2.2 glucose metabolism

overview diagram of metabolism

• single glucose molecule yields up to 38 atp

• glycolysis - 2

• fermentation or respiration - 2

• etc - 34

cellular respiration diagram

cellular respiration step by step

• aerobic pathway, eventually require oxygen

• glycolysis, pyretic

• into intermediate (acetyl coa)

• citric acid or tca, or Krebs

• electron transport chain, final receptor oxygen

  fermentation option

glycolysis

first step of respiration,

• turns one glucose into 2 pyruvate

• anaerobic

• in cytoplasm

• energy investment (split glucose) (donate to glucose 6 phosphate) and energy pay off (generate atp and nah)

• pyruvate moves onto citric acid)

invested two molecules of atp

energy investment and payoff glycolysis

fermentation

allows for the catabolism in the absence of oxygen as the final electron acceptor

yields less energy

recycles nad+

electron acceptors are ethanal (alcoholic fermentation) and pyruvate (lactic acid fermentation)

utilizing fermentation

cellular respiration vs fermentation

Tricarboxylic Acid /Krebs/ Citric Acid cycle

Intermediate step converts pyruvate into Aceytlcoa, enters tca cycle

transfers energy in acetylCoA, to activated carriers NAD+ and FAD

• cycle bc series of 8 steps regenerates starting material

• occurs in mitochondrial matrix

Krebs cycle simplified diagram

• two molecules of acetyl per glucose molecules, goes around Krebs twice,

• makes 2 atp, 6 nadh, 2 fadh2

where is cellular respiration?

• mitochondria

Electron transport system or chain

ETC uses chemiosmosis (coupling of electron transport and movement of h+ (protons))

• electron transport carriers oxidize activated carriers nada and fadh2

• energy produced moves hydrogen ions against their concentration gradient from mitochondrial matrix into inter membrane space setting up a proton gradient

• hydrogens flow back down the concentration gradient through the enzyme atp synthetase

  • catalyzes reaction ADP + Pi into atp

• occurs with oxygen

ETC diagram

ETC key concepts

• electrons move in a sequential chain losing energy with each step in the transfer

• electron’s energy is used for pumping H+ ions across the membrane to set up the gradient

• oxygen is the final electron acceptor, ending the reaction

• etc located in plasma membrane of prokaryotic organism

cellular respiration overall image

yield table

cellular pathway comparisons

fad/fadh

Flavin adenine dinucleotide is a coenzyme from riboflavin (B2 vitamin). It is an energy carrier involved in transferring electrons.

cellular respiration

The catabolic reactions that release electrons from molecules and shuttle them via electron carriers to the final electron acceptor, O2, producing H2O, energy, and CO2

metabolism

The chemical reactions an organism uses to breakdown macromolecules to release energy and then harness it to build new ones

energy carrier

Coenzymes (riboflavin and niacin – B vitamins) that pick-up electrons released in one reaction and bring them to another.  

nad/nadh

Nicotinamide adenine dinucleotide (NAD+)  is a coenzyme from niacin, a B3 vitamin.  It is an energy carrier involved in transferring electrons