Biochem Exam 2 (3-4) Flashcard
Flashcard maker : Patricia Smith
where does the Pentose Phosphate Shunt happen?
this is a product of PPP and it is necessary to make nucleotides and deoxynucleuotides
this product of the PPP is primarily involved in reduction reactions and is most prominent in making fatty acids and dealing with oxidative damage
in the liver, about ____% of liver glucose metabolism goes through the PPP but it is higher in places where you make ___________
5-10 fatty acids (adipocytes)
what does NADPH stand for?
nicotinamide adenine dinucleotide-phosphate (Derived from Niacin)
NADPH is prominent in synthesis of ______ and detoxification of
fatty acid, cholesterol, neurotransmitter, nucleotide, reduction of oxidized glutathion e, cytochrome P450 monooxygenases
thiamine containing enzyme that moves 2 carbon units and has been used to measure thiamine concentrations in people by measuring enzyme activity
if you have a thiamine deficiency, you will develop ____________ which most often comes up in alcoholics and gives rise to ___________
wernicke-korsakoff syndrome wet or dry beriberi
what is the function of transaldolase?
move 3 carbons
the first committed step in the pathway, where regulation primarily occurs, is at _________
glucose-6P to phosphogluconolactone by G6PDH
in PPP, G6PDH is activated by _________ and deactivated by __________
since the kM of G6PDH is ______ than the concentration of [NADPH] in the committed step of PPP, this means that the reaction favors ___________ and must be inhibited
what are the names of the steps, in order, of oxygens oxidation states?
molecular oxygen superoxide radical ion hydrogen peroxide hydroxyl radical
what is the most reactive oxygen species? (can break DNA and lead to mutations in patients)
superoxide reacts with hydrogen peroxide to produce hydroxyl radical
hydrogen peroxide reacts with iron to produce hydroxyl radical
this is caused by a deficiency in NADPH oxidase and it results in multiple fungal infections and problems fighting pathogenic infection
Chronic Granulomatous Disease
hydrogen peroxide makes hydrochloric acid through ___________ which is also used to generate bleach
what are the diseases thought to be associated with free radical injury?
atherogenesis, ischemia (reperfusion injury), alcoholism, ALS, acute renal failure, emphysema
this occurs after an ischemic attack and happens when the blood supply is restored suddenly, leading to a burst of oxygen and a shower of oxygen radicals
this is a major problem caused by peroxides because it disrupts membrane structures
oxygen radicals can attack _____, _____, and ______
lipids, carbs, proteins
what vitamins/bioflaivonoids that can be used to protect ourselves from free radical damage?
vitamin a, vitamin c, vitamin e, green tea, turmeric, chocolate
this enzyme converts superoxide to hydrogen peroxide
Superoxide Dismutase (SOD)
_________ reduces peroxides into water and at the same time, it is oxidized into _______
glutathione Peroxidase (GSH) GSS
glutathione is a _________ containing enzyme and since it is ___________, it is responsible for the ________ environment of the cytoplasm of cells
inside of the cell, _____ bonds are common and outside of the cell (also in the ER), ____ bonds are common
NADPH produced by _____________ maintains the supply of glutathione needed to destroy peroxides
a deficiency in _________ is extremely common with a similar distribution as malaria and sickle cell anemia since they all affect red blood cells
when you have a G6PDH deficiency, __________ form in RBC’s when the cells are exposed to an oxidizing chemical in vitro. These form (like a precipitation of hemoglobin) due to the ________ bonds between hemoglobin molecules since there is not enough reducing activity to keep the hemoglobins in a ______ state
heinz bodies disulfide SH
these are immature RBC’s often seen as a side effect in someone with a G6P DH deficiency
if you put _______ stress on a person who has a glucose-6-phosphate Dehydrogenase activity, there will be displayed symptoms. Situations that put this type of stress are…
oxidative, sulfonamides, aspirin, NSAIDs, Quinine, Quinadine, Napthylene, Fava Beans
in glucose-6-phosphate dehydrogenase deficiency, what change in the normal red blood cell leads to hemolytic anemia?
decreased concentration of NADPH, defect in GSSG
why are RBC’s so sensitive to NADPH?
they only have one way to make NADPH!
why dont RBC’s do the TCA cycle?
they don’t have a mitochondira
glycogen is the main source of energy until about ____ hours of starvation in which ________ becomes the main source of glucose
In Claude Bernard’s Experiment, he concluded that dogs do not eat carbohydrates from looking at the portal vein which _______ the liver and has a _____ glucose conc and the hepatic vein which _______ the liver and has a _______ glucose conc
enters low leaves high
approximately 90 % of gluconeogenesis occurs in the ______, 10% in the ________ and the fraction of glycolysis increases in the _________ during starvation
liver kidney kidney
what are the precursors for gluconeogenesis?
