Summary Pictorial and Graphical Look at Enzymes

Why are enzymes needed?

• Speed up the rate of the hydrolysis and dehydration synthesis of the 4 biochemical organic molecules (carbs, lipids, proteins, and nucleic acids) that make us up and and what we take into our bodies

WHAT IS ACTIVATION ENERGY?WHICH REACTION HAS HIGHER ACTIVATION ENERGY?WHICH REACTION HAS LOWER ACTIVATION ENERGY?

Pictoral Analysis

• Activation Energy= initial energy needed in a chemical reaction

• Graph A– Higher (more) activation

energy needed for a reaction that DOES NOT use an enzyme

• Graph B– Lower (less) activation

energy needed for a reaction that DOES use an enzyme

How an enzymes works?

Enzyme Action (Hydrolysis)• Substrate- substance enzyme

acts on (sucrose or any other macromolecule)– Substrate fit into the enzyme like

a lock and key or induced (wrap around) fit. Induced fit (more than one substrate may fit)

– Forms an enzyme substrate complex

– Substrate gets converted into product

– Products are released and the enzyme can be used again

USE THE VOCABULARY TO DESCRIBE WHAT IS GOING ON IN THIS ENZYMATIC REACTION

Enzymes in Action and can be reused again

Graphical Look at Enzyme Action

• Graph 1– Activation energy is

higher (LARGE ARROW) no enzyme used to speed up the chemical reaction

– This type of graph is called an endergonic reaction graph

• Endergonic= absorbs energy. Product is higher than reactant

substrate

products

products

substrate

Activation energy

Activation energy

Graphical Look at Enzyme Action

• Graph 2- Comparison – Graph B has a higher

activation energy (no enzyme used)in comparison to Graph C (enzyme is used)

– This is an exergonic reaction

• Exergonic- energy is released

– Which reaction will be first to reach completion?

Enzymes Activity at Various pH

• Each enzyme has the best (optimal) condition at which they function

• What are the optimal pH values for the graphs on the left

Enzyme Activity and Temperature

• Different enzymes work best at speeding up biochemical reactions various temperatures

• If enzymes are heated too high they can become denatured

• Denatured= damaged, protein is non-functional

Summary on Enzymes

• Enzymes are protein molecules• Enzymes can be reused again• Enzymes help to speed up biochemical reactions in

living things• Enzymes lower the activation energy therefore

speeding up the biochemical reaction• Use the lock and key or induced fit model to carry out

biochemical reaction• Enzymes are influenced by pH, temperature, amount

of substrate and enzyme present

• http://www.ryancshaw.com/Files/micro/Animations/Enzyme-Substrate/micro_enzyme-substrate.swf