Cellular Respiration: Harvesting Chemical Energy:
VBS Home page,Syllabus, Previous Page, Next Page
1. Energy Flow and Chemical Cycling in the Biosphere.
Diagram the flow of energy and cycling of chemicals in ecosystems, See figure 6.3
Define the following terms related to ecosystems and modes of nutrition:
Comment: autotrophs come in two types: photosynthetic autotrophs rely on sunlight as a source of energy. They include plants, certain protists and some bacteria, especially cyanobacteria. chemosynthetic autotrophs rely on simple inorganic molecules such as hydrogen, hydrogen sulfide,nitrogen compounds or even Fe++ ions as a source of energy and hence do not rely on sunlight at all. Many members of the Domain Archaea are chemosynthetic autotrophs.
2. Overview of cellular respiration:
3. The Metabolic pathway of cellular respiration.
Glycolysis in cytoplasm
Kreb's Cycle in matrix of mitochondrion
Electron Transport Phosphorylation
Comment! Note that cells make ATP by two processes.
4. Explain the five big steps in electron transport
1. NADH and FADH2 donate electrons to electron transport chains
2. Electron transport chains pump H+ to outer compartment of mitocondrion
3. H+ Diffuse to inner compartment through ATP synthase channels
4. ATP synthase catalyzes production of ATP from ADP + Pi(inorganic phosphate)
5. Electrons from the Electron transport chains are accepted by oxygen along with hydrogen ions to make water.
5. Define and explain anaerobic respiration
Comment: Fermentation is not the only type of anaerobic respiration. Certain bacteria are able to produce ATP via electron transport in the absence of oxygen. They do this by using some other electron acceptor. For common alternatives include carbon dioxide or nitrate or sulfate ions. Also note the text's comments about glycolysis being the most wide spread metabolic pathway common to all cells. This suggests that glycolysis evolved very early in the evolution of life and the other stages of cellular respiration developed later.
aerobic cellular respiration
electron transport system
electron transport phosphorylation
substrate level phosphorylation
pgd 09/19/02 revised 09/21/06