cell biology Flashcards
what is a eukaryotic cell
most organelles within the cell are membrane bound- keeps organelles separate from each other
what is a prokaryotic cell
cell with DNA not enclosed in a nucleus and no membrane bound organelles
what is membrane bound organelles
organelles with a membrane covering them (provides compartmentalisation)
function of plasma membrane
to protect cell from surroundings, controls what exits, enters
function of mitochondria
site of ATP production during aerobic respiration
function of cytoplasm
-holds organelles of cell and protects them
-chemical reactions take place
function of ribosomes
synthesising proteins
function of smooth endoplasmic reticulum
-absorption, synthesis and transport of lipids from the gut
function of rough endoplasmic reticulum
-ribosomes attach to it for protein synthesis
function of golgi apparatus
where proteins are processed, modified and then packaged into vesicles for transfer and storage
function of lysosomes
engulf old cell organelles and foreign matter, digest them and return it to the cell for reuse
function of chloroplasts
site of photosynthesis
function of centrioles
organelles used in cell division
function of cytoskeleton
enables cell movement via cilia and flagella and strengtens the structure of the cell to maintain it
function of cellulose cell wall
prevents plant cells from bursting
organelles that do not have a membrane
-ribosomes
-centrioles
-cytoskeleton
-cellulose cell wall
how do organelles work together to secrete a protein
-mRNA copy of the gene is made in nucleus
-mRNA leaves the nucleus through a nuclear pore
-mRNA attaches to ribosome on the rough endoplasmic reticulum. ribosome reads gene to make the proten
-protein moleules are ‘pinched off’ in vesicles and travel towards golgi apparatus
-vesicle fuses with golgi apparatus
golgi processes, modifies and packages protein for release
-packaged protein molecules are ‘pinched off’ in vesicles from golgi and move towards plasma membrane
-vesicle fuses with plasma membrane
-plasma membrane opens to release protein molecules outside
what is a nucleotide
area of prokaryotic cell where loose DNA is formed
what is a plasmid
circular DNA found in prokaryotic cells
function of flagella
allows bacteria to move
function of pili
small hair like structure that allow bacteria to stick to each other or to host cells
function of plasmid
small loop of DNA
function of nucleotide
area within the cytoplasm where the DNA is
function of capsule
waxy and protective
function of cell wall
made out of peptidoglycan which stops the cell from bursting
definition of magnification
how many times the image is zoomed in compared to the actual object
definition of resolution
the smallest distance between two points where they’re seen as separate
magnification equation
magnification = image size/actual size
magnification of a transmission electron microscope
x2,000,000
resolution of a transmission electron microscope
0.2nm
specimen state when using a transmission electron microscope
dead and stained
magnification of a scanning electron microscope
x15 - x200,000
resolution of a scanning electron microscope
10nm
specimen state when using a scanning electron microscope
placed in a vacuum
what image does a scanning electron microscope produce
black and white
3D
magnification of a laser scanning microscope
x200
resolution of a laser scanning microscope
high resolution
specimen state when using a laser scanning microscope
can observe living organisms
what image does a laser scanning microscope produce
colour
3D
magnification of an optical microscope
x1500 - x2000
resolution of an optical microscope
0.2um
what image does the optical microscope produce
2D
