Unit 4: Cell Communication and Cell Cycle Unknown Info (AP Biology 2026) Flashcards

the movement of an organism in response to a stimulus

towards a stimulus

away from a stimulus

the movement in response to chemicals (e.g. bacteria with flagella away from repellants or to nicer locations, neutrophils in humans with infection)

affects only nearby cells

affects cells throughout the organism

signaling molecules that bind to receptors to trigger a response by changing the shape of the receptor protein

receptor that opens or closes an ion channel upon binding with a particular ligand

on skeletal muscle cells that open with acetylcholine; when sodium depolarizes muscle cells they contract

enzymatic active site on cytoplasmic side of membrane (e.g. insulin receptors)

no act as an enzyme, binds to GTP or GDP on intracellular side when a ligand is bound extracellularly

cAMP hunger signal activates the secondary messengers of epinephrine and glucagon

series of protein kinases add a phosphate group to the next protein in a cascade sequence, helps amplify signal, quickly turn response on or off

usually a simpler two-component regulatory system in transduction pathways

cell's phenotype, apoptosis, mutations in receptor or ligand, drugs / chemicals inhibit or excite parts of pathway

when a metabolic reaction turns itself off using its own end product

signals in response to environmental stimuli, light receptors, chemical communication, between plants

often highly specialized cells created from a population of less specialized cells

enter G0 phase, where they stay until they get a signal to reenter the normal cell cycle

an orderly sequence of events that extends from when 2 daughter cells form to when they divide again

majority of cell cycle, metabolic activity = very high, chromosomes duplicated in S phase

before DNA synthesis begins, enzymes for S phase made (i.e. DNA helicase, DNA polymerase, DNA ligase), regular activity resumes, increased protein / organelle

main part of chromosome duplication, DNA copied into sister chromatids

DNA synthesis completion, prepare for cell division, protein synth increased for proteins needed for cell division

most dramatic appearance changes, PMAT and cytokinesis

frequently, constantly sloughed off = must be regenerated

only if damaged (cell division repairs wounds)

never

plant/animal cells must be anchored to a surface to divide (free-floating cells rarely divide)

cells multiply to form single layer and stop dividing when touch each other because of inadequate growth factor supply

secreted by certain body cells, stimulate cells nearby to divide (more densely packed cells = more use up growth factors = divide slower)

cyclically operating set of proteins in the cell that trigger and coordinate major cell cycle events, from environmental conditions outside cell or go signals inside cell

end of G1 (MOST IMPORTANT AS PREVENTS S PHASE) AND NON-DIVIDING STATE, end of G2 (prevents prophase / mitotic phase), metaphase (stops if not all chromosomes are attached to mitotic spindle on M plate)

bind to form a complex that causes the cell cycle to continue, regulated by checkpoints to control progression

cancer of external / internal body coverings (e.g. skin, intestinal lining)

cancer of supporting tissues (e.g. bone and muscle)

cancers of blood-forming tissues (e.g. bone marrow, spleen, lymph nodes)

mutated genes that induce cancer, normally for proper cells growth and CCCS, but convert normal cells into cancerous cells due to mutated genes

normal healthy version of a gene

produce proteins that prevent the conversion of normal cells into cancer cells, detect damage in the cell, use CDK / cyclin complexes to stop cell growth until damage repaired

oncogenes (speed up cycle), tumor suppressors (remove stop checkpoints)

antimitotic drugs disrupt cell division for whole body (vinblastine, taxol), fewer side effects

direct to tumor high-energy radiation that disrupts division