How Cells Harvest Chemical Energy

What is the equation for cellular respiration?

C6H12O6 + 6O2 --> 6CO2 + 6H2O + ATPs (Energy)

What are the three stages of Cellular Respiration?

Stage 1: Glycolysis
Stage 2: The citric acid cycle
Stage 3: Oxidative phosphorylation

Where do the three stages take place?

Glycolysis: Cytoplasm
Citric Acid Cycle: Inside the Mitochondria
Oxidative Phosphorylation: Inner mitochondrial membrane

The Facts:

- Slow-twitch muscles are better for endurance running; they can sustain repeated use, but don't provide lots of speed
- Fast-twich muscles are better for sprinting; they fatigue quickly, but provide lots of speed
- Almost all eukaryotic cells go through cellular respiration
- Glycolysis breaks down glucose into two pyruvate
- Pyruvate is a three-carbon compound used in cellular respiration
- The Citric Acid Cycle breaks down the pyruvate and creates Carbon Dioxide, the main purpose is to supply oxidative phosphorylation with electrons
- Oxidative Phosphorylation deals with the electron chain and chemiosmosis
- Chemiosmosis uses the concentration gradient's potential energy to create ATP
- Fermentation is a type of respiration that doesn't require oxygen
- Certain poisons block the electron transport chain, others inhibit ATP synthase

Some Helpful Terms:

-Redox reaction: The movement from one molecule to another
-Oxidation: Loss of electrons from one substance
-Reduction: Gaining electrons to one substance
-Electron Transport Chain: Serious of redox reactions in which electrons pass in steps to oxygen
-Substrate-Level Phosporylation: An enzyme transfer from a phosphate group, forming ADP to ATP
-Chemiosmosis: Chemical osmosis through the concentration gradient, energy produced used to make ATP
-Lactic Acid Fermentation: Used to regenerate NAD+, converted into pyruvate
-Alcohol Fermentation: Yeast in anaerobic enviroments converts pyruvate to CO2 and ethanol
-Obligate Anaerobes: Organisms that are poisoned by oxygen
-Facultative Anaerobes: Can make ATP with either fermentation or oxidative phosphorylation

Diagram:

Glucose starts off as the energy source. It goes through glycolysis to prepare to become pyruvate, generating 2 ATP molecules just by itself. Then the pyruvate becomes the energy source for either aerobic or anaerobic respiration, the latter going through fermentation, producing Lactic acid or Ethanol. The former that uses oxygen, the pyruvate goes through the Krebs (Citric Acid) cycle, producing CO2 and sent to the electron transport chain, taking in oxygen, producing H2O and some ATP










Summary:
This chapter was very specifically about cell respiration and how the cells make energy (ATP). Basically it goes through the steps of cell respiration- Glycolysis, which prepares the glucose for the citric acid cycle, by making most of it into pyruvate and producing 2 ATP. During the citric acid cycle, oxygen is used to finish creating pyruvate and sending it to the electron transport chain.
Then during oxidative phosphorylation, water is produced, as well as 34-36 ATPs. This produces the most energy. Then fermentation is the cycle of respiration that requires no oxygen, and produces lactic acid and ehtanol.

Cool Video:
 http://www.youtube.com/watch?v=vlZZUtpyCgQ