Ch 9 Cellular Respiration

1. Ch 9Cellular Respiration

2. What is Cellular Respiration?The Big Picture

4. ATP FERMENTATION OXYGEN • Catabolic Pathways and Production of _____ • _________________- catabolic process that is a partial degradation of sugars that occurs without the use of ____________. • _____________________- catabolic pathway that is the most efficient and prevalent. ______________ is consumed as a reaction with organic fuel. In eukaryotic cells, _________________ is the location. • Formula of Cell Respiration CELLULAR RESPIRATION OXYGEN MITOCHONDRION C6H12O6 + 6 O2 6 CO2 + 6 H2O + ENERGY

6. Redox Reactions: • Why do catabolic pathways that decompose glucose and other organic fuels yield energy? • The relocation of electrons released energy stored in organic molecules and is used to synthesize ATP. • Na + Cl  Na+ + Cl- • A redox reaction that relocates electrons (very electronegative) closer to oxygen _____________ chemical energy that can be put to work. • Example with Cellular Respiration Formula RELEASES Pg 162

7. GLUCOSE • Energy Harvest via NAD+ and the Electron Transport chain • Cellular respiration breaks down ____________ and other fuels in a series of steps that strip electrons from glucose (creating sources of energy). • For each electron, a hydrogen atom (proton) is present. The hydrogen atoms are not transferred directly to oxygen but pass to an enzyme called ________ (nicotinamide adenine dinucleotide) • The enzyme __________________ removes a pair of hydrogen atoms (2 e- 2 protons) from the substrate. The enzyme delivers the two electrons along with one proton to its coenzyme, NAD+. The proton is released as an H+ into the surrounding solution. • Formula NAD+ DEHYDROGENASE Pg 162

8. REDUCED FALL ELECTRON TRANSPORT CHAIN • NAD+ is ______________ to NADH. Each NADH molecule formed during respiration represents stored energy that can be tapped to make ATP when the electrons complete their “________” down an energy gradient from NADH to oxygen • Respiration uses an ____________________________ to break the fall of electrons to oxygen into several energy-releasing steps. • Summary: FoodNADH ETC Oxygen

9. GLYCOLYSIS GLUCOSE INVESTMENT • ______________ (the first metabolic stage of respiration) • Glycolysis harvests chemical energy by oxidizing ___________ to pyruvate. • Two Phases • Energy ______________ phase: cell spends ATP • Formula: • Energy ______________ Phase: ATP is produced by substrate-level ___________________ and NAD+ reduction to NADH by electrons released from oxidation of glucose. • Formula: • Net energy yield from glycolysis per glucose is ___ ATP and __ NADH • Glycolysis releases less than a quarter of the chemical energy stored in glucose while the rest remains in the two molecules of pyruvate. • Diagram: • Basic overviewawesome glycolysis • step by stepGlycolysis 2 ATP  2 ADP + 2 P PAYOFF PHOSPHORYLATION 2 NAD+ + 4 e- + 4 H+ 2 NADH + 2 H+ 2 2 Pg 166-167 fig 9.9

15. PRESENT PYRUVATE OXIDATION • The Citric Acid/ Krebs Cycle- occurs when oxygen is ______________ • ______________ enters the mitochondrion via active transport where the enzymes of the citric acid cycle complete the ______________. • Steps of Citric Acid Cycle (p.169 Figure 9.12) • 1. Pyruvate is converted to a compound called acetyl coenzyme A or _________________. • During this step, pyruvate’s carboxyl group which is already fully oxidized is removed and given off as ______ because it has little energy. • The remaining two-carbon fragment is oxidized forming acetate. An enzyme transfers the extracted electrons to NAD+, storing energy as _________. • Coenzyme A is attached to acetate by an unstable bond making the acetyl group very reactive. This results in ______________ and is ready for its acetyl group to be oxidized. ACETYL CoA CO2 NADH ACETYL CoA

