Topic L. Coordination of Cell Processes Flashcards
What is competitive inhibition?
a molecule competes with the substrate for binding to the enzyme’s active site
What is non(competitive) allosteric inhibitions?
a molecule binds to an allosteric site, changing the shape of the enzyme and increasing or decreasing activity
Name three types of covalent modifications that regulates protein activity
- phosphorylation
- methylation
- acetylation
How do alternative sigma factors regulate gene expression?
they recognize different sequences to regulate specific functions, often during stress or environmental change
What are some ways in which cells regulate protein concentration?
- altering RNA topology
- promoter recognition, transcription
What role does transcriptional regression play in protein regulation?
it inhibits the transcription of a specific gene, lowering the production of corresponding proteins
What happens to the lac operon when no lactose is present?
LacI binds to the operator, preventing expressions of the operon
What is the role of allolactose in the lac operon?
Allolactose binds to Lacpreventing it from repressing the operon thus allowing transcription when lactose is present
How does CRIP-cAMP enhance the lac operon’s expression?
CRP-cAMP binds near the promoter and enhances RNA polymerase binding when glucose is intense
What is feedback inhibition?
a regulatory mechanism where the product of a pathway inhibits an earlier enzyme, preventing excess production of the product
