Question

1) Bacteria respond to changes in their environments, such as nutrient availability, by regulating their metabolic pathways. Describe two mechanisms that bacteria use in order to adapt to environmental changes. Include in your answer which mechanism is a short-term or long-term adaptation. (Pg. 364, paragraph 3, sentence 2; paragraph 4, sentence 1)

Answer 1

Examples:

- Short-term adaptation: feedback inhibition

- Long-term adaptation: regulation of gene expression

Step-by-step explanation:

Feedback inhibition is a mechanism where the product of a chemical reaction is utilized to modulate its own subsequent synthesis. In bacteria, feedback inhibition allows regulating different metabolic pathways in response to environmental conditions by modulating enzyme activity through enzyme reaction products. Moreover, bacteria may also respond to environmental inputs by long-term changes in gene expression. For example, bacteria contain transcription factors activated during stress, which are able to activate the transcription of particular genes into messenger RNAs (mRNAs) that would subsequently be used to generate particular enzymes by the process of translation. These transcription factors may bind to specific DNA motifs in order to promote transcriptional activity, thereby regulating the production of the corresponding enzyme.