structure and function of cell organelles Flashcards
what is the function of the nucleus
- nucleus = contains the DNA which codes for protein synthesis
- nuclear envelope = separates the DNA from the cytoplasm
- nuclear pore = allows transport of mRNA out of the nucleus
- nucleolus = synthesis of rRNA and ribosomes
what is the structure and function of the ribosomes
structure:
- 2 subunits made from rRNA
- can be free or attached to RER
function:
- protein synthesis
what is the structure and function of the RER
structure:
- forms a system of flattened sacs called cisternae
- continuous with the nuclear membrane
- may link to the golgi body
- has ribosomes attached
function:
- transports the proteins which are synthesised by the ribosomes attached
what is the structure and the function of the SER
structure:
- forms a system of flattened sacs
- has no ribosomes attached
function:
- synthesis and transport of lipids
what is the structure and function of the golgi body
structure:
- similar to ER, however its more compact
- surrounded by vesicles
function:
- chemically modifies proteins
- produces lysosomes
- produces glycoproteins
- packages proteins for secretion out if the cell
what is the structure and function of the mitochondria
structure:
- rod shaped
- has double membrane, inner and outer membrane
- membranes separated by a narrow fluid filled space
- inner membrane folded to form cristae
- interior is called the matrix, contains enzymes
- contains DNA and ribosomes
function:
- site of aerobic respiration which produces ATP
- cristae increase surface area for aerobic respiration
what is the structure and function of vacuoles in animal cells
structure:
- small membrane bound organelle
function:
- act as a contractile vacuole to maintain osmotic pressure
what is the structure and function of the vacuole in a plant cell
structure:
- large membrane bound organelle
- surrounded by tonoplast
function:
- storage of ions and organic molecules
- maintains osmotic pressure
what is the structure and function of the centrioles
structure:
- two hollow cylinders at right angles to each other
function:
- are used in spindle formation in cell division
what is the structure and function of lysosomes
structure:
- small vacuoles
- formed when part of the golgi body are pinches off
function:
- contain and isolate digestive enzymes
- can release these enzymes and destroy organelles
- digestion of material that has been taken into the cell
what is the structure and function of the chloroplasts
structure:
- have a double membrane
- interior is made from a fluid called stroma, ribosomes, lipids, circular DNA and starch granules
- there are thylakoids, which are flattened sacs
- thylakoids form stacks called granum
- each granum = 2-100 thylakoids
- between the grana and the thylakoids form lamellae
function:
- site of photosynthesis
- the thylakoids contain photosynthetic pigments such as chlorophyll
what is the structure and function of the cellulose cell wall
structure:
- made of cellulose microfibrils in a polysaccharide matrix
function:
- prevents osmotic lysis
- provide strength and support to the cell
- freely permeable to water
what is the structure and function of the plasmodesmata
structure:
- a narrow thread of cytoplasm that passes through the cell walls of adjacent plant cells
function:
- exchange of large organic materials via cytoplasmic streaming
- allows communication between adjacent plant cells
