Energy in a CellCellular

Respiration

Cellular Respiration•Cellular

respiration: process where mitochondria break down food molecules to produce ATP. (energy)

Cellular Respiration•Three stages in

cellular respiration: glycolysis, citric acid cycle, and electron transport chain.

Cellular Respiration•Mitochondria is

called the powerhouse of the cell because it is the site of cellular respiration.

Cellular Respiration•More work a

cell does, the more mitochondria it has.

Cellular Respiration•Glycolysis: first

stage of cellular respiration.

Cellular Respiration•Takes place in

the cytoplasm of the cell.

Cellular Respiration

•One C6H12O6

(glucose) is broken down into 2 pyruvic acid molecules. (a 3 C molecule)

Cellular Respiration•For every

glucose molecule broken down, 2 ATP molecules are produced.

Cellular Respiration•Next, the

pyruvic acid moves into the mitochondria.

Cellular Respiration•Citric acid cycle or

Kreb’s cycle : Pyruvic acid is broken down in a series of reactions to produce 2 CO2 and 1 ATP and electrons are passed on to the electron transport chain.

Cellular Respiration•Electron transport

chain: series of proteins where electrons are passed.

Cellular Respiration•Energy is released

as electrons are passed from one molecule to the next.

Cellular Respiration•The released

energy is used to make ATP.

Overall:

•For every glucose that enters cellular respiration 36 ATP are produced.

Cellular Respiration•Cellular

respiration can be classified as aerobic: cellular respiration occurs in the presence of O2.

Cellular Respiration•Most efficient

form of respiration.

Cellular Respiration•Krebs cycle is

aerobic respiration.

Cellular Respiration•Cellular

respiration can also be classified as anaerobic: respiration that proceeds in the absence of O2.

Cellular Respiration•Glycolysis is

anaerobic respiration.

Cellular Respiration•Not as efficient as

aerobic. Only 2 ATP formed.

Cellular Respiration• In the absence of

O2, pyruvic acid backs up and is eliminated 2 ways:

Cellular Respiration1.In you and me,

pyruvic acid is converted to lactic acid and builds up in the muscles.

Cellular Respiration2.In yeast, pyruvic

acid converted to CO2 and ethyl alcohol. This makes bread rise.

Cellular Respiration•Anaerobic

respiration is also called fermentation.

Cellular Respiration•Which molecule

has the most stored energy: fat or carbohydrate?

Cellular Respiration•Fat – it has

available energy for 51 ATP.