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AP Biology: Cellular Energy Flashcards

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50222327211st Law of Thermodynamicsenergy is neither created nor destroyed, only converted0
50222733902nd Law of Thermodynamicsenergy transfer results in increased entropy >large portion lost as heat1
5022337212potential energystored energy2
5022338872kinetic energymovement energy3
5022338873metabolismthe sum of all the chemical reactions occurring in an organism that are necessary to life **Enzymes control metabolic reactions4
5022344132catabolismbreakdown (hydrolysis) of a molecule which releases potential energy found in chemical bonds between monomers EXERGONIC - releases energy5
5022349047anabolismassembly (synthesis) of molecules which requires kinetic energy ENDERGONIC - absorbs energy6
5022373524Gibbs Free Energy (ΔG)energy available to organisms to perform work ΔG = ΔH - TΔS G = free energy H = enthalpy T = temperature S = entropy7
5022392356enthalpytotal useable energy in system **starts out large but becomes smaller as food is broken down (energy is being released)8
5022394756entropytotal non-useable energy in system **starts at zero but becomes larger as the reactions continue to occur9
5022424428What does it mean if ΔG is negative?energy is available to do work **exergonic ex. result of cellular respiration10
5022424429What does it mean if ΔG is positive?energy is not available to do work because it is "locked up" **endergonic ex. photosynthesis11
5022497682How do cells make an effort to manage energy?couple reactions **Exergonic reaction provides the energy to run an endergonic reaction12
5022500817ATPthis is made in cellular respiration and molecule cells use it whenever they need energy **adenosine triphosphate13
5022524196Is breaking down ATP exergonic or endergonic?exergonic **needed to run endergonic14
5022529180How does a cell use ATP for energy (chemical reactions)?When the cell needs energy, the enzyme breaks off the terminal phosphate group and is added to another molecule, giving it energy.15
5022577163How does a cell use ATP for energy (transport/mechanical)?phosphorylation of protein causes shape change allowing molecule to pass16
5022588381Where is the energy in ATP found?phosphate bonds **kinases break those bonds17
5023833747What are the two ways that cells make ATP?substrate level phosphorylation chemiosmosis18
5023877642What is substrate level phosphorylation?phosphate group transferred on ADP from another organic molecule19
5023877643What is chemiosmosis?energy is used to pump H+ into space, creating area of potential energy, and as protons diffuse across the membrane, they activate ATP synthase, which makes ATP20
5023892826oxidationloss of electrons21
5023892827reductiongain of electrons22
5023895197What do electrons have?energy23
5023919838glycolysisprocess in which glucose is broken in half **Step 1 of cellular respiration24
5023923654How does glucose get into a cell?facilitated diffusion or active transport25
5023925865Which cells do glycolysis?ALL (prokaryotes and eukaryotes)26
5023933663Where does glycolysis occur?cytoplasm27
5023938703What are the products of glycolysis?*2 ATP* (4 made, 2 used) 2 pyruvates 2 NADH28
5024156959pyruvatehalf of a glucose molecule29
5024158967NAD+empty not carrying electrons or protons30
5024158968NADHcarrying electrons or protons31
5024167064oxidative decarboxylationthe "prep step" before the Krebs cycle where pyruvates enter the matrix of the mitochondria to be converted into Acetyl CoA and produce 2 CO₂ and 2 NADH **Acetyl CoA controls whether energy is being made or stored32
5024168699Krebs Cyclethe glucose halves (pyruvates) are broken down further so more energy can be extracted (since there is much energy left in the products of glycolysis) **Step 2 in cellular respiration, also called the citric acid cycle and includes oxidative decarboxylation33
5029466822Where does the Krebs cycle take place?mitochondria34
5029473268Which cells do the Krebs cycle?eukaryotes35
5029501592What are the total products of the Krebs cycle (from both pyruvates total, including oxidative decarboxylation)?6 CO₂ 8 NADH 2 FADH₂ *2 ATP*36
5029527738mitochondriacristae (folds) exist to have more surface area37
5029558749electron transport chainEnergy from the electron carriers creates an area of high proton concentration, and the protons enter and energize ATP synthase, allowing it to make ATP **Step 3 in cellular respiration, also called oxidative phosphorylation38
5029594333Where does the electron transport chain take place?inner membrane space39
5029601134cytochromesproteins embedded in the inner membrane of the mitochondria **transfer electrons in the electron transport chain40
