fermentation

Question 1

fermentation

Answer 1

-occurs in the cytoplasm
-glucose is partially oxidized
-2 ATP per glucose are produced by substrate-level phosphorylation
-in all types, NAD+ is regenerated to keep glycolysis going

Question 2

lactic acid fermentation

Answer 2

-pyruvate is the electron acceptor; lactate is the product
-microorganisms, higher plants, and vertebrate muscle tissue
-lactate dehydrogenase catalyzes fermentation

Question 3

alcoholic fermentation

Answer 3

-yeasts and some plant cells
-requires 2 enzymes to metabolize pyruvate to ethanol
-products are ethanol, CO2, and 2 ATP
-used to produce alcoholic beverages, ethanol fuel, and non-sourdough bread

Question 4

catabolic interconversions

Answer 4

-polysaccharides are hydrolyzed to glucose > enters glycolysis
-lipids are broken down
-glycerol > DHAP > glycolysis
-fatty acids > acetyl CoA > citric acid cycle
-proteins are hydrolyzed to amino acids > glycolysis or citric acid cycle

Question 5

anabolic interconversions

Answer 5

-most catabolic reactions are reversible
-gluconeogenesis- citric acid cycle and glycolysis intermediates are reduced to form glucose
-Acetyl CoA can be used to form fatty acids
-citric acid cycle intermediates can be used to synthesize nucleic acid components

Question 6

Mechanisms that regulate rates of each step in a metabolic pathway:

Answer 6

-change the amount of active enzyme by regulating gene expression
-change enzyme activity by covalent modifications, such as phosphorylation
-feedback inhibition by allosteric enzymes
-substrate availability: if the substrate of a particular enzyme is used up by another pathway, the first enzyme can no longer function, and the pathway shuts down