Microbio exam 1 chapter 4

What structures do all bacteria have?

Cell membrane, cytoplasm, DNA (nucleoid), ribosomes, and usually a cell wall.

Which bacteria lack a cell wall?

Mycoplasma.

What extra structures do some bacteria have?

Capsule, flagella, pili, fimbriae, endospores, plasmids.

What are the three main bacterial shapes?

Coccus (round), bacillus( rod/pill) , spirillum/spirochete(spiral)

What is pleomorphism?

The ability of bacteria to change shape and size.

Name bacterial arrangements.

Pairs (diplo)

Chains (strepto)

Clusters (staphylo),

Tetrads

Palisades.

What is a glycocalyx?

A sticky outer coating that helps with protection and biofilm formation.

What is the function of a capsule?

Prevents phagocytosis and increases virulence.

What is the function of flagella?

Movement and spread of infection.

What are fimbriae used for?

Attachment to surfaces.

What are pili used for?

DNA transfer during conjugation.

What is the function of nucleoid in bacterial internal structures?

Contain genetic information

What is the function of ribosomes in bacterial internal structures?

Is 70s and is in charge of protein synthesis

What is the function of plasmids in bacterial internal structures?

It offers antibiotic resistance

What is the function of endospores in bacterial internal structures?

It allows for survival in harsh conditions 

What are the parts of the flagella?

It consists of filament, hook, basal body

What is the arrangement of flagella?

It ussualy is monotrichous, lophotrichous,  amphitrichous, and peritrichous 

 

Describe gram-positive cell walls.

Thick peptidoglycan, teichoic acids, stain purple.

Describe gram-negative cell walls.

Thin peptidoglycan, outer membrane, LPS with lipid A, stain red.

What component causes severe symptoms in gram-negative infections?

Lipid A (endotoxin).

What causes necrotizing fasciitis?

Streptococcus pyogenes

What causes bacterial meningitis?

Streptococcus pneumoniae and Neisseria meningitidis

What causes tuberculosis?

Mycobacterium tuberculosis

What causes peptic ulcers?

Helicobacter pylori

What causes chlamydia?

Chlamydia trachomatis