Cell organelles Flashcards
(15 cards)
nucleus function
contains DNA
directs the synthesis of ribosomes and proteins.
nucleolus function
sites of rRNA formation, constituent of ribosomes
mitochondrion function
site of aerobic respiration
mitochondrion adaptation for its function
70s ribosomes for protein synthesis
small circle of DNA so mitochondrion can replicate and code for some of its proteins and RNA
cristae provide large SA for attachment of enzymes involved in respiration
cylindrical so larger SA than sphere therefore SA:VOL bigger
diffusion distance reduced by cylindrical size between edge and centre therefore aerobic respiration more efficient
chloroplast adaptations for function of photosynthesis
stroma fluid filled and contains some products of photosynthesis eg lipid droplets and starch grains
contains 70s ribosomes and circular DNA which enable them to synthesis own proteins and self-replicate
name all that makes up the chloroplast organelle
double membrane
circular DNA
granum
70s ribosomes
stroma
rice grain
integral lamella
thylakoid
R.E.R function
where is it present?
ribosomes on outer surface and transports proteins made there
present in large amounts of cells that make lots of protein eg amylase in salivary gland
S.E.R function
associated w/synthesis and transport of lipids
what sort of cells contain endoplasmic reticulum
cells that store large quantities of carbs, proteins and fats, including liver and secretory cells, have extensive ER
ribosomes function and description
ribosome important as site of translation and assembling of polypeptide chain
1 large subunit (2 tRNA attachment sites), 1 small subunit (1 mRNA attachment site)
golgi body role
proteins modified and packaged at golgi body
vesicles containing modified proteins pinch off and move elsewhere in cells or fuse w/cell membrane, secreting proteins by exocytosis
golgi body functions
producing secretory enzymes, packaged into secretory vesicles
secreting carbs eg for formation of plant cell walls
producing glycoprotein
transporting and storing lipids
forming lysosomes, containing digestive enzyme
lysosome function, example
formed by being pinched off golgi body
contain and isolate harmful digestive enzymes from remainder of cells
release these enzymes when cells need to recycle worn out organelles enzymes can also digest material which has been taken into cell eg lysosomes fuse w/vesicle made when white blood cells engulf bacteria by phagocytosis
centriole function
occur in animal cells and most protoctists but not cells of higher plants
two rings of microtubules making hollow cylinders, positioned at right angles to one another
during cell division organize microtubules that make spindle
vacuole function
fluid filled sac bounded by single membrane and tonoplast
contains cell sap which store glucose, amino acids and minerals
supports soft plant tissue
