Table 2

Metabolic and physiological functions tested for the metabolic network
Classification Metabolic function Cellular function Reference
1. Carbohydrates
● Monosaccharides Glucose and fructose metabolism Energy production [28,29]
Glycogen formation short-term energy storage [22]
Ribose Energy production [30,31]
Formation of ribonucleotides
2. Carboxylic acids Degradation of ketone bodies Energy production during fasting [32,33]
and diabetes
3. Lipids
● Cholesterol De novo synthesis (cytosol, peroxisome) Membrane synthesis [34,35]
● Fatty acids Formation of (semi)-essential fatty acids Membrane synthesis [36,37]
β-oxidation of (non)-essential fatty acids Energy production [38-40]
● Triacylglycerides De novo synthesis/ degradation of Mono-, Membrane synthesis [41,42]
Di- and Triacylglycerides
● Phospholipids De novo synthesis/ degradation of: Membrane formation [15,16,41,43-45]
∘ Phosphatidylserines
∘ Phosphatidylcholines
∘ Lysophosphatidylcholines
∘ Phosphatidylethanolamines
∘ Phosphatidylinositol
∘ Sphingomyelin
∘ Cardiolipin
● Sphingolipids Ceramides Membrane formation, apoptosis [46]
4. Proteins
● Amino acids Formation of (non)-essential amino acids Precursors of cellular proteins, nucleic acids, [47,48]
glutathione and thioredoxin
Degradation of (non)-essential amino acids Amino acid homoeostasis, [49]
anaplerotic reactions of TCA cycle
Glutamine formation Ammonia detoxification, Protein [50]
de novo synthesis
De novo synthesis of L-Carnitine Transport of fatty acids from cytosol into [51,52]
mitochondria during β-oxidation
● Tripeptide De novo synthesis of Glutathione Prevention of cellular damage due to ROS [53]
● Polyamines Formation/ degradation of Prutescine and Spermidine Cell growth and division [54,55]
● Proteins De novo synthesis of:
Myosin, Titin, α-Sarcoglycan, Tropomyosin, Troponin T Contractile apparatus, enabling muscular contraction [56,57]
De novo synthesis of Thioredoxin Prevention of cellular damage due to ROS [47,48]
5. Nucleic acids
● Nucleobases De novo synthesis/ degradation of purine Precursors of nucleosides, deoxy-ribonulceotides [58,59]
and pyrimidine nucleotides and ribonucleotides
Salvage of purine and pyrimidine nucleotides Maintaining energy state [60]
De novo synthesis/ rephosphorylation of:
∘ nucleosides (ATP, CTP, GTP, TTP, UTP) Energy production for muscular contraction [59,61-63]
∘ NADH, NADPH Energy production and providing redox-state [64,65]

Karlstädt et al.

Karlstädt et al. BMC Systems Biology 2012 6:114   doi:10.1186/1752-0509-6-114

Open Data