Chem4711(SlideSet8)

Chem4711(SlideSet8) - Metabolism Metabolism making and...

Info icon This preview shows pages 1–11. Sign up to view the full content.

View Full Document Right Arrow Icon
Metabolism
Image of page 1

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

View Full Document Right Arrow Icon
Metabolism – making and breaking stuff Catabolism Anabolism Common intermediates
Image of page 2
Ultimately, can only do reactions that have – G. Δ Photosynthesis – convert light energy into chemical energy Chemotrophs – convert chemical energy into waste products Picture 4 Picture 5 Picture 6
Image of page 3

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

View Full Document Right Arrow Icon
General rules of metabolism 1. For interconversion of A and B, different pathways for A to B and B to A. All pathways must have G<0 Δ Inject energy in one direction 2. Metabolic pathways are highly regulated. Prevent accumulation of intermediates Levels of regulation Genetic regulation Allosteric regulation Exogenous – only use pathway when needed Product regulation – feedback inhibition Substrate level regulation Picture 2
Image of page 4
oordinate regulation Need to regulate multiple pathways simultaneously. . Metabolic pathways have a committed step. Committed step – psuedo-irreversible . In eukaryotes, metabolic pathways are located in specific places. Mitochondria – OxPhos, Citric acid cycle Golgi/ER – protein glycosylation Picture 2
Image of page 5

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

View Full Document Right Arrow Icon
Living organisms – high G state Δ Organized – low S Δ High G compounds Δ Thus, need G to interact with environment. Δ High G compounds in, garbage out. Δ There is a set of optimal concentrations for metabolites, proteins, hat a cell wants to maintain – steady-state. Perturb steady-state, cell responds.
Image of page 6
Enzymes that operate far from equilibrium Ideal for control Turn E on or off, and pathway immediately responds. Enzymes at equilibrium Immediately respond to changes in A or B by varying forward and reverse reactions. Reestablish equilibrium, little effect on overall rate. Picture 2
Image of page 7

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

View Full Document Right Arrow Icon
Suppose a cell needs a reaction with G>0? Δ Direct coupling Ex. Ca +2 ATPase – pumps Ca +2 against concentration gradient . High [Ca +2 ] Low [Ca +2 ] ATP ADP + P i Rule – only hydrolyzes ATP when Ca +2 is pumped. Consecutive reactions Glucose import Picture 11
Image of page 8
Methods to elucidate metabolic pathways Radioactive precursors – 3 H, 14 C, 32 P, 35 S Emit particle (hot e β - from nucleus) Add labeled A and watch what happens. s A a precursor of C? Add A* to cells. Purify C, and ask if it is C* Chemically degrade C* to see where * ended up. oes NOT tell us the pathway, only that A can get to C. Picture 2
Image of page 9

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

View Full Document Right Arrow Icon
nhibitors Inhibit a specific enzyme and look for effects on product formati and intermediate accumulation. an use specific small (or large) molecule inhibitors (drugs, toxins, an use genetic mutants (defective enzymes). epending on Keq, any species could accumulate. eed to inhibit each E to work out pathway.
Image of page 10
Image of page 11
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