Microm quiz 2

Gram positive cocci

Bacillus, staphylococcus, and streptococcus

E coli

a gram negative rod that ferments lactose to produce acid and gas and breaks down the amino acid tryptophan to produce indole

Facultative anaerobes

They can grow without O₂, and they can use O₂ in their metabolism

Which is the function of the iris diaphragm?

adjusts the amount of light that reaches the specimen

Why do we make dilutions when trying to determine the concentration of cells in a culture? 

The dilutions help to distribute the cells so that they are easier to count or determine.

Endospore

metabolically inactive resting stage able to withstand high temperatures, acidity, drying, and irradiation

Sporulation

the process through which a bacterial cell forms an endospore.

Germination

the process by which an endospore rehydrates and resumes metabolic activity to become a vegetative cell.

Important spore formers

include genera such as Bacillus and Clostridium, known for their ability to produce durable endospores.

Obligate aerobes

organisms that require oxygen for survival and growth.

Obligate anaerobes

organisms that cannot survive in the presence of oxygen and rely on anaerobic processes for growth.

Microaerophillic

organisms that require lower levels of oxygen than are present in the atmosphere, typically thriving in environments with 5-10% oxygen concentration.

Aerotolerant anaerobe

grows in the presence of oxygen but never uses aerobic metabolism