Note Taking Biology 31\06-14\06;
Respiration; the chemical reaction which breaks down nutrient molecules to release energy. This process is carried out by mitochondrian.
- The mitochondrian is found in the cytoplasm of a cell, and it has a double membrane.
- We need glucose and oxygen for respiration. Therefore, respiration is linked to nutrition and breathing. Glucose + oxygen = energy+water+carbon dioxide (C6H12O6 + 6O2 = 6H2O + 6CO2 + E(atp))—this is called aerobic respiration).
- There’s another type of respiration called anaerobic respiration which doesn’t require oxygen. Anaerobic respiration is usually carried out when there’s not enough oxygen for the aerobic respiration, and this oftenly occurs when someone does cardiovascular exercise.
- The amount of mitochondria in a cell depends on how much energy it needs.
- The Mitochondria needs some energy to carry out respiration, however, the energy they release is much bigger than the one they use.
- The mitochondria isn’t technically the one which carries out the chemical reaction, it’s just the place where it happens. Enzymes enter to the mitochondria, break down the oxygen and glucose molecules, and then produce energy, water and carbon dioxide.
- This process is needed by humans because it releases energy, which is needed for muscle contraction, making proteins molecules(linking amino acids into long chains), cell division(to repair damaged tissues in order to grow), active transport, transmitting nerve impulses, maintenance of constant body temperature.
- All this energy comes from food. Molecules which are soluble of water are absorbed from the intestine into the blood.
- Glucose is the main energy-providing nutrient.
- In order to use energy, cells need to transform it in ATP(adenosine triphosphate), this is the way in which energy is stored.
- An atp molecule is made of 3 phosphates (which tend to separate, and free the energy), adenosine and ribose.
- When a phosphate molecule separates from the ATP molecule, a water molecule takes and fulfills this place.
- From a glucose molecule, you can obtain 38 molecules of ATP.
- There are three stages in the process in which ATP is formed.
- Aerobic respiration is the opposite of photosynthesis, as when you switch the equation, you obtain the process carried out by plants.
- Anaerobic respiration is the process which releases small amounts of energy (comparing it to the aerobic respiration) by the breakdown of food substances in the absence of oxygen.
- Anaerobic respiration during exercise: Glucose = lactic energy + energy (C6H12O6 = 2C3H6O3 + energy)
- Industrial respiration. Anaerobic respiration in yeast: glucose = ethanol + carbon dioxide + energy ( C6H12O6 = 2C2H5OH + 2CO2 + energy)
- Muscles respire anaerobically when exercising vigorously because there’s not enough oxygen for aerobic respiration. This process usually causes cramps.
- Lactic acid molecules need to be destroyed, and this happens with oxygen, as oxygen breaks down this molecules.
(You need to have the same number of atoms from a same element in each side of a chemical reaction)