Metabolic Pathways
What is the difference between Catabolism and Anabolism?
Catabolism - exergonic break things down. Ex. Glycolysis releases energy.
Anabolism is biosynthetic making of things and an endergonic process. Ex. AA biosynthesis uses energy.
Where are the enzymes of the citric acid cycle found?
The Matric of the mitochondria
Which Enzymes in Glycolysis are themodnamically and Physically coupled?
Steps 6 and 7 GAPDH and PGK.
Where does gluconeogenesis primarily occur?
the Liver (90%) and Kidney (10%)
What are the P/O ratio for NADH and FADH2?
NADH produces 2.5 ATP
FADH2 produces 1.5 ATP
How can you tell which molecule will generate the most energy based on structure?
The structure with the most reduced carbon (one with fewest O and most H's) will be the highest energy.
PLEEASE BE ABLE TO RECOGNIZE THIS GIVEN A PICTURE
What is the main control point of the TCA?
Step 3, Isocitrate DH.
Which Enzyme in glycolysis has a phosphohistidine in the active site?
Phosphoglycerate Mutase (PGM)
Starting from pyruvate how much energy is needed to make a glucose molecule?
6 net ATP equivalents used and 2 NADH equivalents.
If a rotenone inhibitor is present and NADH and FADH2 are present, is oxygen being consumed?
Yes. the Rotenone is a Complex 1 inhibitor, but the FADH2 will bypass complex one and go through the ETC to complex 4, where Oxygen is reduced and therefore consumed.
What is the energy threshold for a molecule to be considered high or low energy?
A delta G hydrolysis of -30.5kJ/mol.
If a compound has a large more negative Delta G it is considered high energy.
If a compound has a smaller less negative Delta G it is considered low energy.
What are the five cofactors that are needed for the PDH reaction?
TPP, Lipoic Acid, Coenzyme A, FAD (flavin) and NAD+.
Which Enzymes of Glycolysis use a Mg2+ co-factor?
Hexokinase, PFK-1, PGK, Enolase, Pyruvate Kinase
What is the cori cycle conceptually speaking?
It is the process by which the body moves lactate to the liver to produce Glucose that is then taken back to the muscles to be used as energy.
Which complex in the ETC will be inhibited by a lack of iron?
ALL of them!
Complex 1: Iron sulfur clusters
Complex 2: Iron Sulfur clusters
Complex 3: Iron sulfer clusters + Iron in the heme-like cytochrome
Complex 4: Iron in the heme-like cytochrome
What are some examples of high energy bonds mentioned in the slides?
Acyl Phosphates, Pep (enol-keto taut), creatine phosphates, thioesters, and phosphoanhydride bonds.
Which enzymes in the TCA have a pro-chiral differentiation?
Aconotase step 2 and furmarase step 7
How many ATPs are made in glycolysis from one glucose?
How about one glucose from Glycogen?
2 NET from free glucose
3 NET from glycogen
How is PFK-1 Regulation different in Gluconeogenesis?
Gluconeogenesis PFK-1 is
Inhibited by: F-2,6-BP , AMP
Activated by: Citrate
Which part of complex 5 spins?
The C-Subunit wheel part of the F0 component.
Given:
ATP + H2O => ADP + Pi Delta G = -30.5
and
fructose-6-phosphate + H2O => fructose + Pi Delta G = -13.8
What is the overall reaction is it spont? Nonspont?
ATP + fructose => ADP + fructose-6-phosphate
It is exergonic spontaneous reaction Delta G = -16.7
Which steps in the TCA + PDH reaction are activated by ADP, which are inhibited by NADH, which are irreversible?
Activated by ADP: PDH and Isocitrate DH
Inhibited by NADH: PDH, Isocitrate DH, and alpha-ketoglutarate DH and citrate synthase.
Irreversible: PDH, Isocitrate DH, and alpha-ketoglutarate DH and citrate synthase.
How is PFK-1 Regulated?
Inhibited by: ATP, Citrate
Activated by: AMP, ADP, and Fructose2,6-bisphosphate
Which 4 steps are new in Gluconeogenesis vs. Glycolysis?
Pyruvate Carboxylase, PEPCK, Fructose-Bisphosphate, and glucose-6-phosphatase
What are the two shuttles used and why are they needed?
Glycerol-phosphate shuttle and Malate-aspartate shuttle are used to transport the Cytosolic NADH made from glycolysis.