What is Cellular Respiration?

Cellular Respiration Overview Transformation of chemical energy in food into chemical energy cells can use: ATP These reactions proceed the same way in plants and animals. Process is called cellular respiration Overall Reaction: –C 6 H 12 O 6 + 6O 2 → 6CO 2 + 6H 2 O

For Animals- Once food is consumed, an organism has to transform it into energy that can be used by the organism. This process is cellular respiration

Energy Glucose+ Oxygen  Carbon Dioxide + Water + Energy The equation in WORDS=

What is the chemical equation for cellular respiration?

CELLULAR RESPIRATION EQUATION: C6H12O6 + 6O2  6CO2 + 6H2O + Energy PHOTOSYNTHESIS EQUATION: 6CO2 + 6H2O + LIGHT  C6H12O6 + 6O2 END

3 Steps There are three steps in the process of cellular respiration: –1. Glycolysis –2. Krebs Cycle (Citric Acid Cycle) –3. Electron transport chain.lectron transport chain G et K runk E veryoneG et K runk E veryone

STEP 1: GLYCOLYSIS –occurs in the cytoplasm –Turns glucose into pyruvate –2 ATP’s are made

Step 2: KREB’S CYCLE (Citric Acid Cycle) –occurs in the mitochondria –It breaks down CO2 –2 ATP’s are made –Also known as the Citric Acid Cycle

Step 3: ELECTRON TRANSPORT CHAIN –Occurs in mitochondria Electron carriers loaded with electrons and protons from the Kreb’s cycle move to this chain-like a 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 Transport32 ATP 36 ATP Anaerobic organisms can’t be too energetic but are important for global recycling of carbon

Anaerobic Cellular Respiration Some organisms thrive in environments with little or no oxygen –Marshes, bogs, gut of animals, sewage treatment ponds No oxygen used= ‘an’aerobic Results in no more ATP, final steps in these pathways serve ONLY to regenerate NAD+ so it can return to pick up more electrons and hydrogens in glycolysis. End products such as ethanol and CO 2 (single cell fungi (yeast) in beer/bread) or lactic acid (muscle cells)

Aerobic Cellular Respiration Oxygen required=aerobic 2 more sets of reactions which occur in a specialized structure within the cell called the mitochondria –1. Kreb’s Cycle –2. Electron Transport Chain