cells Flashcards
what is the function of a nucleus
contains the DNA ehich codes for protein synthesis
what is the function of the nucelar envelope
seperates the DNA from the cytoplasm
what is the function of the nucelar pore
allows the transport of mRNA (out of nucelus)
what is the function of the nucelolus
synthesis of rRNA and robosomes
what is the structure of ribosomes
- consists of 2 subunits made from ribosomal RNA (rRNA) and protein - large and small subunit
- can be free or attached to rough endoplasmic reticulum (RER)
what is the function of ribosomes
protein synthesis
what is the structure of the rough endoplasmic reticulum
- forms a system of flattened sacs (cisternae) which are continuos with the nuclear membrane and may link to the Glori appartus
- RER has ribosomes attached
what is the function of the rough endoplasmic reticulum
transports proteins which are synthesised by the ribosomes attached
what is the structure of the smooth endoplasmic reticulum
- forms a system of flattened sacs (cisternae) which are continuous with the nuclear membrane and may link to the golgi apparatus
- has no ribosomes attaches
what is the function of the smooth endoplasmic reticulum
the synthesis and transport of lipids
what is the structure of the Golgi body/ apparatus
- is a similar structure to ER however is more compact
- surrounded by vesticies
what is the function of the Golgi body/ apparatus
- chemically modifies proteins
- produces lysosomes
- produces glycoproteins
- packages proteins for secretion out of the cell
what is the strcuture of the mitochondria
- rod shaped and 1-10 micrometres diametre
- has a double membrane, the inner and outer membrane
- the membranes are separated by a narrow fluid filled inner membrane space
- the inner membrane is folded to form structures called cristae
what is the function of the mitochondria
- the site of aerboc respiration which synthesises ATP
- the cristae increases the suface area on which part of the respiratory process takes place
what is the structure of vacuoles/vesticles (animal)
- small membrane bound organelle
what is the function of vacuoles/vesticles (animal)
- act as a contractile vacuole to maintain osmotic pressure
what is the structure of vacuoles/vesticles (plant)
- large membrane bound organelle surrounded by a tonoplast
what is the function of the vacuoles/vesticles (plant)
- storage of ions and organic molecules (eg proteins and maintaining osmotic pressure)
what is the structure of centrioles
- consists of two hollow cylinders postitioned at right angles to one another
what is the function of centrioles
are used in spindle fromation (microtubes) in cell division
what is the structure of lysosomes
- 1.0 um in diametre
- small vacuoles fromed when small prtions of the golgi body are pinched off
what are the function of lysosomes
- they contain and isolate digestive enzymes
- they can release these enzymes and destroy organelles
- digestion of materials which has been taken into the cell
- eg white blood cells engulf bacteria by phagocytosis and the lysosomes are used in the digestion of the bacterium
what is the structure of the chloroplast
- 2-10 um in diametre, 1um thick
- have a double memebrane
- the interior is made up of a fluid called stroma, ribosomes, lipids, circular DNA and starch granuales
- there are thylakoids (flattened sacs) these form stacks which are called granum. each granum has 2-100 thylakoids between the grana the thylakoids from iamellae