ADP, ATP and Cellular Respiration Copyright Cmassengale

What Is ATP? Energy used by all Cells Adenosine Triphosphate Organic molecule containing high- energy Phosphate bonds Copyright Cmassengale

Chemical Structure of ATP 3 Phosphates Ribose Sugar Adenine Base Copyright Cmassengale

What Does ATP Do for You? It supplies YOU with ENERGY! Copyright Cmassengale

How Do We Get Energy From ATP? By breaking the high- energy bonds between the last two phosphates in ATP Copyright Cmassengale

What is the Process Called? HYDROLYSIS (Adding H 2 O) H2OH2O Copyright Cmassengale

How Does That Happen? An Enzyme! Copyright Cmassengale

How is ATP Re-Made? The reverse of the previous process occurs. Another Enzyme is used! ATP Synthetase Copyright Cmassengale

The ADP-ATP Cycle ATP-ase ATP Synthetase Copyright Cmassengale

When is ATP Made in the Body? During a Process called Cellular Respiration that takes place in both Plants & Animals Copyright Cmassengale

Cellular Respiration Includes pathways that require oxygen Includes pathways that require oxygen Glucose is oxidized and O 2 is reduced Glucose is oxidized and O 2 is reduced Glucose breakdown is therefore an oxidation-reduction reaction Glucose breakdown is therefore an oxidation-reduction reaction Breakdown of one glucose results in 36 to 38 ATP molecules Breakdown of one glucose results in 36 to 38 ATP molecules Copyright Cmassengale

Overall Equation for Cellular Respiration 6CO 2 + 6H e ATP’s C 6 H 12 O 6 + 6O 2 YIELDS Copyright Cmassengale

What Type of Process is Cellular Respiration? An Oxidation-Reduction Process or REDOX Reaction An Oxidation-Reduction Process or REDOX Reaction Oxidation of GLUCOSE --> CO 2 + H 2 O (e - removed from C 6 H 12 O 6 ) Oxidation of GLUCOSE --> CO 2 + H 2 O (e - removed from C 6 H 12 O 6 ) Reduction O 2 to H 2 O (e - passed to O 2 ) Reduction O 2 to H 2 O (e - passed to O 2 ) Copyright Cmassengale

What Carries the Electrons? NAD + (nicotinadenine dinucleotide) acts as the energy carrier NAD + (nicotinadenine dinucleotide) acts as the energy carrier NAD + is a coenzyme NAD + is a coenzyme It’s Reduced to NADH when it picks up two electrons and one hydrogen ion It’s Reduced to NADH when it picks up two electrons and one hydrogen ion Copyright Cmassengale

Are There Any Other Electron Carriers? YES! Another Coenzyme! YES! Another Coenzyme! FAD+ (Flavin adenine dinucleotide) FAD+ (Flavin adenine dinucleotide) Reduced to FADH 2 Reduced to FADH 2 Copyright Cmassengale

Other Cellular Respiration Facts Metabolic Pathway that breaks down carbohydrates Metabolic Pathway that breaks down carbohydrates Process is Exergonic as High-energy Glucose is broken into CO 2 and H 2 O Process is Exergonic as High-energy Glucose is broken into CO 2 and H 2 O Process is also Catabolic because larger Glucose breaks into smaller molecules Process is also Catabolic because larger Glucose breaks into smaller molecules Copyright Cmassengale

What are the Stages of Cellular Respiration? Glycolysis Glycolysis The Krebs Cycle The Krebs Cycle The Electron Transport Chain The Electron Transport Chain Copyright Cmassengale

Where Does Cellular Respiration Take Place? It actually takes place in two parts of the cell: It actually takes place in two parts of the cell: Glycolysis occurs in the Cytoplasm Krebs Cycle & ETC Takeplace in the Mitochondria Krebs Cycle & ETC Take place in the Mitochondria Copyright Cmassengale

Review of Mitochondria Structure Smooth outer Membrane Smooth outer Membrane Folded inner membrane Folded inner membrane Folds called Cristae Folds called Cristae Space inside cristae called the Matrix Space inside cristae called the Matrix Copyright Cmassengale

Diagram of the Process Occurs in Cytoplasm Occurs in Matrix Occurs across Cristae Copyright Cmassengale

Glycolysis Summary Takes place in the Cytoplasm Anaerobic (Doesn’t Use Oxygen) Requires input of 2 ATP Glucose split into two molecules of Pyruvate or Pyruvic Acid Copyright Cmassengale

Glycolysis Summary Also produces 2 NADH and 4 ATP Also produces 2 NADH and 4 ATP Pyruvate is oxidized to Acetyl CoA and CO 2 is removed Pyruvate is oxidized to Acetyl CoA and CO 2 is removed Copyright Cmassengale