16. DECOMPOSE • 2. Acetyl CoA adds its two-carbon acetyl group to oxaloacetate producing citrate • The next seven steps ______________ the citrate back to oxaloacetate. • 3. Citrate is converted to its isomer isocitrate by the ______________ of one water molecule and the addition of another. • 4. Citrate loses a CO2 molecule and its result is ______________, reducing NAD+ to NADH • 5. Another CO2 is lost, and the result is oxidized, reducing NAD+ to NADH. The remaining molecule is attached to coenzyme A by an ______________ bond. REMOVAL OXIDIZED UNSTABLE

17. PHOSPHATE SUBSTRATE HYDROGENS • 6. CoA is displaced by a ______________ group, which is transferred to GDP, forming GTP, and then to ADP, forming ATP (__________-level phosphorylation) • 7. Two ______________ are transferred to FAD, forming FADH2 and oxidizing succinate. • 8. Addition of a ______________ molecule rearranges bonds in the substrate. • 9. The substrate is oxidized, reducing NAD+ to NADH and ______________ oxaloacetate. • Krebs animation 1 • Krebs Cycle WATER REGENERATING

27. INNER MEMBRANE • Electron Transport Chain • The ETC is a collection of molecules embedded in the ____________________ of the mitochondrion. The folding of the inner membrane of the mitochondrion. • Since the cristae contains many folds, it provides space for ______________ of copies of the chain in each mitochondrion. • Sequence of electron carriers (p. 171 Figure 9.13) • Electron carriers alternate between ______________ and oxidized states as they accept and donate electrons. • Each component of the chain becomes reduced when it accepts electrons from its “uphill” neighbor which is less ________________and returns to its oxidized form as it passes electrons to its “______________,” more electronegative neighbor. THOUSANDS REDUCED ELECTRONEGATIVE DOWNHILL

28. FLAVOPROTEIN ELECTRONS • Steps of the ETC • The first molecule is a ______________ because it has a prosthetic group called flavin mononucleotide (FMN) • The flavoprotein returns to its oxidized form as it passes ______________ to an iron-sulfur protein (Fe*S). • The iron-sulfur protein then passes electrons to a compound called ubiquinone. Ubiquinone is ________within the membrane rather than residing in a complex. • Most of the remaining electron carriers between ubiquinone and oxygen are proteins called ______________. • Cytochromes have a prosthetic ______ group which has an iron atom that accepts and donates electrons. • Each of the cytochromes in the ETC has a ______________ electron-carrying heme group. • FADH2, another reduced product of the citric acid cycle is another source of electrons for the ETC. FADH2 adds its electrons to the ETC at complex II at a ______________ energy level than NADH does. MOBILE CYTOCHROMES HEME DIFFERENT LOWER

29. DIRECTLY EASE • Function of the ETC • The ETC makes no ATP ______________. • The function is to _____ the fall of electrons from food to oxygen to break a large free energy drop into a series of smaller steps that release energy in ______________ amounts. • _________________- The Energy Coupling Mechanism • ATP synthase is an ______________ located in the inner membrane of the mitochondrion. • ATP synthase makes ATP from ADP and inorganic ______________ • ATP synthase works like an ion pump in ______________. • Uses energy of an existing ion ______________ to power ATP synthesis by phosphorylation. • The power source is the proton gradient and therefore is the difference in ______________ of H+ on opposite sides of the membrane. MANAGEABLE CHEMIOSMOSIS ENZYME PHOSPHATE REVERSE GRADIENT CONCENTRATION

30. ACROSS • Chemiosmosis: The process where energy is stored in the form of an H+ gradient ______________ a membrane being used to drive cellular work. (Do not confuse with osmosis) • P 171 Figure 9.14 4 Parts to ATP synthase • How does inner mitochondrial membrane generate and keep the H+ gradient? • Electron transport chain purpose is to _______ the H+ gradient. • The ETC pumps electrons across the membrane (from the mitochondrial ________ to the intermembrane space). • H+ has a tendency to move _______ across the membrane so ions pass through a channel in ATP synthase to drive the phosphorylation of ADP. • The energy stored in an H+ gradient across a membrane couples the redox reactions of the ETC to ATP synthesis: an example of chemiosmosis. • This H+ gradient is referred to as ________-motive force: capacity to do work CREATE MATRIX BACK PROTON

