Chapter 9 CELLULAR RESPIRATION

CH 9 NOTES—PART 1 FOOD ENERGY

CELLULAR RESPIRATION

I. Food Energy A. Food energy is in the BONDS of the food molecules. B. The more bonds a food has the more energy (calories) it contains. C. Body cells break down glucose, to make ATP for energy to do work.

FAT PROTEIN CARBS

II. In the Lab A. Calorimetry- process used to determine Energy content of food by: 1. Burning the food 2. Using heat energy given off by the food to calculate the number of calories in the food.

3. Calorimeter- apparatus used to determine Calories. 4 3. Calorimeter- apparatus used to determine Calories. 4. calorie= amount of energy needed to raise 1 gram of water by 1 degree Celsius.

III. Food Label Calories A. 1 Calorie= 1000 calories C. Example: 250 Calories = 250,000calories

CELLULAR RESPIRATION OVERVIEW CH 9—PART 2 NOTES CELLULAR RESPIRATION OVERVIEW

I. Cellular Respiration Overview A. Breakdown of glucose into ATP B. Occurs mainly in the mitochondria of the cell C. Two types of CR: 1. Aerobic (with oxygen) 2. Anaerobic (without oxygen)

II. Aerobic CR A. “Normal” respiration 1. Requires Oxygen. 2. CO2 and H2O given off as waste products.

B. Glucose has 90 times the energy of ATP 1. If broken down all at once, it would be too much energy for cell to handle. 2. If all the energy was released in one step… most would be lost as heat!

C. 3 Parts to Aerobic CR 1. Glycolysis 2. Krebs Cycle 3. Electron Transport chain

D.Number of ATP produced in each stage is: 1. Glycolysis: produces 4 but uses 2 to start so there is a net gain of 2 ATP 2. Kreb’s Cycle/Citric Acid cycle produces/gains 2 ATP. 3. Electron Transport Chain produces/gains 32 ATP a. What is the total ATP produced?____ b. What is the total ATP gained? _____ 38 36 ***

Equation: Enzymes C6H12O6 + 6 O2 6 CO2 + 6 H2O + 36 ATP(E) Look familiar? How does this equation compare to photosynthesis??_________________

CH 9—PART 3 NOTES AEROBIC RESPIRATION

O2 2 O2 CO2 H2O 2 32 2

A. Occurs in cytoplasm. B. Requires 2 ATP to start. C. Does NOT require oxygen. I. Glycolysis-1st step in ALL Cellular Respiration (Aerobic and Anaerobic)

D. Breaks down Glucose to make: 1 D. Breaks down Glucose to make: 1. 2 Pyruvic Acid moleculesgo to Kreb’s cycle 2. 2 NET ATP (4 made but 2 required to start) 3. 2 NADH (from NAD+)

***NAD+ is an e- carrier/transporter which is always in your cells (similar to NADP+ in photosynthesis) -When NAD+ is carrying high E e- and H, it is called NADH. -Once it drops of the H and e- to the Electron Transport Chain, it turns back into NAD+ -There is another e- carrier called FADH, when it has is carrying high E e- it is called FADH2

E. Glycolysis happens very fast 1. Makes 1000’s of ATP in milliseconds E. Glycolysis happens very fast 1. Makes 1000’s of ATP in milliseconds. 2. Once glucose is gone, cells begin turning stored glycogen into glucose.

II. Krebs Cycle (Citric Acid Cycle) Will not happen without oxygen Takes place in mitochondria Breaks down pyruvic acid (from _________) glycolysis

A. Pyruvate  Acetyl Co A As pyruvic acid (a 3-carbon molecule) enters the mitochondria, one carbon is removed forming CO2. Electrons and H atoms hop on the NAD+ carrier changing to NADH-. The 2-carbon molecule that is left combines with Coenzyme A forming Acetyl CoA.

B. Once Acetyl CoA enters the Krebs cycle: It joins a 4-carbon molecule (already in the krebs cycle) forming Citric Acid, becoming a 6-carbon molecule. Citric Acid is the first molecule formed during the Krebs cycle, so the cycle is sometimes called the Citric Acid Cycle.

C. Changes through the Krebs Cycle As citric acid (6-C’s) moves through the cycle another CO2 is released reducing it to a 5-carbon molecule. Another NAD+ is converted to NADH-

3. As it continues, another CO2 is released reducing it finally to a 4-carbon molecule, and another NADH- forms from NAD+ along with an ADP recharging to ATP.

4. Lastly, One more NAD+ is changed to NADH and FAD is changed to FADH2. The 4 carbon molecule is ready to join with the second Acetyl CoA and go through another turn of the Krebs cycle.

4. Both pyruvic acids produced from 1 glucose go through this process a. Each Pyruvic acid produces 1) 1 ATP 2) 4 NADH (technically only 3 during krebs, the 4th is made before Acetyl CoA enters the Krebs Cycle) 3) 1 FADH2 b. Each pyruvic acid also changes from a 3-carbon, to a 2-carbon, to a 6 carbon, to a 5-carbon, and finally to a 4-carbon molecule.

Citric Acid Cycle Krebs Cycle

https://www.youtube.com/watch?v=emLl7oibl8Q

III. Electron Transport Chain 1. This is where the e- and H atoms carried on NADH and FADH2, from glycolysis and the Krebs Cycle go .

A. How does the Electron Transport Chain work?

1. e- from NADH and FADH2 are passed through a series of carrier proteins in the inner membrane space of the mitochondria.

2. 3. For every two e- that move down the chain, there is enough energy move a H+ across the intermembrane space. This creates a (+) positively charged intermembrane space. The other side of the membrane has a slight negative charge. The positive ions are attracted to the negative side of the membrane.

3. When the H+ comes across an ATP Synthase, it moves through its channel. As this happens, ATP synthase spins with enough energy to change 3 ADP 3 ATP 3 3

4. At the end of the chain, an enzyme combines the low e- electrons with H ions and Oxygen to form water. 3 3

G. Electron Transport Chain 1. Uses high E in e- (carried by NADH and FADH2 ) to create a difference in charge across mitochondria’s inner membrane. 2. This charge difference allows ATP synthase to recharge ADP into ATP as H+ moves back across the membrane

2. There are enough e- to recharge 32 ADP back to ATP. 3 2. There are enough e- to recharge 32 ADP back to ATP. 3. Oxygen is used to take low energy e- and H+ to form water which you exhale (along with the CO2 from Krebs.)

https://www.youtube.com/watch?v=lRlTBRPv6xM

H. TOTAL ATP GAINED FROM AEROBIC CELLULAR RESPIRATION 1. From 1 glucose molecule during AEROBIC cellular respiration cells gain: TOTAL = 36 ATP

**38% of E from one glucose is converted to ATP **62% is given off as body heat. One glucose molecule contains ____kcal Calculate how much energy your cells receive from 1 glucose molecule and how much energy is lost as heat. 686

Comparing PS and CR