Glucogenesis Flashcards
The metabolic process by which organisms produce sugars (namely glucose) for catabolic reactions from non-carbohydrate precursors is called?
Gluconeogenesis or glucogenesis
The formation of glucose and other carbohydrates from other classes of compounds in living cells is called?
Gluconeogenesis or glucogenesis
The importance of gluconeogenesis are?
It produces glucose for the brain and body
Gluconeogenesis occurs when the dietary intake of glucose is _____ to meet the requirements of the brain and body
Insufficient
The daily glucose requirement of the brain of a typical adult human being is about?
120 grams
The daily glucose requirement of the body of a typical adult human being is about?
160 grams
The amount of glucose present in the body fluids of a typical adult human is?
20 grams
The amount of glucose gotten from glycogen is?
190 grams
Gluconeogenesis occurs in all?
Animals
Plants
Fungi
Microorganisms
The major non-carbohydrate precursors used in gluconeogenesis are?
Lactate
Pyruvate
Amino acids
Glycerol
The major site of gluconeogenesis is the?
Liver
The minor site of gluconeogenesis occurs in the?
Kidneys
Little gluconeogenesis also occurs in the?
Brain
Heart muscle
Skeletal muscle
Four functions of gluconeogenesis are?
Maintenance of glucose level
Control of acid-base balance
Maintenance of amino acid balance
Provision of biosynthetic precursors
Gluconeogenesis controls acid-base balance by?
Converting lactate continuously into glucose in the liver
Producing NH3 by amino acids deamination to neutralise acids excreted in urine
The removal of an amino group from an amino acid molecule to convert it into ammonia is called?
Deamination of amino acids
A medical condition characterized by the buildup of lactate (especially L-lactate) in the body, with formation of an excessively low pH in the bloodstream is called?
Lactic acidosis
A metabolic pathway in which lactate produced by anaerobic glycolysis in muscles is transported to the liver and converted to glucose, which then returns to the muscles and is cyclically metabolized is called?
The Cori cycle ( lactic acid cycle)
Who discovered the Cori Cycle?
Carl Ferdinand Cori and Gerty Cori
Gluconeogenesis maintains amino acid balance by?
Degradation of excess amino acids
Synthesis of the deficient amino acids through gluconeogenesis intermediates
Gluconeogenesis provides biosynthetic precursors for the synthesis of?
Glycoproteins
Glycolipids
Structural carbohydrates
The starting material for glycolysis is__1__ while the end product is __2__
- Glucose
2. Pyruvate
The starting material for gluconeogenesis is__1__ while the end product is __2__
- Pyruvate
2. Glucose
Gluconeogenesis and glycolysis aren’t ______ running in opposite directions
Identical pathways
____ of ten enzymatic steps of gluconeogenesis are a reversal of glycolysis
Seven
____ reactions(steps) of glycolysis cannot be used in gluconeogenesis
Three
A chemical reaction where the change in the free energy is negative is called?
An exergonic reaction
The three bypass reactions of gluconeogenesis are?
Conversion of pyruvate into phosphoenolpyruvate
Conversion of fructose-1,6-bisphosphate into fructose-6-phosphate
Conversion of Glucose-6-phosphate into free glucose
The first bypass of gluconeogenesis is called?
Conversion of pyruvate into phosphoenolpyruvate
The enzymes involved in the Conversion of pyruvate into phosphoenolpyruvate(PEP) are?
Pyruvate carboxylase
PEP carboxykinase
Malate dehydrogenase
Pyruvate carboxylase converts pyruvate into?
Oxaloacetate
Pyruvate carboxylase is found on the?
Mitochondria
Oxaloacetate is converted into __1__ by __2__
- Malate
2. Malate dehydrogenase
Why is Oxaloacetate converted into malate?
To enable it to pass through the mitochondria membranes
After crossing through the mitochondria membranes, malate is converted back into oxaloacetate by malate dehydrogenase in the?
Cytoplasm
Lastly oxaloacetate is converted into PEP by?
PEP carboxykinase
The second bypass of gluconeogenesis is the?
Conversion of fructose-1,6-bisphosphate into fructose-6-phosphate
The conversion of fructose-1,6-bisphosphate into fructose-6-phosphate in gluconeogenesis differs from glycolysis by using?
The enzyme fructose-1,6-phosphatase
The conversion of fructose-6-P into glucose-6-P in gluconeogenesis uses the same enzyme as glycolysis called?
Phosphoglucoisomerase
The third bypass of gluconeogenesis is?
Conversion of Glucose-6-phosphate into free glucose
The Conversion of Glucose-6-phosphate into free glucose in gluconeogenesis is carried out by the enzyme?
Glucose-6-phosphatase
Glucose-6-phosphatase is located in the?
Endoplasmic reticulum
Gluconeogenesis occurs because of?
Hypoglycemia(low blood sugar levels)
Hormones assisting gluconeogenesis are?
Cortisol
Thyroxine
Glucagon
Epinephrine
