Nitrogenase Reaction

N2 + 8H+ + 8 e- 16 ATP + 16 H2O right arrow 2 NH3 + H2 + 16 ADP + 16 Pi

 

 

 

 

 

 

 

nitrogenase mechanism diagram

 

 

 

 

 

 

 

 

 

 

 

 

Glutamate dehydrogenase

Structural diagram of the reaction of Glutamate DH

 

 

 

 

 

 

 

 

Glutamine Synthetase

Structural diagram of the reaction sequence of Glutamine Synthase

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Triacylglycerols

structural diagram of lysophosphatidate

 

 

 

 

 

 

 

 

 

 

 

 

Glycerophospholipids

Choline + ATP right arrow Phosphocholine + ADP

Phosphocholine + CTP right arrow CDP-choline + PPi

CDP-choline + Diacylglycerol right arrow Phosphatidylcholine + CMP

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

structural diagram of the reactions in the Glyoxalate cycle

 

2 Acetyl-CoA + NAD+ + FAD right arrow Malate + NADH + H+ + FADH2

 

 

 

 

Isocitrate lyase

structural diagram for the Isocitrate lyase reaction

 

Malate synthase

structural diagram for Malate synthase reaction

 

 

 

 

 

 

 

 

 

 

 

Diagram of the interactions of main metabolic pathways

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Table 1: Average Fuel Storage in a "Normal" 65 kg Man*
Tissue Total amount of fuel Estimated duration of fuel reserve hours (days)
  g kJ Starvation walking running (long distance)
 Liver glycogen 90 1500

3.6

(0.15)

1.2

(0.05)

0.31

(0.013)

 Extracellular glucose 20 320

0.72

(0.03)

0.24

(0.01)

0.07

(0.003)

 Adipose fat 9,000 337,000

816

(34)

259

(10.8)

67

(2.79)

 Protein 8,800 150,000

288

(15)

115

(4.8)

31

(1.3)

Muscle glycogen 350 6,000

1.44

(0.6)

4.8

(0.20)

1.2

(0.05)

* Assuming 12% of body weight is fat for normal men (normal women are about 26%)

Data from E. A. Newsholme & A. R. Leach (1983) Biochemistry for the Medical Sciences, John Wiley, NY. p 337.

 

 

 

 

 

 

 

 

 

 

 

 

 

Table 2: Tissue Fuel Usage in Fed and Fasting States in Humans

 Tissue

Fed 

Fasting
 used released used released
Liver Glucose (stored as glycogen), Amino acids, Fatty acids Fats, Glucose Amino acids, Lactate, Fatty acids, Glycerol Glucose, Ketone bodies
 Kidney  Glucose   Amino acids, Lactate, Fatty acids, Glycerol   Glucose
 Intestine  Glucose, Aspartate & Glutamate, Asparagine & Glutamine Fatty acids, Amino acids other than asx & glx, Carbohydrates     
 Adipose  Glucose     Fatty acids, glycerol 
 Muscle  Glucose (some stored as glycogen), Branched chain amino acids  Lactate, Alanine & Glutamine  Fatty acids, Ketone bodies, Branched chain amino acids  Amino acids other than branched chain, Lactate
 Brain  Glucose  -  Glucose & Ketone bodies  -

 

© R. A. Paselk 2010; Last modified 6 May 2013