20 Matching Annotations
  1. Mar 2023
    1. Recently, redox-responsive biomolecules such as phenazines have been used in several electrochemical strategies to interrogate a range of biological activities30,31 and to control gene expression in living cells32,33, where the redox status of the biomolecules could be measured or manipulated by application of electronic potentials
  2. Oct 2022
    1. NAD+ is used by the cell to "pull" electrons off of compounds and to carry them to other locations within the cell, thus they are called electron carriers

      What is the NAD+ used for?

    2. The oxidation of, or removal of an electron from, a molecule (whether accompanied with the removal of an accompanying proton or not) results in a change of free energy for that molecule - matter, internal energy, and entropy have all changed in the process.

      What does oxidation (removal of an electron from a molecule change about Delta G?

    3. Each of these two types of molecules is involved in energy transfer that involve different classes of chemical reactions. It's interesting that while one class of carrier delivers electrons (and energy), the other delivers phosphates (and energy), but both include an adenine nucleotide(s).

      What does ATP carry and what does NADH carry? How are they similar?

    4. In this course we will examine two major types of molecular recyclable energy carriers: (1) nicotinamide adenine dinucleotide (NAD+), a close relative nicotinamide adenine dinucleotide phosphate (NADP+), and flavin adenine dinucleotide (FAD2+) and (2) nucleotide mono-, di- and triphosphates, with particular attention paid to adenosine triphosphate (ATP).

      What are the two major types of molecular recyclable energy carriers?

    5. Each individual carrier in the pool can exist in one of multiple distinct states: it is either carrying a "load" of energy, a fractional load, or is "empty".

      What state can carriers be in?

    6. Keep in mind that a positive ΔE0' gives you a negative ΔG

      What does a positive deltaE0’ potential give you in terms of delta G’s sign

    7. Using the Nerst equation essentially corrects for the  number of electrons per transfer (here n = 2) and puts things into units biologists can use, and copes with the directionality (sign) for us. F has units of kJ*/volt, E has units of (Volts), so we end up with kJ, a unit of energy.

      What units are used for n, F, E0’, and the final delta G0’

    8. here n is the number of electrons involved in each transfer, and F is a constant that is a positive number

      What is n and F in Delta G0’ = -nFdeltaE0’

    9. E0' values and to help us predict the direction of electron flow between potential electron donors and acceptors.

      What does the E0’ be used to predict?

    10. Different compounds, based on their structure and atomic composition, have intrinsic and distinct attractions for electrons. This quality is termed reduction potential or E0’ and is a relative quantity (relative by comparison to some “standard” reaction).

      What does a reduction potential depend on? What units does it use?

    11. By convention we analyze and describe redox reactions with respect to reduction potentials (E0'), a term that quantitatively describes the "ability" of a compound to gain electrons.

      What is reduction potential? What does it indicate?

    12. If you consider a generic redox reaction and reflect back on the thermodynamic lectures, what factor will determine whether a redox reaction will proceed in a particular direction spontaneously, and what might determine its rate?

      The E0’ potentials can be used to determine the change in delta G and if the delta G is negative then the reaction will proceed spontaneously. If its a negative or a positive delta G it will also determine what direction the reaction will go.

    13. Sometimes a redox tower will list compounds in order of decreasing redox potentials (high values on top and low values on the bottom). Our towers do not- we list (reduced vs. oxidized state) molecule pairs with negative values (highly negative E˚') up top and positive ones (highly positive E˚') towards the bottom. Does presenting the data this way change the redox potential of a compound?

      I don’t think it changes it, It is just a different way of looking at it. Like a reverse. It does not change the potential or the maths.

    14. The electron tower is a tool that ranks different common half reactions based on how likely they are to donate or accept electrons.

      What is the electron tower? What is it used for?

    15. The amount of energy transferred in a redox reaction is associated with the difference between each half reactions' reduction potential, E0

      What is reduction potential E0’ And how is it calculated?

    16. Because oxidation and reduction usually occur together, these pairs of reactions are called oxidation reduction reactions, or redox reactions.

      What is an Oxidation reaction? What is a Reduction Reaction? Do they Happen together or one at a time?

    17. The ETC produces a proton gradient. No ATP is directly generated in this process. However, the proton gradient is then used by the cell (among other things) to run an enzyme called ATP synthase which catalyzes the reaction ADP + Pi --> ATP. This method of ATP production (called oxidative respiration) results in additional- many additional- ATPs being produced.

      How are further ATP’s Produced through the proton gradient?

  3. Jun 2020
    1. In any electrochemical process, electrons flow from one chemical substance to another, driven by an oxidation–reduction (redox) reaction. A redox reaction occurs when electrons are transferred from a substance that is oxidized to one that is being reduced. The reductant is the substance that loses electrons and is oxidized in the process; the oxidant is the species that gains electrons and is reduced in the process. The associated potential energy is determined by the potential difference between the valence electrons in atoms of different elements.
  4. Nov 2017
    1. I think the concept of antioxidants has been misunderstood. What Dr. Tom Levy and I have introduced at our most recent conference is this concept of redox medicine that everything in nature is redox. Dave Asprey:                     Yes. Explain redox for our listeners. This is also in headstrong. Just like define that. It’s so important. You guys will have to hear this. Ron Hunninghake:           Yeah. Well, life is redox. There’s oxidation, there is reduction. Oxidation is when molecules lose electrons and it causes dysfunction of some sort. Reduction is when from some source, such as vitamin C or good quality food, you are able to get electrons back in order to stabilize the molecule and to stabilize the structures that it’s working within.