enzymes Flashcards
what are biological catalyst?
molecules which speed the rate of reactions
are all enzymes biological catalyst?
yes all enzymes are biological catalyst but not all catalyst are enzymes
what type of proteins are enzymes?
globular protein
describe the 2 type of enzymes which can be found
1- intercellular enzymes
: enzymes which catalyze a reaction within cells2- extracellular enzymes
: enzymes which catalyze reactions outside of the cell
how exactly does an enzyme work?
an enzyme works by lowering the activation energy which is the minimum amount of energy needed for successful collision to occur
what are the 2 mechanisms of enzymes?
1- lock and key mechanism
2- induced fit mechanism
define lock and key mechanism
the lock and key mechanism is where the active site of an enzyme has a very specific shape and can only bind to 1 substrate
define induced fit mechanism
the induced fit mechanism is where the active site of an enzyme is able to change slightly to fit onto a substrate
what is an enzyme-substrate complex?
an enzyme substrate is the structure which forms when the substrate has binded to the active site of an enzyme
what are factors effecting rate of reaction
PH concentration temperature enzyme concentration substrate concentration inhibitor concentration
describe how enzyme concentration effects rate of reaction?
as the enzyme concentration increases, the rate of reaction increases only if there is more than enough substrate
describe how substrate concentration effects rate of reaction
initially, as the substrate concentration increases, the rate of reaction increases until the point of saturation where it remains constant
what does saturated enzyme mean?
enzyme whose active site are occupied by substrate molecules
what is Vmax?
Vmax is when enzymes reach their maximum rate as all enzymes become saturated
what is Km?
Michaels men-tent constant which is corresponding X value of 1/2Vmaxx
what affinity?
enzymes binding with substrate/ enzymes recognition of a specific substrate
what is the relationship between Km, Vmax and affinity?
the greater the Km, the greater the 1/2Vmax where a fast reaction occurs with only higher substrate concentration= having lower affinity
what is a buffer solution including how it works?
a buffer solution is used to maintain PH levels by secreting ions
describe how PH and temperature affects rate of reaction
as PH and temperature increases, rate of reaction increases to its optimum and then decreases due to denaturation of enzymes
what is a competitive inhibitor?
inhibitor which binds to the active site preventing the binding of substrate to active site
what is non-competitive inhibitor?
inhibitor which binds to an allosteric site changing the active site of the enzyme
describe the benefit of non-competitive inhibitor in ending product production
once enough products are made, the inhibitor binds to the allosteric site changing the shape of the active site preventing products from being formed
describe the benefit of non-competitive inhibitor in formation of product
once products made are used, the inhibitor un-binds from the allosteric site restoring active site shape allowing more products to be made
what is the relationship of substrate and competitive inhibitors?
the more substrate there is, the more likely it will bind to active site instead of competitive inhibitors
what is the relationship of substrate and non-competitive inhibitors?
the amount of substrate does not matter as active site has already been changed
what are the characteristics of competitive inhibitor against no inhibitor?
*including explanation
1- same Vmax
: As the substrate increases, less inhibitor binds to the active site allowing reaction to occur normally
2- high Km
: Initially there were more inhibitors than substrate slowing the reaction down causing a higher Km= lower enzyme affinity
what are the characteristics of non- competitive inhibitor against no inhibitor?
*including explanation
1-lower Vmax
: the inhibitors disabled the enzyme preventing its maximum rate to be reached
2- same Km
: Despite the disabled enzymes, the working ones were able to work just as well as the no inhibitor reaction causing same km= same affinity
what are immobilized enzymes?
enzymes trapped within an inert material unable to move
what are methods to immobilize enzymes?
1- entrapment
2-ionice/covalent bonding
what are 5 advantages of immobilizing enzymes
1- no contamination of products and enzyme
*products are extracted and enzymes don’t move
2- enzymes can be recovered and re-used
*enzymes found easily and used
3- good for continuous operations
4- greater enzyme stability in varying PH and temp
*protected by the unreactive material
5-many enzymes can react at once in a cell
what is a colorimeter?
measures rate of activity involving colors by seeing the color intensity of a solution
describe how a colorimeter works
- a specific color/wavelength from a light source is directed towards the sample
- the sample absorbs the specific color
- an output is given showing how much light was absorbed
- a link between light absorbed and color intensity can be made depending on the experiment
