Test Four: Lecture 2 Flashcards
Cells use proteins called _________ as catalysts to lower activation energy during chemical reactions. Fill in the blank.
Enzymes
What is a substrate?
A molecule that will undergo the reaction
What is the definition of the active site of an enzyme?
Active site of an enzyme - Is a place where the substrate binds to an enzyme
What is the definition of an enzyme-substrate complex?
Enzyme-substrate complex - when the substrate and the enzyme are connected and different chemical processes take place inside of that area
What is the definition of a multienzyme?
Multienzyme - when several enzymes catalyze different step of a sequence of reactions and are associated with one another in a non-covalently bonded assemblies
Which is not an advantage of using multienzymes verses regular enzymes?
1) The rate of the process is much faster
2) The reacting substance doesn’t leave the complex while it goes through a series of reactions (unwanted side reactions are prevented)
3) All of the reactions that take place within the multienzyme complex can be controlled as a unit so the chances of something going wrong is minimal
___________ are chemical components which assist in an enzyme’s function. ________ are when the cofactor is a non-protein organic molecules (i.e. vitamins). Fill in the blanks.
Cofactors; Coenzyme
For specific enzymes, what happens when a cofactor is not attached to its designed enzyme?
The substrate would not be able to attach itself
Which statement explains how temperature and pH can affect enzymes?
Temperature: If you increase the temperature, it will usually increase the rate of the reaction, by only up to the point called the optimum temperature (where you will have the highest rate of reaction, but if you go past this, the rate will go down
pH: there is an optimum pH (all of the enzymes will have this)
What is the definition of an enzymatic inhibitor?
Enzymatic Inhibitor - substances that bind to an enzyme and decrease its activity; can bind to something called the active site or the allosteric site
What is the difference between a competitive inhibitor and noncompetitive inhibitor?
Competitive Inhibitor - interferes with active site of enzyme so substrate cannot bind
Noncompetitive - has to do with the allosteric site
What is the definition of an allosteric site of an enzyme?
Allosteric Site - serves as a chemical on and off switch within the enzyme
What is the definition of either an (a) allosteric inhibitor or (b) allosteric activator?
Allosteric Inhibitor - when you have an inhibitor attached to the allosteric site; it changes the shape of the enzyme so it can not bind to the substrate
Allosteric Activator - has to be attached to a allosteric site to keep enzymes in their active configuration; opposite of the inhibitor
What is the definition of a biochemical pathway?
Biochemical pathway - a reaction occurring involving enzymes; the product of one reaction, becomes the substrate for the next reaction
What is the definition of metabolism?
Metabolism - the total of all chemical reactions carried out by an organism
