7. Prokaryotic Cell Structures & Functions

Which of the following is not a chemical component of a bacterial cell wall?

Gram negative cell walls contain fewer layers of _____ than gram positive cell walls.

The following outline can be used to identify important bacteria. Fill in a representative genus in the space provided.

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DRAW IT Draw a key to differentiate the following bacteria: cyanobacteria, Cytophaga, Desulfovibrio, Frankia, Hyphomicrobium, methanogens, myxobacteria, Nitrobacter, purple bacteria, Sphaerotilus, and Sulfolobus.

Which of the following pairs is mismatched?

a. anaerobic endospore-forming gram-positive rods—Clostridium

b. facultatively anaerobic gram-negative rods—Escherichia

c. facultatively anaerobic gram-negative rods—Shigella

d. pleomorphic gram-positive rods—Corynebacterium

e. spirochete—Helicobacter

Identify the bacteria involved in respiratory infections using the following laboratory test results:

Gram-positive cocci

Catalase-positive: a. ____________________________________

Catalase-negative

Beta-hemolytic, bacitracin inhibition: b. ____________________________________

Alpha-hemolytic, optochin inhibition: c. ____________________________________

Gram-positive rods

Non-acid-fast: d. ____________________________________

Acid-fast: e. ____________________________________

Gram-negative cocci: f. ____________________________________

Gram-negative rods

Aerobes

Coccobacilli: g. ____________________________________

Rods

Grow on nutrient agar: h. ____________________________________

Require special media: i. ____________________________________

Facultative anaerobes

Coccobacilli: j. ____________________________________

Intracellular parasites

Form elementary bodies: k. ____________________________________

Do not form elementary bodies: l. ____________________________________

Wall-less: m. ____________________________________

Complete the Venn diagram that compares and contrasts Gram-positive and Gram-negative bacteria.

Which cellular structure is important in classifying a bacterial species as Gram positive or Gram negative?

a. Flagella

b. Cell wall

c. Cilia

d. Glycocalyx