o'chem flashcards unit 3 pt1
Enzymes are biological catalyst that?
1) Increase the rate of reaction
2)Does not change in the process/Not used up
3) lower the activation rate
What is an active site
A pocket in an enzyme with a specific shape necessary to bind a substrate
What is is substrate
A reactant in an enzyme-catalyzed reaction
What is specificty?
limit
The limitation of activity of an enzyme to a specific substrate
How does an enzyme work?
1) Bring substrate and catalytic site together
2) Hold substrate @ exact distance and oriantaion
3) Provide acidic or basic reuired for catalysis
4) lower energy barrier by inducing strains in bonds
How does enzymes work?
Proximity effect
Orientation efect
Catalytic effect
Energy effect
What are the 2 theories regarding enzyme - substrate binding?
Lock and key model
Induced fit model
what is the lock and key theory
shape an polarity
the active site is specific to a substrate shape and polarity, so only the correct substrate can bind
lock and key model
only correct substrate can bind
induced fit model
active site changes to better bind to the substrate
what is the difference a catalyst and an enzyme
catalyst are substances
Enzymes are proteins or RNA molecule
Both speeds up the rate of a reaction and is not changed by the reaction.
What is does oxidoreductases do?
oxidation and reduction
what is transferases
transfer of an amino group between substrates
hydolases
braking bonds with addition of h20
look at double bonds
lysases
eliminating double bonds or creating double bonds with functional groups
ligases
bonding together of 2 substrate molecule
ph
changing ph outside the range can slow enzyme activity
exterme PH can denature
temperature
raising temp speeds up reaction, lowering temp slows down reaction
Enzyme Concentration
Increase in a liner form, increase concentration, speeds up reaction
substrate concentration
Increaseing substate increases activity until saturated
what is covalent modification
these are active enzymes that becoms less active. The addition of methylation, acetylation, glycostation or phosphorylation
enzymes that are inactive are called
zymogens
feedback control
End product or final product inhibits metabolic pathway
allosteric enzymes
Binds to a site that is different from the active site
Changes the shape of the enzyme
structure similar to the substarte that competes with the substrate for active site
competitive inhibitor
this does not compete for the active site, it prevents reaction from occuring
non competitive inhibitor
the activiation or deactivation of a particular group on polypeptidechain that are formed or broken. It is a reversiable phosphorylation/dephosorylation
covalent modification
A nerve cell
Neuron
A chemical messenger between a neuron and another target cell; a neuron, muscle cell or cell of a gland
Neurotransmitter
A chemical messenger released by an endocrine gland into the bloodstream and transported therein to reach its target cell.
Hormone
the maintenance of a constant internal environment in the body
Homeostasis
four classes of chemical messengers
Cholinergic messengers- Acetylcholine (ACh) is the main cholinergic messenger
– Amino acid messengers
– Adrenergic messengers
– Peptidergic messengers
– Steroid messengers
Acetylcholine
Control of skeletal muscles
widely distributed in the brain,
plays a role in the sleep–wake cycle
Amino acid messenger
Excitatory Nurotransimtter
Inhibitory Neurotransmitters
Adrenergic Messengers
Chemical messengers, Epinephrine, Histidine and dopamine
Peptidergic Messengers
look for the dots
largest class of hormones
look for the dots
they are on the exterior of the cell
Insulin
accelerates uptake and utilization of glucose in muscles,
it accelerates formation of glycogen in fatty tissue,
it stimulates storage of triacylglycerols
produced from cholesterol.
- male sex hormones, testosterone and androsterone.
- female sex hormones, estrogens and progesterone.
Steroid hormones
What are the diferences between neurotransmitter and hormone?
Physiologyical not chemical.
Neurotransmitter-Between neuron and another target
Hormone-released into the blood stream, transported therein to reach target cell.
Identify group that this belong
transferase
Identify the group that this belongs
hydrolase
Identify the group that this belongs
lyase
which group does this belong
isomerase
Isoleucine is a noncompetitive inhibitor of one of these enzymes. Which is the one that is most effectively inhibited by Ile?
The initial enzyme
E1
increase to a fix value
The regulator binds to the enzyme at a site that is not the active site and modifies the active site.
allosteric regulator
The location within an enzyme where reactant(s) bind and the reaction is catalyzed is called the
active site
This regulator changes shape of the active site to allow the substrate to bind more effectively
positive allosteric regulation
the regulator changes shape of the active site to prevent/inhibits binding of the substrate
negative regulator
level of the end product is low, dissociates, unblocking the active sites
feedback control
What happens when the product concentration is high?
The product binds to the alloesteic site E1 and product is stopped or reduced
What happens when production is low?
The product dissociates from E1 and resumes production
Fat-soluble vitamins
A, D, E, and K and are not involved as coenzymes in catalytic reactions.
Functions of fat soluble vitamins
- soluble in lipids but not in aqueous solutions.
- are stored in the body and not eliminated in urine.
- are important in vision, bone formation, antioxidants, and blood clotting.
What are antioxidant
An antioxidant is a substance that prevents oxidation by reacting with an oxidizing agen
The dietary antioxidants are?
vitamin C, vitamin E, and the mineral selenium.
What type of enzyme will catalyze this reaction?
Oxidoreductase
What type of enzyme will catalyze this reaction?
Isomerase
What type of enzyme will catalyze this reaction?
Hydrolase
What environmental factor(s) exhibit a direct, linear relationship with enzyme activity?
enzyme concentration
