Feedback for Multiple Choice Quiz 32
- These are important generalizations to remember, but even better is to think through the rationale of each of these features for regulation.
- All metabolic reactions are enzyme-catalyzed. The speed and specificity are both required, but so is the control. Uncatalyzed (i.e. chemical) reactions in the cell are nearly always deleterious, e.g. toxic reagents, DNA-modifying reactions, etc.
- Peptide hormones act outside the cell at specific receptors. In contrast the steroid class of hormones enter the cell before binding to their respective receptor molecules.
- This is the prototype of a large (and still growing) number of protein phosphorylation cascade pathways.
- The name in the correct answer is the explanation.
- This is true in plants and animals. A related generalization is that NADH is primarily a mitochondrial coenzyme whereas NADPH is the cytosolic reducing agent.
- Although the first three are used to regulate biological pathways they are not used to communicate between these two. Fructose 1,6 bis phosphate is a metabolite in glycolysis. F2,6 bis phosphate regulates the conversion betwen F6P and F1,6P.
- All of these are hallmarks of opposing pathways. A great example is glucolysis and gluconeogensis. Many of the steps are the same, however the interconversion of F-6-P to F-1,6-P is accomplished by different enzymes that are regulated in the opposite fashion. Most organisms can degrade glucose as well as synthesize it from pyruvate. Humans cannot convert acetyl-CoA to pyruvate.
All of the correct answers have a green check mark.
Incorrect answers have the "red-lit" button next to your choice.