Bacteria vs Virus

Bacteria vs Virus

Bacteria

• Prokaryotic/unicellular

• Contain DNA/ribosomes BUT NO nucleus

Uses of Bacteria

• Fermentation of food: buttermilk/yogurt/cheese

• Decompose organic matter

• Nitrogen fixation

• Help humans digest food

• Biotechnology: make human insulin

How Do Bacteria Work

• Using cells for food: The bacteria break down healthy cells for food, destroying tissues

• Releasing toxins: The bacteria produce a toxin (poisonous protein) that is released into the bloodstream where it can travel throughout the body, disrupting normal activity and damaging tissues

• Bacteria can cause a variety of diseases:

  –Food Poisoning – Scarlet Fever

  –Tuberculosis – Whooping Cough

  –Cholera – Bacterial Meningitis

  –Syphilis – Pneumonia

  –Ulcers – Leprosy

  -Strep Throat – Tetanus

Antibiotics

• Used to treat a variety of bacterial infections

• DO NOT work on viruses

Multiple Choice

What is a pathogen?

• Any microorganism that make us sick

• bacteria only

• virus only

Multiple Choice

Bacteria are

• multicellular

• unicellular

Multiple Choice

Bacteria are

• eukaryotic

• prokaryotic

Virus

• Viruses have DNA or RNA

• Virus must have a host to survive

• Viruses are considered NON-LIVING

How Do Viruses Work?

• Virus injects its DNA into host cell

• Host cell replicates viral DNA instead of cellular DNA

• Virus ruptures host cell releases millions of virus particles

Process of Viral Reproduction

• Attach: The capsid of the virus binds to receptor proteins on the surface of a host cell, tricking the host cell into thinking it’s not a foreign invader.

• Inject: The virus then injects its genetic material (DNA or RNA) into the host cell.

• Assemble: The viral genes are expressed, turning the host cell into a virus-making factory.

• Repeat: The host cell eventually bursts, releasing the hundreds of newly formed viruses to infect 

Lytic Cycle

• Viral replication cycle in which a virus takes over a host cell's genetic material and uses the host cell's structures and energy to replicate until the host cell bursts, killing it. This cycle kills the host cell almost right away. 

Lysogenic

• Viral replication cycle in which the virus's nucleic acid is integrated into the host cell's chromosome, a provirus is formed and replicated each time the host cell reproduces, the host cell is not killed until the cycle is activated. At this time the virus remains quiet for a very long time and it is said to be hidden. 

Multiple Choice

Antibiotics can be used to treat viruses?

• True

• False

Multiple Choice

Viruses must have a host to survive?

• True

• False

Multiple Choice

Viruses are considered non-living.

• True

• False

Multiple Choice

Lysogenic cycle is very quick and will almost immediately kill the host cell.

• True

• False