2.1.1 cell structures Flashcards
Plasma membrane
phospholipid bilayer that controls movement of substances in/out
found in all eukaryotic cells
Cellulose cell wall
a cell wall made of cellulose that provides strength and support
found in plant cells
Peptidoglycan cell wall and where it is found
a cell wall made of peptidoglycan that provides rigidity
found in prokaryotic cells
Nucleus
organelle containing DNA
surrounded by the nuclear envelope covered in nuclear pores
contains a nucleolus that makes ribosomes
found in all eukaryotic cells (except erythrocytes)
cytoskeleton
network of fibres within cytoplasm, made of microtubules and microfilaments
Mitochondria
double bound by an envelope
folds in membrane called cristae with matrix inside to act as the site of aerobic respiration
found in all eukaryotic cells
Ribosome
bound by a single membrane and contains digestive enzymes for protein synthesis
80s in eukaryotic cells
70s in prokaryotic cells
Cytoplasm
site of all chemical reactions
found in all cells
Vacuole
sac filled with water, nutrients and waste products to add rigidity
found in plant cells
Chloroplast
double membrane bound sacs containing stroma for photosynthesis
has internal thylakoid membranes arranged in stacks to form grana linked by lamellae
found in plant cells
Golgi apparatus
modifies and packages lipids and proteins into vesicles and produces lysosomes
found in all eukaryotic cells (except erythrocytes)
Smooth endoplasmic reticulum
produces and processes lipids
found in all eukaryotic cells (except erythrocytes)
Rough endoplasmic reticulum
covered in ribosomes and folds and processes proteins
found in all eukaryotic cells (except erythrocytes)
Lysosome
vesicles full of digestive enzymes bound by a single membrane
found in animal cells
Centriole
hollow ring of microtubules in a cylinder that is used in cell division to form spindle fibre
occurs in pairs to form centrosome
found in animal cells
Circular DNA
contains genetic info
found in prokaryotic cells
Mesosome
folds in the cell wall that produces ATP
found in prokaryotic cells
Potential features of prokaryotic cells
flagellum
pili
plasmid
nucleoid
slime capsule
What is magnification
degree to which the size of the image is larger than the size of the object
What is resolution
degree to which you can distinguish between two very close points
What is the equation for magnification
magnification = image size / actual size
what are the features of a light microscope
cheap
poor resolution - long wavelength of light
can view live specimens
requires staining
what are the features of all electron microscopes
expensive
can only view dead specimens
requires metal salts
high resolution
what image does a transmission electron microscope produce
2D image of the inside of a cell
what image does a scanning electron microscope produce
3D image of the outside surface of a cell
what is the stain for DNA and what colour is it
acetic orcein
dark red
what is the stain for the cytoplasm and what colour is it
eosin
pink
what is the stain for lipids and what colour is it
sudan red
red
what is the stain for starch and what colour is it
iodine
blue/black
what is the stain for the nucleus and what colour is it
nile blue
blue
what are the steps for gram staining gram positive bacteria
apply crystal violet stain
fix dye with iodine
it will appear blue due to thick peptidoglycan cell wall
what are the steps for gram staining gram negative bacteria
apply crystal violet stain
fix dye with iodine
colour won’t change
wash off with alcohol
add safranin which stains it pink
what are the functions of the cytoskeleton
allows movement of and around cells and maintains cell shape
what are microfilaments
made of actin
cell movement and contraction
what are microtubules
made of tubulin
determine cell shape and structure
what are vesicles
move along microtubules by using motor proteins
describe the process of protein synthesis and secretion
DNA is converted into mRNA by transcription
mRNA leaves the nucleus through the nuclear pores
mRNA is processed by the RER and attaches to a ribosome to become a protein by translation
it leaves the RER in a vesicle
it is modified in the golgi and leaves via another vesicle
it fuses with the plasma membrane and leaves via exocytosis
Eyepiece graticule calibration
Each division of the stage micrometer is 0.1 mm
Each division of the graticule is on a scale from 0 to 100
See how many graticule divisions correspond to one stage micrometer division
Divide by amount of graticule divisions to get what one EPGU equals
How do you convert mm into micrometers
x1000
