NAD+ Flashcards
What does NAD+ do in glycolysis?
It is the primary oxidising agent producing NADH.
Which step in glycolysis uses NAD+
Glyceraldehyde 3-phosphate Dehydrogenase.
Hydride Transfer
This is where hydrogen nucleus migrates from one atom to another, accompanied by varying amounts of electrons.
What are the names given to that enzymes utilise NAD+?
Oxioreductases and Dehydrgogenases.
What is resulting NADH produced in respirtation used in?
ETC or LDH.
What are the three pathways of NAD+ oxidation?
Homolactic fermentation
Alcoholic fermentation
ETC.
Homolactic Fermentaiton
Conversion of one glucose into two lactic acids.
Alcoholic Fermentation
Transformation of fructose and glucose by yeast to ethanol, CO2 and heat.
When does homolactic fermentation occur?
In muscles under anaerobic conditions.
What happens to NADH in homolactic fermentaiton?
NADH couples with pyruvate formation to lactate.
When does alcoholic fermentation occur?
Anaerobic conditions in yeast.
What steps of the CAC reduce NAD+?
Isocitrate Dehydrogenase, Oxoglutarate Dehydrogenase and Malate Dehydrogenase.
What makes AKGD a key CAC regulator?
It is inhibited by both its products; NADH and succinyl COA.
What are the two alosterically activators of AKGD?
ADP and Calcium.
What is AKGD classified as?
A redox sensor.
How much NADH is generated per glucose?
10 NADH.
Where was the importance of NAD+ first established?
Joseph Goldbergers studies of dietary effects and its cause on pellagra.
What caused Pellagra?
Niacin deficiency, a precurosr for NAD+
What is the function of NAD+
Accepting hydride to form NADH and fuel OP.
What is the mitochondrial NAD/NADH ratio compared to the cytosol?
7:8 compared to 60:700
What connects the two NAD+/NADH pools?
Glycolysis and NAD biosynthesis.
What are the two complexes facilitating NADH transport across the membrane?
Malate aspartate and Glycerol 3 phosphate shuttle.
Malate Aspartate
Regulates glycolytic/lactate metabolism, transferring NADH from cytosol to mitochondria.
Glycerol 3 phosphate shuttle
Delivers cytosolic reducing equivalents directly into OP.
Due to NAD+ glycolsis regulation, what else does NAD+ regulate?
Pyruvate and NADH flux into the mitochondria.
What is the first step in NAD+ biosynthesis?
Conversion to nicotinamide mononucleotide by nicotinamide phosphoribosyltransferase
What is the second step of NAD biosynthesis?
Formation of nicotinamide ribose by CD73 which its transport into the cell.
What is the third step of NAD biosynthesis?
Re-phosphorylation of nicotinamide ribose.
What is the fifth step of NAD biosynthesis?
Conversion into NAD by Adenylyltransferases
