Intro to Metabolism Wrap-up
Answer these questions in your notes you should discuss with your colleagues! Why do we say that ATP couples reactions? What are enzymes, and how do they affect chemical reactions? What type of biological molecule are enzymes, and what are the levels of their structure? What factors (environmental and otherwise) affect the rates of enzyme-catalyzed reactions? (there are SEVERAL!) Why would boiling an enzyme probably destroy its activity? Agenda and Business Intro to Metabolism Recap
Big Picture Energy Production and Storage Connection Cellular Respiration and Photosynthesis Big Picture Cellular Respiration Enzyme Lab due Friday does not NEED to be typed but you can if you want (you already should have title, purpose, materials, procedures, and data tables you need to include graphs for part I and part II and a conclusion about why the rate decreases over time [remember toothpickase???] and a conclusion/analysis about pH and enzyme activity [what was the optimal pH? What would you guess about the pH of the environment the turnips usually grow in?) Energy Production and Storage
The energy timeline Cellular cash Doesnt last long quickly hydrolyzed Checking account More stable, can convert to cash easily Savings account More stable yet, must be broken down before it can be converted to cash Retirement fund Most stable, longest term energy storage Glycogen/ Starch ATP triglycerides Glucose Connection: Cellular Respiration and PhotosynthesisWhat can you say about the reactants and products of each reaction?What about the energy of each reaction? Big Picture: Cellular Respiration
What is the whole point of cellular respiration? Cellular Respiration and Photosynthesis Jammin to ATP Glucose, Glucose Oxidative Phosphorylation
Check out Glucose, Glucose Glucose -- ah, sugar sugar -- | You are my favorite fuel | From the blood-borne substrate pool. | Glucose -- monosaccharide sugar -- | You're sweeter than a woman's kiss | 'Cause I need you for glycolysis. | I just can't believe the way my muscles take you in. | (For you, they'll open the door.) | All it takes is a little bit of insulin | (To upregulate GLUT4). | Ah, glucose -- ah, sugar sugar -- | You help me make ATP | When my predators are chasing me. | Ah, glucose -- you're an aldehyde sugar, | And you're sweeter than a woman's kiss | 'Cause I need you for glycolysis. | I just can't believe the way my muscles break you down. | (My glycogen is almost gone.) | A few more seconds and I'll be rigor mortis-bound. | (Acidosis done me wrong.) | Your sweet is turning sour, baby. | I'm losing all my power, baby. | I'm gonna make your muscles ache. | No, no, no! | I'm swimming in lactate, baby. | Yes, I'm swimming in lactate, baby. | Now I'm drowning in lactate, baby. | I'm gonna make your muscles ache. | No, no, no! | I'm drowning in lactate, baby. | Ah, glucose -- ah, sugar sugar -- | I used you up and you left me flat; | Now I'll have to get my kicks from fat. | Oh, glucose, glucose, sugar, sugar, | The honeymoon is over now. Enzyme Quiz Recap What is an autotroph? What is a heterotroph?
What do all food chains start with? What do glucose, glycogen, and starch have in common? Why do we eat and breathe? (dont you dare say to live) Endosymbiosis and Energy Recap
What does endosymbiosis have to do with energy? Why did mitochondria evolve when they did? Chapter 9 Cellular Respiration: Harvesting Chemical Energy
YOU MUST KNOW The difference between fermentation and cellular respiration. The role of glycolysis in oxidizing glucose to two molecules of pyruvate. The process that brings pyruvate from the cytosol into the mitochondria and introduces it into the citric acid cycle. How the process of chemiosmosis utilizes the electrons from NADH and FADH2 to produce ATP. Chapter 9 Cellular Respiration: Harvesting Chemical Energy
ENERGY AND METABOLISM RECAP Where does energy come from? Autotrophs Heterotrophs Chapter 9 Cellular Respiration: Harvesting Chemical Energy
How do organisms store energy in the short term and long term? ATP Glucose Glycogen Starch ATP (ya you know me) Where are the high energy bonds?
Where do we get the energy to make those bonds? Chapter 9 Cellular Respiration: Harvesting Chemical Energy
What is the difference between catabolism and anabolism? What is the difference between endergonic and exergonic processes? What is energy coupling, and how does ATP play a role in it? How do we get something to explode?
