Lecture 1 Additional Study

What is the mechanism of LPS

It acts as an endotoxin, being released upon bacterial death and eliciting a potent innate immune response in the host. While small amounts of endotoxin are part of the body's warning system, excessive amounts can overstimulate the immune response, leading to severe illness.

what is a capsule (virulence factor) made up of?

An outer layer primarily made of polysaccharides. Its presence varies among bacteria.

what is the function of the capsule?

Offers various benefits, including aiding in adherence to surfaces, defending against the host's immune system, and general protection. Specifically, capsules can act as antiphagocytic factors by concealing bacterial features from phagocyte receptors.

what kind of bacteria can sporulate and become endospores?

gram positive bacteria

What is a bacteriophage?

a type of virus that specifically infects and replicates inside bacteria

what is inside a capsule

ribosomes and DNA

where can you find LTA? what is its function?

in the peptidoglycan of gram + bacteria. its function includes supporting the thick peptidglycan layer. It has an endotoxin function, but is not as strong as LPS

why can strict aerobes function in oxygen, and strict anaerobes cannot

they have enzymes capable of breaking down oxygen radicals, strict aerobes do not possess these enzymes so they cannot be in the presence of oxygen

what happens during the lag phase

cells are adapting to their environment, turning genes on and off to prepare to grow

what are the chemical requirements for growth

carbon, nitrogen phosphorus, sulfur, iron, and various minerals (Ca, K, Mo, Zn, Co)

why is it required that cells be in an aqueous environment

for the diffusion of nutrients and waste products

for the H+ and OH- ions that cells need

required environmental conditions for cells

temp

pH

osmotic conditions

O2 content

what happens if environmental conditions arent met

slowing of enzymes leading to decrease in growth of cells. If conditions are too bad, the cell can die