University:
Marymont University
Course:
BIO 110 | Introduction to Environmental Science
Academic year:

2020
Views:

192

Pages:

22
Author:

Lily Callahan

Unit 3: Cellular Energetics Big Topics • • • Enzymes Cellular Respiration Photosynthesis Cellular Respiration Big Ideas: • • • • • What are the steps? What goes into step? What comes out of step? Where does step occur? Why is step important? Cellular Respiration Glycolysis INPUT OUTPUT WHERE OCCURS WHY IMPORTANT Glucose 2 NADH 2 ATP 2 Pyruvate Cytosol Substrate Level Phosphorylation NADH (carries electrons to ETC) Breaks down glucose to pyruvate Cellular Respiration Pyruvate Oxidation (Intermediate) INPUT OUTPUT Pyruvate 1 CO2 1 NADH 1 Acetyl CoA WHERE OCCURS WHY IMPORTANT Mitochondrial NADH (carries electrons to ETC) Matrix Prepares pyruvate for Krebs Cycle Cellular Respiration Krebs Cycle/Citric Acid Cycle/TCA INPUT OUTPUT WHERE OCCURS WHY IMPORTANT Acetyl CoA 3 NADH 1 FADH2 1 ATP 2 CO2 Mitochondrial Matrix Substrate Level Phosphorylation NADH & FADH2 (carries electrons to ETC) Completes breakdown of glucose Cellular Respiration Oxidative Phosphorylation INPUT OUTPUT WHERE OCCURS WHY IMPORTANT Electrons (NADH & FADH2) O2 ATP H2O Mitochondrial Cristae Electrons provide energy for proton gradient production Highest ATP yield Cellular Respiration Important Concept • Electron transport chain DOES NOT make ATP • ETC role is to produce the proton gradient • Protons pumped into the intermembrane space Multiple Choice Question Practice Question According to the data, the mice at 10°C demonstrated greater oxygen consumption per gram of tissue than did the mice at 25°C. This is most likely explained by which of the following statements? a. The mice at 10°C had a higher rate of ATP production than the mice at 25°C. b. The mice at 10°C had a lower metabolic rate than the mice at 25°C. c. The mice at 25°C weighed less than the mice at 10°C. d. The mice at 25°C were more active than the mice at 10°C Free Response Question Practice Question Using the information, describe ONE contribution of each of the following in ATP synthesis. • • • Catabolism of glucose in glycolysis and pyruvate oxidation Oxidation of intermediates in the Krebs cycle Formation of a proton gradient by the electron transport chain Free Response Question Practice Question Free Response Question Practice Question Use each of the following observations to justify the claim that glycolysis first occurred in a common ancestor of all living organisms. • • • Nearly all existing organisms perform glycolysis. Glycolysis occurs under anaerobic conditions. Glycolysis occurs only in the cytosol. Free Response Question Practice Question Free Response Question Practice Question A researcher estimates that, in a certain organism, the complete metabolism of glucose produces 30 molecules of ATP for each molecule of glucose. The energy released from the total oxidation of glucose under standard conditions is 686 kcal/mol. The energy released from the hydrolysis of ATP to ADP and inorganic phosphate under standard conditions is 7.3 kcal/mol. Calculate the amount of energy available from the hydrolysis of 30 moles of ATP. Calculate the efficiency of total ATP production from 1 mole of glucose in the organism. Describe what happens to the excess energy that is released from the metabolism of glucose. Free Response Question Practice Question 30 moles produced x 7.3 kcal/mole = 219 kcal Glucose has 686 kcal/mol Efficiency = 219 kcal/686 kcal = 0.319 31% or 32% The excess energy is released as heat. Photosynthesis Big Ideas: • • • • • What are the steps? What goes into step? What comes out of step? Where does step occur? Why is step important? Photosynthesis Light Reactions INPUT OUTPUT WHERE OCCURS WHY IMPORTANT Photons H2O ATP NADPH O2 Thylakoid Membrane ATP produced to fuel Calvin cycle NADPH shuttles electrons for reduction of carbon Photosynthesis Important Concept • Protons pumped into the thylakoid space • Water resupplies the lost electron in PS II • Cyclic vs. Linear Electron Flow Photosynthesis Calvin Cycle/Dark Reactions INPUT OUTPUT WHERE OCCURS WHY IMPORTANT 6 NADPH 9 ATP G3P Stroma Stores energy in the form of G3P (glyceraldehyde-3phosphate) Inorganic Carbon -> Organic Carbon Multiple Choice Question The chemical reaction for photosynthesis is 6 CO2 + 12 H2O + light energy → C6H12O6 + 6 O2 + 6 H2O If the input water is labeled with a radioactive isotope of oxygen, 18O, then the oxygen gas released as the reaction proceeds is also labeled with 18O. Which of the following is the most likely explanation? a. During the light reactions of photosynthesis, water is split, the hydrogen atoms combine with the CO2, and oxygen gas is released. b. During the light reactions of photosynthesis, water is split, c. removing electrons and protons, and oxygen gas is released. During the Calvin cycle, water is split, regenerating NADPH from NADP+, and oxygen gas is released. d. During the Calvin cycle, water is split, the hydrogen atoms are added to intermediates of sugar synthesis, and oxygen gas is released. Free Response Question One of the pigments is chlorophyll a, commonly found in green plants. The other pigment is bacteriorhodopsin, commonly found in purple photosynthetic bacteria. Identify the pigment (chlorophyll a or bacteriorhodopsin) used to generate the absorption spectrum in each of the graphs above. Explain and justify your answer. Free Response Question Practice Question In an experiment, identical organisms containing the pigment from Graph II as the predominant lightcapturing pigment are separated into three groups. The organisms in each group are illuminated with light of a single wavelength (650 nm for the first group, 550 nm for the second group, and 430 nm for the third group). The three light sources are of equal intensity, and all organisms are illuminated for equal lengths of time. Predict the relative rate of photosynthesis in each of the three groups. Justify your predictions. Free Response Question Practice Question