The document discusses key concepts in metabolism including:
- Metabolism extracts energy from fuels like carbohydrates and fats through catabolism and uses this energy to synthesize complex molecules through anabolism.
- Coupled reactions allow thermodynamically unfavorable reactions to proceed by making the overall free energy change negative.
- ATP is the universal energy currency in biological systems, and its hydrolysis drives metabolism by shifting reaction equilibria.
The document discusses different carbon fixation pathways in plants. C4 plants fix carbon dioxide in mesophyll cells before it is transported to bundle sheath cells, concentrating CO2 around Rubisco and reducing photorespiration. This allows higher photosynthesis rates with lower transpiration. C4 plants evolved in hot, dry climates. Crassulacean acid metabolism (CAM) plants fix CO2 at night and store it as malate, releasing CO2 for photosynthesis during the day, reducing water loss. CAM metabolism is inducible and some plants like ice plant switch to CAM in response to salt or drought stress.
The document discusses photosynthesis in C3 and C4 plants. It shows that willow and maize plants will both survive under a sealed cover individually, but only the willow survives when the two are combined, due to the maize plant using oxygen during photosynthesis. It then examines the differences in carbon fixation pathways between C3 and C4 plants, including their A-Ci curves and leaf anatomy, showing C4 plants have adaptations that allow them to more efficiently fix carbon in hot, dry environments. The document depicts the pathways that allow C4 plants like maize to concentrate CO2 around rubisco through compartmentalization between mesophyll and bundle sheath cells.
The rate of photosynthesis is often lower than expected for several reasons: 1) Dark respiration occurs during the day which reduces net photosynthesis, 2) Not all wavelengths of light are absorbed efficiently by leaves, and 3) Factors like photorespiration and suboptimal conditions can limit carbon fixation and respire photosynthates. Leaf anatomy, physiology, and environmental conditions can prevent photosynthesis from reaching its maximum potential.
- The document discusses plant reproduction and alternation of generations between haploid gametophytes and diploid sporophytes in different plant groups like mosses, ferns, gymnosperms and angiosperms.
- It describes how mosses have dominant gametophytes that produce sporophytes which bear spores and how ferns and seed plants have dominant sporophytes.
- It also summarizes the ABC model of flower development in which different combinations of transcription factors determine the identity of floral organs.
The document discusses key concepts in metabolism including:
- Metabolism extracts energy from fuels like carbohydrates and fats through catabolism and uses this energy to synthesize complex molecules through anabolism.
- Coupled reactions allow thermodynamically unfavorable reactions to proceed by making the overall free energy change negative.
- ATP is the universal energy currency in biological systems, and its hydrolysis drives metabolism by shifting reaction equilibria.
The document discusses different carbon fixation pathways in plants. C4 plants fix carbon dioxide in mesophyll cells before it is transported to bundle sheath cells, concentrating CO2 around Rubisco and reducing photorespiration. This allows higher photosynthesis rates with lower transpiration. C4 plants evolved in hot, dry climates. Crassulacean acid metabolism (CAM) plants fix CO2 at night and store it as malate, releasing CO2 for photosynthesis during the day, reducing water loss. CAM metabolism is inducible and some plants like ice plant switch to CAM in response to salt or drought stress.
The document discusses photosynthesis in C3 and C4 plants. It shows that willow and maize plants will both survive under a sealed cover individually, but only the willow survives when the two are combined, due to the maize plant using oxygen during photosynthesis. It then examines the differences in carbon fixation pathways between C3 and C4 plants, including their A-Ci curves and leaf anatomy, showing C4 plants have adaptations that allow them to more efficiently fix carbon in hot, dry environments. The document depicts the pathways that allow C4 plants like maize to concentrate CO2 around rubisco through compartmentalization between mesophyll and bundle sheath cells.
The rate of photosynthesis is often lower than expected for several reasons: 1) Dark respiration occurs during the day which reduces net photosynthesis, 2) Not all wavelengths of light are absorbed efficiently by leaves, and 3) Factors like photorespiration and suboptimal conditions can limit carbon fixation and respire photosynthates. Leaf anatomy, physiology, and environmental conditions can prevent photosynthesis from reaching its maximum potential.
- The document discusses plant reproduction and alternation of generations between haploid gametophytes and diploid sporophytes in different plant groups like mosses, ferns, gymnosperms and angiosperms.
- It describes how mosses have dominant gametophytes that produce sporophytes which bear spores and how ferns and seed plants have dominant sporophytes.
- It also summarizes the ABC model of flower development in which different combinations of transcription factors determine the identity of floral organs.
7. Fig. 8-2 Climbing up converts the kinetic energy of muscle movement to potential energy. A diver has less potential energy in the water than on the platform. Diving converts potential energy to kinetic energy. A diver has more potential energy on the platform than in the water. Potentiële energie Omzetting van potentiële energie in kinetische energie
14. Fig. 8-6a Energy (a) Exergonic reaction: energy released Progress of the reaction Free energy Products Amount of energy released (∆ G < 0) Reactants
15. Fig. 8-6b Energy (b) Endergonic reaction: energy required Progress of the reaction Free energy Products Amount of energy required (∆ G > 0) Reactants
26. Voorbeeld . Hydrolyse van sucrose: G = -7 kcal/mol Sucrose lost echter niet op. Toevoeging van een kleine hoeveelheid sucrase doet sucrose direct hydrolyseren in glucose en fructose.
33. Co-factoren. Naast dat de activiteit van enzymen wordt beïnvloedt door omgeving omstandigheden (pH, T, Ionsterkte) zijn er ook enzymen die moleculen nodig hebben voor hun activiteit (co-factoren). Co-factoren kunnen zijn : metaal atomen zoals Zn, Fe en Cu in hun ionvorm, of organische moleculen.