Microbiology Bacteria - Lecture Notes

A set of vocabulary flashcards covering key terms and concepts in microbiology, particularly focused on bacteria and their characteristics.

Bacteria

Single-celled microorganisms that can exist either as independent (free-living) organisms or as parasites.

Psychrophiles

Bacteria that thrive at relatively low temperatures, typically below 15 °C.

Mesophiles

Bacteria that grow optimally at moderate temperatures, typically between 20 °C and 45 °C.

Thermophiles

Bacteria that grow optimally at high temperatures, typically between 45 °C and 80 °C.

Helicobacter pylori

A type of bacteria that can survive in acidic environments, such as the stomach, and is associated with ulcers.

Obligate aerobes

Bacteria that can only grow in the presence of oxygen.

Obligate anaerobes

Bacteria that cannot grow in the presence of oxygen.

Facultative anaerobes

Bacteria that can grow with or without oxygen.

Gram Stain

A laboratory technique used to identify and differentiate bacterial species based on the characteristics of their cell walls.

Gram Positive

Bacteria with a thick layer of peptidoglycan in their cell wall, retaining the crystal violet stain used in Gram staining.

Gram Negative

Bacteria with a thinner peptidoglycan layer and an additional outer membrane, which do not retain the crystal violet stain.

Normal Flora (Microbiota)

The myriad of microorganisms that reside on or in the human body without causing disease.

Beneficial roles of Normal Flora

Includes competition with pathogens, stimulation of immunity, and synthesis of vitamins.

Opportunistic infections

Infections that occur when the immune system is compromised, allowing normally harmless bacteria to cause disease.

Endotoxins

Toxins contained within the bacterial cells that are released when the bacteria die, potentially causing harmful effects.