Question

1. Calculate the number of ATP produced per carbon atom for a molecule of glucose under oxidative phosphorylation (remember we use as a rule of thumb 2.5ATP per NADH and 1.5ATP per FADH2 based on the number of protons pumped in the ETC). 2. Calculate the number of ATP produced per carbon atom for a saturated fatty acid between 12 and 18 carbons long (make sure you clearly indicate the length of fatty acid you choose, e.g 14:0). Make sure you clearly account for all molecules used in obtaining your answer. 3. Which type of molecule yields more ATP on a per-carbon basis - carbohydrates or fatty acids? How many more ATP per carbon are provided by the more energy-yielding molecule? Why is this the case? What reaction in the metabolic process corresponds to this energy yield? (Hint: What type of reactions result in the release of energy during oxidative phosphorylation? What are the structural differences between carbohydrates and fatty acids?). 4. Your book claims (p. 248) that fatty acids can yield approximately six times as much energy per gram as carbohydrates do. Do your results support this claim? What is the source of the discrepancy?

Ignore question 4.

Answer 1

1. Oxidative phosphorylation is the process by which ATP is formed as electrons are transferred from the reduced forms of nicotinamide adenine dinucleotide (NADH) and flavin adenine dinucleotide (FADH2) to molecular oxygen (O2) by a series of electron transporters (i.e. the electron transport chain).Oxidative phosphorylation is the process by which ATP is formed as electrons are transferred from the reduced forms of nicotinamide adenine dinucleotide (NADH) and flavin adenine dinucleotide (FADH2) to molecular oxygen (O2) by a series of electron transporters (i.e. the electron transport chain).

Without oxygen only 4 molecules of ATP energy packets are produced for each glucose molecule (in glycolysis). Oxidative phosphorylation produces 24–28 ATP molecules from the Kreb's cycle from one molecule of glucose converted into pyruvate.

2.oxidation of 14 c fatty acid

1 mol of ATP is split to AMP and 2P i−2 ATP

8 mol of acetyl-CoA formed (8 × 12) 96 ATP

7 mol of FADH 2formed (7 × 1.5) 10.5ATP

7 mol of NADH formed (7 × 2.5) 17.5 ATP

Total118 ATP

3. Fatty acids produce more ATP per c molecule than carbohydrates .

About 2-2.5 more ATP are produced.

Beta oxidation can be the reason.

Redox. Reactions lead to energy release

During oxidative phosphorylation, electrons are transferred from electron donors to electron acceptors such as oxygen in redox reactions. These redox reactions release the energy stored in the relatively weak double bond of O2, which is used to form ATP.

Lipid molecules contain more energy per gram than carbohydrates(about twice as much) ...Carbohydrates are stored as glycogen in animals whilelipids are stored as fats (in plantscarbohydrates are stored as cellulose and lipids as oils) Lipids have less effect on osmotic pressure within a cell than complex carbohydrates.

Composition Carbohydrate is the abundantly found organic molecule on earth and as the name suggest it is made up of carbon, hydrogen, and oxygen.Fats also have carboxylic acids with hydrocarbon side chains. They are the simplest form of Lipids.

Solubility Carbohydrates are soluble in water.Fats are insoluble in water but soluble in the inorganic solvent like alcohol, ethanol.