Cellular Respiration 2

Compare and contrast Anaerobic cellular respiration and Aerobic cellular respiration. In your answer, address glycolysis, the citric acid cycle, oxidative phosphorylation, lactic acid fermentation, alcohol fermentation, NADH, FADH2 and ATP.  At the most basic level, the difference between Anaerobic and Aerobic respiration is that Aerobic respiration uses O2 and Anaerobic doesn’t. Aerobic also produces much more ATP than Anaerobic does (28-38 vs. 6ish). Both types of respiration include glycolysis in the cytosol and produce 2ATP and NADH. Only aerobic respiration has the citric acid cycle (produces 2 ATP and FADH2) and oxidative phosphorylation (produces 26-28 ATP) both of which occur in the mitochondria. Lactic acid and alcohol fermentation are both used in anaerobic respiration. In lactic acid fermentation, pyruvate reduced by NADH, forms lactate. No  CO2 is released (2 ATP produced). With alcohol fermentation, pyruvate is reduced to ethanol in 2 steps; 1. CO2 released from pyruvate and 2. acetaldehyde reduced to ethanol.


Explain why the disruption of chemiosmosis and the proton motive force can be detrimental to eukaryotic organisms. Provide a real life example. When is chemiosmosis (energy coupling mechanism that uses energy stored in the form of a H+ gradient across a membrane)  and the proton motive force (the gradient of hydrogen ions) are disrupted a eukaryotic organism can not produce ATP and you would see mass cell death and ultimately the death of the organism because no energy is being produced. A real life example is cyanide poisoning. Cyanide damaged the mitochondria and prohibited the production of APT and killed people.


Compare and contrast obligate and facultative anaerobes. Obligate anaerobes and facultative anaerobes carry out fermentation. But only obligate anaerobes carry out anaerobic respiration, but cannot survive in the presence of O2. On the other hand, facultative anaerobes can carry out cellular respiration.

In the following redox reaction, identify which molecules have been oxidized and reduced. Also identify the reducing agents and the oxidizing agents.

C6H12O6 + 6O2 → 6CO2 + 6H2O + Energy

Carbon is oxidized due to the conversion from C6 → 6CO2 (looses electrons) this makes carbon the reducing agent.

Oxygen is reduced by taking electrons from the less electronegative Carbon (O6 → 6CO2), making oxygen the oxidizing agent.



Cellular Respiration

Ap bio seems to just be getting harder and harder. This week was no exception. This week was all about cellular respiration, the steps that go into it and the molecules that make it possible. Cellular respiration is the way our body transforms the food we eat into energy or ATP (adenosine triphosphate). The food must be broken down in the presence of oxygen within our bodies. The reaction is C6H12O6 + 6O2 -> 6Co2 + 6H2O + energy. The 4 main steps of cellular respiration are glycolysis, pyruvate oxidation, civic acid cycle (not Krebs cycle), and oxidative phosphorylation. The process begins with glycolysis, the only process that is outside of the cytoplasm of the cell. Glycolysis is one of the processes that produces ATP and 2NADH when taking in glucose. The next process is pyruvate oxidation, this occurs inside the cytoplasm of the cell. Pyruvate oxidations takes 2 pyruvate from glycolysis and produces 2 CO2 and 2 NADH. This is the only step that does not produce ATP. The next step is the citric acid cycle, this also occurs within the cytoplasm. This step takes 2 AcetylCoA from the previous step and produces 4 CO2, 2ATP, 6NADH, and 2FADH2.  The last step is the big ATP producer – Oxidative Phosphorylation. This process also occurs in the cytoplasm. This step uses 6O2 to produce 34 ATP and 6 H2O. All these steps combined are one of the most important process that occur in our body.

With out the mitochondria and cellular respiration we would be blobs of nothing that didn’t move. We would be dead. This is why mitochondria should have won the election. Without the mitochondria you would be nothing.

Besides the devastating loss this week it was a pretty ok week. The POGIL cleared things up a lot and re watching the Bozeman video was also very helpful. I have high hopes this unit will be clearer than others. I am having a little bit of trouble with understanding the citric acid cycle and what actually happens. Other than that I think I might actually understand whats going on for once!