Explore BrainMass
Share

Explore BrainMass

    3 Questions

    This content was COPIED from BrainMass.com - View the original, and get the already-completed solution here!

    1.Some species of bacteria that live at the surface of sediment on the bottom of lakes are facultative anaerobes; that is, they are capable of either aerobic or anaerobic respiration. How will their metabolism change during the summer when the deep water becomes anoxic (deoxygenated)? If the bacteria continue to grow at the same rate, will glycolysis increase, decrease, or remain the same after the lake becomes anoxic? Explain why.

    2. Most cells are very small. What physical and metabolic constraints limit cell size? What problems would an enormous cell encounter? What adaptations might help a very large cell to survive?

    3.The integrity of the plasma membrane is essential for cellular survival. Could the immune system utilize this fact to destroy foreign cells that have invaded the body? How might cells of the immune system disrupt membranes of foreign cells? (Two hints: virtually all cells can secrete proteins, and some proteins form pores in membranes.)

    © BrainMass Inc. brainmass.com October 9, 2019, 5:27 pm ad1c9bdddf
    https://brainmass.com/biology/membranes-and-cell-walls/3-questions-57916

    Solution Preview

    1.Some species of bacteria that live at the surface of sediment on the bottom of lakes are facultative anaerobes; that is, they are capable of either aerobic or anaerobic respiration. How will their metabolism change during the summer when the deep water becomes anoxic (deoxygenated)? If the bacteria continue to grow at the same rate, will glycolysis increase, decrease, or remain the same after the lake becomes anoxic? Explain why.

    When the deep water becomes anoxic, that means that there is no oxygen left dissolved in the water at that depth. Therefore, there is no oxygen available for cellular respiration. That means that there is no oxygen left to act as the terminal electron acceptor in the electron transport chain in the inner mitochondrial membrane. That means that "oxidative phosphorylation" will not be able to take place. That means that the reduced cofactors like NADH and FADH2 will not be able to be reoxidized back to their oxidized forms (NAD+ and FAD). Therefore, the Krebs cycle will shut down and even glycolysis will back up and no ATP can be made UNLESS some other system kicks in that allows for ATP production in the absence of oxygen. That is what these organisms are ...

    $2.19