Bacterial and Viral Infections

What are the parts of a bacteria?

• Cell wall

• Plasma membrane

• Mesosomes

• Capsule

• Plasmids

• Small loops of DNA

• Long circular DNA

• Pili

• Flagellum

• Ribosomes

What is the cell wall of a bacterium made of?

glycoprotein = usually murein and peptidoglycan

What are mesosomes?

• folds of the plasma membrane

• some scientists believe that is has a function to do with respiration

What is the capsule?

a layer of slime that protects the bacterium from attack by cells of the immune system

Where is the DNA of most of the bacterium stored?

In the long circular coiled up strand = bacterial chromosome

What is the function of pili?

• help bacteria stick to other cells

• used in gene transfer

What is the major difference between a bacterium and a virus?

• Viruses are not cells they are used nuclei acid surrounded by a membrane

• Viruses are smaller

• Viruses have no plasma membrane, no cytoplasm, no ribosomes

What does a virus contain?

• nuclei acid (DNA or RNA)

• Capsid (protein coat)

Some have:

• outer layer called the envelope stolen from previous host cell

• attachment proteins that stick out fo the virus to cling on to a host cell

• some proteins inside the capsid (e.g reverse transcriptase)

What is a pathogen?

• any organism that causes disease

• examples: some bacteria some fungi and all viruses

What do diseases do?

if it develops it can cause a sequence of symptoms which may lead to death