Test 3: Ch. 8 Metabolism Flashcards
BE ABLE TO DRAW OUT THE ATP HYDROLYSIS
WHAT HAPPENS?!?!?
Things about exergonic reactions, also what is an example of Exergonic Reactions?
1) Example: ATP hydrolysis
2) Energy used to drive endergonic reactions
3) -change in G = free energy (energy available to do work)
4) spontaneous reaction (not necessary explosive)
What generally happens in exergonic reactions?
energy is releasing
What does Endergonic Reaction require?
Energy
Tell me two things about Endergonic Reaction?
1) + change in G
2) non-spontaneous
Enzymes: Catalyst. Tell me two things.
1) decrease activation energy needed for reaction (speeds up)
2) recycled
Name some enzymes:
1) normally substrate name and “ase”
2) ATPase
3) lactase
4) cellulase
5) peroxidase
6) catecholase
7) kinase
What happens in the active site?
1) binds and modifies substrate
2) complementary to substrate (fits like a puzzle)
3) substrate specificity
Look at the diagrams
Please, gurrrrlllll
Tell me about activation Energy.
1) initial investment of energy headed to start a reaction
2) exergonic- release more energy than what is absorbed initially
3) endergonic - absorb more energy than is released
How does an exergonic graph look like?
it eventually rises and then the energy of the products are lower than the energy of the reactions (look at the notes, man)
What does an endergonic graph look like?
The energy of the products end up be higher than the energy of the reactions (look at the notes, man)
What does an Exergonic and enzyme look like?
a) enzyme lower EA needed to start a reaction
b) however, start and stop at same point
(look at the notes, man)
What also lower the EA of endergonic reactions?
Enzymes
- change in G is different in energy between what two things?`
reactants and products
What are CoFactors?
1) non-organic molecules that binds to an enzyme
2) it activates the enzyme
3) can control enzyme activity by only providing co-factors when you need it
4) co-factor attaches by ionic bonds
Tell me about them Kinases.
1) phosphorylate other protein
2) can inhibit or activate the protein
3) Phosphorous is covalently attached to another protein
What enzyme changes the shape of molecule?
kinase
Enzyme activity increases in increase of heat up to a point, why?
energy causes energy, enzyme captures substrate, things, then lets go
What happens when the temperature of an enzyme is too hot?
protein unravels (denatures) and it may have no active site on enzyme
Can temporarily denature if not too hot.. why?
cooling can allow renaturation
What is the optimal temperature for most human enzymes?
35 - 37 degrees Celsius
What happens if the pH is too acidic in enzyme solution?
they repel each other (too many +)
What happens if the pH is too acidic in enzyme solution?
too many OH-
What is the optimal pH?
a) 7.4 for most enzymes
b) pepsin (stomach enzyme) works best at pH 2
What are the two sites in allosteric enzymes?
a) active site binds substrate
b) allosteric site binds to
1) inhibitor (stops enzyme)
2) activator (start enzyme)
what is the main purpose of the allosteric enzymes?
to regulate enzyme activity
what is usually used in a multi reaction pathway?
allosteric enzymes
what is usually the 1st in the pathway?
allosteric enzyme
what happens after the 1st pathway thing?
the allosteric inhibitor binds and change shape of active site
what is generally the last product in pathway?
allosteric inhibitor
when is D is not present, the enzyme is on or off?
on
why allosteric?
a) makes the system more energy efficient
b) but making too much of “D”
there is high energy in phosphate bonds: if you break it what will happen?
you will release energy
