The reason for the diffusion of IP 3 into cytosol, while, the DAG remains in the membranes is to be discussed. Concept introduction: The chemical messengers that pass information from the source part to the target part are called hormones. A molecule that acts as a bridge between the hormone and the target part is called the second messenger. The hormones that principally control carbohydrate metabolism are epinephrine, glucagon, and insulin.

Question

The enzyme lactate dehydrogenase (LDH) catalyzes the conversion of pyruvate to lactatein skeletal muscle cells using NAD/NADH during anaerobic “balanced” fermentation.Answer the following questions about this reaction. (a) Write out the two reductive half reactions and indicate the E ̊' for each half reaction. Write out the full balanced reaction for the pyruvate to lactate rxn and indicate the ∆E ̊' for the reaction. (b) What is the free energy change under standard state conditions for thisreaction? Which direction is spontaneous?(c) Assume that in skeletal muscle cells the ratio of [NAD+] to [NADH] is 100, and that the[pyruvate] = 0.40 mM and [lactate] = 4.0 mM. What is the free energy change (∆G')for the conversion of pyruvate to lactate? Indicate the direction in which the reactionis spontaneous under these cellular conditions.

Answer 1

Question

Chapter 24, Problem 42RE

Interpretation Introduction

Interpretation:

The reason for the diffusion of IP3 into cytosol, while, the DAG remains in the membranes is to be discussed.

Concept introduction:

The chemical messengers that pass information from the source part to the target part are called hormones.

A molecule that acts as a bridge between the hormone and the target part is called the second messenger.

The hormones that principally control carbohydrate metabolism are epinephrine, glucagon, and insulin.

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