Microbiology - Bacterial Structures

Front 1

Function and chemical composition of bacterial structure: Peptidoglycan

Back 1

Function: 1. Rigid support 2. Protects against osmotic pressure Chemical composition: Sugar backbone with cross-linked peptide side chains

Front 2

Function and chemical composition of bacterial structure: Cell wall/cell membrane - Gram positive

Back 2

Gram positives only, Function: Major surface antigen, Chemical composition: Teichoic acid, which induces TNF and IL-1

Front 3

Function and chemical composition of bacterial structure: Outer membrane - gram negative

Back 3

Gram negatives only, Function: Site of endotoxin (lipopolysaccharide) and major surface antigen, Chemical composition: Lipid A induces TNF and IL-1, and polysaccharide is the antigen

Front 4

Function and chemical composition of bacterial structure: Plasma membrane

Back 4

Function: Site of oxidative and transport enzymes Chemical composition: Lipoprotein bilayer

Front 5

Function and chemical composition of bacterial structure: Ribosome

Back 5

Function: Protein synthesis, Chemical composition: 50S and 30S subunits

Front 6

Function and chemical composition of bacterial structure: Periplasm

Back 6

Function: Space between the cytoplasmic membrane and outer membrane in gram-negative bacteria, Chemical composition: Contains many hydrolytic enzymes, including beta-lactamases

Front 7

Function and chemical composition of bacterial structure: Capsule

Back 7

Function: Protects against phagocytosis, Chemical composition: Polysaccharide (except Bacillus anthracis which contains D-glutamate)

Front 8

Function and chemical composition of bacterial structure: Pilus/fimbria

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Function: Mediates adherence of bacteria to cell surface; sex pilus forms attachment between 2 bacteria during conjugation, Chemical composition: Glycoprotein

Front 9

Function and chemical composition of bacterial structure: Flagellum

Back 9

Function: Motility, Chemical composition: Protein

Front 10

Function and chemical composition of bacterial structure: Spore

Back 10

Function: Provides resistance to dehydration, heat, and chemicals, Chemical composition: Keratin-like coat and dipicolinic acid

Front 11

Function and chemical composition of bacterial structure: Plasmid

Back 11

Function: Contains a variety of genes for antibiotic resistance, enzymes, and toxins, Chemical composition: DNA

Front 12

Function and chemical composition of bacterial structure: Glycocalyx

Back 12

Function: Mediates adherence to surfaces, especially foreign surfaces (eg indwelling catheters), Chemical composition: Polysaccharide

Front 13

Function of this structure: IgA proteases

Back 13

Function: Allow some organisms to colonize mucosal surfaces

Front 14

Which bacteria have IgA proteases?

Back 14

1. Streptococcus pneumoniae 2. Neisseria meningitidis 3. Neisseria gonorrheae 4. Hemophilus influenzae