SBI4U – Grade 12 AP Biology – Metabolism Test Metabolism Main Ideas Labs Plant Pigments & Photosynthesis & Cell Respiration Sunlight, which is ultimately converted to heat, enters an ecosystem along with recycled chemical elements that are necessary for life. Cellular Respiration – About 40% of the energy in a glucose molecule is transferred to ATP during cellular respiration making about 36-38 ATP. Glycolysis – occurs in the cytoplasm – During glycolysis each glucose molecule is broken down into 2 molecules of the compoundpyruvate. In eukaryotic cells, pyruvate enters the mitochondrion – From there it is oxidized to CO2. ATP is than generated. – has 10 steps that are broken down into 2 main phases 1-3 energy is in the form of ATP. So ATP is hydrolyzed to ADP in two steps 7-10 glycolysis substrate level phosphorylations occur. The formation of ATP through the transfer of a phosphate group to ADP Krebs cycle / Citric Cycle – occurs in the matrix of the mitochondria – active transport – only occurs when oxygen is present, and processes lipids, proteins and carbohydrates Oxidative Phosphorylation – amounts for the most energy extracted from food
– has two stages – Electron transport chain – Pumps in the cristae – Moves the NADH and FADH2 => redox power – Chemiosmosis – H+ passes through ATP synthase – ATP synthase makes ATP Glucose è NADH è E.T.C. è Proton Motive Force è Fermentation (Anerobic) – Uses an electron transport with an e- acceptor other than O2 – Fermentation uses phosphorylation instead of electron transport chain to generalize ATP Photosynthesis – Process that converts solar energy into chemical energy – Consists of the light reactions & calvin cycle Mesophyll – are where chloroplasts are found, are located in the middle of the leaf and have about 30-40 chloroplasts Thylakoids – contains the chlorophyll; connected sacs in the chloroplasts Chloroplast è Granum (Grana) è Thylakoid è Chlorophyll *stroma is the matrix of the chloroplast Light reactions – Splits water molecules – Releases O2
– Reduce NADP+ to NADPH – Generate ATP from ADP by photophosphorylation Calvin Cycle – Forms sugar from CO2; ATP + NADPH – Carbon fixation (incorporating CO2 into organic molecules) Pigments – pigments absorb visible lights – different pigments absorb different wavelengths; wavelengths that are not absorbed are reflected or transmitted Plants – most plants are C3 plants – photorespiration and O2 is used by rubisco – C4 plants – – to minimize the cost photorespiration into 4-carbon compounds – CAM – – opens their stoma at night and close during the day.