BIOLOGY TOPIC 8 METABOLISM (HL)
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BIOLOGY TOPIC 8 METABOLISM (HL) - Leaderboard
BIOLOGY TOPIC 8 METABOLISM (HL) - Details
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43 questions
| 🇬🇧 | 🇬🇧 |
| What happens in non-competitive inhibition? (4) | Inhibitor binds to allosteric site = changes the shape of the active site indirectly blocks reaction effects cant be lowered by increasing substrate |
| What is metabolism? | Sum of all anabolic and catabolic reactions to maintain life |
| How do enzymes affect activation energy? | Lowers EA = Speeds up rate of reaction |
| What is catabolism? what type of reaction is it? | Breaks down molecules bonds = releases energy = exergonic |
| What is anabolism? What type of reaction is it? | Forms molecule bonds = needs energy = endergonic |
| What is an enzyme inhibitor? | Prevents substrate-enzyme complex forming |
| How is a substrate-enzyme complex formed? (4) | Conformational change to active site = induced fit model specific and complementary destabilises bond in substrate lowers activation energy |
| What happens in competitive inhibition? how can effects be lowered? (3) | Inhibitor binds to active site = structurally + chemically similar to substrate directly blocks reaction effects can be lowered if substrate conc increases |
| What happens in non-competitive inhibition? (4) | Inhibitor binds to allosteric site = changes the shape of the active site indirectly blocks reaction effects cant be lowered by increasing substrate |
| What is an example of competitive inhibition? how does it work? (5) | Relenza - treatment for influenza binds to neuraminidase active site prevents cleavage of docking proteins prevents virons releasing from infected cells = prevents spread |
| What is an example of non-competitive inhibition? (4) | Cyanide binds to cytochrome oxidase complex (IV) changes active site = electrons cant release with oxygen = ETC shuts down ATP production shuts down = death |
| What is the allosteric site? | Place on enzyme where an inhibitor can bind, which changes active site |
| What is feedback inhibition? | Final product in a series inhibits an enzyme from an earlier step by binding to allosteric site to control the amount of product made negative feedback loop |
| What is an example of end product inhibition? (4) | Threonine = isoleucine (amino acid) in plants and bacteria first converted into intermediate w threonine deaminase isoleucine binds to allosteric site (non-competitive) excess isoleucine prevents further production |
| What is the effect of inhibition on enzyme kinetics? | Non-competitive < competitive <uninhibited |
| How are NAD+ and FAD+ reduced? | NADH FADH2 +2H+ + 2E- |
| What is phosphorylation? | Adding a phosphate group to a molecule to make it less stable more reactive and prevents it from diffusing back |
| Where does glycolysis take place? | Cytoplasm |
| What are the steps of glycolysis? (4) | 1) phosphorylation = uses 2 atp to make glucose more reactive and prevents diffusion = hexose bisphosphate 2) lysis = 6c into two 3C triose phosphates 3) oxidation = H atoms removed for oxidation of 2NAD+ into 2NADH 4) 2 ATP formed w substrate level phosphorylation 2 pyruvates |
| What happens during the link reaction? what is added and what is lost: what is formed? how many times does it happen (5) | Decarboxylated = loses 1c to form co2 loses 2H+ to reduce NAD+ Coenzyme A CoA added to form acetyl CoA pyruvate (3c) = acetyl coA (2c) happens twice for each glucose (bec 2 pyruvates per glucose) |
| What happens during krebs cycle? what is removed? what is formed? how many times does it happen (5) | Acetyl coA (2C) = oxaloacetate (4c) = citrate (6c) 2 carbons released w decarboxylation (4CO2) 6 NADH and 2 FADH2 = 4atp occurs twice |
| Where does krebs cycle happen? | Mitochondrial matrix |
| Where does ETC happen? | Inner membrane (Cristae) |
| What happens in ETC to make atp? | Releases energy stored in H carriers (oxidative phosphorylation |
| What are the steps of the ETC? | 1) Proton motive force = NADH + FADH2 oxidised to release electrons and protons electron energy used to pump h+ from matrix proton buildup in intermembrane space 2) ATP made with chemiosmosis of H+ with ATP synthase = made with ADP + Pi 3) oxygen reduced = removes de energized electrons and free protons to form water and maintain H+ gradient |
| Label a mitochondria (5) | Cristae =folds to increase surface area to volume ratio intermembrane space = max H gradient inner membrane = ETC and ATP synthase for oxidative phosphorylation matrix = enzymes and pH for krebs cycle outer membrane = transport proteins for pyruvates |
| Label and draw a chloroplast (8) | Grana = increase sa: vol ratio Thylakoid = makes up grana has ETP and ATP synthase for photophosphorylation. Has max H gradient double membrane structure = endosymbiosis photosystem 1 and 2 with pigments for max light absorption stroma: enzymes and pH for Calvin cycle lamellae = connects and separates grans for max efficiency 70s ribosomes circular and naked dna |
| What does the light dependent reactions produce? | ATP and NADPH |
| What are the steps for the light dependent reaction? (6) | 1) P1 and P2 electrons get excited w light energy = transferred to carrier molecule 2) excited electrons from p2 transferred to ETC used to translocate H+ into thylakoid 3) proton motive force (chemiosmosis) produces ATP with ATP synthase using ADP and Pi 4) de-energised electrons from p2 move to p1 5) NADP+ reduced into NADPH with excited electrons from p1 6) electrons from P2 are replaced with electrons from photolysis of water |
| What are the electrons in p2 used for? | ETC to produce ATP with ATP synthase and chemiosmosis of H+ using ADP and Pi |
| What are the electrons in p1 used for? | To reduce NADP into NADPH (hydrogen carrier) |
| How are electrons in p2 replaced? | With photolysis of water, when water is split with light energy into 2H+ O2 and 2e- |
| How are electrons in P1 replaced? | With deenergised electrons from p2 |
| What is photoactivation? | Release of high energy electrons |
| What happens during cyclic photophosphorylation? what is needed? what is not needed? (5) | Only ps1 no water needed o2 not made NADPH not made excited electron = ETC = ATP used for extra ATP for cell energy |
| What happens during non-cyclic photophosphorylation? what is used? what is the purpose? (4) | PS1 and PS2 photolysis of water o2 made NADPH made used for making organic compounds |
| What are the steps of the calvin cycle? | 1) Carbon fixation = Ribulose bisphosphate (RuBP 5c) is catalyzed with rubisco to attach CO2 2) 6C two glycerate-3-phosphate (GP) formed = 3 RuBP + 3CO2 = 6GP 3) GP reduced into TP triose phosphate with 6NADPH (H atoms) and 6ATP (energy) for 6GP 4) RuBP remade = 1 TP = 1/2 glucose so 2 cycles needed 5) 5 TP used to remake RuBP (5C molecule) using 3 ATP |
| Which enzyme is used in calvin cycle? | Rubisco is used to catalyse the attachment of co2 to ribulose biphospate Rubp |
| What was calvins experiment? what substances were used? how were the different stages of the calvin cycle shown? (5) | Radioactive C14 in HCO3 ion solution incorporated in photosynthesis after diff time periods algae killed by adding to heated alcohol dead algal samples were analyzed with 2D chromatography separated different carbon compounds made showed diff stages of calvin cycle |