Cellular Respiration PPT PDF

The Cellular Level of Organization Objectives: 1. Outline the steps of cellular respiration. 2. Describe the structure and function of the cell membrane and its selective permeability. 3. Explain different types of cellular transport. 4. Explain osmosis and the effects of isotonic, hypotonic, an...

The Cellular Level of Organization Objectives: 1. Outline the steps of cellular respiration. 2. Describe the structure and function of the cell membrane and its selective permeability. 3. Explain different types of cellular transport. 4. Explain osmosis and the effects of isotonic, hypotonic, and hypertonic solutions on cells. 5. Describe the factors contributing to resting membrane potential.  The Cell Membrane Extracellular side of membrane Glycoprotein Double layer (bilayer) of phospholipid molecules Phospholipid bilayer Transmembrane protein Hydrophobic fatty acid “tail” Cholesterol Intracellular side molecules Hydrophilic of membrane phosphate “head”  Mitochondri on Function: “Powerhouse”- uses glucose to make energy (ATP) – Takes glucose from food, turns it into ATP Structure: – Outer Membrane – Christae- folded inner membrane – Intermembrane Space- space between christae and outer membrane – Matrix-fluid around cristae  Metabolism Review! Metabolism: whole range of biochemical processes that occur within a living organism that includes both: – Anabolism (building up) synthesis of new molecules (uses energy) – Catabolism (tearing down) decomposition of complex molecules to simpler molecule (i.e. breaking down fat in order to provide the body with energy)  ATP Review ATP Structure Adenosine Adenine Ribose Phosphates P P P ATP  ATP Review How Do We Get Energy From ATP? Dephosphorylation – By breaking the bonds between the last two phosphates in ATP – This bond is very high energy, breaking it releases that energy Hydrolysis reaction- meaning the addition of water breaks the molecules apart ATPase catalyzes this reaction  How is ATP Re-Made? Phosphorylation – The reverse of the previous process occurs – The majority of ATP is made via ATP synthase ATP synthase is an enzyme Not all ATP is made this way though (more on this later  Two Types of Phosphorylation Substrate Level Phosphorylation – A phosphate is transferred directly from a substrate onto ADP – Does NOT use ATP Synthase – Occurs during Glycolysis & The Krebs Cycle Oxidative Phosphorylation – Occurs after the electron transport chain passes electrons along the chain and stores their energy to drive ATP synthase – Uses ATP Synthase – Occurs following the electron transport chain  When is ATP Made in the Body? Aerobic = With Oxygen Anaerobic = Without Oxygen Overall Equation for Cellular Respiration Glucose C6H12O6 + 6O2 YIELDS 6CO2 + 6H20 + e- + 36-38ATP’s  Cellular Respiration Is A REDOX Reaction An Oxidation-Reduction Process is known as a REDOX reaction – If a molecule is oxidized, then it loses electrons. Molecules that are oxidized usually lose Hydrogen atoms – If a molecule is reduced then it gains electrons. Molecules that are reduced usually gain Hydrogen atoms. Molecules are reduced because they pick up electrons, and electrons are negative, so it is a reduction in charge.  Cellular Respiration as a REDOX Reaction Glucose is oxidized (loses electrons) and O is 2 reduced (gains electrons) *Oxygen is the final electron acceptor in cellular respiration* Oxygen is reduced (gains electrons) to water (H2O)  Question: If electrons are being stripped from glucose- where do they go? Answer: They are picked up by electron “carriers” and taken to the mitochondria where they are delivered to the electron transport chain Two Carrier Molecules 1. NAD+ (nicotinadenine dinucleotide) - Reduced to NADH 2. FAD+ (Flavin adenine dinucleotide) – Reduced to FADH2 *Remember, it’s “reduced” because it has MORE electrons, so it is MORE negative  Other Cellular Respiration Facts Metabolic Pathway- breaks down carbohydrates – Exergonic- high-energy glucose broken into CO2 and H2O – Catabolic - larger Glucose breaks into smaller molecules (H2O and CO2)  1. Glycolysis – Anaerobic – Occurs in the Cytoplasm 2. Krebs Cycle - Aerobic - Takes place in the matrix of the mitochondria 3. Electron Transport Chain – Aerobic – Takes place across the inner Stages of membrane of the Cellular mitochondria Respiration  Key Points of Glycolysis Takes place in the Cytoplasm Anaerobic Starts with Glucose Glucose has 6 carbons Ends with two molecules of Pyruvate (Pyruvic Acid) Pyruvate has 3 carbons (3 +3 =6) Two Stages INPUT stage requires 2 ATP OUTPUT STAGE produces 4 ATP and 2 NADH NOTE: 4 output-2 input= 2 Net ATP Think about the input stage as starting a business (like a lemonade stand). It costs money to start (in this case energy).  