Phosphofructokinase Is Regulated by a Number of Factors, Including High

question 24

Multiple Choice

Phosphofructokinase is regulated by a number of factors, including high levels of ATP.Why is this enzyme regulated by ATP levels?

• A)If ATP levels are high, this provides a mechanism to directly inhibit the Krebs cycle, thus preventing further generation of NADH, FADH₂ and ATP molecules that are not needed.
• B)If ATP levels are high, it is important to directly inhibit the reaction that commits the substrate to glycolysis to allow the substrate to be available for other reactions, since the cell has ample energy.
• C)If ATP levels are high, it is important to inhibit ATP synthase, and phosphofructokinase directly inhibits ATP synthase.
• D)If ATP levels are high, this provides a mechanism to directly inhibit the electron transport chain, thus preventing the formation of a proton gradient in the intermembrane space of mitochondria.

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Definitions:

Carrying Value

The value at which an asset is recognized on the balance sheet, factoring in depreciation, amortization, and impairment charges.

Fair Value

An estimate of the price at which an asset or liability could be traded in a current transaction between willing parties, other than in a forced or liquidation sale.

Goodwill

represents the excess of the purchase price over the fair value of the net assets of the acquired company in a business combination.

NCI

Non-Controlling Interest, a line item on the consolidated balance sheet that reflects the equity in a subsidiary not attributable directly or indirectly to the parent company.