pyruvate, lactate, amino acids, glycerol
this GNG precursor comes from pyruvate
this GNG precursor comes from pyruvate and TCA intermediates
this GNG precursor comes from dihydroxyacetone phosphate
the reaction of GNG that involves pyruvate carboxylase takes place in what sub-cellular location?
the reaction of GNG that involves glucose-6-phosphatase occurs in what sub-cellular location?
what are the reactants of gluconeogenesis?
2 Pyruvate, 4 ATP, 2 GTP, 2 NADH, 2 H
what are the products of gluconeogenesis?
glucose, 2 ADP, 2 GDP, 2 NAD+, 6 Pi
oxaloacetate is converted to ______ or ______ to be transported out of mitochondria
in order to transport oxaloacetate out of the mitochondira, it has to be ________ to malate in the mitochondria and then ________ back to oxaloacetate in the cytoplasm
the mitochondria has a _______ environment and the cytoplasm has a ___________ environment
oxaloacetate is converted to aspartate in the mitochondria via __________ from glutamate and then converted back to oxaloacetate in the cytoplasm by ____________
transamination cytoplasmic transaminase
the cofactors necessary for pyruvate carboxylase activity are _______, _______, and _______ ions and the activator necessary is ________
biotin, magnesium, manganous, acetyl CoA
Biotin is covalently attached to __________. When it is attached, it functions as a carrier of _________
carboxylase protein activated CO2 (HCO3-)
this binds biotin with a high affinity and therefor can prevent pyruvate carboxylase from converting pyruvate to oxaloacetate
what proteins are involved in Glucose-6-Phosphatase’s complex function?
phosphatase, translocase 1, translocase 2
this subunit of G6Pase is on the side of the membrane that is not in direct contact with the cytoplasm. It catalyzes hydrolysis of G6P to glucose
this subunit of G6Pase mediates transport of glucose-6-phosphate from the cytoplasm to the opposite side of the ER membrane, where the phosphatase enzyme is located
T1 (translocase 1)
this subunit of G6Pase mediates transport of the phosphate back to the cytosol
T2 (translocase 2)
these are the only cells able to convert G6P back to Glucose aka the only cells with glucose-6-phosphatase activity. They are responsible for returning glucose back to circulation after its absorption from portal blood, intestinal lumen, or glomerular filtrate.
liver, intestine, kidney .
how is glucose-6-phosphatase in the liver different from others?
maintains blood glucose levels, maintains supply of glucose to other tissues, rate of catalysis depends on substrate supply, not regulated by feedback inhibition
pyruvate dehydrogenase converts pyruvate to _______ and is inhibited by ________ and _________
Acetyl CoA NADH ATP
pyruvate carboxylase is stimulated by high levels of __________ and ________
pyruvate, Acetyl CoA
pyruvate dehydrogenase is ___________ by insulin and _________ by phosphorylation of serine at its E1a subunit
Fructose-1,6-bisphosphatase is inhibited by _________ and ________ and activated by _________
AMP F-2,6-Bisphosphate Citrate
conversion of PEP to Glucose is ______ by Glucagon and ________ by Insulin
Pyruvate Carboxykinase is . activated by _______ and ________ and inhibited by _______
glucagon steroids insulin
Insulin targets ______ but Glucagon does NOT
Insulin targets ______ metabolism but Glucagon does NOT
in gluconeogenesis, PFK2 is _______ when it is phosphorylated
glucocorticoids increase the synthesis of __________ and __________
PEP carboxykinase, glucose-6-phosphatase
this is the process of transporting lactate from muscle and erythrocytes to the liver for re-synthesis of glucose. This process means that erythrocytes and muscles can . use glycolysis efficiently since they don’t have to supply the energy for glucose!
this is when pyruvate in the muscle is transaminated into Alanine, brought to the liver, and transformed back into pyruvate, giving off its amino group for another transamination reaction
what are the major metabolic problems of individuals with deficiencies . in gluconeogenic enzymes?
hypoglycemia, acidosis (from build up of substrates such as lactate, pyruvate, and alanine)
what are the symptoms associated with hypoglycemia or acidosis from metabolic problems with individuals in gluconeogenesis?
adrenergic effect responses (anxiety, sweating, heart palpation) or neuroglycopenia (confusion, coma, seizures, death)