Cell Biology Review

These flashcards cover essential vocabulary related to cell biology, particularly focusing on the processes of membrane transport, cellular respiration, and gene expression.

Selective Permeability

The property of a membrane that allows certain substances to diffuse across it more easily than others.

Diffusion

Spontaneous movement of a substance from a region of high concentration to low concentration.

Facilitated Diffusion

Diffusion across a concentration gradient with the help of transport proteins and channels.

Active Transport

The movement of ions or molecules across a membrane in a single direction against a concentration gradient, requiring energy.

Passive Transport

The diffusion of a substance down a concentration gradient without the need for energy.

Osmosis

Diffusion of water across a selectively permeable membrane from a region of low solute concentration to a region of high solute concentration.

Hypertonic

A solution that has a high solute concentration relative to another solution.

Hypotonic

A solution that has a lower solute concentration relative to another solution.

Isotonic

A solution that has the same solute concentration as another solution.

Exocytosis

The process of secreting materials from a cell by vesicles fusing with the plasma membrane.

Endocytosis

The process where cells engulf external material, forming vesicles to bring the material within.

Integral Proteins

Membrane proteins that span the entire lipid bilayer.

Peripheral Proteins

Proteins that only bind to one side of the lipid bilayer.

Gated Channel

A channel protein that opens and closes in response to specific stimuli.

Carrier Protein

A transport protein that facilitates the diffusion of small molecules across a membrane.

Gradient

A difference in solute concentrations across a selectively permeable membrane.

Channel Protein

A type of transport protein that allows specific ions or molecules to cross membranes.

Citric Acid Cycle

A series of enzyme-catalyzed chemical reactions that form part of cellular respiration, producing ATP and electron carriers.

Electron Transport Chain

A series of protein complexes that transfer electrons and create a proton gradient for ATP synthesis.

ATP Synthase

An enzyme that synthesizes ATP from ADP and inorganic phosphate using the proton gradient.

Lactic Acid Fermentation

A metabolic process that converts glucose into lactic acid and regenerates NAD+ under anaerobic conditions.

Alcohol Fermentation

A metabolic process that converts glucose into ethanol and carbon dioxide, regenerating NAD+.

Telomere

The repetitive nucleotide sequences at the ends of linear chromosomes that protect them from deterioration.

Telomerase

An enzyme that adds nucleotides to the ends of telomeres, preventing their shortening during DNA replication.

RNA Interference (RNAi)

A biological process in which RNA molecules inhibit gene expression or translation by destroying specific mRNA molecules.

Chromatin

The complex of DNA and proteins that makes up chromosomes in eukaryotic cells.

Promoter

A DNA sequence that initiates transcription of a particular gene.

Euchromatin

A less condensed form of chromatin that is accessible for transcription.

Heterochromatin

A densely packed form of chromatin that is not usually transcribed.

Point Mutation

A change in a single nucleotide base pair in a DNA sequence.

Missense Mutation

A point mutation that results in the substitution of one amino acid for another in the resulting protein.

Nonsense Mutation

A mutation that creates a premature stop codon in the DNA sequence, leading to a truncated protein.

Frameshift Mutation

A mutation that shifts the reading frame of the genetic message by inserting or deleting a nucleotide.

Gene Regulation

The process by which cells control the expression of genes to respond to changes in their environment.