Bacterial structures

Question 1

Chemical composition:

• Sugar bacbone with peptide side chains crosslinked by transpeptidase

Function:

• Gives rigid stupport, protects against osmotic pressure

Define structure

Answer 1

Peptidoglycan

Question 2

Chemical composition:

• Peptidoglycan for support
• Lipoteichoic acid induces TNF and IL-1

Function:

• Major surface protein

Define structure

Answer 2

Cell wall/cell membrane (gram positives)

Question 3

Chemical composition:

• Lipid A induces TNF and IL-1
• O polysaccharide is the antigen

Function:

• Site of endotoxin (lipopolysaccharide (LPS))
• major surface antigen

Define structure

Answer 3

Outer membrane (Gram negative)

Question 4

Chemical composition:

• Phospholipid bilayer

Function:

• Site of oxidative and transport enzymes

Define structure

Answer 4

Plasma membrane

Question 5

Chemical composition:

• 50 S and 30 S subunits

Function:

• Protein syntheisis

Define structure

Answer 5

Ribosome

Question 6

Chemical composition:

• Contains many hydrolytic enzymes
• including B-lactamase

Function:

• space b/t the cytoplasmic membrane and out membrane in gram negative bacteria

Define structure

Answer 6

Periplasm

Question 7

Chemical composition:

• Polysaccharide (except Bacillus anthracis which contains D-glutamate)

Function:

• Protects agianst phagocytosis

Define structure

Answer 7

Capsule

Question 8

Chemical composition:

• Glycoprotein

Function:

• Mediate adherence of bacteria to cell surface
• sex pilus forms attachement b/t 2 bacteria during conjucation

Define structure

Answer 8

Pilus/Fimbria

Question 9

Chemical composition:

• Protein

Function:

• Motility

Define structure

Answer 9

Flagellum

Question 10

Chemical composition:

• Keratin-like coat
• dipicolinic acid
• peptidoglycan

Function:

• Resistant to dehydration, heat and chemicals

Define structure

Answer 10

Spore

Question 11

Chemical composition:

• DNA

Function:

• Contains variety of genes for antibiotic resistance, enyzmes, and toxins

Define structure

Answer 11

Plasmid

Question 12

Chemical composition:

• Polysaccharide

Function:

• Mediates adherence to surfaces, especially foreign surfaces (e.g. indwelling catherters)

Define structure

Answer 12

Glycocalyx