Autotrophs are organisms such as a plant that makes its own food. For example, during photosynthesis plants use the sun's energy to convert water and carbon dioxide into sugars. Autotrophs are also called producers. Heterotrophs are organisms that cannot make their own food, such as humans, meaning "other eaters." Heterotrophs are also called consumers.

 What happens to all this food once it is made by plants?

 Cellular Respiration is the process by which cells obtain energy from glucose.  Cells break down simple food molecules (sugar) and release the energy they contain.

Energy flow occurs through the ecosystem The products of photosynthesis are the chemical ingredients for cellular respiration, while the products of cellular respiration are the chemical ingredients for photosynthesis.

Chemical Energy Just like the molecules in gasoline and other fuels, organic compounds are a form of potential energy called chemical energy. The stored chemical energy of foods such as peanuts can be released through cellular respiration.

Relationship of Cellular Respiration to Breathing Cellular respiration is an aerobic process, meaning that it requires oxygen Breathing supports cellular respiration by providing the body with oxygen and removing carbon dioxide.

Overall Equation for Cellular Respiration In cellular respiration, the atoms in glucose and oxygen are rearranged, forming carbon dioxide and water. The cell uses the energy released to produce ATP.

Cellular respiration breaks down organic molecules to yield energy in the form of ATP

 Steps  1: The first stage takes place in the cytoplasm, and molecules of glucose are broken down (anaerobic-no oxygen used).  2-3: The second and third stage occurs in the Mitochondria, and there, small molecules are broken down into even smaller molecules (aerobic- needs oxygen).  Energy is released at all stages = ATP

ATP provides the energy for cellular work ATP: (adenosine triphosphate) main energy source that cells use for most of their work An ATP molecule contains potential energy, much like a compressed spring. When a phosphate group is pulled away during a chemical reaction, energy is released.

The ATP Cycle ATP is constantly recycled in your cells. Millions of ATP molecules are used and regenerated per second! Cellular Respiration provides chemical energy to assemble ADP to ATP

Mitochondria Mitochondria are found in almost all eukaryotic cells including plant and animal cells. Its structure is key to its role in cellular respiration.

Mitochondria Its complex folding pattern of membranes and spaces allows for many sites where reactions can occur. Parts of the Mitochondria Outer membrane Inner Membrane Matrix – fluid inside Cristae – folds

Cellular Respiration involves Glycolysis, the Citric Acid Cycle, and Electron Transport Chain

Stage I: Glycolysis The first stage in breaking down a glucose molecule, called glycolysis (splitting sugar), takes place outside the mitochondria in the cytoplasm of the cell.

 Glycolysis  Series of reactions which break the glucose molecule down into two molecules called pyruvate  Process is an ancient one-all organisms from simple bacteria to humans perform it the same way  Yields 2 ATP molecules for every one glucose molecule broken down  Doesn’t require oxygen – anaerobic

Stage 2: The Citric Acid or Krebs Cycle (named after Hans Kreb) The Krebs cycle finishes the breakdown of pyruvic acid molecules to carbon dioxide, releasing more energy in the process. The enzymes for the this cycle are dissolved in the fluid matrix.

 Continues to break down gluclose  Takes the pyruvate and breaks it down, releasing CO2  Production of only 2 more ATP but loads up energy for the next stage

Stage 3: Electron Transport Chain The final stage occurs in the inner membranes of mitochondria. This stage yields the most ATP about 34 ATP

 Energy and remaining substance from the last step is carried over to create ATP from ADP.  In this final step, energy is provided to form a total of 34 ATP 

Fermentation in Human Muscle Cells When your lungs and bloodstream can't supply oxygen fast enough to meet your muscles' need for ATP. Your muscle cells use fermentation, to make ATP without using oxygen.

 Breaking down glucose without oxygen  Fermentation does not give off as much energy as Cellular Respiration.

Fermentation in Microorganisms Yeast (a microscopic fungus) is capable of both cellular respiration and fermentation. Fermentation in yeast produces ethyl alcohol. The carbon dioxide that is released during fermentation creates bubbles and pockets that make bread rise. The alcohol evaporates during baking.

It's the carbon dioxide that is released by yeast that makes baked goods rise.

Wine is the product of yeast fermentation in fruit juice, while beer is the product of yeast fermentation in grain

 Both involve the same chemical compounds, but are the reverse processes.  Cellular Respiration produces CO 2, while Photosynthesis uses up CO 2 in the atmosphere.  Cellular Respiration uses O 2, but Photosynthesis produces it.  Photosynthesis requires energy from the sun, Cellular respiration gets energy from breaking down the chemical bonds in sugar molecules.

 Adenosine Triphosphate

1. In what type of cell does cellular respiration occur? 2. What is the organelle in the cell where cellular respiration occurs? 3. How many parts are there to cellular respiration? 4. What are the products of cellular respiration? 5. What are the reactants of cellular respiration? 6. What is the energy molecule which is produced from this process?

 36 ATP for aerobic vs. 2 ATP for anaerobic  Glycolysis 2 ATP  Kreb’s 2 ATP  Electron Transport34 ATP 38 ATP