Glycolysis Diagram Copyright Cmassengale

Fermentation Occurs when O 2 NOT present (anaerobic)  Occurs when O 2 NOT present (anaerobic)  Called Lactic Acid fermentation in muscle cells (makes muscles tired)  Called Alcoholic fermentation in yeast (produces ethanol)  Nets only 2 ATP Copyright Cmassengale

A Little Krebs Cycle History Discovered by Hans Krebs in 1937 Discovered by Hans Krebs in 1937 He received the Nobel Prize in physiology or medicine in 1953 for his discovery He received the Nobel Prize in physiology or medicine in 1953 for his discovery Forced to leave Germany prior to WWII because he was Jewish Forced to leave Germany prior to WWII because he was Jewish Copyright Cmassengale

Krebs Cycle Summary Requires Oxygen (Aerobic) Requires Oxygen (Aerobic) Cyclical series of oxidation reactions that give off CO 2 and produce one ATP per cycle Cyclical series of oxidation reactions that give off CO 2 and produce one ATP per cycle Turns twice per glucose molecule Turns twice per glucose molecule Produces two ATP Produces two ATP Takes place in matrix of mitochondria Takes place in matrix of mitochondria Copyright Cmassengale

Krebs Cycle Summary Each turn of the Krebs Cycle also produces 3NADH, 1FADH 2, and 2CO 2 Each turn of the Krebs Cycle also produces 3NADH, 1FADH 2, and 2CO 2 Therefore, For each Glucose molecule, the Krebs Cycle produces 6NADH, 2FADH 2, 4CO 2, and 2ATP Therefore, For each Glucose molecule, the Krebs Cycle produces 6NADH, 2FADH 2, 4CO 2, and 2ATP Copyright Cmassengale

Krebs Cycle ATP NETS: 3NADH, 1ATP, 1FADH 2, & 2CO 2 Copyright Cmassengale

Electron Transport Chain Summary 34 ATP Produced 34 ATP Produced H 2 O Produced H 2 O Produced Occurs Across Inner Mitochondrial membrane Occurs Across Inner Mitochondrial membrane Uses coenzymes NAD+ and FAD+ to accept e- from glucose Uses coenzymes NAD+ and FAD+ to accept e- from glucose NADH = 3 ATP’s NADH = 3 ATP’s FADH 2 = 2 ATP’s FADH 2 = 2 ATP’s Copyright Cmassengale

Electron Transport Chain Animation Electron Transport Chain Animation Copyright Cmassengale

Cellular Respiration Summary the ultimate goal of cellular respiration is to convert the chemical energy in nutrients to chemical energy stored in adenosine triphosphate (ATP). ATP can then release the energy for cellular metabolic processes, such as active transport across cell membranes, protein synthesis, and muscle contraction.

To transfer the energy stored in glucose to the ATP molecule, a cell must break down glucose slowly and capture the energy in stages.

The first stage is glycolysis. ○ In the process of glycolysis a glucose molecule is broken down into pyruvic acid molecules and ATP molecules. ○ Glycolysis is a series of reactions using enzymes that takes place in the cytoplasm.

If oxygen is available, the next stage is the two-step process of aerobic respiration, which takes place primarily in the mitochondria of the cell.

The first step of aerobic respiration is called the citric acid or Krebs cycle. ¨ The pyruvic acid formed in glycolysis travels to the mitochondria where it is chemically transformed in a series of steps, releasing carbon dioxide, water, and energy (which is used to form 2 ATP molecules) Pyruvic acid -> carbon dioxide + water + energy (2 ATP)

○ The second step of aerobic respiration is the electron transport chain. ¨ Most of the energy storing ATP molecules is formed during this part of the cycle. The electron transport chain is a series of chemical reactions ending with hydrogen combining with oxygen to form water. Carbon dioxide is released as a waste product as it is formed in several stages of the Krebs cycle. ¨ Each reaction produces a small amount of energy, which by the end of the cycle produces many (up to 36) ATP molecules. ¨ The ATP synthesized can be used by the cell for cellular metabolism

If no oxygen is available, cells can obtain energy through the process of anaerobic respiration. A common anaerobic process is fermentation. Fermentation is not an efficient process and results in the formation of far fewer ATP molecules than aerobic respiration.

There are two primary fermentation processes: ○ Lactic acid fermentation occurs when oxygen is not available, for example, in muscle tissues during rapid and vigorous exercise when muscle cells may be depleted of oxygen. ¨ The pyruvic acid formed during glycolysis is broken down to lactic acid, and in the process energy is released (which is used to form ATP). ¨ The process of lactic acid fermentation replaces the process of aerobic respiration so that the cell can continue to have a continual source of energy even in the absence of oxygen, however this shift is only temporary and cells need oxygen for sustained activity. ¨ Lactic acid that builds up in the tissue causes a burning, painful sensation.

Alcohol fermentation occurs in yeasts and some bacteria. ¨ In this process, pyruvic acid formed during glycolysis is broken down to produce alcohol and carbon dioxide, and in the process energy is released (which is used to form ATP).