How is ATP synthase in the chloroplast?
The chloroplast adenosine triphosphate (ATP) synthase uses the electrochemical proton gradient generated by photosynthesis to produce ATP, the energy currency of all cells. Protons conducted through the membrane-embedded Fo motor drive ATP synthesis in the F1 head by rotary catalysis.
Do chloroplasts have ATP synthase?
The chloroplast ATP synthase catalyzes the light-driven synthesis of ATP and is activated in the light and inactivated in the dark by redox-modulation through the thioredoxin system. It has been proposed that this down-regulation is important for preventing wasteful hydrolysis of ATP in the dark.
Where does ATP synthase occur in the chloroplast?
The chloroplast adenosine triphosphate (ATP) synthase is located in the thylakoid membrane and synthesizes ATP from adenosine diphosphate and inorganic phosphate at the expense of the electrochemical proton gradient formed by light-dependent electron flow.
What is ATP synthase powered by?
Structure of ATP Synthase This is a motor that is powered by H+ ions flowing across the membrane. The part within the mitochondria, stroma of the chloroplast, or inside the bacterial or archaeal cell is called F1-ATPase.
Do both mitochondria and chloroplasts have ATP synthase?
The bulk of ATP synthesis in plants is performed by ATP synthase, the main bioenergetics engine of cells, operating both in mitochondria and in chloroplasts.
How many protons are in one turn of chloroplast ATP synthase?
three protons
ATP synthesis is coupled to the transfer of three protons through the ATP synthase from the lumen to the stroma; thus, ATP formation is thermodynamically possible when the ΔμH+ across the thylakoid membrane is more than three times the ΔG of ATP formation.
How does ATP synthase motor work?
Motor to Generator In our cells, food is broken down and used to pump hydrogen ions across the mitochondrial membrane. The F0 portion of ATP synthase allows these ions to flow back, turning the rotor in the process. As the rotor turns, it turns the axle and the F1 motor becomes a generator, creating ATP as it turns.
What is the process of generating ATP in mitochondria and chloroplasts called?
The common pathway used by mitochondria, chloroplasts, and procaryotes to harness energy for biological purposes operates by a process known as chemiosmotic coupling—reflecting a link between the chemical bond-forming reactions that generate ATP (“chemi”) and membrane-transport processes (“osmotic”).
How does ATP synthase rotate?
The Fo rotor spins in response to proton (H+) flow down a concentration gradient across the membrane. This rotation causes the central stalk (axle) to rotate, altering the conformation of components of the F1 base, driving the synthesis of ATP.
How fast does ATP synthase spin?
about 130 revolutions per second
With saturating ATP of 2 mM, full speed rotation of about 130 revolutions per second was observed which corresponded to a kcat for ATP hydrolysis of 390 s−1.
How is ATP synthase made?
During photosynthesis in plants, ATP is synthesized by ATP synthase using a proton gradient created in the thylakoid lumen through the thylakoid membrane and into the chloroplast stroma. Eukaryotic ATP synthases are F-ATPases, running “in reverse” for an ATPase. This article deals mainly with this type.
How do the ATP synthase in the mitochondria and chloroplast differ?
In chloroplasts, ATP synthase receives protons from thylakoid lumen, which volume is small as compared to the mitochondrial intermembrane space (IMS) and which pH value can drop to the values below 5 (Oja et al., 1999), while in the mitochondrial IMS it drops only slightly below 7 (Moore and Rich, 1985; Porcelli et al. …
What powers the ATP synthase enzymes in both mitochondria and chloroplasts?
14-3-3 protein is a regulator of the mitochondrial and chloroplast ATP synthase.
Does ATP synthase spin clockwise or counterclockwise?
The rotation of the β subunit conformers during rotational catalysis. In looking at the F1 from the “bottom” or membrane oriented side of the complex, rotation of the γ subunit is counter-clockwise for ATP hydrolysis, and clockwise in ATP synthesis (see [9] for a review).
Does ATP synthase actually rotate?
Like hydroelectric turbines, ATP synthase components rotate in response to the proton flow, and this rotational energy is then coupled to ATP synthesis.
Does ATP synthase work backwards?
The reaction catalyzed by ATP synthase is fully reversible, so ATP hydrolysis generates a proton gradient by a reversal of this flux.
Why is chloroplast better than mitochondria?
Mitochondria and chloroplast are organelles found in a plant cell….Mitochondria vs Chloroplast.
| Mitochondria | Chloroplast |
|---|---|
| Known as the powerhouse of the cell, it is responsible for energy metabolism and cellular respiration | Larger and much more complex than a mitochondrion, it is the site where photosynthesis takes place. |
What is the molecular architecture of the chloroplast ATP synthase?
The molecular architecture of the chloroplast ATP synthase, which confers redox regulatory properties requires further investigation, in light of the molecular structure of the enzyme complex as well as the physiological significance of the regulation system.
How does ATP synthase work?
In mitochondria, eubacteria and chloroplasts, the synthesis of ATP is made by a complex molecular machine known as ATP synthase. We want to understand how this machine works, and to use that knowledge for medical benefit. We work mainly on the enzyme from mitochondria, and increasingly on the enzymes from eubacteria.
How is ATP synthesized from ADP and ADP?
ATP synthase catalyzes the final step of oxidative or photophosphorylation, the synthesis of ATP from adenosine diphosphate (ADP) and P i. 1–5 Proton translocation, down the electrochemical gradient, through the membrane-embedded F 0 subcomplex supplies the energy for ATP synthesis on the peripheral F 1 subcomplex.
What are the different types of ATP synthase?
ATP Synthase 1 V-ATPases☆. Vacuolar proton-translocating ATPases (V-ATPases) are found in almost all eukaryotic cells. 2 The Heliobacteria. The ATP synthase of Hbt. 3 Cellular Bioenergetics. The ATP synthase is freely reversible, and its direction depends on the thermodynamic balance between Δp and the matrix Δ Gp. 4 ATP23 Peptidase.