of our genes at the same time? Why?
Do we need all of our genes expressed all the time? Why?
Why do we have so many genes?
These are just a few of the questions you need to start asking yourself. Humans have hundreds of thousands of genes. Many are needed all the time (constitutive), but others are only needed when the cell get's certain signals.
During mitosis, for example, did you see the production of DNA polymerase and the replication complex during the start of G1, or did you only see it after you passed the first restriction point? Do we keep DNA polymerase around just in case we are going to do some nuclear division?
Consider: The first restriction point determines if you are going to prep for division. When you have enough cyclin-dependent kinase available, you pass the restriction point. CDK signals the cell to get ready for division. How does this signal work? It changes gene expression (i.e., we activate regulated genes).
Think about the human body and homeostasis. Think about hormones. Are you always producing everything, or do you need to trigger some events? Could that trigger then be a regulated gene?
Today, your goal is to reflect on why some genes are regulated and some are constitutionally produced.
Daily Challenge: Why do we need gene regulation? Today, reflect on the need and use of gene regulation. Why would an organism need to have some genes that it could turn on or off? Why would you need to control gene expression? Can gene regulation affect evolution?
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