unit 2 biochem - Unit 2 Week 7 Session Objectives 1 Define...

Info icon This preview shows pages 1–3. Sign up to view the full content.

View Full Document Right Arrow Icon
Unit 2: Week 7: Session Objectives: 1 Define and briefly explain the role of entropy, and enthalpy in biochemical reactions Enthalpy ( H)  is the change in chemical bond energy in a reaction (bond energy of products minus the bond energy of reactants). Also called HEAT  CONTENT.  Entropy ( S)  is a measure of disorder. It is often negligible in reactions  (ATP hydrolysis) in which the number of reactants and products are equal (and  no gas is formed). 2 Give examples of biochemical, mechanical and transport work. Mechanical work ->  the high energy phosphate bond of ATP is  converted into movement by changing the conformation of a protein (ex. myosin  head group) Transport work (active transport) ->  ATP is used to transport a  compound against its [ ] gradient. (EXAMPLE: ATPASES) Biochemical Work->  formation of chemical bonds. would be unfavorable  without using ATP and the removal of products (intermediates that continue  down the pathway) and accumulation of more substrates (EXAMPLE ENGERY  OF REACTION) 3 Calculate the overall delta G of a series of reactions if given the delta G for each individual reaction Just add all of them together, summative 4 Describe the role of ATP as an energy carrier, specifically the role of the high energy phosphate bonds (Figure 19.2) -B onds between the phosphate groups are called Phosphoanhydride  bonds. -ATP unstable because the closely grouped negative phosphate groups  (repel and strain) -When those bonds are broken (Hydrolysis), energy is released  (products->ADP and phosphate are more stable) -Release energy as HEAT. BUT in the cell it is NOT hydrolyzed directly  (heat is inefficient for transfer to energy requiring processes. INSTEAD  enzymes transfer the phosphate group directly to metabolic intermediates or proteins (phosphoric transfer reaction) to drive their reactions forward. 5 Compare the redox coenzymes, FAD, NAD and NADPH as the cell's electron carriers (Figure 19.9, 19.10) - NAD  accepts two e  as a HYDRIDE ion (H ¹ ) to form NADH, and a  proton  is released into the medium. Usually involved in oxidation of  ALCOHOLS and ALDEHYDES. -FAD  accepts two e  as hydrogen atoms (w/1 e  each), which are 
Image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
donated from separate atoms. INVOLVED in the formation of a double  bond or a disulfide. forms FAD(2H). Listed as FAD(2H), because it often  accepts a total of 2 e , one at a time, never going to the fully reduced  state (FADH ) -NADP  is similar to NAD  and has the same reduction potential, BUT it  has an extra phosphate group on the ribose. Affects its enzyme binding.  Most enzymes use either or, but not both. Used by glucose 6-P  dehydrogenase to transfer e  from glucose 6-P to NADP  (instead of 
Image of page 2
Image of page 3
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

What students are saying

  • Left Quote Icon

    As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

    Student Picture

    Kiran Temple University Fox School of Business ‘17, Course Hero Intern

  • Left Quote Icon

    I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

    Student Picture

    Dana University of Pennsylvania ‘17, Course Hero Intern

  • Left Quote Icon

    The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

    Student Picture

    Jill Tulane University ‘16, Course Hero Intern