the cell

what does the cell membrane do

outer boundary that allows cell interaction with its external environment

what is the function of the nucleus

directs cell actvities

what is the function of the cytoplasm

contains organelles that perform specific functions

where is the cytoplasm found

between the plasma membrane and the nucleus

general functions of the cell membrane

separation, encloses and supports cell contents, attatches to extracellular environment, ability to recognise and communicate with other cells, determines what moves in and out of cells

what diffuses across the lipid bilayer

fatty acids

steroids

some vitamins

oxygen and carbon dioxide

certain drugs and alcohol

passive transport

does not require energy

what is required for primary active transport

ATP is required

primary active transport e.g calcium transport out of cells

10000 times more calcium outside, calcium binds to carrier site inside cell stimulating shape change, a hinge like motion of carrier protein releases the calcium onto the opposite side of the membrane

what is cotransport (symport)

molecule or ion moving in the same direction

what is countertransport (antiport)

molecule or ion is moved in the opposite direction

how does an electrochemical gradient happen

different concentrations of certain substances

what is bulk transport used for

molecules that are too large to be transported across a membrane by carriers

bulk transport is performed by

exocytosis and endocytosis

what is the cytoplasm

a jelly like matrix made up of cytosol and organelles

what is the function of the cytoplasm

provide the cell with shape and form, provides forum for enzyme reactions to occur, packages chemicals for transport to other parts of the cell and facilitates the excretion of waste products

what is the cytoskeleton

a structural supporter which gives the cell shape and anchors some organelles

what is the mitochondria

rod like double membrane structure

what does the mitochondria do

it generates atp and is independent of the nucleus

what does the rough ER do

site of protein synthesis

what does the smooth ER do

lipid synthesis and stores calcium

what does the golgi apparatus do

modify proteins, pack them into vesicles and store and ship them to other destinations

what are the peroxisomes

membrane sacs with enzymes that detoxify harmful substances in the liver

what are lysosomes

powerful digestive enzymes that hydrolyse macromolecules taken into cell and ingest bacteria