Table of Contents
- 1 How is the hydrogen ion gradient formed?
- 2 What drives the production of ATP by ATP synthase?
- 3 What kind of membrane transport is used to build the H+ gradient?
- 4 What maintains the hydrogen ion concentration gradient?
- 5 How does pH affect ATP synthase?
- 6 How does the proton gradient drive ATP synthesis?
- 7 What is the pH gradient of cellular respiration?
- 8 What causes the proton gradient across the membrane?
- 9 How does a transmembrane pH gradient form?
- 10 How does membrane growth affect energy storage in cells?
How is the hydrogen ion gradient formed?
Complex I establishes the hydrogen ion gradient by pumping four hydrogen ions across the membrane from the matrix into the intermembrane space. Complex III pumps protons through the membrane and passes its electrons to cytochrome c for transport to the fourth complex of proteins and enzymes.
What drives the production of ATP by ATP synthase?
What drives the production of ATP by ATP synthase? Hydrogen ions move down their concentration gradient through ATP synthase from the thylakoid space to the stroma. The flow of hydrogen ions through ATP synthase drives the phosphorylation of ADP to ATP.
What kind of membrane transport is used to build the H+ gradient?
Proton Gradients and ATP synthase One particular ion gradient with biological significance is the proton (H+) gradient. This type of gradient is established through active transport involving proton pumps.
How is the proton gradient formed in cellular respiration?
In cellular respiration, hydrogen ions (protons) move down their concentration gradient through a membrane protein to produce ATP. The gradient of protons is established by the electron transport portion of oxidative phosphorylation, which is used to transfer protons into the intermembrane space.
What is the role of the electron transport chain in forming the H+ gradient across the inner mitochondrial membrane?
28. What is the role of the electron transport chain in forming the H+ gradient across the inner mitochondrial membrane? The chain is an energy converter, using the exergonic flow of electrons from NADH and FADH2 to pump H+ from the mitochondrial matrix into the intermembrane space.
What maintains the hydrogen ion concentration gradient?
Concentration gradients are generated and maintained across biological membranes by ion pump enzymes that transport ionic solutes such as sodium, potassium, hydrogen ions, and calcium across the membrane. Energy is required to produce a gradient, so the gradient is a form of stored energy.
How does pH affect ATP synthase?
Low pH increases the acid concentration in the mitochondrial matrix, a condition that normally causes ATP production. Low pH increases the OH- concentration in the matrix resulting in ATP production by ATP synthetase.
How does the proton gradient drive ATP synthesis?
The proton gradient produced by proton pumping during the electron transport chain is used to synthesize ATP. Protons flow down their concentration gradient into the matrix through the membrane protein ATP synthase, causing it to spin (like a water wheel) and catalyze conversion of ADP to ATP.
What are 4 methods of transport across the membrane?
The basic types of membrane transport, simple passive diffusion, facilitated diffusion (by channels and carriers) and active transport are summarized in Fig.
How is a gradient of H plus ions formed across the inner mitochondrial membrane?
Electron transport chain: Electron transport and pumping of protons (H+), which creates an H+ gradient across the membrane.
What is the pH gradient of cellular respiration?
about -1 pH unit
In a typical cell, the proton-motive force across the inner membrane of a respiring mitochondrion is about 200 mV and is made up of a membrane potential of about 140 mV and a pH gradient of about -1 pH unit.
What causes the proton gradient across the membrane?
The various events that cause the proton gradient across the membrane are: (i) The splitting of water molecule takes place on the inner side of the membrane. (ii) As electrons move through the photosystems, protons are transported across the membrane.
How does a transmembrane pH gradient form?
Under such conditions, when fatty acid vesicles grow through the incorporation of additional fatty acid, a transmembrane pH gradient is spontaneously generated. The formation of this pH gradient captures some of the energy released during membrane growth, but also opposes and limits further membrane area increase.
How is ATP generated in the electron transfer chain?
The ATP generated from this reaction go on to power most cellular reactions necessary for life. In the electron transfer chain, electrons move along a series of proteins to generate an expulsion type force to move hydrogen ions, or protons, across the mitochondrial membrane.
What happens to the electrons in the proton gradient?
The electrons, in addition to hydrogen and oxygen, then react to form water in an irreversible reaction. This is the last complex that translocates four protons across the membrane to create the proton gradient that develops ATP at the end.
How does membrane growth affect energy storage in cells?
The coupling of membrane growth to energy storage could have provided a growth advantage to early cells, once the membrane composition had evolved to allow the maintenance of stable pH gradients. Modern cells rely on electrochemical proton gradients for energy transduction and metabolism.