Contact: Dr. Christos Chinopoulos MD, PhD

How to convert absorbance to enzyme activity: Assume an absorbance change (DA) of 0.001 per second. Multiply by 60, in order to convert it to 'per minute', i.e. 0.001*60=0.06. Divide it with the extinction coefficient of the reactive compound, e.g. if DTNB, it is 14150 M−1*cm−1, so you get: 0.06/14150=4.24e-6. Divide this by the length of the light path, if you use 1 cm cuvette, it is 1. You probably used less than 1 mg of enzyme (i.e. mitochondria), so if you used i.e. 50 microgr of mitochondria, divide by 0.05, to convert to 'per mg'. So, 4.24e-6/0.05= 8.48e-5. This is in M/min/mg. If you wish to convert to mol/min/mg, multiply by the total volume (in milliliters), and divide by 1000. Finally, it is best to convert to nmol/min/mg, so multiply by 1000000000.
LIMIT YOUR CARBOHYDRATE DAILY INTAKE TO LESS THAN 20 gr PER DAY. Do not eat bread, pasta, rice, cereals, potatoes, and of course sugar-containing sweets and beverages. Limit your fruit daily intake, so that you don't exceed 20 gr of carbohydrates per day. Avoid eating vegetables that grow under the surface of the earth (i.e. carrots, they contain too much glycogen or starches), and stick to those that grow above the surface of the earth (i.e. lettuce, they contain much less glycogen and starches). A well-balanced daily food intake consists of: 17 gr of carbohydrates, 70 gr of protein and 170 gr of fat (yes, fat).

The Myths and Lies of Ansel Keys, and what it has costed to the world:

Dietary Carbohydrates Impair Healthspan and Promote Mortality.
Ravichandran M, Grandl G, Ristow M. Cell Metab. 2017 Oct 3;26(4):585-587
The prospective cohort study, named PURE, found that in >135,000 participants from 18 countries, nutritive carbohydrates increase human mortality, whereas dietary fat reduces it, requesting a fundamental change of current nutritional guidelines. Experimental evidence from animal models provides synergizing mechanistic concepts as well as pharmacological options to mimic low-carb or ketogenic diets.

We will discuss this subject later on this year, in the meantime, here is a nice little video about sugars:

Also, please watch the movie called "Fed Up":

Questions for Lactic acidosis seminar (no bla-bla, just pathways, substrates, enzymes, products and regulators as requested):

1) Reactions and regulation of glycolysis
2) Reactions of glycogenesis and glycogenolysis
3) Reactions of gluconeogenesis from lactate
4) Citric acid cycle
5) Urea cycle
However, in your laboratory material, calculation of enzymatic activity (EA) is given in a slightly different way:
The above explanation is a snapshot of a laboratory practice entitled 'AN EXPERIMENTAL STUDY ON THE AMIDOLYTIC ACTIVITY OF TRYPSIN', which has been removed from your curriculum. In this equation there are two differences from the explanation I detailed above, namely the presence of 'f', which is a conversion factor, and that instead of providing the amount of the enzyme, it is given as 'vo'......volume of the enzyme solution (ml)". In my opinion, it is wrong to give the volume of the enzyme solution because its concentration also matters, thus the amount should be given instead. Of course, in the laboratory practice we know what is the enzyme concentration, thus to 'simplify' calculations the equation is formulated such as to accept the volume of the enzyme solution.

Questions for Fructose intolerance/Mc Ardle's disease seminar (no bla-bla, just pathways, substrates, enzymes, products and regulators as requested):

1) Fructose catabolism
2) Reactions and regulations of gluconeogenesis
3) Reactions and regulations of glycogen metabolism
4) Galactose catabolism
5) Regulation of pyruvate dehydrogenase complex
Regarding mitochondrial PEPCK (also known as PEPCK-M or PCK2), and its ‘potential’ role in gluconeogenesis
It is speculated that PEPCK-M expression in mouse liver may potentiate but not replace, PEPCK-C mediating gluconeogenesis (J Hepatol. 2013 Jul;59(1):105-13), and may be a significant source of gluconeogenic flux (Biochim Biophys Acta. 2014 Apr;1840(4):1313-30). Furthermore, and in contrast to its cytosolic counterpart, hormones or nutrients that are known to regulate gluconeogenesis do not transcriptionally regulate the gene coding for PEPCK-M, PCK2 (J Biol Chem. 2014 Aug 8;289(32):22090-102). Finally, PEPCK-M is expressed in cell types that do not perform gluconeogenesis (J Biol Chem. 2014 Aug 8;289(32):22090-102). Instead, PCK2 is known to be a stress response gene involved in tumor cell adaptation (J Biol Chem. 2014 Aug 8;289(32):22090-102). So: PEPCK-M may participate in gluconeogenesis in rats or mice, but this has never been shown for humans, while for humans the role of PEPCK-M in non-gluconeogenesis-related pathways is well characterized. Finally, please look into the concept of “pyruvate cycling pathway” and the role of PEPCK-M (J Neurosci Res. 2013 Aug;91(8):1030-43).

BUT: in the midterms, semi-final and final exams you need to answer what you were taught in the lectures, which -as erroneously as they may be- mention that PEPCK-M is involved in gluconeogenesis.

Questions for LPL deficiency and carnitine deficiency seminar (no bla-bla, just pathways, substrates, enzymes, products and regulators as requested):

1) Beta-oxidation
2) Entry of medium- and long-chain FA in the mitochondrial matrix through the carnitine system
3) Citric acid cycle
4) Urea cycle
5) Oxidation of odd-number of chain FA

Questions for Hereditary htyperammonemias seminar (no bla-bla, just pathways, substrates, enzymes, products and regulators as requested):

1) Urea cycle
2) Purine nucleoside cycle
3) Detoxification functions of carnitine
4) Degradation of glutamine in the kidney
5) The glutamate-glutamine metabolic cycle

Questions for EXTRACELLULAR MATRIX seminar:

1) Components of the extracellular matrix (elaborate)
2) MMPs in tumor metastasis
3) Wound healing and tissue repair
Reading material regarding HIF, p53 mTOR, and PPAR system in the regulation of metabolism:
Metabolism and human nervous system (seminar)

Questions for Metabolic Syndrome Seminar:

1) Features of the Metabolic Syndrome (Table 1) of seminar pdf
2) Diagnosis of the Metabolic Syndrome
3) Management of the Metabolic Syndrome (Table 2) of seminar pdf
4) Treatment of Insulin resistance in Metabolic Syndrome
5) Treatment of dyslipidaemia in Metabolic Syndrome
Questions for B12 deficiency and methylmalonyl acidemia seminar (no bla-bla, just pathways, substrates, enzymes, products and regulators as requested):

1) Urea cycle
2) Methyl-trap hypothesis
3) Detoxification functions of carnitine
4) Catabolism of odd-number of chain of fatty acids
5) Citric acid cycle