BIOLOGY 1A03 Lecture Notes - Lecture 1: Galactose, Growth Medium, Start Codon

• School: McMaster University
• Department: Biology
• Course: BIOLOGY 1A03
• Professor: Rosa Da Silva

Document Summary

Describe the differences between constitutive and regulated gene expression. Examine how a response to an environmental change can lead to changes in gene regulation. Identify the levels at which gene expression can be regulated. A nutrient-rich environment containing amino acids and carbohydrates. The dna of bacteria is contained in a circular chromosome, folded into many loops. Bacteria often have small circles of additional dna called plasmids. Bacteria have both a plasma membrane and a cell wall. Regulated genes are expressed only when needed. Important when we consider that cells must be able to metabolize macromolecules such as carbohydrates into usable sources of cellular fuel (atp) Glucose is the carbohydrate that is the preferred energy source of e. coli. If we expose a bacterial culture to only a limited amount of glucose, we will find that once the glucose is used up, bacterial growth is arrested. Changes in cell behaviour the glucose effect.