Call us toll-free

Quick academic help

Don't let the stress of school get you down! Have your essay written by a professional writer before the deadline arrives.

Calculate the price

Pages:

275 Words

$19,50

Does phosphorylation occur in photosynthesis

The catabolic pathways of glycolysis and respiration capture the chemical energy in glucose and other fuels and store it in ATP. Glycolysis, occurring in the cytosol, produces ATP, pyruvate, and NADH; the later two, may then enter the mitochondria for respiration. A mitochondrion consists of a matrix in which the enzymes of the krebs cycle are localized, a highly folded inner membrane (cristae) in which enzymes and the molecules of the electron transport chain (ETC) are embedded, and an intermembrane space between the two membranes, to temporarily house H+ that has been pumped across the inner membrane during the redox reactions of the ETC (a proton motive force (the definition is given below in the text) drives oxidative phosphorylation as protons move back through ATP synthases located in the membrane).

Oxidative phosphorylation occurs across internal ..

The coupling in oxidative phosphorylation uses a more complicated (and amazing!) mechanism, but the end result is the same: the reactions are linked together, the net free energy for the linked reactions is negative, and, therefore, the linked reactions are spontaneous.

Photophosphorylation occurs during photosynthesis

For a more complete description of each step in oxidative phosphorylation (indicated by the numbers), .

Phosphorylation of ADP (Equation 8) is coupled to the oxidation-reduction reaction of NADH and O2 (Equations 9 and 10). Electrons are not transferred directly from NADH to O2; rather, electrons pass through a series of intermediate electron carriers in the inner membrane of the mitochondrion. Why? This allows something very important to occur: the pumping of protons across the inner membrane of the mitochondrion. As we shall see, this proton pumping that is ultimately responsible for coupling the oxidation-reduction reaction to ATP synthesis.

Glycolysis, occurring in the cytosol, breaks glucose into two molecules of pyruvate. So partially oxidizes glucose (C6) into two pyruvate (C3) molecules. The Krebs cycle, which is a catabolic pathway, located in the mitochondrial matrix, converts a derivative of pyruvate (acetyl CoA) into carbon dioxide. In some of the steps of glycolysis and the krebs cycle, dehydrogenase enzymes transfer electrons to NAD+. NADH passes electrons to the electrons transport chain. This chain accepts energized electrons from reduce coenzymes NADH and FADH2. Energized electrons are harvested during glycolysis and Krebs cycle. Those electrons will eventually combine with hydrogen ions and oxygen to form water. The energy released in each step of the chain is used to synthesize ATP by oxidative phophorylation. Oxidative phosphorylation accounts for almost 90% of the ATP generated by respiration. About 10% of the ATP generated for each molecule of glucose oxidized to carbon dioxide and water is produced by substrate-level phosphorylation, in which an enzyme transfers a phosphate group from a substrate to ADP.

Chemistry for Biologists: Respiration

Oxidative phosphorylation occurs in mitochondria and photophosphorylation occurs in chloroplasts.

In glycolysis, each six-carbon glucose molecule is converted into two molecules of pyruvate. The next two stages of cellular respiration require oxygen. The Krebs cycle releases carbon dioxide and generates high-energy molecules. Oxidative phosphorylation, the last stage in cellular respiration, produces more ATP than any other metabolic pathway.

Which of the three stages of cellular respiration—glycolysis, the Krebs cycle, or oxidative phosphorylation—could organisms have used four billion years ago, before photosynthesis by cyanobacteria released oxygen into the atmosphere?

14.06.2011 · Our understanding of how oxidative phosphorylation occurs at the ..
Order now
  • UNMATCHED QUALITY

    As soon as we have completed your work, it will be proofread and given a thorough scan for plagiarism.

  • STRICT PRIVACY

    Our clients' personal information is kept confidential, so rest assured that no one will find out about our cooperation.

  • COMPLETE ORIGINALITY

    We write everything from scratch. You'll be sure to receive a plagiarism-free paper every time you place an order.

  • ON-TIME DELIVERY

    We will complete your paper on time, giving you total peace of mind with every assignment you entrust us with.

  • FREE CORRECTIONS

    Want something changed in your paper? Request as many revisions as you want until you're completely satisfied with the outcome.

  • 24/7 SUPPORT

    We're always here to help you solve any possible issue. Feel free to give us a call or write a message in chat.

Order now

Respiration What is respiration

To generate ATP, cells use a proton-pumping system made up of proteins inside the mitochondria to generate ATP. Before we examine the details of ATP synthesis, we shall step back and look at the big picture by exploring the structure and function of the mitochondria, where oxidative phosphorylation occurs.

Pentose phosphate pathway - Wikipedia

Two major types of mitochondrial proteins (see Figure 9, below) are required for oxidative phosphorylation to occur. Both classes of proteins are located in the inner mitochondrial membrane.

Georgia Virtual Learning > Home

The three major steps in oxidative phosphorylation are (a) oxidation-reduction reactions involving electron transfers between specialized proteins embedded in the inner mitochondrial membrane; (b) the generation of a proton (H+) gradient across the inner mitochondrial membrane (which occurs simultaneously with step (a)); and (c) the synthesis of ATP using energy from the spontaneous diffusion of electrons down the proton gradient generated in step (b).

AP Biology Animations - Biology Junction

For each glucose molecule entering glycolysis: 1) A net gain of two ATPs is produced by substrate-level phosphorylation. 2) Two molecules of NAD+ are reduced to NADH. Energy conserved in the high-energy electrons of NADH can be used to make ATP by oxidative phosphorylation. Energy-Investment phase includes five steps that split glucose in two and consumes ATP. So I do not expect you to memorize the structures or steps of glycolysis, but you should understand the process, where it occurs and the major molecules required and produced. For the different steps, see the text book.

Cellular Respiration Animation - Sumanas, Inc.

In order to couple the redox and phosphorylation reactions needed for ATP synthesis in the body, there must be some mechanism linking the reactions together. In cells, this is accomplished through an elegant proton-pumping system that occurs inside special double-membrane-bound organelles (specialized cellular components) known as mitochondria. A number of proteins are required to maintain this proton-pumping system and catalyze the oxidative and phosphorylation reactions.

Order now
  • You submit your order instructions

  • We assign an appropriate expert

  • The expert takes care of your task

  • We send it to you upon completion

Order now
  • 37 684

    Delivered orders

  • 763

    Professional writers

  • 311

    Writers online

  • 4.8/5

    Average quality score

Order now
  • Kim

    "I have always been impressed by the quick turnaround and your thoroughness. Easily the most professional essay writing service on the web."

  • Paul

    "Your assistance and the first class service is much appreciated. My essay reads so well and without your help I'm sure I would have been marked down again on grammar and syntax."

  • Ellen

    "Thanks again for your excellent work with my assignments. No doubts you're true experts at what you do and very approachable."

  • Joyce

    "Very professional, cheap and friendly service. Thanks for writing two important essays for me, I wouldn't have written it myself because of the tight deadline."

  • Albert

    "Thanks for your cautious eye, attention to detail and overall superb service. Thanks to you, now I am confident that I can submit my term paper on time."

  • Mary

    "Thank you for the GREAT work you have done. Just wanted to tell that I'm very happy with my essay and will get back with more assignments soon."

Ready to tackle your homework?

Place an order