Gluconeogenesis pt 1

Liver, kidney

The major site of Gluconeogenesis is the _____, however it can also occur in the _____

Lactate, amino acids, glycerol

The 3 major precursors to glucogeogenesis

Pyruvate, glucose

The gluconeogenesis pathway converts ____ into _____

Substrate cycle

The 3 irr steps in glycolysis must be BYPASSED in Gluconeogenesis by a ______

Same

The direction of the pathway is reciprocally regulated so that glycolysis and gluconeogenesis DON’T at the ____ time

Substrate cycle

A pair of rxns that are NOT fully active at the same time because of reciprocal allosteric controls

PEP and Pyruvate, F6P and F-1,6-biphosphate, Glucose and G6P

What are the 3 substrate cycles in Gluconeogenesis?

• __________ substrate cycle ( Pyruvate kinase )

• _______ substrate cycle ( PFK)

• ________ substrate cycle (Hexokinase)

futile cycle

Cycles that run concurrently in opposite directions and essentially “cancel”  each other out

inc

Substrate cycles can _____ metabolic signals w/ the overall FLUX

diff

Substrate cycles are ATP driven cycles that operate at 2 ____ rates

6

An input of ____ ATP equivalents is needed for gluconeogenesis

• thus, this amount of ATP is needed to make 1 molecule of glucose from 2 molecules of pyruvate

anabolic

Gluconeogenesis is anabolic/catabolic ?

pyruvate carboxylase, PECK , F-1,6-biphosphatase, G6phosphatase

what are the 4 new enzymes in Gluconeogenesis to bypass the 3 IRR rxns in Glycolysis?

ligase

What type of enzyme is pyruvate carboxylase?

Phosphoryl coupled oxidation

What type of RXN is PECK?

hydrolase

What type of enzyme is F-1,6-biphosphate?

hydrolase

What type of enzyme is G6phosphatase ?

PEP, OAA, mitochondria, biotin, 4

Gluconeogenesis step 1: Pyruvate Carboxylase

• The conversion of pyruvate into _____ begins with the formation of _______in the _______ by pyruvate carboxylase

• Pyruvate carboxylase uses the vitamin _____ as a coenzyme

• its reaction mechanism occurs in ______ steps.

malate, cytoplasm, OAA, NADH, PEP

Gluconeogenesis step 2: PECK

• In the mitochondrion, Oxaloacetate (OAA) is reduced to _____ and transported into the ______ where it is reoxidized into _____ with the generation of cytoplasmic _______

• _____ is then synthesized from OAA by PECK

PEP Carboxykinase

PECK is short for _____

PEP, hydrolysis, F-1,6-biphosphate

Gluconeogenesis step 9: F-1,6-biphosphate

• ______ is metabolized by the enzymes of glycolysis in the reverse direction until the next irreversible step:

  • the _______ of of _______

• Enzyme catalyzing this hydrolysis reaction is F-1,6-biphosphatase

glucose, liver, G6P, ER, G6P, glycogen

Gluconeogenesis step 11: G6phosphatase

• The generation of free ______, which occurs essentially only in the _____ is the final step of gluconeogenesis

• ________ is transported into the lumen of the ______

• G6phosphatase (an integral membrane on the inner surface of the ER), catalyzes the formation of glucose from _______

• In tissues that do not dephosphorylate glucose, G6P is converted into ______ for storage

abundant, needed

Glycolysis will be predominate when glucose is _____ and ATP is ________

reciprocally

Gluconeogenesis and Glycolysis Are _____ regulated

irr

Pyruvate Carboxylase

• rev or irr?

rev

PECK

• rev or irr?

irr

F-1,6-biphosphatase

• rev or irr?