Cellular Respiration  The organic compounds that animals eat and plants produce are converted to ATP through Cellular Respiration.  Oxygen makes the production of ATP more efficient.  Metabolic processes that use oxygen are called aerobic.  Metabolic processes that do not use oxygen are called anaerobic.

Cellular Respiration Overview  C 6 H 12 O O 2  6 CO H 2 O ATP  Plants and Animals both undergo cellular respiration.  Aerobic Respiration takes place in the mitochondria of plants and animals.

Cellular Respiration Overview  Stage 1- Glycolysis: Glucose is broken down into pyruvate, producing NADH and ATP in the cytoplasm of cells.  Stage 2 (Aerobic)-Krebs Cycle: With O 2, pyruvate and NADH are used to make a large amount of ATP in the mitochondria of plant and animal cells.  Stage 2 (Anaerobic)- Fermentation: Without oxygen, pyruvate is converted into lactate or ethyl alcohol in the cytoplasm of cells.

Cellular Respiration

Stage One: Glycolysis  Glycolysis: Glucose from food, is broken down in the cytoplasm of cells.  Step 1: Phosphate groups from 2 ATPs are transferred to a glucose molecule.  Step 2: The six carbon compound is broken into two 3-carbon compounds with a phosphate group.

Stage One Glycolysis  Step 3: Two NADH molecules are produced and another phosphate group is added to each of the 3-carbon compounds.  Step 4: Each of the 3-carbon compound is converted to pyruvate and each molecule produces 2 ATP  Used: Glucose, 2 ATP  Produced: 2 pyruvate, 4 ATP, 2 NADH

Chapter 5

Cellular Respiration

Stage 2: Krebs Cycle  Krebs Cycle: The pyruvate molecule enters the mitochondrion and are broken down into a 2- carbon compound and release CO 2  Step 1- The 2-carbon compound is combined with a 4-carbon compound to make a 6-carbon compound  Step 2- CO 2 is released from 6- carbon compound to form a 5-carbon compound. Electrons are transferred to NAD+ to make NADH

Stage 2: Krebs Cycle  Step 3- CO 2 is released from the 5-carbon compound making a four carbon compound. A molecule of ATP and NADH are made.  Step 4- The 4-carbon compound is converted and electrons are transferred to an electron acceptor-FAD which makes the electron carrier FADH 2.  Step 5- The new four carbon compound is converted to the 4-carbon compound to begin the cycle. NADH is produced.

Krebs Cycle Review  Aerobic cellular respiration that takes place in the mitochondria of cells.  Also called the Citric Acid Cycle  Used: pyruvate  Produced: CO 2, NADH, FADH 2, ATP

Krebs Cycle

Electron Transport Chain  The electrons carried by NADH and FADH 2 enter an electron transport chain of the inner membrane of the mitochondria.  The energy in the electrons allow proteins to pump (actively transport) H + ions out of the inner compartment to the outer compartment of the mitochondria.

Electron Transport Chain  A concentration gradient of H + ions will be produced and the H + will flow by facilitated diffusion through a ATP that will make ATP.  Used H + ions and electrons will combine with O 2 to produce water.

Electron Transport Chain

Electron Transport Chain of Aerobic Respiration

Aerobic Respiration Review  Glycolysis Used: 1 Glucose, 2 ATP Used: 1 Glucose, 2 ATP Produced: 2 pyruvate, 2 NADH, 4 ATP Produced: 2 pyruvate, 2 NADH, 4 ATP  Krebs Cycle Used: 2 pyruvate Used: 2 pyruvate Produced: 2 FADH 2, 8 NADH, 2 ATP, 6 CO 2 Produced: 2 FADH 2, 8 NADH, 2 ATP, 6 CO 2  Electron Transport Used: 8 NADH, 2 FADH 2, 6 O 2 Used: 8 NADH, 2 FADH 2, 6 O 2 Produced: ATP, 6 H 2 O Produced: ATP, 6 H 2 O

Net Results of Respiration  Used: 1 Glucose, 6 O 2  Produce: 6 H 2 O, 6 CO 2, ATP  1 C 6 H 12 O O 2  6 CO H 2 O ATP

Anaerobic Respiration  When no oxygen is available, fermentation is an anaerobic process that can produce ATP  Two main types of anaerobic respiration are Lactic Acid and Ethyl Alcohol Fermentation  Without oxygen NAD+ needs another way to cycle into NADH

Lactic Acid Fermentation  In Lactic Acid fermentation, glucose is still broken down to pyruvate through glycolysis  Using NADH, the pyruvate is converted into another 3-carbon compound called lactate and ATP is produced.  During exercise, without oxygen, cells in muscles break down pyruvate to lactate to produce ATP

Ethyl Alcohol Fermentation  In Alcohol Fermentation, glucose is broken down into pyruvate through glycolysis.  The pyruvate is broken down into a 2- carbon compound releasing CO 2.  Using NADH the 2-carbon compound is converted to ethyl alcohol (ethanol).  Alcoholic beverages and bread us alcoholic fermentation.

Lactic Acid and Alcoholic Fermentation  When oxygen is not present, cells recycle NAD + through fermentation.

Respiration in the Absence of Oxygen  When oxygen is present, aerobic respiration occurs to produce ATP. When oxygen is not present, fermentation occurs instead.

Cellular Respiration vs. Fermentation