Gluconeogenesis Flashcards
(19 cards)
Primary fuel of the BRAIN and RED BLOOD CELLS
Glucose
An average human requires __ of glucose a day.
160
Glucose __% of this daily requirement is consumed by the brain
75%
During prolonged __, glucose
must be synthesized from non-carbohydrate
precursors.
starvation/fasting
Synthesis of glucose from __
precursors:
• Pyruvate, lactate, glycerol, some amino
acids, TCA cycle intermediates
non-carbohydrate
Occurs when glycogen reserves are already __.
depleted
NOT the exact reverse of glycolysis
• Differs in the irreversible steps
• Enzymes that catalyze the reversible steps are the __
same
Occurs in the MITOCHONDRIAL MATRIX
Pyruvate to OAA
1b. OAA to Malate
Once formed, malate is then transported across
the mitochondrial membrane to the
cytosol
Gluconeogenesis Overall Reaction
Glucose + 4 ADP + 2 GDP + 6 Pi + 2 NAD+
Why DOESN’T AN INDIVIDUAL FEEL HUNGRY while
drinking alcoholic beverages?
• Sensation of hunger means that gluconeogenesis is __.
occurring
Alcohol Metabolism
GNG inhibition by alcohols
• __ promotes reduction of oxaloacetate back
to malate
NADH
GNG inhibition by alcohols
No __ becomes AVAILABLE for gluconeogenesis
OAA
GNG and Hypoglycemia
• After a __ plenty of alcoholic drink, an
individual feels very hungry
night’s
GNG and Hypoglycemia
Physiological conditions:
• GNG is INHIBITED when alcohol is metabolized.
• Glycogen reserves are __
depleted
Blood glucose levels are significantly low:
HYPOGLYCEMIA
__ is in the danger of being deprived of glucose.
Brain
GNG and Glycolysis in tandem
• During a STRENUOUS EXERCISE:
• ATP requirements shoot up to a level that
cellular respiration cannot compensate.
• O² SUPPLY in the muscle becomes DEPLETED.
• ETC and Krebs cycle __.
• Conditions become ANAEROBIC that pyruvate
is diverted for LACTATE PRODUCTION.
Stop
Lactate accumulation in the muscle is later on
suppressed by the
Cori Cycle