Light it on fire!!!Blow it up!!! YA!! But whats happening chemically? What gas has to be present in order for something to blow up? Cellular Respiration is the oxidation or EXPLOSION of glucose
At the atomic level, oxidation deals with transferring electrons When you oxidize something, it loses electrons Since the electrons carry energy, the energy is transferred Cellular Respiration is the oxidation or EXPLOSION of glucose
So what happens to the substance that lost the electrons? Since it gains the electrons (and gets more negative) we say it gets reduced Oxidation-Reduction reactions are abbreviated Redox Cellular Respiration is the oxidation or EXPLOSION of glucose
How can you remember which gains and which loses? OIL RIG Oxidation Is Loss Reduction Is Gain Cellular Respiration is the oxidation or EXPLOSION of glucose
Lets Model REDOX!!! REMEMBER OIL RIG!! The orange balls represent electrons What happens when you LOSE an electron? What happens when you GAIN an electron? How can we pass the energy across the room without any of us moving?? Cellular Respiration is the oxidation or EXPLOSION of glucose
This is how energy gets transferred in cellular respiration!! Oxygen has a pretty high electron affinity, so its at the end of the chain So why do we need oxygen??? Chapter 9 Cellular Respiration: Harvesting Chemical Energy
CELLULAR RESPIRATION BIG PICTURE Who: which organisms do cellular respiration? What: what are the general inputs and outputs of the process? When:when did it evolve?When does it occur? Where:where in the cell does it occur? Why:why is it so important? An Overview of Cellular Respiration Details of ATP Synthase Chapter 9 Cellular Respiration: Harvesting Chemical Energy
HARVESTING ENERGY BY EXTRACTING ELECTRONS Energy based on electrons and their energy levels!! The more excited an electron is, the higher its energy level! Electrons transferred = maintain energy if stays in same energy level Redox reactions involve the transfer of electrons (REDOX) Remember:OIL RIG Oxidation Is Loss (of electrons) Reduction Is Gain (of electrons) partial redox!?- based on electron affinity (or the tendency of an atom to gain electrons) move from less electronegative molecule to a more electronegative molecule and drop in energy level (slowly becoming oxidized from C-H bonds to O bonds) NAD+ (a coenzyme, by the way) NAD e H=NADH NADH will carry (or transfer!) these e-and p+ to the e- transport chain (ETC) Chapter 9 Cellular Respiration: Harvesting Chemical Energy
Using what we know We know cellular respiration makes ATP We know it uses oxygen Well start from the end and work backwards Mitochondria Lets Model the ETC!! 3 volunteers to be NAD+ 1 volunteer to be FAD
3 volunteers to be the ETC pumps 3 volunteers to hold the protons in the cristae 1 volunteer to be ATP Synthase 2 volunteers to be oxygen 2 volunteers to ADP 2 volunteers to be phosphate And PHOSPHOLIPIDS! Turn in lab/lab notebook to back counter if you dont have it today, turn it in late on Monday
Take out your notes, diagrams, etc for CR Video: Cellular Respiration Starting from the Finish ATP Cellular Respiration
ATP Synthase is like a motor as it turns, it attaches a phosphate to ADP to make ATP How does it turn? (hint: how does a wind mill or a water mill turn?...) Hydrogen ions (or H+) flow through ATP Synthase, turning it! How do the hydrogen ions get into the cristae?... H+ H+ H+ H+ H+ ATP Cellular Respiration REDOX!! OIL RIG
Electrons are lost by one substance and gained by another Just like we passed the electrons in class, electrons are passed down the electron transport chain But the electrons dont travel alone they travel with a proton H+ The electron is accepted by the ETC and the proton (H +) goes into the cristae e- H+ + e- H+ + e- H+ + e- So where do the electrons and protons come from??
Cellular Respiration Each oxygen at the end of the electron transport chain accepts 2 electrons and 2 protons (H+) forming water (a product of cellular respiration!!) The buildup of the H+ inside the cristae can now flow through ATP synthase, bonding a P to the ADP Since this phosphorylation of ADP to make ATP uses oxygen, we call it oxidative phoshporylation So where do the electrons and protons come from?? H+ H+ H+ e- e- H+ e- H+ e- H+ O + 2 e- + 2 H+ H20 H+ H+ NADH and FADH2 are the proton/electron carriers!!
Cellular Respiration NADH and FADH2 are the proton/electron carriers!! When unenergized they exist as NAD+ and FAD NAD+ picks up one electron and proton and carries it to the ETC FAD picks up two electrons and protons and carries them to the ETC So where do the FADH2 and NADH get their protons and electrons?... e- + H+ e- + H+ e- + H+ NADH and FADH2 are the proton/electron carriers!!
