chapter 2 Flashcards
what are the 8 things a bacteria cell has (prokaryotic)
pili
flagella
capsule
cell wall
cell membrane
DNA strand
plasmid
cytoplasm
what are the 11 things an animal cell has
cytoplasm
cell membrane
ribosome
RER
SER
nucleus
mitochondria
lysosome
centriole
cytoskeleton
golgi apparatus
what are the 11 things a plant cell has
mitochondria
chloroplasts
cell wall
cell membrane
vacuole
cytoplasm
ribosomes
SER
RER
nucleus
golgi apparatus
function of the nucleus
stores genetic information
controls cells activities
holds instructions to create proteins
nuclear pores on nuclear envelope allow for RNA to leave and enter
what is the function of a nucleolus
makes ribosomes
RNA is then used to make rRNA for protein synthesis
what is the function of a cell membrane
made of lipids and proteins (phospholipid layer)
regulates ins and outs of the cell
has receptors to respond to hormones/chemicals
what is the function of the chloroplast
small and flat
double membrane
granum are stacked to make grana which are linked by lamella
the stack of grana is called a thylakoid
where photosynthesis takes place (either in grana or stoma)
what is the function of mitochondria
site of aerobic respiration
ATP is produced
more active cells have more mitochondria
what is the structure of a mitochondria
has a double membrane
inner membrane folds on each other to form cristae
matrix is its ‘cytoplasm’
contains granules and ATP synthesis particles
what is the function of a ribosome
where proteins are made
made of rRNA and proteins
what is the structure of a ribosome
small
free in cytoplasm or connected to the RER
no membrane
80s in eukaryotic cells for complex proteins
70s in prokaryotic cells
what is the function of the golgi apparatus
adds carbs to proteins
secretes carbs
transports and stores lipids
forms lysosomes
where molecules are labelled and directed
what is the structure of golgi apparatus
group of fluid filled membranes
vesicles often seen round the edge
membrane folds to form cisternae
secutary vesicles pinch of cisternae to form outgoing vesicles
what is the function of a centriole
involved in seperation of of chromosomes during cell division
involved in production of spindle fibres
found in pairs (centrosomes)
made of micro tubuoles
what is the function of lysosomes
contains digestive enzymes
exocytosis and phagocytosis
digest old or invading cells
what is the function of the RER
folds and processes proteins being made at the ribosomes
fluid filled space surrounded by ribosomes
what is the function of the SER
synthesises and stores carb and lipids
no ribosomes but similar structure to the RER
what is the function of a vesicle
small fluid filled sac in a cytoplasm with a membrane
transports substances in and out of cell
formed by golgi apparatus or the SER RER
what is the structure of cilia
hair like
outer membrane has 9 pairs of microtubules
what is the function of cilia
sweep motion
moves substances to move on surface
what is the function of flagellum
microtubules in tail allow for flagellum to move
used to propel cell
what is the function of pili and capsule
protects bacteria
allow to stick to surfaces and to escape imune system
attaches to specific surfaces or other cells
what are the three components of the cytoskeleton
microfilaments (cell movement and cell contraction during cytokinesis)
microtubules (scaffold like structure which determines shape of cell also act as tracks for movement of organelles like vesicles)
intermediate fibres (gives support to cells )
where is the cytoskeleton
throughout the cytoplasm in eukaryotic cells
what is the definition of resolution
the minimum distance between two objects in which they can still be viewed as seperate
what is the definition of magnification
how many times larger is the image compared to the object
benefits to light microscope
cheap
easy to use
portable and small
colour
negatives to light microscope
uses light which has large wavelength so small resolution 0.2 micro meters
cant observe below 2 micro meters
max magnification is X2000
benefits to using electron microscope
uses electrons which has small wavelength so high resolution of 0.0002 micro meters
max magnification is X150000
dead or alive specimens
no vacuum
negatives of an electron microscope
expensive
large
hard to use
black and white unless coloured with computer
dead specimens
has to be in a vacuum
what is a TEM
transmission electron microscope
image is 2D
electron gun produces beam of electrons
focused onto specimen by lenses
denser areas come up darker as the areas absorb electrons
resolving power is 0.1 nm
really thin specimens so electrons can pass through
what is a SEM
scanning electron microscope
image is 3D
beam of electrons are shot at specimen which bounce of to receptors which then is sent to computer where image is built
don’t need to be thin
how many micrometres in a milimetre
1,000
how many nanometres in a micro metre
1,000
how many nanometres in a centimetre
10,000,000
how many micro metres in a centimetre
10,000
how would you prepare a slide for the light microscope
for dry mount
cut specimen thin
place it on slide
then place cover slip over it
for wet mount
place specimen onto cover slip
add drop of water or oil or dye
then place cover slip at angle lowering it into position
then wipe excess liquid with tissue
Why must the liquid medium used in wet mounts have a similar refractive index to glass?
To prevent diffraction between the liquid and the glass and thus preventing image distortion.
Examples of differential staining
Gram stain technique, Acid-fast technique
what is the purpose of differential staining
to identify different cellular components and cell types
Purpose of the Gram stain technique
To differentiate between Gram positive and Gram negative bacteria.
Purpose of the Acid Fast technique
to differentiate between species of Mycobacterium and other bacteria
advantages of staining
See more detail, increases contrast, allows you to identify different cells and cellular components like organelles
Positively charged dyes
Crystal violet, methylene blue
negatively charged dyes
Nigrosin, Congo red
what does sudan red stain
lipids
what is methylene blue
all purpose stain
what does iodine blue stain
The cellulose in plant cell walls yellow
+
Starch granules blue/black might look violet under MS
what stains cytoplasm
Eosin
what does Acetin Orcein stain
DNA + stains chromosomes dark red.
