Cell organelles Flashcards
Mitochondria
-Role is the site of aerobic respiration, so to produce ATP
-Double membrane to control the entry and exit of material, inner is folded to form cristae, providing a large SA for enzymes and proteins
-Matrix is inside, containing enzymes involved in respiration
Endoplasmic reticulum
-A series of membrane folds spreading through the cytoplasm
-Space between the folds is filled with fluid that transports substances
-Rough ER has ribosomes on surface, it folds and processes proteins made at the ribosomes
-Smooth ER has no ribosomes on surface, it synthesises and processes lipids
Lysosomes
These contain digestive enzymes (lysozymes) which digest invading cells
Chloroplasts
-Role is to carry out photosynthesis
-Chloroplast envelope controls the entry and exit of substances (double membrane)
-Inner membrane is the thylakoid membrane which stack to form grana, which are linked by lamellae.
-Photosynthesis occurs in the grana or stroma
Plasma membrane
-Controls the entry and exit of substances into and out of the cell
-Made up of a phospholipid bilayer
Nucleus
-Largest organelle containing DNA
-Surrounded by the nuclear envelope
-Nuclear pores allow the passage of large molecules
-Nucleolus synthesises ribosomes (small dark structure)
-Nucleoplasm is the granular, jelly-like substance making up most of it
Ribosomes
-Very small cytoplasmic granules floating freely in the cytoplasm OR attached to the rough ER
-Sites of protein synthesis
-70S (prokaryotes) or 80S (eukaryotes)
Golgi apparatus
-A stack of membranes making up flattened sacs (cisternae) containing vesicles
-Processes and packages new lipids and proteins
-Also makes lysosomes
Golgi vesicles
-Fluid filled sacs surrounded by a membrane and produced by the golgi apparatus
-Stores lipids and proteins made by it and transports them out the cell
Cell wall
-Provides strength and rigidity
-Made up of cellulose (or chitin in fungi)
Vacuole
-A membrane-bound, fluid filled sac that contains cell sap.
-The membrane is called the tonoplast
-Helps to maintain pressure and keep it rigid
Algal cells
Have the same organelles as plant cells
Fungal cells
Similar to plant cells but have a chitin cell wall (not cellulose) and no chloroplasts as they don’t photosynthesise
What is a virus?
A non-cellular, non-living particle made up of genetic material and protein that can invade living cells. They are much smaller than DNA.
What organelles does a virus have?
-Attachment proteins allow the virus to attach to host cells
-Capsid is a protein coat which transfers the virus genome between cells
-Lipid envelope
-Genetic material
-Enzyme reverse transcriptase
-NO plasma membrane, ribosomes, or cytoplasm