Module part 5 Enzymes Flashcards
An enzyme is a ___ which functions as a ___, speeding up reaction rate by loweing activation energy. They are long chains of amino acids folded up to a specific three dimensional shape.
Some enzymes need a non protein molecule, those enzymes are called a ___ without an ___, it’s called an ___
Globular Protein
Biological Catalyst
Holoenzyme
Cofactor
Apoenzyme
Enzyme:
RNA molecules with enzymatic activity
Enzymes of the digestive tract and in blood are present as ___ or ___
Enzymes with the highest specificity and accuracy, have a proof reading functions ____. They also cause the polymerisation of deoxyribonucleotides into a DNA strand. It is catalyzed by the ___ ion.
Ribozymes
Zymogen
Proezymes
DNA polymerase, Magnesium
Types of specificity (4)
Absolute Specificity
Group specificity
Reaction Specificity
Stereospecifcit
Types of Enzyme Models (2)
Set three dimensional Form
Enzyme changes shape so it embraces the substrates, weak bonds like hydrogen and ions hold it in place
Lock and Key or Template model
Induced - Fit Model
Enzyme, Induced Fit Model:
It can lower activation energy by:
Acting as a ___ for ___
___ the substrates to stabilize the ___
Providing a favorable ___
Participating directly in the ___
Template, Substrate Orientation
Stressing, Transition State
Microenvironment
Catalytic Reaction
Major classes of Enzymes (6)
EC1 - Two reactions, transferring electrons (Lactic acid Fermentation)
EC2 - Transfer a part of a molecule to another (like protein transfer)
EC3 - Use water to cleave a molecule to two different molecules (cleaving of amino acids so they arent bound)
EC4 - Cleaves a molecule without water or oxygen. (Urea cycle) So either generates a double bond or a ring
EC5 - Converting of molecule to one of its isomers (like Glucose to fructose)
EC6 - Combines molecules together (Putting two strands together)
EC1 - Oxidoreductases
EC2 - Transferases
EC3 - Hydrolases
EC4 - Lyases
EC5 - Isomerases
EC6 - Ligases
Factors Affecting Reaction Velocity
T
H
S
E
P
P
A
T
Temperature
Hydrogen Ion Conc. (pH)
Substrate conc.
Enzyme Conc.
Products of the reaction
Presence of Inhibitor
Allosteric Effects
Time
Enzyme Factors:
Temperature maxes out before dipping at ___
pH depends on the enzyme, ___ thrives in acid while ___ thrives in bases
When ____ is present, the enzyme concentration rises directly proportionally to it Products inhibit it in large accumulations
40 C
Pepsin, Trypsin
sufficient subtrate
Enzyme:
Study of Reaction rate andd how changes are made in response to an experimental parameter is known as ___
The equation that defines the rate of enzyme reaction to substrate concentration is the ____ equation:
Vo = ___ / ___ + ___
Kinetics
Michaelis-Menten Equation
Vo = Vmax/Km + S
Km = (K-1+K2) / K1
Enzyme Kinetics:
___ The linear representation more convenient for determining Vmax
Lineweaver-Burk (double reciprocal) Plot
Enzyme inhibition:
Normal examples of inhibitors include ___, ___, ___ and ___
Causes cell toxicity ____
Types of Enzyme Inhibition (2)
drugs, antibiotics, poisons, anti-metabolites
Toxicants
Reversible Inhibitors
Irreversible Inhibitors
Types of Reversible Inhibitors
Occupies the spot of the substrate normally
Doesn’t attack the active site directly but alters the shape of the enzyme in the process
Only binds to an existing Enzyme-substrate complex, reduces Km and Vmax values
Competitive
Non-Competitive
Un-competitive
