2.1.1 eukaryotic cell Flashcards
(19 cards)
describe structure + function of the cell membrane
separated cytoplasm form external environment
made of phospholipids, carbs., cholesterol, proteins
selectively permeable
control entry + exit of substances
compartmentalisation of reac.
fluid mosaic model
describe structure + function of nucleus
largest organelle
contains chromatin = DNA + histones
forms chromosomes
nuclear envelope = double mem.
membrane = nuclear pores; entry + exit of mols
involved in transcription stage of protein synthesis (mRNA)
describe structure + function of nucleolus
responsible for ribosome production
made of proteins + RNA
produces rRNA = combones w/ proteins = ribosomes!
describe structure + function of mitochondria
site of cellular respiration
produce ATP
membrane = envelope
inner membrane = cristae; highly folded; contains respiratory enzymes
fluid = matrix
contains mtDNA = can reproduce + make enzymes
describe structure + function of lysosomes
vesicle containing hydrolytic enzymes
breaks down waste materials, pathogens (phagocytosis)
responsible for apoptosis
describe structure + function of cytoskeleton
network of fibres; needed for shape + stability
controls cell + organelle movement
made of microfilaments, microtubules, + intermediate fibres
explain the function of the components of the cytoskeleton
microfilaments = contractile fibres made of actin; cell movement + contraction (cytokinesis)
microtubules = globular tubulin; determine cell shape; tracks for movement of organelles
intermediate filaments = mechanical strength + maintain cell intergrity
describe structure + function of centrioles
hollow cylinders; ring of microtubules arranged at right angles
part of CS (not in flowering plants + fungi)
2 centrioles = centrisome; assembles + organizes spindle fibres
describe structure + function of flagella
whip like structure
enables cell mobility
can be sensory organelle = detect chemical changes
9+2 arrangement
describe structure + function of cilia
hair like structures
mobile = beat in rhythmic manner; move fluid + objects near cells (mucus or eggs)
stationary = sensory organelle on cell surface
9+2 arrangement
explain the 9+2 arrangement
2 central microtubules surrounded by 9 pairs of microtubules
pairs of MT slide over each other = beating
describe structure + function of RER
made of cisternae
had ribosomes on outer surface
synthesise + transport proteins
continous w/ nuclear envelope
describe structure + function of SER
made of cisternae
synthesise and store lipids + carbohydrates
continuous w/ nuclear envelope
describe structure + function of ribosomes
site of translation during protein synthesis
can be 70S or 80S
free floating or attached to RER
NOT membrane bound
describe structure + function of golgi apparatus
made of cisternae
contains no ribosomes
modifies + packages proteins into vesicles
secretory vesicle = exit cell
make lysosomes
describe structure + function of cellulose cell wall
surrounds cell wall
made of cellulose; embedded in pectins
freely permeable
gives structure + rigidity; contents of cell press against it
protective layer; hard to digest
some have lignin = extra protection and slightly impermeable
describe structure + function of vacuoles
membrane bound sacs
contains cell sap containing sugars, amino acids, proteins, waste products
can contain pigments = give cell colour
maintains turgor
membrane = tonoplast; selectively permeable
describe structure + function of chloroplast
responsible for photosynthesis; in stems and leaves
membrane = envelope
fluid = stroma
internal structure of thylakoids; stack together to make granum
= site of light dependant reac.
grana joined by lamellae
starch produced = starch grains
contain DNA + ribosomes
what is the endosymbiont theory
theory that chloroplast + mitochondria evolved from prokaryotes
cell were initially simple
