chapter 14 genetics reading

common processes regulated at the genetic level

1. metabolism (ex. enzymes are only required when sugar is present in their environment) 2. response to environmental stress (ex osmotic shock or heat shock) 3. cell division (proteins only necessary when cell is about to divide)

regulatory proteins:

bind to DNA and affect rate of transcription of 1 or more nearby genes

unregulated genes have ______ levels of expression and are also called _____ genes

constant; consititutive

what kind of genes encode proteins needed for bacterium survival?

constitutive genes

what is the benefit of gene regulation?

encoded proteins are produced only when they are required: cell avoids wasting valuable energy making proteins it doesnt need (efficient, important because bacteria exist in an environment that is frequently changing to temperature/nutrients/etc)

gebe regulation enhances efficiency in terms of ____

energy use

phenomenon on which the level of gene expression can vary under different conditions:

gene regulation

most common way to regulate gene expression?

influence initiation of transcription

what step does gene regulation occur at?

it can occur at any steps in gene expression

genes arent necessarily "turned on/off", a more accurate way to put it is:

level of gene expression is increased or decreased

repressor

regulatory protein, binds to DNA and inhibits transcription (negative control)

2 types of regulatory proteins

repressors and activators