Describe the relative level of lac operon transcription high

Describe the relative level of lac operon transcription (high, low, none) and the level of cAMP (high, low) that would be found in cells utilizing the following carbon sources. How does the level of environmental glucose regulate intracellular cAMP levels? Fatty acids can be used as carbon sources for the generation of the energy. Two-carbon units are removed from fatty acids by \"oxidize-hydrolyze-oxidize.\" Remove a two carbon unit from a fatty acid (do not forget the \"SCoA steps.\" How many ATP\'s can be produced by the complete catabolism of this two-carbon unit? Per carbons oxidized to CO2, what molecule is a more efficient for energy storage, glucose or a 6 carbon fatty acid? Explain.

Solution

10) Carbon source lac operon transcription cAMP levels

glucose high low

maltose none none

lactose   none none

glucose and lactose none none

glucose and maltose none none

lactose and maltose none none

Glucose is the preferred carbon source for most bacteria

11) Concentration of glucose in the medium influence the regulation of cAMP levels.Adenylate cyclase recognizes the level of nutrients in the environment and reduces the c AMP synthesis in their presence.there is indeed a second transition affecting the intracelluar concentration of cAMP at very low concentration of external glucose concentration but this transaction is strain dependent among the laboratory cultures of E.coli.

12) Fatty acid metabolism is a catabolic process.Anabolic process that create bilologically important molecule.an important source of energy because they are reduced and anhydrous.

Fatty acid oxidation is also referred to as beta-oxidation because 2 carbon units are cleaved off at the beta-carbon position of an activated fatty acid. The cleaved 2 carbon unit forms acetyl-CoA and produced an activate fatty acid with two few carbons, acetyl-CoA, NADH, and FADH2.

NADH

8 (beta-oxidation) + 27 (TCA) = 35 NADH X 2.5 ATP/NADH = 87.5 ATP

FADH2

8 (beta-oxidation) + 9 (TCA) = 17 FADH2 X 1.5 ATP/FADH2 = 25.5 ATP

GTP

9 GTP = 9 ATP

Total ATP from complete oxidation of an 18 carbon fatty acid:

87.5 + 25.5 + 9 = 122 ATP

Subtract 2 ATP (ATP-->AMP) required for activation of the fatty acid:

122-2 = 120 ATP

13)Glucose is the more efficient for energy storage,per carbons to co2,Not only fats give energy per gram like glucose