BACTERIA AND VIRUSES

Who named viruses?

Martinus Beijernick

What does the name Virus mean?

Virus is Latin for Poison

What is the only way viruses can reproduce?

They can only reproduce by infecting other cells

In what macromolecule are the instructions for making new viruses found?

Nucleic acids

List and explain the three components of virus structure

1. Have a core of DNA or RNA

2. Protein coat (capsid which allows them to sneak into host cell)

3. Many different shapes and sizes

List and explain the four ways we classified viruses

1. If they have DNA or RNA

2. Shape: cubic, spiral, spherical, or complex

3. Host: bacterial, plant, animal, including insects

4. Mode of transmission: respiratory, oral, sexual, blood, zootonic

Explain the process of lytic bacterial infection

1. Virus enters the cell or inject its DNA/RNA into the cell

2. So begins to make thousands of copies of the virus DNA

3. Viral DNA assembles into new viruses

4. Cell pops (lyses) and releases new viruses

Explain the process of a lysogenic bacterial infection

1. Virus enters the cell or DNA is injected into cell

2. Virus genes incorporated into cells DNA, which is called the prophage

• remains dormant

• Genes copied with each cell division

• When activated, enters lytic cycle

What two groups did kingdom Monera divide into?

Eubacteria and archaebacteria

Eubacteria

1. More species than archae

2. Live almost everywhere; soil, water, intestines

3. Cell wall contains a protective layer of peptidoglycans

What are peptidoglycan made of?

Carbohydrates and amino acids

Archaebacteria

1. Can live in normal and harsh environments

2. Lack peptidoglycan and cell wall

3. Unaffected by antibiotics

4. DNA shares more sequences in common with eukaryotes than eubacteria

Cocci

Spherical shaped; can form long chains

Bacilli

Rod shaped

Spirilla

Spiral or cork screw shape

Explain how each type of bacteria gets its energy/nutrients

1. Photoautotrophs: carry out photosynthesis

2. Chemoautotrophs: get energy from chemical reactions to make food using carbon dioxide, does not require light

Obligate aerobes

require a constant supply of oxygen

Obligate anaerobes

do not require oxygen, must live in absence of it

Facultative anaerobes

Can switch between cellular respiration and fermentation

Binary fission

asexual, replicated DNA and splits in two

Conjugation

Exchange of genetic information(DNA), increases genetic diversity

List four ways bacteria are important

Decomposers, nitrogen fixers, used in food, production, used in biotechnology

Decomposers

Breakdown and recycle, dead matter and sewage

Nitrogen fixers

Bacteria found in soil and/or in nodules on plant roots

used in food production

yogurt, cheese, sour cream, etc.

Used in biotechnology

Recombinant DNA technology that leads to production of helpful proteins, like insulin and enzymes used in medical treatment

What are two ways bacteria, cause disease?

1. bacteria, damage cells, and tissues by breaking down host cells for food

2. Bacteria create toxins that harm the host cell

How is the way that bacteria caused disease different than viruses?

They differ since viral infections will eventually end in popping

MRSA

caused by antibiotic resistant staphylococcus

Tuberculosis

Damages and destroy cells in lungs

Strep throat

Caused by streptococcus

How do Antibiotics treat bacterial infections.

Antibiotics can directly kill bacteria, or indirectly, kill bacteria by slowing down their growth and reproduction so that the immune system cells can catch up and kill bacteria

What are the three ways we can control bacteria?

Sterilization, disinfectant, food preservation

Sterilization

Kills bacteria through usage of heat, chemicals, or radiation

Disinfectant

Kill bacteria on surfaces

Food preservation

Uses refrigeration, cooking to appropriate temperatures

HPV

Often transmitted sexually, human/animal host, 100+ strains that affect skin and mucous membranes

HIV

Cause of AIDS, attack immune system, transmitted through blood in other body, fluids, human/animal host

Common cold

Can be caused by almost 200 different viruses, respiratory transmission, animal/human host

Influenza

Typically, respiratory disease, can lead to pneumonia, hard on old and young, easily mutates, Human host

Ebola

hemorrhagic disease, transmitted through contact with infected blood and body fluids, animal/human host

How do we prevent the spread of viruses?

Vaccines, hand washing, covering mouth, staying away from sick people