CELLULAR RESPIRATION  Biology I

INTRODUCTION TO CELLULAR RESPIRATION Both photosynthesis and cellular respiration provide energy for life. Photosynthesis uses solar energy to produce glucose and O2 from CO2 and H2O 6CO2 + 6H20 + ATP C6H12O6 + 6O2 Occurs in Chloroplasts

during the oxidation of glucose to CO2 and H2O Cellular respiration makes ATP and consumes O2 during the oxidation of glucose to CO2 and H2O C6H12O6 + 6O2 6CO2 + 6H2O + ATP Occurs in mitochondria So what is the relationship between photosynthesis and cellular respiration?

+ Sunlight energy ECOSYSTEM Photosynthesis in chloroplasts CO2 Glucose ATP ECOSYSTEM Sunlight energy Photosynthesis in chloroplasts Cellular respiration in mitochondria (for cellular work) Heat energy +

Breathing (respiration) provides for the exchange of O2 and CO2 between an organism and its environment. Happens in the lungs

Cellular respiration breaks down glucose molecules and banks their energy in ATP. Occurs in the mitochondrion of cells. C6H12O6 CO2 6 H2O ATPs Glucose Oxygen gas Carbon dioxide Water Energy O2 +

What is the relationship between respiration and cellular respiration? CO2 O2 Bloodstream Muscle cells carrying out Cellular Respiration Breathing Glucose + O2 CO2 +H2O +ATP Lungs

75% used for life-sustaining activities (involuntary) The human body uses energy from ATP for all its activities. ATP powers almost all cellular and body activities 75% used for life-sustaining activities (involuntary) The other 25% of this is used for...

Both plant and animal cells carry out the final stages of cellular respiration in their mitochondria.

Glucose is a main energy source used by all cells. Cells don’t “burn” glucose. Instead, they gradually release the energy from glucose and other food compounds. This process begins with a pathway called glycolysis. Glycolysis releases a small amount of energy

First Phase – Glycolysis Occurs in the cytoplasm Anaerobic – no oxygen needed Breaks down glucose into simpler substances Produces a net gain of 2 ATP molecules

Second Phase – Krebs Cycle Occurs in the mitochondria Aerobic – oxygen required Begins with products from glycolysis

Each “turn” of the Krebs Cycle yields: Totals: 2 ATP molecules 4 CO2 molecules

Third Phase – Electron Transport Chain   Uses the energy stored in the products of the Krebs Cycle make 32 ATP molecules. Water is produced as a byproduct