Eleni Hadjipanteli Substrate Enzyme

What are Enzymes? Organic molecules; Proteins *Globular *suffix –ase Catalysts that help speed up reactions Power of specific activation Help break down substances - work by weakening or breaking chemical bonds

Reactions Activation Energy: the minimum amount of energy necessary for a chemical reaction to occur. Enzymes function by lowering activation energy Active Site: where the substrate fits **Denaturation Extreme levels of pH Extremely high temperature

Lock and Key Enzymes are Specific …..A.K.A (Lock) Precise fit between the enzyme site and substrate Substrate…..A.K.A (Key) Enzyme Substrate

Induced Fit Enzymes accommodate the substrate Induces a change in shape Stretches bonds and makes reaction easier because it weakens the bonds React with similar substrates

Explain the factors that affect enzymes? pH: Optimum pH levels: 7 Neutral (humans) 1-7 Acidic (specialized enzymes) Substrate Concentration: ↑ Substrate Concentration ↑ Reaction Velocity -proportionally Temperature: ↑ Temperature ↑ Movement of molecules Reaction Rate increases ↑ However, Extremely high temperatures denature

pH

SUBSTRATE CONCENTRATION

TEMPERATURE

What are Inhibitors? Block the way so substrate is unable to get in Reduce rate of enzyme reactions Work at low concentrations Can be competitive or non-competitive - usually competitive for the active site Inhibitor

Inhibition Competitive Inhibition Inhibitor competes with substrate for active site Substrate encounters with active site ↓ therefore reaction rate ↓ Non-Competitive Allosteric Inhibition “Other Site” on enzyme Allosteric site fits the inhibitor Causes active site to change shape so substrate can’t bind

End-Product Inhibition -The first enzyme is controlled by the end product of the enzyme pathway -Sufficient amount of end product, stops the assembly line