voice of the genome

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.

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.

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.