Cellular Respiration NADH and FADH2 are the proton/electron carriers!! When unenergized they exist as NAD+ and FAD NAD+ picks up one electron and proton and carries it to the ETC FAD picks up two electrons and protons and carries them to the ETC So where do the FADH2 and NADH get their protons and electrons?... e- + H+ e- + H+ e- + H+ Lets start with glucose Where do the NADH and FAD2 go???
Recap Glycolysis 2 ATP Glucose 6 C 4ATP Net: 2 ATP 2 NAD+ Pyruvate 3 C 2 NADH + e- ETC Pyruvate Pyruvate 3 C Where do the NADH and FAD2 go??? CO2 NAD+ NADH + e- ETC CoenzymeA AcetylCoA (Acetyl = 2 C) NAD+ NADH + e- ATP NADH + e- NADH + e- Krebs Cycle FAD 2 CO2 FADH2 + e- Proton Gradient = concentration of H+ higher inside membrane than outside
Chemiosmosis flow of ions across membrane Which part of cellular respiration requires oxygen? What do we call the process of making ATP from this step? What do we call the process of making ATP without oxygen? In which part does this type of ATP formation happen? Back for more H+ and e-!!! e- H+ NADH + e- NAD+ H+ + e- NAD+ NADH + e- H+ H+ + e- H+ e- e- H+ e- H+ e- H+ + e- H+ FADH2 + e- FADH H+ O + 2 e- + 2 H+ H20 H+ ATP ADP + P Which part of cellular respiration requires oxygen?
What do we call the process of making ATP from this step? What do we call the process of making ATP without oxygen? In which part does this type of ATP formation happen? Glycolysis ETC Krebs Cycle So which parts of cellular respiration require oxygen?
Glycolysis ETC Krebs Cycle So which parts of cellular respiration require oxygen? How much ATP can we get without oxygen? When theres no oxygen
Which steps can we do without oxygen? Which steps cant we do? So how much ATP can we get with fermentation? When theres no oxygen
2 ATP Glucose 6 C 4ATP Net: 2 ATP 2 NAD+ Pyruvate 3 C 2 NADH + e- ETC? Pyruvate 3 C Pyruvate 3 C NO!Because the ETC requires oxygen to accept the electrons from NADH and FADH2 Fermentation NADH and FADH2 donate to alcohol in alcoholic fermentation (yeast bread, beer) NADH and FADH2 donate to lactic acid in lactic acid fermentation (skeletal muscles BURN!!!) Regulation of Cellular Respiration
Do we always need the same amount of ATP? When might we need more or less? What substances regulate the rates of reactions? (hint: theyre proteins) How do we regulate the action of enzymes? Did-you-get-it Quiz Which process or processes do you think the original anaerobic bacteria used? Glycolysis Cellular respiration Photosynthesis Where specifically do the following take place? Krebs cycle ETC What are the roles of the following molecules in cellular respiration? Glucose NADH O2 ATP Synthase Recap Key Terms and Ideas
What drives the formation of ATP? Where do the electrons for the ETC come from? Where do the proton pumps (proteins that pump protons) get the energy to pump protons from? Why is the inner membrane folded? Manipulatives You have yellow, orange, and blue papers with the reactants, products, and processes for cellular respiration With your partner, match the processes with their titles and products and put them in the order they occur in cellular respriation Glucose hydrolyzed into two pyruvate molecules 2 net ATP, NADH
Glycolysis Glucose hydrolyzed into two pyruvate molecules 2 net ATP, NADH Citric Acid Cycle or Krebs Cycle Pyruvate loses CO2; remaining 2 C molecule bonds with Coenzyme A (CoA); electrons and H sequestered by NADH 2 x NADH AcetylCoA broken down further, releasing two CO2 molecules; electrons and H sequestered by NADH and FADH2 2 x (3 NADH and 1 FADH2), 2 ATP Electron Transport Chain Inner membrane proteins reduced by NADH and FADH2 Redox passage of electrons due to difference in electron affinity Oxygen reduced by electrons from inner membrane proteins; binds with 2 protons and released as waste H2O Reduction of oxygen Chemiosmosis Proton motive force/electrochemical gradient/proton gradient drives formation of ATP HUGE production of ATP Daily Grade Quizzie Number a scrap piece of paper 1 20.
