Mitochondria & Cellular Respiration

Mitochondria: the powerhouses of the cell! Learn about cellular respiration and ATP.

Use the reading below to answer the questions that follow. Mitochondriaare the powerhouses of the cell because they “burn” or break the chemical bonds of glucose to release energy to dowork in a cell. Remember that this energy originally came from the sun and was stored in chemical bonds by plants during photosynthesis. Glucoseand other carbohydrates made by plants during photosynthesis are broken down by the process of aerobic cellular respiration (requires oxygen) in the mitochondria of the cell. This releases energy(ATP) for the cell. The more active a cell (such as a muscle cell), the more mitochondria it will have. The mitochondria are about the size of a bacterial cell and are often peanut-shaped. Mitochondria have their own DNA and a double membrane like the nucleus and chloroplast. The outer membrane is smooth, while the inner membrane is convoluted into folds called cristaein order to increase the surface area.The cristaegreatly increases the surface area of the membrane so that carbohydrates(simple sugars) can combine with oxygento produce ATP, adenosine triphosphate (the energy molecule of the cell). The electron transport chain takes place across the membranes of the cristae (crista, singular). Inside the folds or cristae is a space called the matrix that contains enzymes needed for the Kreb's Cycle.Adenosine triphosphate (ATP)is the energy molecule used by all cells to do work. It is a nucleotide made upof a nitrogen-containing base, a 5-carbon sugar, and 3 phosphate groups. ATP is able to store and transport chemical energy within cells. The LAST TWO phosphate groups, are joined by HIGH-ENERGY bonds. When these bonds are broken, energy is released for cells to use and ADP forms. Enzymes help to break and reform these high-energy bonds. Use the reading above to answer the following questions. Click on the blank lines to make the word bank pop up. 1. What cell process occurs in the mitochondria? cellular respiration2. What kind of cells might have MORE mitochondria? muscle cells3. What simple sugar is broken down in the mitochondria? glucose4. Where does the energy in glucose come from ORIGINALLY? plants5. Why is cellular respiration an aerobic process? requires oxygen6. What energy is released when the chemical bonds of glucose are broken? ATP7. Why is the inner mitochondrial membrane folded? Increase surface area8. What are the folds called? cristae9. What does ATP stand for? Adenosine triphosphate10. What helps weaken these bonds so energy can be released and then later help reform them? enzymes11. When ATP loses a phosphate group energy is released for cells and a molecule of ADP forms.