Chem4711%28SlideSet8%29

Chem4711%28SlideSet8%29 - Metabolism Metabolism making and...

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

View Full Document Right Arrow Icon
Metabolism
Background image of page 1

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

View Full DocumentRight Arrow Icon
Metabolism – making and breaking stuff Catabolism Anabolism Common intermediates
Background image of page 2
imately, can only do reactions that have –ΔG. otosynthesis – convert light energy into chemical energy emotrophs – convert chemical energy into waste products "C" + O 2 CO 2 H 2 + 1/2O 2 H 2 O CO 2 + H 2 O + hv CH 2 O + O 2 CH 2 O + O 2 CO 2 + H 2 O
Background image of page 3

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

View Full DocumentRight Arrow Icon
General rules of metabolism 1. For interconversion of A and B, different pathways for A t and B to A. All pathways must have ΔG<0 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 A B C D P E 1 E 2 E 3 E 3
Background image of page 4
dinate regulation eed to regulate multiple pathways simultaneously. etabolic pathways have a committed step. ommitted step – psuedo-irreversible eukaryotes, metabolic pathways are located in specific plac itochondria – OxPhos, Citric acid cycle olgi/ER – protein glycosylation A B C D P
Background image of page 5

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

View Full DocumentRight Arrow Icon
ing organisms – high ΔG state Organized – low ΔS High ΔG compounds s, need ΔG to interact with environment. h ΔG compounds in, garbage out. re is a set of optimal concentrations for metabolites, protein t a cell wants to maintain – steady-state. turb steady-state, cell responds.
Background image of page 6
nzymes that operate far from equilibrium Ideal for control Turn E on or off, and pathway immediately responds. nzymes at equilibrium Immediately respond to changes in A or B by varying forwa and reverse reactions. Reestablish equilibrium, little effect on overall rate. A B
Background image of page 7

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

View Full DocumentRight Arrow Icon
Suppose a cell needs a reaction with ΔG>0? 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 A B A B C
Background image of page 8
thods to elucidate metabolic pathways Radioactive precursors – 3 H, 14 C, 32 P, 35 S Emit β particle (hot e - from nucleus) Add labeled A and watch what happens. a precursor of C? Add A* to cells. Purify C, and ask if it is C* Chemically degrade C* to see where * ended up. es NOT tell us the pathway, only that A can get to C. A B C
Background image of page 9

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

View Full DocumentRight Arrow Icon
bitors nhibit a specific enzyme and look for effects on product form nd intermediate accumulation. use specific small (or large) molecule inhibitors (drugs, toxin use genetic mutants (defective enzymes). ending on Keq, any species could accumulate.
Background image of page 10
Image of page 11
This is the end of the preview. Sign up to access the rest of the document.

Page1 / 67

Chem4711%28SlideSet8%29 - Metabolism Metabolism making and...

This preview shows document pages 1 - 11. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online