Respiration
What is respiration: Aerobic respiration is the controlled release of energy from food using oxygen. The food involved in respiration is glucose. The energy is trapped in molecules of ATP.
Energy carriers involved in respiration ADP: Adenosine DiPhosphate ADP is a low energy molecule. Adenine Ribose P Adenosine DiPhosphate
Energy carriers involved in respiration ATP: Adenosine TriPhosphate The process of adding a phosphate is known as phosphorylation. ATP is a high energy carrier. ATP stores and supplies energy.
Energy carriers involved in respiration ADP + P + energy ATP + water In respiration, glucose breaks down to form ATP which is used for muscle movement, urine production and protein production. ATP + water ADP + P + energy
Energy carriers involved in respiration NAD+ : Nicotinamide Adenine Dinucleotide NAD+ is a low energy molecule. NAD+ + 2 electrons + H NADH NADH is a high energy molecule.
Aerobic Respiration Is the controlled release of energy from food using oxygen. Glucose + Oxygen Carbon dioxide + Water + Energy C 6 H 12 O 6 + 6O 2 6CO 2 + 6H 2 O + Energy Glucose is converted to ATP during aerobic respiration.
Stage 1 in Aerobic Respiration Stage 1 is called glycolysis It is anaerobic process (does not require oxygen) Only releases a small amount of energy Glycolysis takes place in the cytosol (cytoplasm minus the cell organelles)
Stage 1 (Glycolysis) Glucose is split into a two 3 carbon molecules (pyruvic acid). Glucose two 3 carbon + small amount molecule of energy (ATP)
Glycolysis (Stage 1) ADP + P ATP + water Glucose 2 pyruvic acid 2 NAD+ 2 NADH
Stage 2 (Krebs Cycle) It requires oxygen Releases a large amount of energy It takes place in the mitochondria Complete breakdown of the 3 carbon molecule to form carbon dioxide and water. Carbon dioxide and water are the end products of aerobic respiration.
Stage 2 Krebs Cycle Cytosol (stage 1) Stage 2
ADP + P Events in Stage 2 of respiration CO 2 Pyruvic acid or pyruvate Acetyl CoA 2e + H NAD+ NADH CO 2 NADH NAD+ 2e + H Krebs Cycle 6e 3 NAD+ 3 NADH CO 2 ATP + water
Stage 2 (Krebs cycle) Pyruvic acid loses a CO 2 molecule to form a 2 carbon molecule (acetyl coenzyme A) Pyruvic acid also loses 2 electrons which combines with NAD+ and a H to form NADH. Anywhere NADH is made in the Kreb cycle, it enters the Electron Transport System (E.T.S) NAD + + 2e + H NADH
Kreb Cycle (stage 2)» Kreb cycle occurs here»» Inner membrane» (electron transport system)
Kreb s cycle Acetyl CoA is broken down into carbon dioxide and protons (H). Acetyl CoA also releases high energy electrons. Aerobic respiration - YouTube
Electron Transport System Located on the inner membrane of the mitochondria. NADH release electrons to help form more ATP. At the end of the system, electrons combine with oxygen and hydrogen to form water. Electron Transport Chain - YouTube
Anaerobic Respiration Anaerobic respiration is the controlled release of energy from food without the use of oxygen. It does not use oxygen. Anaerobic respiration is also known as fermentation
Stage 1 Glycolysis Glucose NAD+ ADP + P NADH ATP + water 2 pyruvic acid Muscle No available oxygen Yeast 2 lactic acid 2 ethanol + 2CO 2 (Lactic acid fermentation) (Alcohol fermentation)
Anaerobic Respiration (fermentation) In the absence of oxygen pyruvic acid is converted to lactic acid in muscles or ethanol and carbon dioxide in yeast. No ATP is formed at this point
Anaerobic respiration In the making of bread, yeast fermentation occurs. The ethanol evaporates of the bread and the CO 2 causes the bread to rise. The use of yeast helps make beer and wine. With the absence of oxygen, fermentation occurs.
Anaerobic respiration When not enough oxygen reaches the human muscle during exercise, cramp occurs. Lactic acid builds up in the muscle. Sian Welch & Wendy Ingraham - The Crawl - 1997 - YouTube
To prepare and show the production of alcohol by yeast Limewater Water bath (30 o C) Oil Boiled glucose + yeast
To prepare and show the production of alcohol by yeast Boil glucose solution for 5 mins (removes oxygen, to create an anaerobic condition). Add dried yeast to glucose solution. Cover liquid with oil (prevents oxygen reentering solution)
To prepare and show the production of alcohol by yeast Carbon dioxide turns the limewater milky during this anaerobic process (fermentation). CONTROL: Carry out this experiment without the yeast.
To show the production of ethanol (alcohol) Filter the solution to remove yeast cells. Add potassium iodide solution. Add sodium hypochlorite solution (brown orange colour) Place in hot water bath Turns pale yellow colour in presence of alcohol.