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AP Biology: Cellular Energy Flashcards

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53459917221st Law of Thermodynamicsenergy is neither created nor destroyed, only converted0
53459917232nd Law of Thermodynamicsenergy transfer results in increased entropy >large portion lost as heat1
5345991724potential energystored energy2
5345991725kinetic energymovement energy3
5345991726metabolismthe sum of all the chemical reactions occurring in an organism that are necessary to life **Enzymes control metabolic reactions4
5345991727catabolismbreakdown (hydrolysis) of a molecule which releases potential energy found in chemical bonds between monomers EXERGONIC - releases energy5
5345991728anabolismassembly (synthesis) of molecules which requires kinetic energy ENDERGONIC - absorbs energy6
5345991729Gibbs Free Energy (ΔG)energy available to organisms to perform work ΔG = ΔH - TΔS G = free energy H = enthalpy T = temperature S = entropy7
5345991732What does it mean if ΔG is negative?energy is available to do work **exergonic ex. result of cellular respiration8
5345991733What does it mean if ΔG is positive?energy is not available to do work because it is "locked up" **endergonic ex. photosynthesis9
5345991734How do cells make an effort to manage energy?couple reactions **Exergonic reaction provides the energy to run an endergonic reaction10
5345991735ATPthis is made in cellular respiration and molecule cells use it whenever they need energy **adenosine triphosphate11
5345991736Is breaking down ATP exergonic or endergonic?exergonic **needed to run endergonic12
5345991737How 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.13
5345991738How does a cell use ATP for energy (transport/mechanical)?phosphorylation of protein causes shape change allowing molecule to pass14
5345991739Where is the energy in ATP found?phosphate bonds **kinases break those bonds15
5345991740What are the two ways that cells make ATP?substrate level phosphorylation chemiosmosis16
5345991741What is substrate level phosphorylation?phosphate group transferred on ADP from another organic molecule17
5345991742What 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 ATP18
5345991743oxidationloss of electrons19
5345991744reductiongain of electrons20
5345991745What do electrons have?energy21
5345991746glycolysisprocess in which glucose is broken in half **Step 1 of cellular respiration22
5345991747How does glucose get into a cell?facilitated diffusion or active transport23
5345991748Which cells do glycolysis?ALL (prokaryotes and eukaryotes)24
5345991749Where does glycolysis occur?cytoplasm25
5345991750What are the products of glycolysis?*2 ATP* (4 made, 2 used) 2 pyruvates 2 NADH26
5345991751pyruvatehalf of a glucose molecule27
5345991752NAD+empty not carrying electrons or protons28
5345991753NADHcarrying electrons or protons29
5345991755Krebs 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 decarboxylation30
5345991756Where does the Krebs cycle take place?mitochondria31
5345991757Which cells do the Krebs cycle?eukaryotes32
5345991758What are the total products of the Krebs cycle (from both pyruvates total, including oxidative decarboxylation)?6 CO₂ 8 NADH 2 FADH₂ *2 ATP*33
5345991759mitochondriacristae (folds) exist to have more surface area34
5345991760electron 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 phosphorylation35
5345991761Where does the electron transport chain take place?inner membrane space36
5345991763What are the products of the electron transport chain?32 ATP37
5345991764In the electron transport chain, how is the energy from the electrons used?to pump protons into the inner membrane space38
5345991765In 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 ATP39
5345991766Why 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.40
5345991767What 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.41
5345991768Basic 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.42
5345991769What happens if the oxygen runs out in the electron transport chain?fermentation43
5345991770fermentationanaerobic 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 glycolysis44
5345991771alcoholic fermentationtype of fermentation in which ethyl alcohol is the product **used by prokaryotes and simple eukaryotes (yeast) **beer, wine, bread45
5345991772lactic acid fermentationtype of fermentation that is used by eukaryotes when O₂ is limited **soy sauce, cheese, yogurt, sore muscles46
5345991773What 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 done47
5345991774What 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 during48
5345991775Why 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 energy49
5345991776photosynthesisendergonic process done by photoautotrophs that converts light energy into chemical energy **Glucose has more energy than CO₂ and H₂O50
5345991777Formula for photosynthesis:6CO₂ + 6H₂O → C₆H₁₂O₆ + 6O₂51
5345991778What are the four requirements for photosynthesis?carbon dioxide water light pigments52
5345991779Why is carbon dioxide required for photosynthesis?used to make carbohydrates53
5345991780Why is water required for photosynthesis?provides hydrogen and oxygen for carbohydrates and electrons to keep pigments "loaded"54
5345991781Why is light required for photosynthesis?provides energy **7 wavelengths, humans see whatever color is reflected55
5345991782Why are pigments required for photosynthesis?absorb light **The more pigments a plant has, the more light it absorbs.56
5345991783What is a pigment's role in photosynthesis?absorb light get excited lose electrons electrons passed to other electron carriers57
5345991784chlorophyll 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 photosynthesis58
5345991785accessory pigmentspigments that absorb a wide range of light and pass absorbed energy to chlorophyll59
5345991786carotenepigment that appears orange60
5345991788Where are pigments found?in prokaryotes: embedded in membranes in eukaryotes: embedded in the thylakoid membranes of chloroplasts61
5345991789chloroplastssite of photosynthesis62
5345991790thylakoidindividual sac in a chloroplast63
5345991791stromainterior of chloroplast64
5345991792granumstack of thylakoids in a chloroplast65
5345991793photophosphorylationusing light energy to phosphorylate66
5345991794What is the difference between NADP and NAD?NADP is used in photosynthesis, NAD used in cellular respiration **Think P for photosynthesis67
5345991795What allows organisms to grow?Energy and nutrients from food68
5345991796What are the two types of photosynthesis?cyclic photophosphorylation complex photosynthesis69
5345991797cyclic 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 flow70
5345991798complex 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 oxidized71
5345991799NADP+NAD+ with phosphate group added that carries electrons and protons to reduce the CO₂72
5345991800light 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 REQUIRED73
5345991801light 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 REQUIRED74
5345991802carbon fixationthe incorporation of carbon from carbon dioxide into an organic compound by an autotrophic organism **Occurs in the Calvin cycle75
5345991803Steps 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 generated76
5345991804Similarities between light dependent reactions and the electron transport chain:-Produce ATP -Electrons passed between cytochromes -Oxygen molecule is split in half77
5345991805Differences 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)78
5345991806How 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.79
5345991807C3 plantsplants that undergo a variation of photosynthesis in which they take in CO₂ and run the Calvin cycle during the day Ex. maple leaf80
5345991808C4 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. corn81
5345991810What are four factors that affect the rate of photosynthesis?light intensity temperature CO₂ concentration oxygen concentration82
5345991811How does light intensity affect photosynthesis?As light intensity increases, the rate of photosynthesis increases. -Only to a point -Eventually, all pigments are saturated with light83
5345991812How 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 denature84
5345991813How does CO₂ concentration affect photosynthesis?As concentration increases, the rate of photosynthesis increases.85
5345991814How does oxygen concentration affect photosynthesis?As concentration increases, the rate of photosynthesis decreases. -happens when the plant is water stressed and stomates are closed86

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