Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Bio100 (Paddack) Lecture 7 (9/14/16) I. II. Energy (Ch 5) A. 2 Laws of Thermodynamics B. Types of energy 1. Kinetic energy 2. Potential energy C. Chemical Reactions Cellular Respiration (Ch 6) A. Overview B. Redox reactions C. Three key steps 1. Glycolysis 2. Citric Acid Cycle 3. Oxidative Phosphorylation D. Fermentation (Anaerobic Respiration) 1. Lactic acid fermentation 2. Alcohol fermentation Energy – capacity to perform work • Kinetic Energy Chemical Energy • A type of Potential Energy - energy of motion • Stored in bonds of molecules – e.g., C6H12O6 • Potential Energy • Results from arrangement of atoms - stored energy (from location or structure) Potential energy kinetic energy Potential Energy is created by a concentration gradient (H+) How do organisms get energy? 1 Energy stored in ATP can be released to fuel other reactions ATP Powers Cellular Work 3 phosphate groups on ATP create HIGH POTENTIAL ENERGY Figure 5.12 A Energy required Energy released Overview of Cellular Respiration https://www.youtube.com/watch?v=N4d7Wp9kKjA Overview of Cellular Respiration Isn’t Glycolysis simple? (Fig. 6.6) Figure 6.7C 2 “Grooming” pyruvate for The Citric Acid Cycle Stage 2: The Citric Acid Cycle (aka Krebs Cycle); in the mitochondrial matrix Energy banked: 6 NADH 2 FADH2 Net ATP: 2 Figure 6.8 Energy banked: 2 NADH The structure of the mitochondria is important to cellular respiration Stage 3: Oxidative Phosphorylation (in cristae of mitochondria) Energy spent: 10 NADH 2 FADH2 1 NADH ~ 2.5 ATP 1 FADH2 ~ 1.5 ATP Net ATP: ~ 28 https://www.youtube.com/watch?v=3y1dO4nNaKY How does food become fuel? Figure 6.15 How is ATP produced? • Substrate-level phosphorylation – during Glycolysis and Citric Acid Cycle Figure 6.7 B • Chemiosmosis – during Oxidative Phosphorylation • Food is broken down (by enzymes) into molecules that can enter cellular respiration at some step. 3 Fermentation What happens to the pyruvate? In the absence of oxygen… • Also uses glucose to convert ADP to ATP • Occurs in absence of oxygen • Net ATP production (per glucose): 2 Fermentation - happens entirely in cytoplasm - yields 2 ATP (net) Lactic acid fermentation Pyruvate NADH NAD+ But in the presence of oxygen, cells continue with Lactate Fermentation Alcohol fermentation Ethanol CO2 How do organisms get energy? Cellular Respiration Glucose Glycolysis 2 ATP Pyruvate and NADH Cytoplasm -----------------------------------------------------------------------------Mitochondria Citric Acid Cycle Oxidative Phosphorylation 2 ATP • Plants are autotrophs - original energy source is sunlight • Animals are heterotrophs – original energy source is food around 28 ATP 1. Write the 1st & 2nd Laws of Thermodynamics. 2. How does the 1st Law of Thermodynamics relate to the topics of cellular respiration & photosynthesis? 3. Define: Kinetic energy, potential energy, thermal energy, chemical energy. 4. What is the purpose of forcing a lot of protons (H+) to one side of a cell membrane (what benefit does it have)? 5. Write the chemical equation for cellular respiration. 6. Where does cellular respiration take place? 7. Define ATP. 8. How many ATP are created per glucose in cellular respiration? 9. Define: oxidation, reduction, redox.. 10. Name 2 co-enzymes that are used to ‘shuttle’ electrons in cellular respiration. 11. List the 3 stages of cellular respiration, state what part of the mitochondria each occurs, and state the output of each stage. 12. What final element is needed to have the process of cellular respiration complete (the last thing to receive the electrons and protons that were moving around). 13. Why does fermentation occur? Why is it less helpful than aerobic respiration? 14. List the 2 types of fermentation – one performed by yeasts & bacteria, the other by organisms such as us. 4