Title: BV2 / BV2 - 2 / Modul 5 / Introduction to carbohydrate metabolism

Q: What can the transformation of one compound to another be?
A: The transformation of a compound into another can be spontaneous or not

Q: What does the Gibbs function (Delta-G) allow us to calculate?
A: Allows us to calculate whether the transformation of one compound to another is spontaneous or not

Q: What can be used to calculate if a transformation of one compound to another is spontaneous?
A: The Gibbs function (Delta-G)

Q: What is metabolism?
A: The set of life-sustaining chemical transformations within the cells of living organisms

Q: Which metabolic process does require energy?
A: Anabolism

Q: Which metabolic process releases energy?
A: Catabolism

Q: What is the problem with (metabolic) reactions?
A: The transformations being spontaneous not

Q: How can the problem with (metabolic) reactions be fixed?
A: By making the reactions more "favourable" and couple "unfavourable" to "favourable" reactions

Q: What does a negative delta-G entail?
A: That the reaction is spontaneous (1-2)

Q: What does a positive delta-G entail?
A: That the reaction isn't spontaneous

Q: What factors affect the enzymes activity catalyzing a reaction between a substrate and a product?
A: - Temp
- pH
- Charge
- Availability
- Kinetics
- Regulators
- Co-factors
- Enzyme affinity
- Midpoint potential
- Concentration

Q: What is the primary cellular energy currency?
A: Adenosine triphosphate

Q: From what is ATP formed?
A: It is formed by the breakdown of food sources

Q: In which three main parts can ATP be divided up in?
A: - Ribose
- Adenine
- Phosphate groups

Q: What is the formula for ATP catalysis?
A: ATP+H2O -> ADP + P_i

Q: WHat is DG of the reaction ATP+H2O -> ADP + P_i?
A: DG = - 30.5 kJ/mol

Q: What is bioenergetics?
A: Bioenergectis is the mechanism by which energy is made available to power "uphill" reactions

Q: What is the addition of Pi to ADP in the cell?
A: The addition is energectically unfavourable in the cell

Q: Why is Pi+ADP coupled to 2H+ + O2 -> H2O?
A: Because the addition of Pi to ADP is energectically unfavourable in the cell, it is therefore coupled to said redox reaction

Q: Which reaction is Pi + ADP coupled to?
A: The redox reaction 2H+ + O2 -> H2O

Q: How can the system be manipulated (enzymes/reactions/reactabillity)?
A: Change in temp, pH, concentration, availability, etc...

Q: How can something be made favourable?
A: Putting energy in -> making it favourable

Q: What does the synthesis of ATP require?
A: Making ATP needs energy

Q: Where does the main breakdown of carbhydrates occur?
A: Main breakdown of carbohydrates in the TCA-cycle (?)

Q: What is an exergonic reaction?
A: Is a chemical reaction where the change in the free energy is negative -> indicates a spontaneous reaction if the system is closed and the initial and final temps are the same
- A process where there is a positive flow of energy from the system to the surroundings

Q: What is an endergonic reaction?
A: A chemical reaction where the standard change in free energy is positive, and an additional driving force is needed to perform this reaction
- A heat abosorbing, nonspontaneous reaction or an unfavourable reaction

Q: What is delta G?
A: DG = G_final - G_initial

Q: How can DG be described?
A: ΔG is the change in free energy of a system as it goes from some initial state, such as all reactants, to some other, final state, such as all products

Q: How can an unfavourable reaction be made favourable?
A: By adding energy -> putting energy into the system

Q: What makes up oxidative phosphorylation?
A: Together, the electron transport chain and chemiosmosis make up oxidative phosphorylation

Q: What is chemiosmosis?
A: In biology, chemiosmosis refers to the process of moving ions (e.g. protons) to the other side of the membrane resulting in the generation of an electrochemical gradient that can be used to drive ATP synthesis.

