Structure of prokaryotic cells

Cells (AQA AS Biology) PART 2 of 6 TOPICS

TOPICS: Structure of eukaryotic cells Structure of prokaryotic cells and viruses Methods of studying cells All cells arise from other cells Transport across cell membs Cell recognition and the immune system

Structure of prokaryotic cells:

Prokaryotic cells are different to eukaryotic cells in many ways:

They are smaller to eukaryotes
They have no membrane-bound organelles
They have no nuclei but a loop of DNA
They have murein (a glycoprotein) in their cell walls

In addition prokaryotes have structures such as having more than one plasmids, a capsule surrounding the cell and more than one flagella.

Viruses:

Viruses are a-cellular and are non-living. They have a protein coat with a nucleic acid in the middle (DNA). It has an attachment protein which attaches to a cell.

NB: As part of AQA, only the illustration of complex and spherical viruses need to be known. Above is a description of a complex virus and spherical is where HIV is under

which will be covered in later topics.

] That is all for the structure of prokaryotes and viruses [