Exam 1 Study Questions

Question 1

Compare and contrast Gram (-) and Gram (+) bacteria in at least 5 ways, describing structures and features.

Answer 1

Gram positive
-Thick peptidoglycan layer
-no outer lipid membrane
-no O-specific side chains present
-Teichoic acids present
-NAM is linked by a peptide interbridge
-gel-like layer below peptidoglycan layer

Gram negative
-Thin peptidoglycan layer
-Outer lipid membrane present
-O-antigen side chains present
-Teichoic acids not present
has periplasm
-Lipid A
-has porins in the upper membrane

Question 2

Describe the composition of the lipid bilayer. Explain why it is semi-permeable.

Question 3

Describe endospore formation. Explain how this state is helpful to bacteria.

Question 4

Describe the starting reactants and end products of glycolysis, the TCA cycle, and the Pentose Phosphate Pathway and Photosynthesis and indicate the useful intermediates/ connections between each of these pathways.

Answer 4

Starting reactants:
-Glycolysis:
-TCA cycle:
-PPP:
-Photosynthesis:

End products:
-Glycolysis:
-TCA cycle:
-PPP:
-Photosynthesis:

Question 5

What is fermentation? What is its metabolic purpose? Name two molecular products and the medical significance of these products.

Answer 5

-Fermentation: anaerobic pathway for breaking down glucose by using glycolysis. It doesn’t finish oxidizing glucose.
-The metabolic purpose: stops short of oxidizing glucose and uses organic intermediates as terminal electron acceptors.
-molecular processes: Lactic acid which is used for food preservation and propionic acid which is used for dairy fermentation

Question 6

Compare and contrast prokaryotes and eukaryotes in at least 5 ways, describing structures and features.

Answer 6

Prokaryotes:
-No Nucleus
-unicellular
-smaller
-have a cell wall
-DNA is circular

Eukaryotes:
-Have a nucleus
-membrane-bound organelles
-mostly multicellular
-larger
-DNA is linear