7.2 Study Guide Flashcards
Define an enzyme and a substrate. Explain their relationship within the body.
Enzymes are proteins responsible for catalyzing the building or breaking down of molecules for the body. Substrates are molecules that bind to enzymes to be either built up or split down into something(s) new. They bind together to perform chemical reactions.
What is the term for the section of an enzyme structured to incorporate and produce a reaction with a specific substrate (or substrate group)?
The section of an enzyme structured to incorporate and produce a reaction with a specific substrate is that enzyme’s active site.
True or False: As catalysts, the purpose of enzymes in chemical reactions is to boost the amount of energy required for the reactions to occur.
False. As catalysts, the purpose of enzymes in chemical reactions is to reduce the amount of energy required for the reactions to occur.
Name at least two of the four main properties of enzymes. Explain why enzymes’ properties allow them to be so variable and built so specifically.
Properties of enzymes: Reaction Specific (built for specific substrates and reactions); Reusable (not consumed during reactions); Protein-based (usually); Affected by cellular conditions. The functional variability allowed by these four properties allows enzymes to be built to perform specific reactions in specific conditions many times.
Describe (draw in an actual test) the graphs comparing chemical reaction rate to enzyme concentration and substrate concentration respectively. Explain why both graphs plateau by some point.
Both graphs follow the same trends, with an immediate increase in reaction rate as enzyme/substrate concentration increases which gradually slows down until it finally plateaus. This increase in reaction rate is due to higher collision rates caused by more equal amounts of enzymes and substrates increasing the likelihood of reactions occurring. The plateau occurs whenever enzyme and substrate concentrations become equal exactly, as there can no longer be a higher likelihood of collisions.
Explain why graphs comparing chemical reaction rate to temperature are centered around specific temperature levels as well as why the graph for humans would be different from that of an extremophilic bacterium.
Graphs comparing chemical reaction rate to temperature are centered around specific temperatures because different enzymes are built to function at or around specific temperatures and denature at extreme relative lows or highs. In any given organism, most of its enzymes would be structured to function best around its average body temperature, thus extremophilic bacteria living in uncommonly high or low temperatures would have enzymes made to function around drastically different temperatures than human enzymes.
Describe why there are multiple ‘optimal’ pH levels for enzyme-catalyzed chemical reactions in the human body.
While temperature levels throughout the body are generally about the same, that cannot always be said regarding pH levels. Some areas of the body, like the stomach, for example, are purposefully much more acidic or basic than other areas due to their functions (in the stomach’s case, digestion). This means that the enzymes within them must be made to function at those differing acidities, creating multiple optimal pH levels throughout the body.
Based on the relationships between chemical reaction rate and various factors, describe the optimal environment for stimulating maximum enzyme activity and efficiency for an enzyme produced within a human stomach.
The optimal environment for enzyme activity in the human stomach would be one with a pH of 2.5 and a temperature of approximately 37 degrees C. (body temperature). It would also have perfectly equal concentrations of enzymes and substrates to maximize the likelihood of successful collisions.
Based on the relationships between chemical reaction rate and various factors, describe the optimal environment for stimulating minimum enzyme activity and efficiency for an enzyme produced within a human stomach.
The least optimal environment for enzyme activity in the human stomach would be one with a pH wildly different from 2.5, like 11.5, and a temperature wildly different from 37 degrees C., like 0 degrees or 100 degrees. It would also have little to no substrates to minimize even further the likelihood of a successful collision.
Compare and contrast the methods and effects of enzyme activators, competitive inhibitors, and allosteric inhibitors.
While enzyme activators and allosteric inhibitors both apply their effects using the same method, they apply opposite effects, with activators making enzymes functional and allosteric inhibitors making them dysfunctional. Additionally, while both inhibitor types apply the same effect onto enzymes, they do so in different methods, with competitive inhibitors blocking substrates from bonding with enzymes and allosteric inhibitors changing enzymes’ active site shapes to make substrates unable to bind.
