Term
| What do autotrophs do to make energy? |
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Definition
| Autotrophs like plants use sunlight energy, CO2 and H2O to make organic compounds like glucose and also O2 (oxygen). This process is photosynthesis. |
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Term
| What do hetertrophs do to make energy? |
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Definition
| Heterotrophs like animals make their energy from organic compounds like glucose and also O2 (oxygen) from autotrophs to make CO2, H2O and ATP energy. This process is known as cellular respiration. |
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Term
| What is the equation for cellular respiration? |
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Definition
| C6H12O6 + 6O2 -> 6CO2 + 6H2O + ATP Energy |
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Term
| What is the equation for photosynthesis? |
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Definition
| Sunlight energy + 6H2O + 6CO2 -> C6H12O6 + 6CO2 |
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Term
| What is ATP and what is it made of? |
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Definition
| ATP is the energy currency of the cell. It is adenosine triphosphate and it is made of very high energy phosphoanhydride bonds. The adenosine is adenine and a ribose sugar. |
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Term
| What happens when ATP undergoes hydrolysis? How does it gain back a phosphate group? |
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Definition
| When ATP undergoes hydrolysis, it loses one phosphate group. This release of the high energy phosphoanhydride bond results in usable energy (Gibbs Free) which can be used in cellular work and chemical synthesis. The released phosphate group can come back through food or sunlight through phosphorylation. Simultaneous give and take, once one loses, another gains. |
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Term
| What are the steps of energy transformations? (the coupled and redox reactions) |
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Definition
| 1. Light energy gives CO2 and H2O energy to make glucose (endergonic) 2. Glucose gives off energy and reverts back to CO2 and H2O (exergonic) 3. ADP + Pi accept the energy from the glucose and phosphorylate into ATP (endergonic) 4. ATP undergoes hydrolysis and gives off one phosphate group to power another process |
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Term
| Explain redox reactions and give examples. |
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Definition
| Oxidation: 1. loss of elections 2. loss of protons 3. gain of oxygen Reduction: 1. gain of electrons 2. gain of protons 3. loss of oxygen Ex: Cl2 + 2e- -> 2Cl- (reduction: Cl2 gained e-) CH4 + O2 - H4 -> CO2 (oxidation: CH4 gained oxygen and lost protons) |
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Term
| Explain the reducing agent and the oxidizing agent in coupled reactions. |
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Definition
| Reducing agent: a molecule that donates electrons/protons/takes oxygen so its corresponding compound becomes oxidized, to allow for a reduction to occur Oxidizing agent: a molecule that accepts electrons/protons/leaves oxygen so its corresponding compound becomes reduced, to allow for an oxidation to occur |
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Term
| What are the two main agents associated with coupled/redox reactions and what is their job? |
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Definition
| NADH oxidizes to NAD+: nicotinamide adenine dinucleotide and FADH2 oxidizes to FAD: flavin adenine dinucleotide are the main agents because they are high energy electron carriers. Accept or donate electrons to be used in redox/coupled reactions. |
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Term
| Explain the oxidation and reduction of NADH. |
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Definition
| When NADH oxidizes, it becomes NAD+. So, it loses one hydrogen (equivalent to 1 e- and 1 H+) and it loses another e- to become positive instead of neutral. When NAD+ is reduced, it gains 1 Hydrogen and 1 e- to become the neutral NADH. |
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Term
| Explain the oxidation and reduction of FADH2 and FAD. |
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Definition
| When FADH2 oxidizes to FAD, it gives off 2 hydrogens, equivalent to 2 e- and 2 H+, making the neutral FAD. When FAD is reduced to FADH2, it gains two hydrogens which are the 2 e- and 2 H+. |
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Term
| Briefly explain the first step of cellular respiration. |
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Definition
| The first step in cellular respiration is glycolysis. It is the breakdown of glucose into 2 pyruvates. Its net yield is 2 ATP and 2 NADH. |
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Term
| Briefly explain the second step(s) of cellular respiration. |
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Definition
| Firstly there is pyruvate oxidation and then there is the Citric Acid (Krebs) Cycle. The 2 pyruvates oxidize to form 2 Acetyl-CoA which then turn into 6 CO2. The net yield is 2 ATP, 8 NADH and 2 FADH2. |
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Term
| Briefly explain the third step of cellular respiration. |
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Definition
| The third step is Oxidative phosphorylation. It uses the high energy electron carriers from Krebs Cycle (mainly the 8 NADH and some of the 2 FADH2) to make a lot of ATP. It yields the most ATP with roughly 32 ATP made. |
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