Lecture 4/5 Flashcards
What is Lineweaver-Burke Plot equation?
y=ax+b
What is Y in the Lineweaver-Burke Plot equation?
Y = 1/vo
What is A in the Lineweaver-Burke Plot equation?
Slope:
Km/Vmax
What is X in the Lineweaver-Burke Plot equation?
1/[S]
What is B in the Lineweaver-Burke Plot equation?
Y intercept
1/Vmax
What is Competitive inhibition?
It is when an inhibitor blocks the substrate from binding to the active site of the enzyme.
When dealing with a competitive inhibitor, will the binding affinity of the enzyme change?
No, it will only appear to change due to the inhibitor binding to the active site of enzymes.
What is the structural shape of a competitive inhibitor?
It is generally the same shape as the solute it is competing with.
How can you detect a Competitive inhibitor?
You will see an increase in Km.
What causes non-competitive inhibitor?
Caused by allosteric inhibition of active site distal to the substrate
How does a non-competitive inhibitor work?
An agent bound at an allosteric site causes decreased functionality of the enzyme.
Evokes a conformation change that slows the reaction rate.
Is binding reversible in non-competitive inhibitors?
Yes
Does the non-competitive inhibitor affect the substrates ability to bind to the active site?
Nope
How can you detect a Non-competitive inhibitor?
Decrease in Vmax
What is mixed inhibition?
When an agent binds to a allosteric site causing a decreased level of functionality in the enzyme
- Slows reaction rate and binding affinity
How can you detect a mixed inhibitor?
You will see a decrease in Vmax and an increase in Km
What happens in allosteric activation?
It is a up-regulator
You will see a decrease in Km
What happens in a covalent activation?
It is a up-regulator
You will a increase in Vmax. But no change in Km
What two major roles do enzymes play in the regulation of pathways.
They can speed up reactions or they can limit them.
true or false:
Enzymes that catalyzes rate-limiting reactions and branch point reactions are well positioned to extert control over metabolism?
True.
What is a branching metabolic pathway?
It is where an enzyme can change between two or more streams for what should be produced
How do you slow down a reaction rate?
With a rate limiting reaction Enzyme.
It can be due to a high Km, or Low Vmax
What is the principle of mass action?
The more of solute you have determines that reaction rate.
True or false:
Allosteric modulators do NOT follow the principle of mass action.
False,
they do.
Why are explosive reactions casued by mass action important?
They allow for measurable physiological changes at a faster rate.
How can you arrange enzymes and other proteins on a family tree?
Through the examination of their amino acids.
What is conserved as enzymes evolve and change due to mutation?
The active site gouge.
What would casue alleles to differ in frequency from warmer weather to colder weather?
- Selective pressure
- The temperature affects the bonds within the enzyme. The greater the bonds the better it can hold up in warmer weather. Inversely true for the cold.
What enzyme is SUPER important for the regulation of glycolysis?
Phosphofructokinase -
Allosterically modulated enzyme.
What two molecules regulate Phosphofructokinase?
Citrate and AMP
What does Citrate do?
When citrate is combined, according to mass action with its regulatory site, it decreases the catalytic activity. IE - lowers Km
What does AMP do?
AMP increase the catalytic activity when it combines with its active site.
IE increases Km