Yes, you may use your notes 2. 3. 1. 4. 5. 7. 6. 8. 9. 10. 11. 12. 13 18: write the letter of the steps below for cellular respiration in correct order
Process A Proton motive force/electrochemical gradient/proton gradient drives formation of ATP B Inner membrane proteins reduced by NADH and FADH2 C AcetylCoA broken down further, releasing two CO2 molecules; electrons and H sequestered by NADH and FADH2 D Oxygen reduced by electrons from inner membrane proteins; binds with 2 protons and released as waste H2O E Glucose hydrolyzed into two pyruvate molecules F Pyruvate loses CO2; remaining 2 C molecule bonds with Coenzyme A (CoA); electrons and H sequestered by NADH 19. What is the purpose of cellular respiration?
20. What is the purpose of photosynthesis? 2. 3. 1. 4. 5. 7. 6. 8. 9. 10. 11. 12. 13 18: write the letter of the steps below for cellular respiration in correct order
Process A Proton motive force/electrochemical gradient/proton gradient drives formation of ATP B Inner membrane proteins reduced by NADH and FADH2 C AcetylCoA broken down further, releasing two CO2 molecules; electrons and H sequestered by NADH and FADH2 D Oxygen reduced by electrons from inner membrane proteins; binds with 2 protons and released as waste H2O E Glucose hydrolyzed into two pyruvate molecules F Pyruvate loses CO2; remaining 2 C molecule bonds with Coenzyme A (CoA); electrons and H sequestered by NADH 18. 16. 15. 17. 13. 14. 19. What is the purpose of cellular respiration?
To make ATP = energy for cellular work 20. What is the purpose of photosynthesis? To store energy as food in glucose/to make glucose from energy from sun Write the number wrong on their paper Hand it back Each question is worth 5 pts (so -3 = 85%...) Warm-up Where does photosynthesis take place?
What are the reactants of photosynthesis? What are the products of photosynthesis? Why is photosynthesis evolutionarily a good thing? Do anabolic reactions require energy or release energy? Science Magic Trick Why do the chloroplasts glow?!
Its all about the electrons Science Magic Trick Science Magic Trick excited electrons!! Photosynthesis: what you didnt know you already knew
What looks familiar in this diagram of photosynthesis? How are photosynthesis and cellular respiration similar? How are photosynthesis and cellular respiration connected? Photosynthesis: what you didnt know you already knew
Whats the main purpose of photosynthesis? What do we need to make glucose? CHO Where will we get them? Electrons (the things chemical bonds are made of) Energy (remember: were building something [anabolic] which requires energy) Where does photosynthesis happen? Photosynthesis: The Big Picture Light-Dependent Reactions
Calvin Cycle (Light-Independent Reactions) Light-Dependent Reactions (Light-Independent Reactions)
Calvin Cycle (Light-Independent Reactions) Warm-up Use the cards at your table to review the steps in the light reactions and Calvin cycle of photosynthesis Light strikes PSII, exciting electrons PSII is oxidized
Light Reactions Water is split by PSII, electrons from water are gained by PSII PSII is reduced Thylakoid membrane proteins are reduced; protons are pumped through the membrane ETC proteins are reduced and a proton gradient is generated NADP+ acquires H+ and e- from NADP+ reductase in ETC NADPH now carries H+ and e- Protons flow through ATP Synthase Chemiosmosis generates ATP Enzyme Rubisco attaches CO2 to 5C molecule (RuBP) to make unstable 6C molecule, which breaks down into 2 3C molecules Carbon fixation Calvin Cycle ATP phosphorylates one 3C molecule Activation NADPH delivers H+ and e- to 3C molecule making G3P (glyceraldehyde-3-phosphate) Reduction 2 G3P molecules may be joined to make glucose Output OTHER 3C molecule regenerated into RuBP (5C CO2 receptor) Regeneration of RuBP Rubiscos got a problem Problem: Rubisco can add CO2 or O2 Why is that bad?
When stomata (leaf holes) are closed, O2 builds up so Rubisco is less efficient 2 solutions for hot/dry weather: C4 and CAM CAM Plants Summarize Using the diagrams, notes, and your brains, write a summary about the light reactions and Calvin cycle of photosynthesis Include these in your summary: H2O, O2, CO2, NADP+, NADPH, ADP, Pi, ATP, G3P, glucose, Rubisco, thylakoid, chlorophyll, stroma, light