gluconeogenesis
The process by which noncarbohydrate precursor molecules are converted into glucose
One Day
The stores of glucose are enough to support metabolism of a person for
Liver
The major tissue in which gluconeogenesis takes place is the
endoplasmic reticulum
The conversion of glucose 6-phosphate to glucose takes place in the
phosphoenolpyruvate carboxykinase
The reaction that uses GTP and not ATP as its high-phosphoryl-transfer potential donor is
fructose 2,6-bisphosphate
The compound ____________ activates glycolysis and inhibits gluconeogenesis via conversion of fructose 1,6-bisphosphate
PFK2
controls the synthesis and degradation of fructose 2,6-bisphosphate
oxaloacetate
An intermediate that is decarboxylated and phosphorylated to produce
phosphoenolpyruvate
Biotin
This essential nutrient is required for the carboxylation of pyruvate in humans
Cori
The ____________ cycle is responsible for converting muscle lactate into glucose in the liver
The daily glucose requirement for a typical adult brain
120g
The amount of glucose in the bloodstream and other body fluids
20g
The process of forming glucose from amino acids
gluconeogenesis
Glycerol from fats is modified first by glycerol kinase and then a second enzyme to enter gluconeogenesis at the intermediate
dihydroxyacetone phosphate
The gluconeogenesis step responsible for reversing pyruvate kinase
PEPCK
(T/F) In spirit, gluconeogenesis is the reversal of glycolysis
False
Some amino acids are converted to glucose via conversion to pyruvate and
oxaloacetate
The enzyme that carboxylates pyruvate is oxaloacetate
pyruvate carboxylate
The cellular compartment where the first step in gluconeogenesis occurs
mitochondria
ATP in the reaction catalyzed by PEPCK is used to fix ________________ to biotin
carbon dioxide
Transport of oxaloacetate produced by PEPCK utilizes the mitochondrial and cytosolic enzyme
malate dehydrogenase
Adenosine monophosphate will have a(n) ________________ on PFK and a(n) ________________ effect on fructose 1,6-bisphosphatase.
activating / inhibiting
Hormones that activate PKA ________________ the flux of carbon to glucose.
Increase
The ________________ cycle refers to the metabolic reactions by which glucose is converted
into lactate in skeletal muscle, and then lactate is converted back into glucose in the liver.
Cori
The first step in gluconeogenesis is the ________________ of pyruvate to form oxaloacetate.
Carboxylation
Biotin provides ________________ for the pyruvate carboxylase reaction.
a long flexible arm for the active-site location of substrate, carboxylation of pyruvate, & group transfer from one site of the enzyme to another
The phosphoryl donor in the formation of phosphoenolpyruvate is
GTP
The enzymes involved in shuttling carbons involved in gluconeogenesis from the mitochondria
to the cytosol are called
malate dehydrogenase.
Glucose 6-phosphatase takes place in which cellular location?
the endoplasmic reticulum
High levels of ATP and citrate
indicate a high-energy-well-fed state, promote gluconeogenesis, & inhibit glycolysis
Phosphofructokinase (PFK) is a highly regulated enzyme. Which of the following statements
about PFK is correct?
None of the above
The bifunctional enzyme is also known as
phosphofructokinase II
Hormonal activation of cyclic AMP levels
increases the activation of gluconeogenesis.
The major site for gluconeogenesis is in which of the following tissues?
The liver
High blood sugar after a meal ________________ the level of insulin released by the pancreas
increases
In general, the liver
does not utilize glucose under starvation/low-energy conditions, acts as a glucose buffer for the rest of the body, & is a producer of glucose for the body under low-energy conditions.
Insulin resistance is a hallmark of
Type 2 diabetes
Lactate produced in muscle tissue is converted to ________________ by ________________.
glucose / the Cori cycle
The primary raw materials for gluconeogenesis are
lactate and amino acids
How many high-energy phosphate bonds are expended in gluconeogenesis?
Six