31. CHLOROPLASTS PROKARYOTES • Other examples of chemiosmosis • ______________ use to generate ATP during photosynthesis (light drives ETC) • ______________ generate H+ gradients across their plasma membrane, then tap the proton-motive force to make ATP and pump nutrients and waste across the membrane, and to rotate their flagella. • Electron Transport • ETC and ATP Synthesis • CR Overview (long) • ETC

32. Total ATP Production by Cellular Respiration • Energy flow: glucose NADH ETCproton motive force ATP • Three main parts of cell respiration • Glycolysis (substrate-level phosphorylation): __ ATP, __ pyruvate, __ NADH • Citric Acid Cycle (_________ Cycle) substrate level phos.: __ ATP, __ NADH, __ FADH2 • Electron Transport chain (oxidative phosphorylation): __ or __ ATP • Totals: __ or __ ATP 2 2 2 KREBS 2 6 2 32 34 36 38

33. REGENERATE • Fermentation • Fermentation consists of glycolysis and reactions that ______________ NAD+ by transferring electrons from NADH to pyruvate or derivative of pyruvate. • The NAD+ can be reused to oxidize sugar by glycolysis resulting in two (net) ATP. • Two types of Fermentation • ______________ Fermentation Steps: • Pyruvate is converted to ethanol (ethyl alcohol) in two steps. The first step releases CO2 from the pyruvate which is converted to the two-carbon compound acetaldehyde. • In the second step, acetaldehyde is reduced by NADH to ethanol. This regenerates the supply of NAD+ needed to continue glycolysis. • Examples: : ALCOHOLIC bacteria: yeast, humans use it to brew beer, make wine, and bread.

34. LACTIC ACID • ______________ acid fermentation Steps: • Pyruvate is reduced directly to NADH to form lactate as an end product with no release of CO2. (Lactate is the ionized form of lactic acid) • Examples of Lactic acid fermentation: • Microbial fermentation produce acetone and methanol • ____________________________ make ATP by lactic acid fermentation when oxygen is scarce. • Strenuous exercise when sugar catabolism for ATP production outpaces the muscles supply of oxygen from the blood. • This build up of lactate causes muscle fatigue and pain. • fermentation 1 • Evolutionary Significance of Glycolysis • Both ______________ and ______________ use ______________ to generate _____. HUMAN MUSCLE CELLS PROKARYOTES EUKARYOTES GLYCOLYSIS ATP

35. ENERGY PHOTOSYNTHESIS CHLOROPLASTS SUGAR Chapter 10- Photosynthesis • Sunlight: the main source of ____________ on Earth • ________________: process by which light energy from the sun is captured by ________________and is converted to chemical energy stored in _________ and other organic molecules. • ________________are “producers”: produce their food from CO2 and other inorganic raw materials obtained from the environment. • The main source of organic compounds for all ________________ organisms. • Almost all plants are autotrophs, specifically ___________________since they use light as a source of energy to synthesize organic compounds. • Examples: p.182 Figure 10.2 • ________________are “consumers”: obtain their organic material by consuming compounds produced by other organisms. • Almost all heterotrophs are dependent on __________________ for food and oxygen AUTOTROPHS NONAUTOTROPHIC PHOTOAUTOTROPHS HETEROTROPHS PHOTOAUTOTROPHS

36. 6 CO2 + 6 H2O + LIGHT  C6H12O6 + 6 O2 • Introduction to Photosynthesis • Formula (LEARN): • Plant structure: p. 183 Figure 10.3

37. CHLOROPHYLL PIGMENT ABSORBED MESOPHYLL • ________________gives a plant or leaf its green color as it is a green ________________located within chloroplasts. It is the light energy ________________by chlorophyll that drives the synthesis of organic molecules • Chloroplasts are found in the cells of the ________________, the tissue in the interior of a leaf • Carbon dioxide enters the leaf and oxygen exits by the ________________which are tiny pores. • An envelope of two membranes encloses the ________________, the dense fluid within the chloroplast. • The ___________ are a system of interconnected membranous sacs that segregate the stroma from the thylakoid space. • Thylakoids can be stacked in columns called _____________. • Chlorophyll is located in the thylakoid ________________. STOMATA STROMA THYLAKOIDS GRANA MEMBRANE

