The products of a pathway, or the products of specific reactions in the pathway, will often inhibit upstream regulatory enzymes in that pathway. That makes sense - if the products of a pathway are abundant, then the pathway can be shut off to save energy or divert molecules into other pathways. We can use a similar rule of thumb to predict whether a pathway will be active in different biological states. For example, the liver stores glucose (in the form of glycogen), and will release glucose into the bloodstream when blood sugar levels drop. This glucose can come from the synthesis of glucose or breakdown of stored glycogen. This is important for maintaining blood sugar levels. What would you predict is the relationship between blood sugar levels and glycogen phosphorylase enzyme activity? A positive relationship (when blood sugar levels are high, glycogen phosphorylase activity is also high). A negative relationship (when blood sugar levels are high, glycogen phosphorylase activity is low). There is no relationship between blood sugar levels and glycogen phosphorylase activity.

fill in the blank  An enzymatic protein in its active state with all its cofactors is called a (                   ) while an enzyme missing a cofactor to make it active is called an (              ).

The highest energy point of the serine protease reaction is the formation of the tetrahedral oxyanion intermediate on the original carbonyl carbon of the scissile peptide bond. True or False? DIPF is an irreversible inhibitor of serine proteases. True or False? The acyl-enzyme intermediate is the transition state of the reaction. True or False?  Serine proteases are classified as isomerases. True or False?

Phosphofructokinase (PFK-1) is one of the most regulated enzymes in metabolism. Based on all of the principles we have learned in this class, which of the following would be most likely to be an allosteric activator of PFK-1?   a Pyruvate   b Acetyl CoA   c Citric acid   d glucose

What type of enzyme regulation is the most readily (quickly) reversible?

The enzymes used in the regulation of chemical reactions during the citric acid cycle are synthesized via which of the following pathways?   Choose from the following: (A) ribosomes / mRNA attached to the ribosomal endoplasmic reticulum (B) free or polyribosomes associated with mRNA

In living cells, true equilibrium is dangerous because if the rate of a forward reaction is equal to the rate of the reverse reaction, a wasteful cycle is produced during which the cell gains no new nutrients.  In this situation, the cell will eventually die.  Therefore, organisms have many ways of ensuring that reactions move only in the forward direction.  One of these means is control over reactant concentration. The Citric Acid Cycle is a series of reactions that occur in eukaryotic cell mitochondria which are essential for providing energy to living cells.  During one of these reactions, a molecule known as oxaloacetate is combined with acetyl coenzyme-A to produce citrate.  Normally, the concentration of oxaloacetate in mitochondria is very low.  If the cell is in need of more energy and the concentration of oxaloacetate increases, what will happen to the direction and of this reaction?  How do you suppose this affects the overall amount of energy product produced?

When the product of reaction \\( A \\) becomes the reactant of reaction \\( B \\), the metabolic pathway is cyclic divergent bidirectional convergent linear

A small molecule is produced from a set of enzymatic reactions from a precursor substrate. It has been shown that the small molecule is able to regulate its own production. In your own words, and based on course material only: a. Identify the regulatory process and; b. Explain how this process works

For each of the statements below about the dUTPase enzyme, mark whether it is true or false. If it is false, change the language to make the statement true. _______If the dUTPase enzyme is the rate determining step in a larger metabolic pathway, the reaction likely lies near to equilibrium and is irreversible. _______For the dUTPase reaction, it is not likely that DG’ = DG°’ _______ dUTPase has a higher affinity for its substrate than for its product, but both of these are higher than the affinity for the transition state _______Kinetic analysis of dUTPase using Michaelis-Menten methods assumes that the formation of the E*S complex has a large negative value for DG