the 1st unicram (4 part 2) Flashcards
What are enzymes?
protein catalysts which aid in the acceleration of reactions
Examples of some enzyme supported reactions?
Hydragtion of CO2 to form carbonic acid
What happens during the transitionary stae of a reaction?
Transitionary stae has higher energy than reactants or products
Energy gets provided by the vibrational energy within a system. Molecule which has enough energy to overcome the activation energy will undergo a reaction
The more substrate molecules that reach activation energy, the fast the reaction
Enzymes reduce the activation energy of a reaction, decreasing time taken to convert reactants into products
What is the active site?
Region of the enzyme where substrate and any additional prosthetic groups bind to. Consists of many amino acid residues which help with:
Binding site amino acids (Aids in substrate orientation)
Catalytic site amino acids (Aids in breaking or forming of new bonds)
3D cleft like structure
Specicifity of the binding site is dependant on the precision of arrangement of amino acids
What is irreversible enzyme inhibition?
When an inhibitor molecule binds to the enzyme so tightly, the enzyme is made non-functional
OR
Covalent bonds permanently alter the active site of the enzyme
What is reversible enzyme inhibition?
When the inhibitor molecule can bind and unbind to the enzyme without permanent damage
Can be due to blocking of the active site or attaching to the allosteric site
How does irreversible inhibition work?
Irreversible inhibitor molecules have strong electrophilic groups, they react with nucleophiles within the structure of the enzyme
What are Enzyme pathways?
The use of multiple enzymes to complete the conversion of one compound into another
Enzyme catalysed reactions are singular chemical reaction steps
What are the basic strategies for metabolism?
Production/utilisation of ATP within the metabolic pathway
Production/utilisation of NADPH within the metabolic pathway (Major electron donor, donates electrons)
Biomolecules are constructed from several smaller building blocks
Biosynthetic and degradative pathways are almost always distinct and separate
How are enzyme pathways regulated?
Allosteric interactions
Modification of enzyme via covalent bonding
Concentration of enzyme
Compartmentalisation of enzyme pathways
Metabolic specialisation of organs
Allosteric interactions: Negative + Positive
binding negative or positive allosteric effectors to enzymes can either inhibit or activate a reaction pathway
Covalent modification of enzymes
Phosphorylation: Increases negative charge
acetylation: hide the positive charge
Prenylation: alters hydrophobicity of the enzyme
Metabolic specialisation of organs?
Different organs within complex eukaryotic organisms have a diverse range of metabolic processes which are unique for them
Organisation of enzyme pathways will increase overall efficiency
