Bio Biochem exam III review

Inducible Operons

A type of operon that is normally off but can be turned on in response to specific signals, allowing the transcription of genes for enzymes needed to metabolize certain substrates. Usually have a repressor bound that must be removed

Repressible Operons

A type of operon that is normally on but can be turned off in response to specific signals, often involving the binding of a corepressor to a repressor, preventing transcription of genes.

cAMP

A secondary messenger molecule in cells that is produced from ATP and plays a crucial role in signaling pathways, particularly in regulating gene expression in response to external signals.

Adenylyl Cyclase

An enzyme that catalyzes the conversion of ATP to cyclic AMP (cAMP), playing a key role in the signaling pathways that regulate various physiological processes.

Gs Pathway

A signaling pathway that involves the activation of G protein-coupled receptors, leading to the stimulation of adenylyl cyclase and an increase in cAMP levels, ultimately affecting downstream cellular responses.

Gq Pathway

A signaling pathway that activates phospholipase C, leading to the production of inositol trisphosphate (IP3) and diacylglycerol (DAG), which stimulate calcium release and protein kinase C activation, respectively.

Acetylcholine

A neurotransmitter involved in muscle contraction and various functions in the central and peripheral nervous systems. It plays a key role in transmitting signals across synapses.

Competitive Inhibitor

A substance that binds to the active site of an enzyme, competing with the substrate and reducing the rate of enzymatic reactions. Km increases and Vmax stays the same

Noncompetitive Inhibitor

A type of enzyme inhibitor that binds to an enzyme regardless of whether the substrate is bound, reducing the overall number of active enzyme molecules and decreasing the reaction rate without affecting substrate binding. Vmax decreases and Km stays the same (not usually observed in nature since truly equal affinity is impossible)

Mixed Inhibitor

An enzyme inhibitor that can bind to either the enzyme alone or the enzyme-substrate complex. It decreases Vmax and can either increase or decrease Km depending on the relative affinities for the enzyme and complex.

Uncompetitive Inhibitor

An enzyme inhibitor that only binds to the enzyme-substrate complex, resulting in a decrease in both Vmax and Km. This type of inhibition is characterized by its ability to prevent the complex from converting to product.

Missense Mutation

A type of genetic mutation where a single nucleotide change results in the substitution of one amino acid for another in the resulting protein. This can lead to alterations in protein function and stability.

Nonsense

mutation that introduces a premature stop codon in the protein sequence, leading to a truncated and often nonfunctional protein.