Prokaryotic cells and Virus Structure

Capsule

Prevents desiccation, protects cell from antibiotics and viruses.

Ribosomes

Smaller than eukaryotic (70s not 80s)

Capsule

Prevents desiccation, protects cell from antibiotics and viruses.

Ribosomes

Smaller than eukaryotic (70s not 80s)

DNA

Single circular loop

Plasmid

Small loops of DNA- contain useful genes

Cell wall

Made of murein

Flagellum

Used for movement

Mesosome

Prokaryotic cells have one membrane- the membrane infold (mesosome) is in the cytoplasm. Increases surface area for respiration and photosynthesis

Binary Fission- Definition

A type of asexual reproduction observed in Prokaryotes

Binary Fission steps

Step 1- DNA and plasmids replicate

Step 2- Cell elongates, DNA moves to opposite poles of the cell

Step 3- Cytoplasm begins to divide, new cell walls begin to form

Step 4- Cytoplasm divides to produce two daughter cells, contain identical DNA loop, can contain different number of plasmids.

Viruses

Neither prokaryotic nor eukaryotic, acellular non-living particles (not made of cells), 1000x smaller than bacteria, consist of RNA protected by a protein coat called the capsid, may also be enclosed in a lipid envelope, capsid or lipid envelope will have attachment proteins/antigens- help them recognise a host.

Virus replication

Require the aid of a living cell in order to reproduce.

Step 1- Virus detects host cell by recognising protein marker on its membrane. Attaches to cell using attachment proteins.

Step 2- Virus injects genetic material into cell.

Step 3- Cell reproduces the genetic material and reads it creating new viral proteins.

Step 4- Virus leaves cell using some of the cells own membrane to form itself.