asd Flashcards
Catabolism (break down) occurs via
oxidation
Anabolism (build up) occurs via
reduction
Oxidation
Gain oxygen
Lose H and electrons
Reduction
lose oxygen
Gain H and electrons
What are the standard conditions of delta G
pH=7
1 mole concentration of products and reactants
298 K
When K>1, the reaction is proceeding to the _____
right
ATP–> ADP + Pi produces how much NRG
-7.3 kcal/mol
ATP–> AMP+ PPi produces how much NRG
-10.9
PPi –> Pi and P produces how mich NRG
-4
What molecule carries the same amount of NRG as when ATP is hydrolyzed to form ADP+ Pi?
-7.3 kcal/mol.
Thioester. -7.3 kcal of NRG is stored in-between the [thiol group of co-A] and carboxyllic acid.
How can we alter Keq?
Principle of mass reaction and coupling
According to Le Chateliers principle, altering the amount of products and reactants will affect what?
Kinetcs
The first 3 steps of glycolysis are ______ & __________
coupled
irreversible
Addition/elimination rxn
Atoms are added or removed to multiple bonds
Substitution
1 FG is replaced with another
Rearrangement rxn
FG are rearranged
Oxidation and reduction
electrons are transferred from 1 molecule to another
What helps to maintain our pH?
acetic acid
bicarb
pka
strength of a acid
When is the buffering capacity of acid and bases perfect?
When pH=pKA.
How do kidneys regulate our blood pH?
Excrete H+ ions and reabsorb HCO3-.
What determines acid/base balance?
H+ (CO2) and HCO3-
increase blood pH. What will happen?
decrease excretion of H and bicarb
In respiratory acidosis, the eqn shifts to
LEFT
Metabolic acidosis occurs when
- add a strong acid (lactate and ketone bodies).
2. Lose HCO3-
How can we lose HCO3- to cause metabolic acidosis?
Diarrhea and weakened kidney function
Metabolic alkalosis occurs when
- take a strong base (antiacid)
2. Lose acid via vomiting
When we vomit, what happens to our pH?
pH will increase because we are throwing up an acid.
Metabolic alkalosis
Reducing agent
a substance that is responsible for the reduction that occurs by being oxidized
Oxidizing agent
Brings about an oxidation by being reduced.
Are co-factors and co-enzymes proteins?
No. They are not proteins.
Are co-factors and co-enzymes organic/inorganic?
Co-enzymes- organic and vitamins
Co-factors- inorganic
Co-factors
Metal ions or trace elements that interact with the enzyme using NON-COVALENT interactions
Co-factors interact with enzymes via ________ interactions
NON-COVALENT
Give examples of co-factors
Mg2+ Se Cu Zn Fe
Mg2+ is a cofactor for which enzyme
ATPase
Se is a cofactor for which enzyme
glutathione peroxidose
Cu is a cofactor for which enzyme
cytochrome c oxidase
Zn is a cofactor for
superoxidase mutase.
Fe is a cofactor for
heme
2 types of co-enzymes
- Co-substrate- temporarily bind and leaves changed
2. Prosthetic group- permanently binds and does not leave changed
Ex. of co-substrate
Co-substrates bind and leave changed.
NAD+–> NADH
Holoenzyme
protein and non-protein component
Enzymes are regulated by what?
- pH
- Temperature
- covalent modifications (phosphorylation)
The reaction rate _____ for ever 10 degrees celcius
doubles
Enzymes are normally found at what pH
4-8
Except gastric enzymes. They are usually found at pH 2.5
How does our stomach have a low pH?
The low pH in our stomach is maintained by H+/K+ ATPases.
H+ is pumped into the lumen of our stomach and combined with Cl-. This makes the stomach more acidic,
What do we do when we have heartburn, ulcers or indigestion?
We want to make the stomach less acidic. To do this, we want to inhibit gastric pumps (H+/K+ pumps).
Gastric pump inhibitors
-prazole
- omeprazole
- lansoprazole
- esomeprazole
bad thing about inhibiting gastric pumps?
can cause hyprochloridia.
Kinetics depend on what 3 things:
- Substrate concentration
- Enzyme-substrate affinity
- Vmax.
MM plot is a _____ curve and approaches Vmax _______
- hyperbolic
2. asymptotically- because at a certain point, all of our enzymes are saturated and we cannot go faster.
MM plot axes
Y axis- V0
X axis- substrate concentration.
LB plot
LB plot is the inverse of MM
Y axis- 1/V0
X axis- 1/[S]
Y indicator= 1/V0
X indicator= -1/Km
Slope= Km/Vmax
Metaloenzymes
Enzymes that require metal cofactors
If metal ions are chelated, then what happens?
The enzymes will not work.
Example of a metaloenzyme?
Hexokinase.
needs Mg2+.
Example of a metaloenzyme?
Hexokinase.
needs Mg2+.
What happens in lead poisoning?
In lead poisoning, Pb (a metal), will disturb 2 enzymes that are important for the production of Heme.
To treat, we will give the patient (Ca-EDTA and dimercaprol). Pb has a higher affinity for EDTA than Ca and it will diplace.
Irreversible inhibitors
[II] will bind to the enzyme PERMENTALY at the active site.
The kinetics are the same as non-competitive.
Vmax- decrease
Km-does not
How can we overcome irreversible inhibitors?
Make new enzymes.
Allosteric enzymes display _______
cooperativity.
How do metabolites bind to allosteric enzymes?
Metabolites will bind NON-COVALENTLY to the allosteric enzyme at sites other than the active site.
Metabolites (effectors) of allosteric enzymes can be what?
- Activators
2. Inhibitors
What will activators do to the allosteric enzyme?
Increase affinity and decrease Km
What will inhibitors do to the allosteric enzyme?
decrease affinity and increase Km
Zymogens are also called
proenzymes
