Organelles and functions

Biology Notes






Prokaryotic Cells Eukaryotic Cells
Small cells <5µm Larger cells >10m
Always unicellular Often Multicellular
No Nucleus or any membrane-bound organelles Always have a nucleus and other
membrane-bound organelles: Double
membranes e.g. nucleus, mitochondria and
chloroplasts; Single membranes e.g.: Golgi
complex and Endoplasmic reticulum
DNA is circular without proteins…

Biology Notes




Chloroplasts
Chloroplasts are between1-5 µm
A granum is a stack of thylakoid
Found in cytoplasm of plant cells.
Has an inner membrane which is less permeable.
Inside a stack of granum there is chlorophyll
Photosynthesis takes place in the chlorophyll and
the stroma
Contain starch, DNA and ribosomes…

Biology Notes




Cell Membranes
Membranes made of proteins, phospholipids and sugar
Made of Carbohydrate chains
Forms a barrier between cell and its surroundings
Controls the passage of materials in and out of the cells
Recognises other cells
Receptor sites for hormones and neurotransmitters
Transmission of nerve impulses
Compartmentalization of cell…