38. H2O CO2 H O • The oxygen released from photosynthesis is due to the splitting of ____ and not _____. • The _______ is incorporated into sugar and ____ is released as waste. • Photosynthesis is a _________ process • Water is split, and electrons are transferred along with H+ ions from the __________ to CO2, reducing it to a sugar. • Since electrons __________ in potential energy as they move from water to sugar, this requires energy which is provided by ___________. REDOX WATER INCREASE LIGHT

39. 2 DEPENDENT CHEMICAL ATP NADPH • Photosynthesis is broken up into ____ phases: • The light-________________reactions (photo): • Solar energy is converted to __________ energy (____ and ______) • Light absorbed by chlorophyll drives a transfer of electrons and Hydrogen from water to an acceptor called ____________. • Water is ______ and releases oxygen. • Solar power is used to reduce NADP+ to NADPH by adding a pair of ________________along with a hydrogen nucleus or H+ • ATP is generated by chemiosmosis by ________________________. • Two products: NADPH and ATP NADP+ SPLIT ELECTRONS PHOTOPHOSPHORYLATION

40. CO2 FIXATION • Calvin cycle (synthesis): Light independent reactions (sort of) • _______ from the air is incorporated into organic molecules already present in chloroplast. This process is called carbon ________________. • Next, the fixed carbon is reduced to ________________ by the addition of electrons. Reducing power is provided by ________________. • To convert CO2 to carbohydrate, the Calvin cycle also requires ________________ energy in the form of ATP. • Dark reactions because it does not require light directly but needs the products of the light reactions. • Products: Sugar (glyceraldehyde-3-phosphate then ________________) CARBOHYDRATE NADPH CHEMICAL GLUCOSE

41. WAVES DISTANCE • Sunlight and the light Spectrum • Light is a form of energy known as electromagnetic energy and travels in rhythmic _________. • Wavelength: the ________________ between crests of waves • Electromagnetic spectrum: the entire spectrum of ________________ ranging in wavelength from _______ a nanometer (gamma rays) to _______ a kilometer (radio waves). RADIATION < >

42. VISIBLE PHOTONS INVERSELY • ____________ Light: From 380 nm to 750 nm. • ___________: discrete particles that act like objects with a fixed quantity of energy. • Energy of photons is ________________ related to the wavelength of the light; shorter wavelength, the ________________ the energy. • The sun radiates the full spectrum but the atmosphere only ________________ visible light to pass through. • Visible light drives ________________. GREATER ALLOWS PHOTOSYNTHESIS

43. PIGMENT WAVELENGTHS • ______________- substance that absorbs visible light. • Different pigments absorb (and reflect) light of different ________________and cause the absorbed wavelengths to disappear. • The color we see is the color that is the most ______________ by the pigment. • Example: seeing green or black, or white. • ____________________- instrument that can measure the ability of a pigment to absorb various wavelengths of light. • It directs beams of light of different wavelengths through a solution of pigment to measure the ________________ of light transmitted at each wavelength. • ________________Spectrum- graph plotting a pigment’s absorption v. wavelength. • Pg 187 Figure 10.9 REFLECTED SPECTROPHOTOMETER FRACTION ABSORPTION

44. EFFECTIVENESS ACTION • Significance: By analyzing absorption spectra of chloroplast pigments, scientists can compare the relative ________________ of different wavelengths for driving photosynthesis. (How do we know which wavelength is most effective?) • ________________ spectrum- graph plotting the rate of photosynthesis (____ release or ____ consumption) v. wavelength • ________________- the main photosynthetic pigment • Chlorophyll a v. Chlorophyll b-Chlorophyll b is an accessory pigment that has a slight structural difference which allows them to absorb slightly different colors (and have different colors). • ________________- yellow and orange hydrocarbons that absorb violet and blue-green light. • These can broaden the spectrum of photosynthesis and provide __________________: ability to absorb and rid excessive light energy that would damage chlorophyll or interact with oxygen. O2 CO2 CHLOROPHYLL CAROTENOIDS PHOTOPROTECTION

