MT2 Flashcards
Glucogenic
Metabolites that can be converted to glucose through gluconeogenesis
Ketogenic
Metabolites that cannot be converted to glucose through gluconeogenesis
Aerobic respiration approx ATP yield
32
Anaerobic resp approx ATP yield
2
Regulation of the citric acid cycle (3)
Allosteric feedback inhibibition
Allosteric activation by ADP
Product inhibition
Cataplerotic reactions
Are reactions that take intermediates of TCA cycle out to make other things.
Anaplerotic reactions
Are reactions that replenish the intermediates of the TCA cycle
pyruvate carboxylase anapleurotic or catapleurotic?
anapleurotic and gluconeogenic because it generates oxaloacetate from pyruvate using ATP
Pyruvate: Aerobic oxidation
Pyruvate –> acetyl CoA and oxidation to the TCA cycle
Pyruvate: anaerobic fermentation
cytosolic regeneration of NAD+
by production of lactate or ethanol
Pyruvate: anapleurotic carboxylation
conversion of pyruvate to oxaloacetate by pyruvate carboxyalse
Reciprocal regulation of pyruvate carboxylase and pyruvate dehydrogenase by Acetyl-CoA
When Acetyl-CoA levels are high, it inhibits pyruvate dehydrogenase and activates pyruvate carboxylase.
Pyruvate dehydrogenase complex
catalyzes the IRREVERSIBLE oxidative decarboxylation of pyruvate to Acetyl CoA
- provides oxalo so that the TCA cycle has enough intermediates to use the Acetyl CoA
- saves glucose when energy can come from fat
Reactions forming QH2
Complex 1 oxidizes NADH
Complex 2 oxidizes succinate and then FADH2
Fatty acid oxidation produces QH2
Glycerol 3 phosphate shuttle indirectly
cytochrome c
a small membrane soluble protein containing a heme prosthetic group
P:O ratio
number of phosphorylations of ADP per number of oxygen atoms reduced.
Not a whole number because ATP synthesis is imperfectly linked to electron transport.
The rate of oxidative phosphorylation depends on the rate of fuel catabolism. Relies on having NADH and QH2
Uncoupling in oxphos is?
Dissipation of the proton gradient without ATP synthase.
Achieved by uncoupling proteins or chemicals.
Some is always happening, and can help reduce free radicals.
May even cause ATP synthase to work in reverse, hydrolyzing ATP
Generates heat
Chylomicrons
Transport triaglycerols from intestines to adipose and other tissues.
After TGs are taken up by the adipose tissue, the remaining lipoprotein is taken up by the liver
VLDL
Transport TG from liver to adipose and other tissues.
After TG taken up by adipose tissue, the remaining lipoproteins have mostly cholesterol and are mostly LDL
LDL
Taken up by peripheral tissues to get cholesterol.
LDL not taken up by cholesterol tissues are cleared by liver.
When levels are too high, LDL deposited into arterial wall.
HDL
Transport cholesterol from tissues to liver.
Cholesterol excreted from liver.
High HDL counteracts cholesterol deposition by LDL
What are lipoprotein classes important for?
Transport of highly insoluble lipids.
Oxidation of very long chain fatty acids
In peroxisomes
No ATP yield
Oxidation of unsaturated fatty acids
Require additional enzymes for degredation
Dehydrogenase for even number
Isomerase for odd number of double bonds
Lower energy yield than for fatty acids