Biology Enzymes

Enzymes consist o f ________ bound w/ ________

amino acids + peptide bonds

A measure of amount of entropy needed for a reaction to occur

activation energy

speed up the rate of a chemical reaction by lowering the activation energy

organic catalysts

enzymes can be used _____ and _____ and are effective in _______________

over and over + small quantities

same atons but different arrangement

isomer

enzynes end in _____

-ase

position on the enzyme that will bind w/ substrate to cause a chemical reaction

active site

The active site is rigidly shaped for one substrate, the ttwo are precisely complementary to each other (one enzyme fits one substrate)

Lock and Key Theory

a chemical reaction is occuring in the substrate

Enzyme-Substrate Complex (ES complex)

Enzyme is partially flexible

Induced fit model

Increase the rate of enzyme catalyzed reactions

Cofactors and coenzymes (Prosthetic groups)

________ are ORGANIC molecules that are required by certain enzymes to carry out the chemical reaction

coenzyme (what is)

______ bind to the enzyme's active site to improve ability to match the substrate and improve efficiency

coenzyme (how do they work)

example of a ________: vitamin C is needed for connective tissue (w/o it would cause scurvey which is the lack of vitamin C)

coenzyme (example)

__________ are classified as INORGANIC substances

Cofactor (what is)

Example of a _______: Ions + minerals (zinc -> needed to bind to enzyme used for synthesis of DNA)

Cofactor (example)

________ slow the rate of enzyme catalyzed reactions

inhibitors

____________ form a covalent bond with the enzyme at its active site therefore permenently blocking the sybstrate (no reaction can occur)

Irreversible Inhibitor (what is)

Ex. of _______________: poisons, such as cyanide -> blocks enzymes needed in cellular regeneration so lactic acid builds until fatal

Irreversible Inhibitors (example)

__________ form a temporary bond with the enzyme therefore slows the reaction rate while the inhibitor is bound to the substrate

Reversible inhibitor -> the effects can be overcome by adding more substrate, increases the probability of binding with substrate (what is)

ex. of _______: some pharmaceuticals such as ibuprofen

reversible inhibitor (example)

Coenzymes/cofactors, inhibitors, and environemtnal conditions are __________________________________

factors that affect rate of enzyme activity

Closely Matches the substrate so it competes for the enzyme's active site (ex. Naxalone)

Competative Inhibitors

______ CONTROL chemical rxns

Regulators

_____ STOP chemical rxns

Inhibitors

_______: position distant from the active site, capable of binding to regulator or inhibitor

Allosteric Site

__________ alters the shape of the enzyme's active site and therfore impacts the function of the enzyme

Noncompetitive Inhibitors/ Allosteric Inhibitors

_____________ adjusts cell activity

Metabolic Processes

enzyme exists in an inactive shape until an allosteric regulator binds/alters the enzyme into an active site

Positive allosteric regulator

enzyme is active until a regulator binds to the allosteric site altering the active site so it no longer matches the substrate

Negative allosteric regulator

Reaction rate is slower b/c lower molecular motion means fewer enzyme substrate complex formed (low ENTROPHY slow reaction)

Activity BELOW optimal temperature

Enzymes tertiary and quaternary shape changes as H bonds break active site doesn't match substrate (denatures)

Activity ABOVE optinal temperature

___ is a measure of the concentration of hydrogen ions in a solution

pH

A change in pHh leads to breaking bonds that hold tertiary structure of the enzyme

Enzyme denatures

A solution that resists pH (changes upon addition od acid or base)

Buffers (ex. buffers in blood)

There is a fixed amount of enzyme but in an increasing amount of substrate

substrate concentration

At a low concentration of substrate, there is a steep increase in the rate of reaction with increasing substrate concentration

amt enzyme > amt of substrate

As the concentration of substrate increases, the enzyme becomes saturated with substrate

amt enzyme < amt of substrate

There is a fixed amount of substrate but an increasing amount of enzyme

enzyme concentration

As the enzyme concentration increases, the rate of reaction will increase b/c...

amt of enzyme catalyze the reaction

A point will be reached when no matter how much enzyme is present, the reaction will not occur any quicker b/c...

reaction is complete, no substrate remains