the two basic types of cells are Prokaryotic and Eukaryotic cells
The prokaryotic kingdom consists of bacteria and cyanobacteria
Prokaryotic cells have no nuclei or any other membrane-bound cell organelles.
most prokaryotic cells are extremely small and their DNA is not associated with anyproteins and lies free in the cytoplasm.
A cell wall is always present in a prokaryotic cell.
all other living organisms ( not bacteria or cyanobacteria ) have cells that contain membrane bound organelles such as nuclei and mitochondria.
These are called Eukaryotic cells .
Eukaryotic cells are larger than prokaryotic cells.
not all Eukaryotic cells have cell walls.
parts of the Eukaryotic cell
Mitochondria: these are the site of the later stages of aerobic respiration
nucleus: contains chromosomes and a nucleolus. the DNA in the chromosomes contain the instructions for protein synthesis.
nucleolus: dense body within the nucleus where ribosomes are made.
Rough endoplasmic reticulum (rer): system of interconnected , membrane bound flattened sacs which attach to ribosomes where proteins made by the ribosomes are transported through the ER to other parts of the cell.
Ribosomes: made of RNA and protein, these small organelles are found free in the cytoplasm or attached to the endoplasmic reticulum . these are the site of protein synthesis.
parts of the Eukaryotic cell (2)
cell surface membrane: Phospholipid bilayer containing proteins and other molecules forming a partially permeable barrier
Smooth Endoplasmic reticulum (ser): like rough ER, but does not have any attached ribosomes . Smooth ER makes lipid and steroids (e.g. reproductive hormones)
Golgi apparatus: stacks of membrane-bound sacs formed by fusion of vesicles from the ER. modifies proteins and packages them in vesicles for transport.
Lysosome: round sacs containing digestive enzymes and bound by a single membrane. Involved in the breakdown of unwanted structures within the cells when old cells are to be replaced or being developed. The Acrosome is a specialised lysosome.
Centrioles: every animal cell has one pair of centrioles, which are hollow cylinders made up of a ring of nine protein microtubules. they are involved in the formation of the spindle during nuclear division and in transport within the cell cytoplasm.