E. coli

Definition

Escherichia coli (E. coli) is a gram-negative, rod-shaped bacterium commonly found in the lower intestine of warm-blooded organisms. While most strains are harmless, some can cause serious food poisoning and infections.

5 Must Know Facts For Your Next Test

1. E. coli is often used as a model organism in microbiology to study DNA replication and protein synthesis.
2. Certain strains of E. coli, such as O157:H7, produce toxins that lead to severe foodborne illnesses.
3. E. coli can acquire genetic diversity through horizontal gene transfer mechanisms like transformation, transduction, and conjugation.
4. The lac operon in E. coli is a classic example of gene regulation studied under Operon Theory.
5. E. coli infections can be particularly dangerous for individuals with immunodeficiency.

Review Questions

• What mechanisms allow E. coli to achieve genetic diversity despite being asexual?
• How does the lac operon regulate gene expression in E. coli?
• Why are certain strains of E. coli more pathogenic than others?

Related terms

Horizontal Gene Transfer: The movement of genetic material between bacteria through mechanisms such as transformation, transduction, and conjugation.

Lac Operon: A set of genes in E. coli used to study gene regulation and metabolic control.

Immunodeficiency: A state in which the immune system's ability to fight infectious disease is compromised or entirely absent.