Where does the pyruvate go after glycolysis? If there is oxygen – Cellular respiration will proceed – Pyruvate will enter the mitochondria and be oxidized to acetyl co-a This process creates 2 CO2 and 2 NADH If there is no oxygen – No cellular respiration will occur – Fermentation occurs – Pyruvate is converted to lactic acid or alcohol (if you’re a yeast… which you’re not)  Fermentation Occurs when O2 NOT present (anaerobic) Lactic Acid fermentation in muscle cells (makes muscles tired) Alcoholic fermentation in yeast (produces ethanol) (remember you are a multicellular organism- aka not yeast) Without O2 only a nets 2 ATP from glycolysis Remember- normal cellular respiration with oxygen makes 36-38 ATP  Acetyl CoA Krebs Cycle Summary What is the Krebs Cycle? Answer: Cyclical series of oxidation reactions that give off CO2 and produce one Krebs ATP per cycle 2 Cycle 6 Krebs Facts 2 Occurs in matrix of mitochondria 6 Aerobic (needs oxygen) 2 Turns twice per glucose that started cellular respiration (because 2 pyruvate) Input – 2 pyruvate (from glycolysis) Output (total from two turns) – 2 ATP – 6 NADH (4 per pyruvate) – 2 FADH2 (1 per pyruvate) – 2 CO2 Fun Fact: On average a person exhales about 2.3 pounds of carbon dioxide  All we have are electron carriers, now what…? All NADH (10 total) and FADH2 (2 total) go to electron transport chain (ETC) ETC is a series of transmembrane proteins embedded in the inner membrane (christae) of the mitochondria 2 NADH 2 NADH 6 NADH, 2 FADH2 2 Pyruvat e 2 2 ?  Electron Transport Chain Electron transport chain strips Hydrogens from the electron carriers. – The hydrogens are pumped into the intermembrane space (IMS) – Electrons are used to power the pumping Every NADH yields 10 H+ pumped into the IMS Every FADH2 yields 6 H+ pumped into the IMS This creates a transmembrane potential- there are more H+ on one side of the membrane than the other The transmembrane potential then powers the ATP Synthase  H H H + + H H + H H H H + H+ HH + + H H + H+ + + H + + H + + + + ATP Synthase  Quick Detour: What Is Transmembrane Potential?  Transmembrane Potential In the intermembrane space of the mitochondria there are more protons than in the matrix This difference in charge is considered a ”potential” – Also known as an electrochemical gradient Protons flow from an area of high concentration to an area of low concentration – This is just diffusion down H + their electrical/concentration gradient ATP Synthase The Work Horse! ATP Synthase Vide o Clip  How does H+ translate to ATP? 4 H+ → 1 ATP – Pumped across ATP Synthase Therefore: – 10 H+ per NADH → 2.5 ATP – 6 H+ per → 1.5 ATP  Cellular Respiration Summary HOWEVER THIS IS A RANGE! (~30-38 ATP) Dependent on cell type and enzyme efficiency Glycolysis Krebs } Cycle NADH 2 8 Go to FADH2 - 2 ETC! ATP 4 2 ETC ATP Produced NADH in 10 x 2.5 25 FADH2 in 2 x 1.5 3 ATP out of - 28 Per Glucose ETC molecule! ATP Total -From 28 + 4 +From 2 Krebs! Glycolysis! = 34  Helpful Videos! Crash Course on Cellular Respiration – https://www.youtube.com/watch? v=00jbG_cfGuQ&t=709s Amoeba Sisters – Cellular Respiration- (Skip to 3:05 to start with Glycolysis) – https://www.youtube.com/watch?v=eJ9Zjc- jdys&list=PLwL0Myd7Dk1GNmS-BqgKHB0Due2phZ- Dg&index=2  Genetic Mutations Affect Protein Structure! This can be very damaging in the electron transport chain. – There are many diseases that result from mutations – Below are examples (you do not need to memorize!) Electron Transport Chain Poisons! Block the ETC from working What happens to ATP production if the ETC is blocked? More common ETC poisons: – Rotenone Used as insecticide, piscicide – Cyanide – Oligomycin Inhibits bacterial growth  Most common cause of cyanide poisoning is smoke inhalation – Certain vinyls and plastics release cyanide when burned – These are very common in many household objects  Lotto Winner Poisoned- Death Still Unsolved Wild bitter wild almonds contain cyanide 8 - 32 bitter almonds will give a lethal dosage of cyanide. LD50 for cyanide is 50 mg - 200 mg. Domestic sweet almonds do not (you’ve eaten almonds and felt fine… right?)