Intro to Microbiology

What are microbes?

Organisms less than 100 um that are unicellular & acellular

What percentage of Earth’s biomass consists of microbes?

60%

Why are some microbes important for the environment?

They perform photosynthesis and are crucial for biochemical cycles

Who is the "Father of Microscopy"?

Anthony Van Leeuwenhoek

What was Anthony Van Leeuwenhoek's contribution to microbiology?

Developed microscopes and first observed microorganisms

What theory did Koch's postulates support?

Germ Theory of Disease

What are the three main features of a microscope?

magnification, resolution and contrast

What is magnification?

The ratio of an image's size to its actual size

What affects resolution in a microscope?

Quality of lens and the wavelength of light

What is contrast in microscopy?

The ability to distinguish an object from the background

What is the best magnification of a common light?

1000x

What is the resolution limit of a light microscope ?

1 um

What type of microscope uses electrons instead of light?

Electron Microscope (EM)

How much can an electron microscope magnify?

over 250,000 x

What is the resolution of an EM?

1 nm

what are the two types of EM?

Scanning EM and Transmission EM

What does TEM do?

passes electrons through a thin specimen to see internal structures

What does SEM do?

Scans the surface of a specimen, producing a 3D image

What is the purpose of staining in microscopy?

Enhances contrast by coloring cells or structures

What is the chromophore in staining?

The color component of a stain

What are the ionizable dyes used for?

Staining cells based on charge interactions

What is negative staining ?

Stains the background, leaving the organism clear

What is spontaneous generation?

The belief that living organisms arise from non-living matter

Who performed an experiment with meat and maggots to disprove spontaneous generation?

Francesco Redi

What were the results of Reid's experi ment?

Maggots only appeared in the open jar, proving flies cause maggots not spontaneous generation

Who conducted the swan-neck flask experiment?

Louis Pasteur

What are Koch's postulates?

Steps that prove a microorganism causes disease