Biology - Microbiology

Experiment to check for the most effective soap:

1. wash hands with one type of soap and dry

2. Press one of those fingers against agar jelly

3. repeat steps using different types of soaps and wait one week to see bacteria growth

How was penicillin discovered?

Dr Alexander Flemming left a petri dish with a bacteria in it in his lab and a week later it grew into penicillin.

How was spontaneous generation disproved?

It was disproved by Louis Pasteur's swan neck experiment

Structure of a bacteria:

How do bacteria divide?

binary fission

What is a microbe?

a microbe is a living thing too small to be seen by the naked eye.

Disinfectants:

Used on inert surfaces to kill microbes e.g. bleach

Antiseptics:

Kill microbes on living tissue but you would not ingest it.

Antibiotics:

Kill bacteria in animals or humans by making it hard for the bacteria to multiply. You can ingest it.

Structure of an Amoeba

What is a zone of inhibition?

The area around the antibiotic disk in which bacteria cannot grow

3 conditions bacteria need to grow:

Oxygen, moisture and sunlight.

Bacteria:

Unicellular, reproduce by binary fission, most are harmless, some can photosynthesise

Yeast:

Multicellular, have a cell wall, feed extracellularly, release digestive enzymes on their food (saprophytic nutrition)

Yeast cell:

Generalised virus structure:

Viruses:

Not living, can reproduce inside a host cell e.g. influenza, aids, HIV, HPV

Fungi and bacteria:

Fungi are furry, bacteria are shiny