Enzymes and stuff.

Objs:
-What are enzymes
- Describe models to illustrate functions
-What do enzymes do?

Starch + Water = Amylase = Maltose

Lipid + Water = Lypase = Fatty Acid + Glycerol

Protein + Water = Protease = Amino Acids

Sucrose + Water = Sucrase = Fructose and Glucose

Maltose + Water = Maltase = Glucose

Big molecules being broken down into smaller ones = hydrolysis reaction, hydro: there should therefore, before the reactant should be water.

Substrate reacted with an enzyme = Products.

Enzyme = Biological Catalyst = speeds up reaction in living organisms

The body produces Hydrogen Peroxide. It is toxic for us, but we have an enzyme, catalayse, which breaks it down to make water and oxygen.

Molecules have more kinetic energy, collide more, but this is by heating. Can't heat up hydrogen peroxide, is in body, is why enzymes are handy.

An enzyme works by lowering the acitivation energy needed, which is a barrier to the rate of reation, therefore, the enzymes speed it up. (See catalyst.)

What do enzymes do?

Speed up reactions by lowering activation energy needed, which acts as a barrier.

Why are Enzymes Catalysts?

Substrate Energy is always higher then product energy. The barrier gets lowered with an enzyme. Enzymes are catalysts as they lower the activation energy required to drive a reaction.

The nature of Enzymes:

They are globular proteins. Globular proteins have a globular shape. If the shape is wrong, it won't function properly, if the tertiary structure is wrong. The tertiary fold relies on primary, as it is defined by the sequence of amino acids.

Enzymes are usually quite large, only a small area is important though. The active site: a specific shape due to the way it folds up. If something affects the active site, the enzyme will not be functional.

Enzyme + Substrate = Enzyme Substrate Complex + Products.

The substrate and enzyme have COMPLIMENTARY shapes. Like jigsaw pieces, they fit together, but they aren't identical.

At the end, the enzyme is unchanged and can be reused, whereas products diffuse away.

Enzyme + Substrate = Enzyme Substrate Complex, REACTION TAKES PLACE = Enzyme + Products.

Enzymes are:

• Proteins of high molecular weight.
  
• A bio-catalyst.
  
• Sensitive to temperature changes.
  
• Sensitive to pH
  

Enzyme and substrate have to hit at right force AND be of complimentary shape.

Models...

Lock and Key model, 1894, if there's not a specific key in the lock, the door won't open style metaphor. In an enzyme catalysed reaction the enzyme bonds to the substrate to form a complex.

Induced Fit Model, a glove is vaguely the same shape as a hand, when a hand is in the glove the fit 'induces' to fit it. Explains that the enzyme changes shape, and takes into account that they have some flexibility.

Once the substrate has bound to the enzyme, that bind tells the enzymes to change the shape to therefore become a perfect fit. Therefore, a reaction can't take place until the induced fit has happened.

Oh, and this was a side note, 'Saw chancges take place with x-ray defraction, therefore, better model.' Don't have a clue what I was on about. Suggestions?

-Nin.