cell structure Flashcards
structure of cell surface membrane?
surface of animal cells
in cell wall of plant + prokaryotic cells
made of lipids + proteins
function of cell surface membrane?
regulates movement of substances in + out cell
receptor molecules - respond to chemicals
structure of cell wall?
rigid
made of cellulose
structure of nucleus?
nuclear envelope - double membrane + pores
chromatin - made of DNA + proteins
nucleolus
function of nucleus?
DNA -instructions to make proteins
pores - allow movement between cytoplasm + nucleus
nucleolus - makes ribosomes
structure of lysosome?
membrane bound
no internal structure
function of lysosome?
digestive enzymes - digest invading cells / break down worn out parts of cell
structure of ribosome?
floats free
attached to RER
made of proteins + RNA
no membrane
structure of RER?
system of membranes
fluid filled space
surface covered with ribosomes
function of RER?
folds + processes proteins
structure of SER?
same as RER
no ribosomes
structure of vesicle?
fluid filled sac
membrane bound
function of vesicle?
transports substances in + out cell
structure of golgi apparatus?
fluid filled flattened sacs
membrane bound
vesicles at edges
function of golgi apparatus?
processes + packages lipids / proteins
makes lysosomes
structure of mitchondrion?
double membrane
inner folds - cristae
inside cristae - matrix ( enzymes for respiration )
function of mitchondrion?
site of aerobic respiration
site of ATP production
require energy
structure of chloroplast?
flattened structure
double membrane
thylakoid membranes - stack up - grana
grana linked by lamellae - thin pieces of thylakoid
structure of centriole?
hollow cyclinders from microtubules
( protein cyclinders )
function of centriole?
involved in separation of chromosomes
structure of cilia?
cross section - outer membrane + ring of 9 pairs of microtubules
inside ring - 2 microtubules in centre
function of cilia?
microtubules allow movement for susbtances
structure of flagellum?
stick out cell surface
membrane bound
2 pairs of microtubules in centre
9 microtubules edge
function of flagellum?
microtubules contract - movement
where are proteins made?
ribosomes
what proteins do the ribosomes on RER make?
the proteins attached to cell membrane
what proteins do the free ribosomes in cytoplasm make?
the proteins that stay in cytoplasm
what happens to the new proteins produced at RER?
are folded + processed
where are the new proteins transported to?
golgi apparatus in vesicles
what happens to the proteins at the golgi apparatus?
further processing + enter more vesicles to be transported around cells
what is the cytoskeleton?
network of proteins threads running through cytoplasm
4 functions of cytoskeleton?
1) microtubules + microfilaments support cells’s organlles
2) strengthen + maintain cell shape
3) responsible for movement of materials
4) proteins cause movement - cilia + flagella from cytoskeleton protein filaments
what does it mean by the cytoskeleton is dynamic?
constantly changing to allow response to changes in cell
5 differences between eukaryotic + prokaryotic cells?
eukaryotic:
larger
linear DNA
nucleus
cellulose cell wall
flagella made of microtubules
prokaryotic:
smaller
circular DNA
polysaccharide cell wall
flagella made of protein flagellin
what type of cell is bacteria?
prokaryotic
what is the resolution and magnification of a light microscope?
resolution - 0.2 micrometres
magnification - x 1500
what does a light microscope view?
whole cells / tissues
how do laser scanning confocal microscopes work?
laser beam
tagged with fluroscent dye
light focused through pinhole on detector
what type of image does a laser scanning microscope produce?
3D
what does a laser scanning microscope view?
different depths in thick specimens
how do transmission electron micrscopes work?
electromagnets focus beams of electrons
transmitted through specimen
darker parts absorb more electrons
what do transmission electron microscopes view?
range of organelles
only thin specimens
how do scanning electron microscopes work?
scan beam of electrons
knocks off electrons from specimen
gather in cathode ray tube
what do scanning electron microscopes view?
surface of specimens
what type of image does a scanning electron microscope produce?
3D
lower resolution than TEM
what are the 2 common stains for light microscopes + their functions?
methylene blue - stains DNA
eosin - stains cell cytoplasms
why are different stains used in light microscopes?
they show different things
how are samples stained for electron microscopes?
objects dipped in solution of heavy metals
metal ions scatter electrons - contrast
how do you prepare a dry mount?
thin slice
tweezers, specimen in centre of slide
cover slip
how do you prepare a wet mount?
drop of water on slide
tweezers, specimen
stand cover slip upright on slide + tilt
drop of stain next to 1 edge of cover slip
paper towel on opposite edge
stain gets drawn under slip
what is an eyepiece graticule?
transparent ruler fitted onto eyepiece
what is a stage micrometre?
microscopic slide with accurate scale
