Chemical Reaction & Enzymes Flashcards
Metabolism
in any living thing thousands of chemical reactions take place at the same time to support life
Chemical reaction
the process of breaking existing bonds, rearrangement of atoms and formation of new bonds
What are the three parts of a chemical reaction?
breaking, rearrangement, and formation
What do all chemical reactions need to start?
Activation energy
Activation energy
the energy required to break existing chemical bonds
What are the three ways to speed up a chemical reaction?
heat, motion, and catalysts
Catalysts
substances that accelerate or promote chemical reactions
Enzymes
the biological active catalysts that facilitate chemical changes in the human body by lowering the activation energy
Uncatalyzed reaction
a chemical reaction without an enzyme
Catalyzed reaction
a chemical reaction with an enzyme
Enzymes are what kind of organic molecule?
proteins
Enzymes exist as what?
polymers
Why are enzymes polymers?
because they are proteins
Active site
region of an enzyme where the substrate binds
What is temporarily formed when a substrate binds to an active site?
an enzyme-substrate complex
What is the importance of the specificity of an active site?
only allows one type of substrate to bind to the enzyme; catalyzing only one specific reaction
How are enzymes formed?
through protein synthesis
Enzyme mechanisms steps
the substrate binds to the enzyme forming an enzyme-substrate complex, the enzyme changes shape resulting in an induced fit, the substrate is broken down, and finally the products are released
Cofactors
an inorganic chemical structure attached to an enzyme that aids in enzyme function
Inorganic cofactors
are attached to the enzyme and are required for their normal function
Organic cofactors
are not attached to enzymes and have specific functions in assisting enzymes
What are the six major classes of enzymes?
oxidoreductase, transferase, hydrolase, isomerase, ligase, and lyase
Oxidoreductase
transfers electrons from one substance to another
Transferase
transfers a functional group
Hydrolase
splits a chemical bond using water
Isomerase
Converts isomer to another
Ligase
bonds two molecules together
Lyase
splits a chemical bond in the absence of water
Which class of enzymes participate in oxidation-reduction?
Oxidoreductase
The rate of a chemical reaction may be accelerated by what?
an increase in enzyme concentration or substrate concentration
Saturation
occurs when so much of a substarte is present that all enzyme molecules are actively engaged in the chemical reaction, resulting in no furthable (notable) increase in reaction rate
Inhibitors
substances that bind to an enzyme and turn it off, preventing it from catalyzing the reaction
Competitive inhibitor
interferes with active site of an enzyme so substrate cannot bind
Allosteric inhibitor
changes shape of enzyme active site so substrate cannot bind to enzyme
What determines the likelihood of competitive inhibitor occupying the active space?
the concentration of the substrate
Inhibition
a molecule that binds o an enzyme and blocks its activity
How are enzymes named?
root + -ase
Enzymes are highly what?
highlt specific
How do enzymes break down substrates?
they put stress in the substrate bonds
Why are enzymes needed in small quantities?
becuase enzymes are reused
What kind of conditions are required for enzymes to maintain their functional shape?
optimal conditions (temperature, pH)
What are the two forms of enzyme regulation?
activation and inactivation
Activation
binds a specific cofactor to an enzyme
What kind of molecules are cofactors usually?
metals (Zn, Fe, Mg) and vitamins (B, C, K)
Inactivation
binds inhibitors
How do allosteric inhibitors differ from competitive inhibitors?
competitve inhibitors compete for the active site while allosteric inhibitors alter the overall shape of the enzyme
The prefix allo- means what?
wrong
The suffix”-steric” means what?
shape
