Unit 4 Flashcards
Cell communication
cells can influence behaviors of other through signalling and receiving signals
Short distance cell communication
very short range w cells close together like neurotransmitters
Long distance cell communication
cells far from each other, communicate through bloodstream hormones
Target cell
the cell that is being communicated with from the cell at the far distance
Hormone
released into bloodstreams and elicits certain responses
Ligand
a signalling molecule that bonds to a receptor site of another molecule
Ligand gated cell receptor
basically a receptor where once the right molecule has bonded, the channel will open and allow molecules or ions to enter
Cell membrane receptor
proteins on the surface of cells to get signals from outside sources
Signal transduction pathway
a pathway of steps that creates cellular responses
Phosphorylation cascade
basically where one enzyme phosphorylates another and creates a chain
G protein-coupled receptor
ligand binds to gpcr and then it prompts signals and causes chain reaction in g proteins and messengers
Cellular response
any action that a cell takes after getting a signal
Second messenger
- small
- non protein & water soluble
- molecule or ion
relays signals to inside of cell from a receptor
cAMP
a secondary messenger made of ATP
Gene expression
when a gene turns on and makes rna and then a protein
Mutation
irregular change in nucleotide sequences of dna
Negative feedback
returns the system back to the target set point
ex. body temperature regulation by like sweating and shivering
reduces change
Positive feedback
amplifies responses and processes in organisms
amplifies change
Homeostasis
maintaining a stable body/internal environment
Cell cycle
basically just the life cycle of a cell
birth - growth - division
Interphase (G1, S, G2)
doctor
D - dna replication (s phase)
O - organelle duplication
C - cell growth
T - transcription/translation
O - obtain nutrients
R - respiration
Mitosis (prophase, metaphase, anaphase, telophase)
P - centriole and spindle fibers form
M - chromosomes line up in the middle and spinde fibers attach at center
A - chromosomes pulled apart and now each half is a daughter chromosome
T - nuclear envelope begins to form, cleavage forms
Cytokinesis
final part of mitosis where the cytoplasms and organelles actually divide too
Daughter cells
the created cells from mitosis
Diploid
full set of chromosomes -> 2n = 46
Haploid
half number of chromosomes -> n = 23
Polyploidy
genetics where people have more than two sets of chromosomes
Chromosome
tightly wound dna in the nucleus of the cell which has genetic info
Sister chromatids
are the exact same copies of each other
Centromere
the middle region of the chromosome where spindle fibers attach for metaphase
Centriole
at the poles of the cell where spindle fibers form and are used in cell division
Spindle fiber
used to pull chromosomes apart in anaphase
Nuclear division
the nucleus divides before the cell divides
Cell cycle checkpoints
G1 checkpoint - cell growth is happening properly, can stop growing now
G2 checkpoint - dna synthesis going good and cell growth continuing and being right
M checkpoint - spindle check point where meta to ana is checked
Cyclins
partner with cyclin dependent kinases to control progression of the cell cycle
Cyclin dependent kinases
Cancer
uncontrolled cell growth because of mutations
Apoptosis
programmed cell death where the cell kills itself, it is then digested
protects cells around it
paracrine signalling
local signalling through local regulators diffuse across to each other
think neurotransmitters
endocrine signalling
long distance, through bloodstream
kinases
add phophates