Q: Which processes have oxidative phosphorylation as the last step/next step for their products?
A: - Glycolysis
- TCA cycle
- Beta-oxidation

Q: What are examples of monosaccarides in carbohydrate metabolism?
A: - D-glucose
- D-galactose
- Fructose

Q: What are examples of disaccarides in carbohydrate metabolism?
A: - Sucrose - glucose+fructose
- Lactose - D-galactose+D-glucose

Q: Which 3 stages can glucose metabolism (glycolysis) be divided into?
A: - Stage 1 - Investment
- Stage 2 - Cleavage
- Stage 3 - Harvesting

Q: What happes during the 1st/investment stage?
A: - Trap glucose in the cell
- Destabilize/activate

Q: What happes during the 2nd/cleavage stage?
A: - Convert 2 3-carbon molecules (glycolysis)

Q: What happes during the 3rd/harvesting stage?
A: - Gain NADH
- Gain ATP (substrate level phosphorylation)
- Dehydrate

Q: What can be said about triglycerides (tri-acyl-glycerol)?
A: - They are highly reduced
- Anhydrous (nonpolar)

Q: What is an anhydrous substance?
A: A substance is Anhydrous i it doesn't contain any water - nonpolar

Q: What is the energy storage of triglycerides per person?
A: 420 000kJ

Q: What is the energy storage of protein per person?
A: 100 000 kJ

Q: What is the energy storage of glycogen per person?
A: 2500 kJ

Q: What is the energy storage of glucose per person?
A: 170 kJ

Q: What happens in stage 1 of glycolysis (investment stage)?
A: 1. Phosphorylate - trap & destabilize
2. Isomerase - aldose to ketose
3. Phosphorylate - destabilise & commit

Q: What happens in stage 2 of glycolysis (cleavage stage)?
A: 4. Aldolase: GAP + DHAP
- (GlycerAldehyde-3-Phosphate + DiHydroxyAcetone-Phosphate)
5. Isomerase: DHAP -> GAP
- DiHydroxyAcetone-Phosphate -> GlycerAldehyde-3-Phosphate

Q: What happens in stage 3 of glycolysis (harvesting stage)?
A: 6. Gain NADH
7. Substrate level phosphorylation
8. Reposition P_i
9. Dehydration (increased P potential)
10. Substrate level phosphorylation

Q: Which steps are included in upper glycolysis?
A: Step 1-5
Glucose -> Glyceraldehyde-3-phosphate

Q: Which steps are included in lower glycolysis?
A: 6-10
1,3-bisphosphoglycerate -> pyruvate

Q: What is NADH/NADPH?
A: Nicotinamide Adenosine Dinucleotide is called the reducing power of chemical reactions and is usually a co-enzyme in reduction / oxidation (redox) reactions. (ie dehydrogenases )

Q: What is NAD+/NADH?
A: The redox couple NAD + / NADH is a universal electron carrier, which undergoes reversible reactions. Thus, the reactions coupled to NADH are usually reversible.

Q: WHy are the reactions coupled with NADH/NAD+ usually reversible?
A: Because it undergoes reversible redox reactions

Q: Where is NADPH involved?
A: NADPH (the phosphoric acid addition to NADH) is exclusively involved as a reductant in metabolism. ie FA synthesis and the cell maintains a high NADPH / NADP + ratio

Q: What is NADP usually used as in metabolism?
A: As a reductant

Q: What is NADPH?
A: A molecule with a phosphoric acid addition to NADH

Q: What can be said about NADH reducing power?
A: NADH has considerable reducing power

Q: What is NADHs electromotive force?
A: Its electromotive force, when catalyzing a redox reaction between oxygen molecules, is 1.13 V

Q: What is NADHs standard free energy charge?
A: Its standard free energy change is ΔG ° ′ = −218 jK /
mol (for every two electrons)

Q: What can the reducing power of NADH do?
A: The reducing power of NADH can drive the synthesis of several ATP molecules inside mitochondria