5029613109What are the products of the electron transport chain?32 ATP41
5029618688In the electron transport chain, how is the energy from the electrons used?to pump protons into the inner membrane space42
5029618689In the electron transport chain, how is the energy from the H+ gradient (difference in the amount of protons in two areas) used?to energize ATP synthase **makes lots of ATP43
5029639727Why do you need oxygen to survive?It is required for the electron transport chain because it transfers electrons (accepts them) to keep the chain going. If it isn't there, the chain runs out of electrons and stops.44
5029663539What are the steps of the electron transport chain?--1. NADH (reduced) from matrix joins with the first cytochrome in the chain. --2. Electrons are passed along from cytochrome to cytochrome in chain. --3. Energy allows other cytochromes to pick up 2 protons from the matrix and pump them into the inter membrane space. --4. Last cytochrome in chain donates the electrons to 2 protons and 1/2 O₂ to make an H₂O molecule. --5. 2 protons in the inner membrane space reenter the matrix through ATP synthase. --6. FADH₂ enter at the 2nd site. --7. NADH (from glycolysis) adds its 2 electrons via a shuttle protein.45
5029737061Basic summary of cellular respiration:--1. Glycolysis breaks down glucose into pyruvates. --2. Pyruvates diffuse into mitochondria. --3. Electron carriers (NADH & FADH₂) carry electrons released from breakdown of glucose to electron transport chain. --4. Electron transport chain uses energy of electrons to create area of high proton concentration. --5. Oxygen removes electrons from electron transport chain.46
5029755879What happens if the oxygen runs out in the electron transport chain?fermentation47
5029758289fermentationanaerobic pathway used to oxidize NADH (meaning it is turned into NAD+) that keeps glycolysis going **there are only a finite amount of NAD+ molecules available because if all the NAD+ molecules are reduced (NADH), then there is no more glycolysis48
5029776860alcoholic fermentationtype of fermentation in which ethyl alcohol is the product **used by prokaryotes and simple eukaryotes (yeast) **beer, wine, bread49
5029841463lactic acid fermentationtype of fermentation that is used by eukaryotes when O₂ is limited **soy sauce, cheese, yogurt, sore muscles50
5029896133What happens when there is a high energy demand for a short period of time?cells use glycolysis, but not for very long, and you breathe very heavily after you're done51
5029904554What happens when there is a high energy demand for a long period of time?cells use cellular respiration until glucose or oxygen begins to run out, and you breathe regularly during52
5029909617Why do athletes train?to get their body parts developed to better provide energy **heart: fit athletes are able to deliver more blood per heartbeat **lungs: muscles around lungs are able to expand lungs more during breathing to get more oxygen **muscles: developed muscles are able to receive more blood flow **more blood = more oxygen = more energy53
5035604454photosynthesisendergonic process done by photoautotrophs that converts light energy into chemical energy **Glucose has more energy than CO₂ and H₂O54
5035625179Formula for photosynthesis:6CO₂ + 6H₂O → C₆H₁₂O₆ + 6O₂55
5035642300What are the four requirements for photosynthesis?carbon dioxide water light pigments56
5035647142Why is carbon dioxide required for photosynthesis?used to make carbohydrates57
5044326004Why is water required for photosynthesis?provides hydrogen and oxygen for carbohydrates and electrons to keep pigments "loaded"58
5044328530Why is light required for photosynthesis?provides energy **7 wavelengths, humans see whatever color is reflected59
5044331181Why are pigments required for photosynthesis?absorb light **The more pigments a plant has, the more light it absorbs.60
5044684207What is a pigment's role in photosynthesis?absorb light get excited lose electrons electrons passed to other electron carriers61
5044424040chlorophyll amain pigment in a plant that absorbs mainly red and blue but reflects green (which is why we perceive a plant as green) **participates directly in the light-dependent reactions of photosynthesis62
5044439235accessory pigmentspigments that absorb a wide range of light and pass absorbed energy to chlorophyll63
5044441504carotenepigment that appears orange64
5044441505xanthophyllpigment that appears yellow65
5044447040Where are pigments found?in prokaryotes: embedded in membranes in eukaryotes: embedded in the thylakoid membranes of chloroplasts66
5044455795chloroplastssite of photosynthesis67
5044466713thylakoidindividual sac in a chloroplast68
5044469905stromainterior of chloroplast69
5044470217granumstack of thylakoids in a chloroplast70
