Enzymes Flashcards
What type of energy reaction, do all reactions require?
Activation energy.
What is an activation energy?
Minimum ammount of energy required react, is known as the activation energy.
State the meaning of the term enzyme.
Enzymes are proteins, and catalysts, that lower the activation energy, by providing a different pathway, without undergoing a permanent change.
Describe the lock and key hypothesis.
The substrate, binds to the COMPLEMENTARY active site of an enzyme, and forms an enzyme - substrate - complex, then it is broken down, and some products are formed.
What determines the enzymes active site?
detremined by the enzymes tertiary structure.
Describe how the substrate bind (make sure you include the term active site)
The enzymes active site, and substrate, initially, arent completely complementary. However, as the substrate tries to bind, the active sites shape, changes shape to become complementary.
Describe the effect of increased enzyme concentration, on rate of recation. And also describe what heppens when the substrate is in excess, or if the substrate is limited.
Increased enzyme substrate concentration, means increased active sites available, thus increasing the probability of enzyme substrate complexes.
When substrate is in excess, increased enzyme concentration, increases the rate of reaction.
When substrate is limited, increased enzyme concentration, will cause the rate of reaction to plateou.
Describe the effect of increased substarte concentration, on the rate of reaction. And describe what happens when enzyme concentration is in excess, and when enzyme concentration is limiting.
Icreasing substrate concentration, increases probability of enzyme substrate complexes.
When enzyme concentration is in excess, increasing substrate concentrtion, increases the rate of reaction.
When enzyme concentration is limiting, increasing substrate concentration, cause the rate of reaction to plateou.
Whta is a competitive inhibitor, and describe how it works. And describe what would happen if you would increase the substrate concentration.
it is an inhibitor. A competitive inhibitor, is complementary to the active site, lowring the probability of an enzyme - substrate - complex.
It binds to the active site, but only temporarly, therefore, the maximum rate of reaction is eventually reached
Increasing substrate concentration, will increase the chances of enzyme - substrate - complexes.
What is a non- competitve inhibitor, and describe how it works. and describe what happens when increasing substrate concentration.
It is an inhibitor. A non competitive inhibitor, binds to another part of the enzyme, thus causing the shape of the active site to change, and when the active site is not complementray to the substrate, it prevents the formation of enzyme substrate complexes.
This decreases the rate of reaction, as well as the maximum rate of reaction, since increasing substrate concentration is no longer effective.
Describe how an increase in temperature, affects the structure of the active site.
After optimum temperature, the rate of reaction sharply decreases, this is because high temperature, breaks down the hydrogen bonds in the tertiary structure, and therefore its active site. This reduces the probability of an enzyme - substrate complex, hence, reducing the rate of reaction.
At a very high temperature, we say the enzyme has denatured.
Describe how ph affects the structure of an enzymes active site.
All enzymes have an optimum pH. A change in ph, can break both hydrogen, or ionic bonds in the tertiary structure of an enzyme, and therefore, its active site.
What do you call the other part of an enzyme?
Allosteric site.
