3.2.1.1 EUKARYOTIC CELL ORGANELLES STRUCTURE + FUNCTION Flashcards
Structure of nucleus:
- large organelle enclosed by a double membrane (an envelope) perforated by pores
- contains chromosomes and one or more nuclei
Function of nucleus:
- chromosomes contain DNA which controls synthesis of proteins
- ribosomes formed in the nucleolus
- contains DNA of the cell
Structure of mitochondria:
- has an outer and inner membrane which forms a cristae (folded)
- inside the inner membrane is the matrix containing enzymes, a circular DNA, ribosomes and starch grains
Function of mitochondria:
- the site of AEROBIC RESPIRATION and responsible for producing ATP
Structure of chloroplasts:
- has a chloroplast envelope- double membrane which controls what enters + exits the cell
- contains a matrix called the stroma which are stacked in places to form grana containing chlorophyll- contains circular DNA, ribosomes and starch grains
Function of chloroplasts:
Photosynthesis due to chlorophyll being present
Structure of endoplasmic reticulum:
3D system of sheet like membranes, spreading throughout cytoplasm of cells
Structure of rough endoplasmic reticulum:
- ribosomes present on outer surface of membranes
Function of rough endoplasmic reticulum:
- ribosomes provide a large surface area for the synthesis of proteins and glycoproteins
- provides a pathway for the transport of materials, especially proteins throughout the cell
Structure of the smooth endoplasmic reticulum:
- lacks ribosomes on its surface and is often more tubular in appearance
Function of the smooth endoplasmic reticulum:
- synthesises, stores and transports lipids and carbs
Structure of the Golgi apparatus:
- similar to the SER but more compact- like a pile of pitta break
- consists of a stack of membranes which make up flattened sacs (cisternae), with small, rounded, hallow structures called vesicles
Function of the Golgi apparatus:
- relieves proteins synthesised on the ER and prepares them for excretion from the cell
- adds carbs and proteins to make glycoproteins
- forms lysosomes
- produces secretary enzymes
- transports, modifies and stores lipids
Structure of lysosomes:
- formed when vesicles produced by the Golgi apparatus contain enzymes such as proteases and lipases
- a vesicle containing digestive enzymes
Function of lysosomes:
- hydrolyse material ingested by phagocytic cells- such as white blood cells + bacteria
- release enzymes to the outside of the cell (exocytosis) in order to destroy material around the cell
- digest worn out organelles
- completely breakdown cells after they have died
Structure of ribosomes:
- 80s- found in eukaryotes, 70s- found in prokaryotes
- small cytoplasmic granule found in all cells on/ in RER or cytoplasm
- made of protein + RNA
Function of ribosomes:
- site of protein synthesis
Structure of cell wall:
Consists of cellulose micro fibrils and other polysaccharides
Function of cell wall:
Provides mechanical strength to the cell in order to prevent it from bursting
Structure of vacuole:
- fluid filled sac bounded by a single membrane called the tonoplast
Function of vacuole:
- support herbaceous plants and parts of woody plants by making cells turgid
- sugars + AAs may act as a temporary food store
Function of vacuole:
- support herbaceous plants and parts of woody plants by making cells turgid
- sugars + AAs may act as a temporary food store