Viruses/Cancer

In a grey area between being alive or not alive.

All parasitic, responsible for diseases in various species (even bacteria)

Smaller than cells

Basic structure

    Capsid - not a cell wall, just basically a box made of protein containing genetic material

    Genetic material - could be DNA or RNA

Reproduction (done by the cell attacked)

    Will float around until it bumps into target

    Caspid proteins react with specific molecules in the cell wall

    Entry into a cell and uncoats DNA into the cell

    The cell’s mRNA will go through transcription and create more capsid proteins

    The viral DNA will replicate

    The virus will self assemble and exit from the cell

Viroid

    A circular RNA molecule that infects certain plants

        Like a virus but without the capsid, much simpler

Prion

    An infectious misfolded protein    

widely accepted hypothesis

    A normal protein is misfolded (has an abnormal tertiary structure)

    This molecule tends to misfold any similar protein that it comes in contact with.

Cancer

The cell cycle is controlled, particularly in a multicellular organism.

Several genes are involved in control of the cell cycle.

A mutation in one of these genes may result in uncontrolled cell division.

Daughter cells inherit this uncontrolled cell division.

Cells tend to be unspecialized.

If the cells that are growing out of control remain in the same location, it is considered a benign tumour.

benign: aren’t harmful (can be depending on where they are)

If the cells spread in the body (metastasis), starting new tumours, it is considered a ‘true’ cancer.

Cancer is difficult to treat because the cancerous cells are part of the body.