2.1.1 cell structure Flashcards
magnification equation
size of image / actual size of object
magnification definition
how many times larger the image is than the actual size of object being used
resolution definition
ability to see individuals objects as separate entities
diffraction
tendency of light waves to spread as they pass close to physical structures such as those present in specimens studied
1 graticule division
number of micrometers / number of graticule divisions
7 characteristics of life
Movement
Reproduction
Sensitivity
Growth
Respiration
Excretion
Nutrition
Cell theory
all living organisms are made of cells
the cell is the basic unit of structure and organisation of life
all new cells arise from others
why is the cell theory still a theory
as theres no evidence to know all new cells arise from others as no-one was alive when the 1st cell was produced
also virus contradict the theory as they’re non living and need a host cell
features and examples of prokaryotes
archeabacteria, eubacteria
always unicellular
smallest type of cell
DNA = circular and free in the cytoplasm
features and examples of eukaryotes
protista, fungi, plantae, animalia
multicellular except protist and yeast
larger than prokaryotes
DNA = in nucleus as chromosome, linear
what does prokaryote stand for
before nucleus
what was the first cell
archae
what do all cells have
plasma membrane
cytoskeleton
cytoplasm/cytosol
organelles
what is cytosol
everything except the organelles
endosymbiosis
taking in and living alongside
what are proteins produced by cells
hormones and enzymes
intracellular proteins
used within the cell
made in the cytoplasm
makes lyzozymes
lyzozymes
hydrolytic enzymes found in lysosmes
extracellular proteins
made in ribosomes on RER
exported out the cell to be used elsewhere in the body
makes hormones and digestive enzymes
what organellles are involved in protein production and export
nucleus
ribosome
rough endoplasmic reticulum
golgi apparatus
vesicle
steps of protein production
mRNA leaves nucleus via nucleur pore
travels through cytoplasm to ribosome on RER
ribososome reads code on mRNA to build protein out of amino acids
protein travels through cisternae of RER
protein is pinched off in vesicle and travels along golgi
vesicle fuses to golgi and protein is modified and packaged into vesicle for export
vesicle travels to plasma membrane and fuses to it
protein is released by exocytosis
cyto
cell
cytoskeleton
network of fibres neccessary for the shape and stability of the cell
- the container of the cell
4 main function of the cytoskeleton
cell shape
cell movement
holds organelles in place
movement of organelles within cell
3 types of fibres in the cytoskeleton
microtubules
microfilaments
intermediate fibres
structure and function of microtubules
globular tubulin and polymerise tubes
used to formscaffold like structure to determine shape of cell
acts as tracks for moving organelles
form spindle fibres
structure and function of microfilaments
contractile fibres formed from protein actin
responsible for cell movement + cell contraction- cytokenesis
structure and function of intermediate fibres
give mechanical strength to cells and help maintain their integrity
where in the cell are microfilamets
concentrated around the outside of the cell
where in the cell are microtubules
form network around the inside of the cell
where in the cell are intermediate fibres
randomly scattered around the cell
structure of centerioles
9 microtubules arranged in a cylinder
function of centerioles
produce spindle fibres in cell division
structure of cilia and undulipodia
9 pairs of microtubules with a pair in the middle
each have a motor protein
function of cilia and undulipodia
turn in corkscrew motion to waft mucus or propel sperm
structure of flagellae
single actin fibre
function of flagellae
move in whip-like fashion to propel bacteria