5044626870photophosphorylationusing light energy to phosphorylate71
5044631808What is the difference between NADP and NAD?NADP is used in photosynthesis, NAD used in cellular respiration **Think P for photosynthesis72
5044635077What allows organisms to grow?Energy and nutrients from food73
5044640128What are the two types of photosynthesis?cyclic photophosphorylation complex photosynthesis74
5044643549cyclic photophosphorylationsimple form of photosynthesis that is performed by photosynthetic bacteria (cyanobacteria) in which only ATP is made (no NADPH is made- no biosynthesis) **cyclic electron flow75
5044645919complex photosynthesisphotosynthesis that occurs in the chloroplasts of eukaryotes (plant cells) that produces ATP and a source of reducing power **oxidation-reduction reaction: CO₂ is reduced and H₂O is oxidized76
5044676153NADP+NAD+ with phosphate group added that carries electrons and protons to reduce the CO₂77
5050217625light dependent reactionsalso called light reactions, this is the first half of photosynthesis in which light energy is converted to chemical energy Location: thylakoid membranes Products: ATP, NADPH, oxygen **light REQUIRED78
5050229664light independent reactionsalso called dark reactions or the Calvin cycle, this is the second half of photosynthesis in which products of light reactions are used to make carbohydrates and carbon fixation occurs Location: stroma Products: glucose, ribulose bisphosphate (to keep cycle running) **light NOT REQUIRED79
5050304177carbon fixationthe incorporation of carbon from carbon dioxide into an organic compound by an autotrophic organism **Occurs in the Calvin cycle80
5050251851Steps of light dependent reactions:*1. Photosystem I receives light* --pigments lose e- to Ferredoxin, Fd passes e- to NADP+ reductase *2. Photosystem II receives light* --pigments lose e- to Plastiquinone, Pq passes e- to cytochrome complex, cytochrome complex passes e- along to Plastocyanin, PC passes e- to PS-I *3. Protein Z breaks water apart* --H+ in thylakoid space, e- passed onto PS-II to replenish, 1/2 oxygen released *4. Protein gradient built up in thylakoid space* --as 2 protons pass across thylakoid membrane, ATP is generated81
5050253713Similarities between light dependent reactions and the electron transport chain:-Produce ATP -Electrons passed between cytochromes -Oxygen molecule is split in half82
5050255943Differences between light dependent reactions and the electron transport chain:-Location (chloroplast vs. mitochondria) -Amount of ATP produced (little vs. a lot) -Electron carriers (NADPH vs. NADH)83
5050323347How do the two sets of photosynthetic reactions work together?The light dependent reactions trap sunlight energy in chemical form and the light independent reactions use that chemical energy to produce stable, high-energy sugars from carbon dioxide and water.84
5050337998C3 plantsplants that undergo a variation of photosynthesis in which they take in CO₂ and run the Calvin cycle during the day Ex. maple leaf85
5050337999C4 plantsplants that undergo a variation of photosynthesis in which they store CO₂ into a 4-C molecule during the night and run the Calvin cycle during the day Ex. corn86
5050338000CAM plantsplants that undergo a variation of photosynthesis in which CO₂ is taken in and stored as organic acid at night, and CO₂ is released from the acid and enters the Calvin cycle during the day Ex. cactus87
5050340656What are four factors that affect the rate of photosynthesis?light intensity temperature CO₂ concentration oxygen concentration88
5050340657How does light intensity affect photosynthesis?As light intensity increases, the rate of photosynthesis increases. -Only to a point -Eventually, all pigments are saturated with light89
5050343941How does temperature affect photosynthesis?As temperature increases, the rate of photosynthesis increases. -Only to a point -molecular motion increases, collisions increase -if temp is too high, enzymes may denature90
5050344006How does CO₂ concentration affect photosynthesis?As concentration increases, the rate of photosynthesis increases.91
5050347881How does oxygen concentration affect photosynthesis?As concentration increases, the rate of photosynthesis decreases. -happens when the plant is water stressed and stomates are closed92
5050347882leaf93
5044462050mesophyll cella type of cell, found near the surfaces of plant leaves, that is specialized for the light-dependent reactions of photosynthesis94
5050467559stomataopenings in leaves to exchange photosynthetic gases: water vapor, carbon dioxide, and oxygen95
5050467561guard cellscells that regulate the stomata; they close if there is too much water96

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