Mutations and Molecular Biology Concepts

This set of flashcards covers key vocabulary and concepts related to mutations, protein function, and cell signaling mechanisms in molecular biology.

Mutation

A change in the DNA sequence that can alter gene function.

Null allele

An allele that results in a nonfunctional protein, often due to a mutation that leads to an amorph.

Hypomorph allele

An allele that produces a functional protein, but with reduced activity compared to the wild type.

Nonsense mutation

A mutation that changes a codon encoding an amino acid into a stop codon, leading to truncated proteins.

Silent mutation

A mutation that does not change the amino acid sequence of a protein despite a change in the DNA sequence.

Frameshift mutation

A mutation caused by the insertion or deletion of nucleotides that alters the reading frame of the gene.

Active transport

The movement of molecules across a cell membrane against their concentration gradient, requiring energy.

Endocytosis

The process of taking material into the cell by engulfing it with the cell membrane.

Second messengers

Small molecules that propagate a signal within the cell after the initial receptor-ligand interaction.

Adenylyl Cyclase (AC)

An effector enzyme activated by GPCRs that converts ATP to cAMP, a second messenger.

Signal amplification

A process where one signaling molecule leads to the activation of multiple downstream molecules.

Effector enzyme

An enzyme in a signaling pathway that mediates the cellular response to a signal.

Receptor specificity

The unique ability of receptors to bind specific ligands due to their chemical properties.

Endocytosis

The process in which cells internalize materials by engulfing them in membrane-bound vesicles.

Vasoconstriction

The narrowing of blood vessels resulting from the contraction of their muscular walls.

Phosphorylation cascade

A series of chemical reactions during which enzymes transfer phosphate groups to proteins, often amplifying a signal.