EnzymesEnzymes

Chapter 7 Power PointChapter 7 Power Point

What do enzymes do?What do enzymes do?

• Enzymes speed up chemical reactionsEnzymes speed up chemical reactions• A candy bar will break down over time, A candy bar will break down over time,

but without enzymes this would take but without enzymes this would take around 6 to ten yearsaround 6 to ten years

• Your body cannot wait that long for it to Your body cannot wait that long for it to break down so that your body can use itbreak down so that your body can use it

• So to speed things up it use enzymesSo to speed things up it use enzymes

Doesn’t Chewing food break it Doesn’t Chewing food break it down enough?down enough?

• NopeNope• No matter how finely you chew No matter how finely you chew

bits of food up your body needs bits of food up your body needs them to be broken down further them to be broken down further into even smaller parts and into even smaller parts and enzymes aid in this processenzymes aid in this process

For ExampleFor Example

• Starch SugarsStarch Sugars• Proteins Amino AcidsProteins Amino Acids

Some examples of Some examples of enzymes:enzymes:

• lipases split fats into glycerol lipases split fats into glycerol and fatty acids;and fatty acids;

• amylases break down starch into amylases break down starch into simple sugars;simple sugars;

• proteases break down proteins;proteases break down proteins;• cellulases break down cellulose;cellulases break down cellulose;

• Enzymes are globular proteins - Enzymes are globular proteins - their molecules are round in shape.their molecules are round in shape.

• They have an area - usually They have an area - usually thought of as a pocket-shaped gap thought of as a pocket-shaped gap in the molecule -which is called thein the molecule -which is called the active site.active site.

• Some enzymes are found inside Some enzymes are found inside cells (intracellular enzymes), cells (intracellular enzymes),

• Some enzymes are released so Some enzymes are released so they have their effects outside they have their effects outside the cell (extracellular enzymes). the cell (extracellular enzymes).

• Substrates: are the molecules that Substrates: are the molecules that bind to the active sitebind to the active site

• Enzymes are specific in that only Enzymes are specific in that only specific substrates may fit into the specific substrates may fit into the active site (Your body has active site (Your body has hundreds of enzymes that each hundreds of enzymes that each recognize a specific substrate)recognize a specific substrate)

• The substrate fits like a key in a The substrate fits like a key in a locklock

• The enzyme speeds up the The enzyme speeds up the process of conversion of process of conversion of substrates (reactants) into substrates (reactants) into products products

• Enzymes are sometimes called Enzymes are sometimes called catalyst because they speed up a catalyst because they speed up a reactionreaction

Enzymes work bestEnzymes work best• At specific temperature rangesAt specific temperature ranges

• At specific pH rangesAt specific pH ranges Example pepsin which breaks down Example pepsin which breaks down

proteins into amino acids works best in proteins into amino acids works best in an acidic environmentan acidic environment

Ok now what happens once an Ok now what happens once an enzyme breaks things down?enzyme breaks things down?

• Now that an enzyme has broken Now that an enzyme has broken down the food that you eat into down the food that you eat into smaller parts and pieces it can smaller parts and pieces it can now be sent into the now be sent into the bloodstream and those parts can bloodstream and those parts can be used by cells to use.be used by cells to use.

Enzymes do not only break down Enzymes do not only break down molecules but they also build molecules but they also build

molecules that your body can usemolecules that your body can use• Catabolic Reaction: Breaks down a Catabolic Reaction: Breaks down a

molecule into simpler parts (proteins molecule into simpler parts (proteins broken down into amino acids)broken down into amino acids)

• Anabolic reaction: Builds up molecules Anabolic reaction: Builds up molecules into more complex parts (amino acids into more complex parts (amino acids put together to build muscle)put together to build muscle)

• If you add up all of the anabolic reactions If you add up all of the anabolic reactions and the catabolic reactions in an organism and the catabolic reactions in an organism you will have its metabolismyou will have its metabolism

• Metabolism: All of the chemical reactions Metabolism: All of the chemical reactions occurring in an organisms bodyoccurring in an organisms body

The path a cheeseburger takes to The path a cheeseburger takes to get broken downget broken down