45. ABSORBS EXCITED • Chlorophyll and Light • When a molecule ________________a photon of light, one of the molecule’s electrons is elevated to an orbital where it has more potential energy (from ground state to ___________ state). • A compound absorbs only photons that have specific wavelengths which is why each pigment has its ________________ absorption spectrum. • The electron ________________ stay in an excited state so will drop to its ground state which releases excess energy as _____________. • Chlorophyll in isolation will also release light (_____________) as well as heat. • P. 189 Fig. 10.11 • Example: Car roof on a hot day (which is coolest?) UNIQUE CANNOT HEAT FLUORESCENCE

46. PHOTOSYSTEM PIGMENT PROTEINS • ________________: Reaction Center associated with Light-Harvesting Complexes • Photosystems are composed of reaction centers surrounded by a number of light-harvesting complexes that consist of ____________ molecules bound to particular ___________. • The number and variety of pigment molecules allow a photosystem to harvest light over a ________________ surface of the spectrum. • Picture: LARGER

47. SPECIAL • Reaction Center- protein complex that includes two ________________chlorophyll a molecules and a molecule called the primary electron acceptor. • These chlorophyll a molecules, because of their environment enable them to use the energy from light to boost one of their electrons to a ________________ energy level. • First step of the light reactions: ___________-powered transfer an electron from the special chlorophyll a molecule to the primary electron acceptor (_________ reaction). • Photosystems convert light energy to chemical energy to be used to ________________ sugar. • The ________________membrane contains two types of photosystems that cooperate in the light reactions. • Photosystem II (PSII) [first] (Chlorophyll a- ______) Photosystem I (PSI) (Chlorophyll a- ______) HIGHER SOLAR REDOX SYNTHESIZE THYLAKOID p680 p700

48. PIGMENT • Reactions in the Photosystem- Noncyclic electron flow pg190 • Photon of light hits a ________________ in a light harvesting complex and is moved to other pigment molecules until it reaches a P680 molecule in PS II. It excites one of the two P680 molecules. • The electron is then ________________by the primary electron acceptor. • An enzyme splits a water molecule into two electrons, two H+ ions and ½ O2. Electrons are supplied one by one to the ________ replacing an electron ______ to the primary electron acceptor. Oxygen combines with another oxygen to form O2. • Each excited electron passes from the primary electron acceptor of PS II to PS I by an ________________________________. CAPTURED p680 LOST ELECTRON TRANSPORT CHAIN

49. FALL ATP • TRANSFERRED • The exergonic “______” of electrons to a lower energy level provides energy for _____ synthesis. • At the same time, light energy was ________________by a light harvesting complex to the PS I reaction center, exciting an electron of a P700 molecule. The excited electron is then captured by PS I primary electron acceptor, creating an electron “hole” in P700. Hole is filled by an electron that reaches the bottom of the electron transport chain from _________. • Excited electrons are passed from PS I’s ________________________________ down a electron transport chain through the protein ________________ (Fd). • The enzyme NADP+ reductase transfers electrons from Fd to NADP+. Two electrons are required for its ________________ to NADPH. • Summary: Light reactions use solar power to generate ATP (chemical energy) and NADPH (reducing power) which will fuel the ________________. • non cyclic- good! PS II PRIMARY ELECTRON ACCEPTOR FERRODOXIN REDUCTION CALVIN CYCLE

50. CYCLIC I II CYCLE • Reactions in the Photosystem- _____________ electron flow • Under certain conditions, photoexcited electrons can take a cyclic electron flow which uses photosystem ___ but not photosystem ___. • Electrons ______ back from ferredoxin (Fd) to the cytochromes complex and back from there on to a P700 in the PS I reaction center. • ATP is ______________. • There is no production of ________________ and no release of ________________. • Why use cyclic electron flow? • Noncyclic electron flow generates an ________________ amount of ATP and NADPH but the Calvin cycle uses _________ ATP than NADPH so cyclic electron flow can provide more ATP. • A rise in NADPH can result in shift to cyclic electron flow which allows ATP to catch up to NADPH (_____________________). GENERATED NADPH OXYGEN EQUAL MORE SUPPLY & DEMAND Cyclic & noncyclic