1. Do our cells breathe?

2. …Using glucose to make energy (ATP)

3.  If plants need ATP (energy) to form glucose, how can glucose be a source of energy for plants and animals?  How does our body use glucose to make energy?  Why do your muscles get really sore when you exercise intensely, but not when you pace yourself?  How do you get wine from grapes?

4.  Plants get energy from the sun and store it in the bonds of ___________. glucose

5. How do we get energy? – by eating food. What types of food provide the most energy? – Carbs (sugars or glucose) have the most energy e.g. candy bars, wheat, potatoes, rice, pasta What does your body do to the food you eat? - Our body digests our food (breaks apart bonds), releasing energy

6.  Breaking bonds releases energy!  Energy is “stored” in the glucose bonds; breaking them releases the energy  What form of energy do our cell (and our body) use?  the molecule ATP  So.. our body breaks down glucose and uses it to make ATP (ENERGY!)  Which organelle is responsible for producing energy for our cells?  The MITOCHONDRIA

7.  ATP (adenosine triphosphate) is a nucleic acid that can transfer energy within the cell.  Ex: a small amount of energy from a glucose molecule can be used directly…  The extra energy is transferred to ATP.  The energy in ATP is stored in the bonds between the phosphates (ATP has 3 phosphates). http://www.brooklyn.cuny.edu/bc /ahp/LAD/C7/graphics/C7_atp_2.GIF

8.  Remember…cellular respiration is using glucose to make energy  Step 1: glycolysis  glyco = refers to glucose  lysis = break apart  Glycolysis = break down 1 glucose into 2 pyruvic acid molecules, which have three carbons each (splits glucose in half)  Also makes 2 ATP !  Takes place in the cytoplasm

9.  Why would we need to break down glucose in the cytoplasm first before we use it in the mitochondria? (think transport)  Glucose molecules are too large to move into the mitochondria, so glycolysis makes them smaller to get through the mitochondria’s membranes

10.  After glycolysis, there are two possible paths:  Aerobic respiration – requires oxygen  An aerobic respiration – does not require oxygen; happens if oxygen is lacking Oxygen? NO Anaerobic Respiration Aerobic Respiration YES

11.  An aerobic process (requires oxygen).  Reaction releases energy from the chemical bonds of carbohydrates.  Takes place in the mitochondria.  Equation: 6O 2 + C 6 H 12 O 6 6H 2 0 + 6CO 2 + 36ATP Oxygen + Glucose Water + Carbon Dioxide + Energy

12. Equation for photosynthesis: Energy + 6H 2 O + 6CO 2 C 6 H 12 O 6 + 6O 2 Equation for aerobic cellular respiration: 6O 2 + C 6 H 12 O 6 6H 2 0 + 6CO 2 + 36ATP

13. http://www.channelislandsrestoration.com/photos/images/Isl andFox1.jpg http://www.rhs.org.uk/chelsea/2005/exhibitors/plants/images/GlebeCott agePlants.jpg http://www.ucmp.berkeley.edu/fungi/basidio/mushroomsismall.jpg

14.  Plants  Animals  Fungi  Protists  Some bacteria  …almost everything alive!

15.  Recap: Step 1 = glycolysis – 2 ATPs produced in cytoplasm and enter mitochondria.  For aerobic respiration, in mitochondria:  Step 2 = Krebs Cycle (Citric Acid Cycle) – in matrix  Step 3 = Electron Transport Chain – in inner membrane  ATP is generated in each step, but most of the ATP is made in the Electron Transport Chain

16.  Right before the Krebs Cycle, the Pyruvate from glycolysis is converted to Acetyl-CoA.  During Krebs, the Acetyl-CoA is broken down into CO 2 & electrons (H + ).  2 ATP are created.  The electrons then move on to the Electron Transport Chain.

17.  We start with one molecule of glucose and end up with 6 CO 2 molecules, a handful of electrons (H + ) and 4 ATP molecules.  The CO 2 is waste that will move out of the cell (and which you exhale).  The 4 ATP molecules can be used by the cell as energy.  What about the other 32 ATPs from our equation?

18.  Embedded in the mitochondria inner membrane are proteins called electron carriers.  The electrons (H + ) from Glycolysis and the Krebs Cycle are passed from electron carrier to electron carrier (like a bucket brigade).  With every pass, energy is released from the electrons, and ATP is made.  As a result, 32 ATP are made in the Electron Transport Chain.

19. C 6 H 12 O 6 + 6O 2 → 6CO 2 + 6H 2 O + 36 ATP Glucose + Oxygen → Carbon dioxide + Water + ATP (Krebs Cycle)

20.  What happens with respiration of lipids, proteins, and nucleic acids?  Starch: broken down into glucose, which enters glycolysis  Fats: broken down into fatty acids and glycerol; fatty acids are cut into 2-carbon compounds, converted to Acetyl-CoA, and enter the Krebs Cycle  Proteins: broken down into amino acids, which can be converted into Acetyl-CoA or other compounds that enter the Krebs cycle at various points  The amino group is removed & excreted as urea.

21. Nucleic AcidsProteins Carbohydrates Lipids Amino Acids Sugars Fatty Acids/ Glycerol Pyruvate Acetyl-CoA Krebs Cycle Urea H2OH2O CO 2 Nucleotides

22.  During aerobic respiration, where do the electrons (H + ) end up as they are passed from protein to protein?  They end up in the loving arms of oxygen.  When oxygen accepts electrons, water is made.  If oxygen wasn’t there to accept the electrons, the Electron Transport Chain would get backed up, and no energy would be produced.  What type of respiration happens when there is no oxygen? …and where does it happen?

23.  AKA: fermentation  Two types:  Alcohol fermentation  Lactic acid fermentation  Both take place in the cytoplasm.  Each creates 2 ATP from each pyruvic acid molecule. http://www.schmohz.com/images/beer- fermenter.jpeg

24.  Yeast can do aerobic or anaerobic respiration.  Grapes turn to alcohol by adding yeast in containers with out oxygen.  Bread rises because yeast gives off CO 2 bubbles while fermenting in dough. http://www.utoronto.ca/greenblattlab/images/a/yeast%201.jpg

25.  When humans (and other animals) exercise intensely, their muscles often use more O 2 than is available  When O 2 runs out, muscles switch to anaerobic respiration to try to keep up with energy demand.  This is lactic acid fermentation.  The build up of lactic acid is what makes your muscles sore. http://www.donlemmonsknowhow.com/img/exercise- session.jpg

26.  You get way more ATP from aerobic cellular respiration than from fermentation.  Fermentation is mostly used to provide organisms with short-term bursts of energy when oxygen is not available. http://www.athleticsireland.ie/content/wp- content/uploads/2006/08/washington.jpg