Respiration+Reading+Assignment


 * Cellular respiration** is the break down of carbon-based molecules for energy.
 * Mitochondria** are the site of **Aerobic Respiration (when oxygen is present, ATP production can be taken to the max).**
 * Oxygen** enters the body through the **lungs**, and the actual exchange takes place at the **alveoli**. **Oxygen** enters the blood stream (through diffusion) and gets distributed to all of the body cells. **Carbon dioxide** is also exchanged here (more diffusion) and exhaled.

In animals, **Glucose** is the result of the digestion of carbohydrates. (Carbohydrase enzymes such as amylase!) In plants, **Glucose** is the result of photosynthesis.


 * __ All eukaryotes __**** use __cellular respiration__ to make energy .**

Respiration Equation: C6H12O6 + O2 à H2O + CO2 + ATP All organisms can use Glucose and Oxygen to carry out aerobic respiration. Plants produce Glucose (sugar) and Oxygen as excess products of photosynthesis. Prokaryotes and eukaryotes (including plants) turn those products into Carbon Dioxide, Water and a lot of Energy (ATP).

Eukaryotes can use mitochondria to maximize the amount of energy available in carbon-based molecules (such as glucose). 2. The **Kreb’s Cycle** occurs in the matrix of the mitochondria. 3. The **Electron Transport Chain** occurs in the cristae (folds) of the inner membrane.
 * Mitochondria** contain an **outer membrane**, **inner membrane**, **cristae** (folds in the inner membrane) and **matrix** (similar to the stroma of the chlorplast).
 * Aerobic respiration takes place in the following stages:**
 * 1. Glycolysis** (split sugar) occurs in the cytoplasm.
 * Glycolysis can occur without oxygen (anaerobic respiration). If more energy is needed without oxygen present, lactic acid fermentation can allow glycolysis to continue (but humans will feel the burn!).



Aerobic respiration occurs in a series of events: 1. Glucose is isolated from carbohydrate molecules. (Digestion) 2. Glucose diffuses into cells. (Facilitated diffusion) 3. **Glycolysis** splits Glucose into 2 **pyruvate** (pyruvic acid) molecules in the cytoplasm = 2 ATP 4. Pyruvate molecules diffuse into mitochondria. 5. **Kreb’s Cycle** enzymes breaks down pyruvate into CO2 and H+= 2 ATP. 6. CO2 is released and H+ move to the **Electron Transport Chain**. 7. O2 receives the H+ as 34 more ATP are made, making H2O. 8. Without Oxygen, the process would stop after Kreb's Cycle. Energy conversions for respiration:

Chemical Energy à Chemical Energy Glucose à ATP


 * Eukaryotes use chemical energy from the bonds of food to make ATP. Oxygen is necessary to make A LOT of ATP.**


 * Fermentation occurs in all organisms when Oxygen is lacking.**
 * In conditions of low oxygen:**
 * Animals** can only perform lactic acid fermentation (usually in the muscles during high intensity exercise).
 * Yeast and bacteria** can perform either lactic acid fermentation (yogurt, cheese manufacturing) or alcoholic fermentation (bread, wine, beer manufacturing).

Retrieval Questions Answer the following questions without going back to the reading. Then after you have written out your answers, go back to the reading and check yourself. Indicate that you have corrected your own answers by correcting them in a different color pen. 1. Where does oxygen and carbon dioxide exchange in humans? Which type of membrane transport is this? 2. There are three main regions of a cell and mitochondria where the three stages of aerobic respiration occur. Identify these parts. 3. Place the following in order of occurrence: Glycolysis, Electron Transport Chain, Digestion, Kreb's Cycle, Pyruvate, Facilitated Diffusion of Glucose 4. Do humans undergo fermentation? If so, for what purpose? 5. Write the equation for respiration. Illustrate which parts of the equation are the first Chemical Energy source and the second Chemical Energy made.