Metabolism Flashcards
What are the differences between a large negative deltaG value and a low negative deltaG value?
Large negative deltaG - high energy compounds - favorable - products will have a lower free energy than the reactant(s) - less energy input required for breaking bonds of reactant(s).
Low negative deltaG - more stable compounds - if products of a reaction have low negative deltaG, the reaction would be considered a regulatory step in the pathway.
What would be some general products of a catabolic pathway?
Catabolic pathways break down molecules into simpler, energy-depleted molecules such as CO2, water, and NH3, while also synthesizing high energy compounds such as ATP, NADH, NADHP and FADH2.
Define substrate level phosphorylation. Give 3 examples.
The formation of ATP by phosphoryl group transfer from a substrate; Involves soluble enzymes and chemical intermediates.
- Glyceraldehyde-3-phosphate dehydrogenase
- Pyruvate kinase
- Succinate thiokinase
What are two differences between anabolic and catabolic processes?
Anabolic processes construct complex molecules from simpler ones & occurs in the cytosol
Catabolic processes breakdown complex molecules into simpler ones & occurs in the mitochondria.
List the three functions of phosphorylation.
Negativity - Can change interactions overall
Trapping - Traps molecule in that department
Enzymes - Enhances active site interaction
What is oxidative decarboxylation?
Irreversible oxidation process. Carboxyl group is removed as CO2 and replaced with a thioester derivative of CoA.
How does NADP+ differ from NAD+?
NADP+ has the hydroxyl group at C2 being esterfied with a phosphate.
What are isozymes?
When two or more enzymes are encoded by different genes but catalyze the same reaction.
Provide 3 methods to get around an unfavorable reaction in a metabolic pathway.
- Coupling unfavored reactions with favored ones
- Activating proteins through phosphorylation,
dephosphorylation or adenylation. - Ion concentration gradients
Define homeostasis and provide an example of a cellular process that helps maintain homeostasis.
Maintenance of a dynamic steady state in an organism through the careful control of biochemical processes.
or
Biological regulation of small molecule concentrations in an internal environment to maintain normal function of metabolic processes.
Example: Gluconeogenic hormones respond to low glucose levels in the blood and promote the synthesis of glucose from glycogen.
What is flux?
Net metabolic flow in one direction or another
What are metabolites?
Metabolic intermediates that can sometimes be used for more than one reaction.
What water soluble vitamins serve as the backbone of some coenzymes?
Niacin, riboflavin
What is the reactive portion of Coenzyme A?
The sulfhydryl group. The thioester linkage is less stable than an ester.
What type of vitamins are A, D, E, and K?
Fat soluble vitamins
