Cellular Respiration continued

Cellular Respiration is a metabolic process like burning fuel Releases much of the energy in food to make ATP This ATP provides cells with the energy they need to

carry out the activities of life. C6H12O6+O2 CO2 + H2O + ATP

Stage Two: Production of ATP

•Krebs Cycle The Krebs cycle is a series of reactions that produce energy-storing molecules during aerobic respiration. •Electron Transport Chain During aerobic respiration, large amounts of ATP are made in an electron transport chain.

Krebs cycle history

Discovered by Discovered by Hans KrebsHans Krebs in in 19371937

He received the He received the Nobel PrizeNobel Prize in in physiology or physiology or medicine in 1953 medicine in 1953 for his discoveryfor his discovery

Forced to leave Forced to leave Germany prior to Germany prior to WWII because he WWII because he was Jewishwas Jewish

Krebs Cycle (Citric acid cycle)

Completes the breakdown of glucose Takes the pyruvate (3-carbons) and breaks it down, the

carbon and oxygen atoms end up in CO2 and H2O

Hydrogens and electrons are stripped and loaded onto NAD+ and FAD (coenzymes) to produce NADH and FADH2

Production of only 2 more ATP but loads up the coenzymes with H+ and electrons which move to the 3rd stage

Occurs in the matrix inside the mitochondrion

Electron Transport chain

Before breaking down what happens during the electron transport chain, watch these two clips that describe the process.

Click here for ETC animation

Youtube video on ETC

Electron Transport Chain

Electron carriers (coenzymes) loaded with electrons (hydrogen atoms) and protons from the Krebs cycle move to this chain-like series of steps (staircase).

As electrons drop down stairs, energy released to form a total of 32 ATP

Oxygen waits at bottom of staircase, picks up electrons and protons and in doing so becomes water

Energy Tally

36 ATP for aerobic vs. 2 ATP for anaerobic› Glycolysis 2 ATP› Kreb’s 2 ATP› Electron Transport 32 ATP

36 ATP

Anaerobic organisms can’t be too energetic but are important for global recycling of carbon

•Cellular respiration works opposite of photosynthesis carried out by autotrophs.

•The products of respiration are used as the reactants for photosynthesis.