Explanation:
For electron transport chains:
- a H+ concentration gradient is required for oxidative phosphorylation in the electron transport chain of the mitochondria and phosphorylation in the chloroplast, and thus the production of ATP
- the H+ ion gradient must favor the flow of electrons into the stroma of the chloroplast and matrix of the mitochondria
However, differences include:
- In photosynthesis, H+ is obtained from photolysis and accumulates within the thykaloid space, while in respiration the H+ is obtained from NADPH and FADH2
- The high concentration of H+ outside the membrane leads to increased H+ concentration, due to its high permeability. Photosynthesis involves the thykaloid membrane while respiration involves the mitochondrial membrane
- This forms a gradient where there is a differential in the number of protons on either side of the membrane
- the protons flow into the stroma through the enzyme ATP synthase, which makes the energy storage molecules of ATP from the reduction of ADP and inorganic phosphate, Pi. Similarly, H+ flows into the mitochondrial matrix in respiration.
- During photosynthesis, NAD+ functions as the terminal electron acceptor and is reduced to NADPH. while H2O is the terminal acceptor in respiration.
Further Explanation:
Photophosphorylation describes a process in which the H+ made in previous steps of photosynthesis, and free electrons are used to obtain energy stored as ATP; in the electron transport chain move down the chain the energy they release is used in pumping protons out of the thykaloid space.
During the light reaction, light is absorbed by pigments in phosystem II (PSII). This energy is transferred among pigments til it gets to the reaction center, and is transferred to P680; this promotes an electron to a higher energy level where it then goes to an acceptor molecule.
- Water supplies the chlorophyll in plant cell with replacement electrons for the ones removed from photosystem II. Additionally, water (H2O) split by light during photolysis into H+ and OH- acts as a source of oxygen along with functioning as a reducing agent.
- in the ETC, the molecule NADP is reduced to NADPH by providing H+ ions. NADP and NADPH are integral to the Calvin cycle where monosaccharides or sugars like glucose are produced after the modification of several molecules.
Respiration in the mitochondria utilizes oxygen for the production of ATP in the Krebs’ or Citric acid cycle via the oxidization of pyruvate(through the process of glycolysis in the cytoplasm).
- Oxidative phosphorylation describes a process in which the NADH and FADH2 made in previous steps of respiration process give up electrons in the electron transport chain- these are converted it to their previous forms, NADH+ and FAD.
- Electrons continue to move down the chain and the energy they release is used in pumping protons out of the matrix of the mitochondria.
- This forms a gradient where there is a differential in the number of protons on either side of the membrane the protons flow or re-enter the matrix through the enzyme ATP synthase, which makes the energy storage molecules of ATP from the reduction of ADP.
- At the end of the electron transport, three molecules of oxygen accept electrons and protons to form molecules of water
Learn more about photosynthesis at brainly.com/question/4216541
Learn more about cellular respiration at brainly.com/question/11203046
Learn more about cellular life at brainly.com/question/11259903
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