Proteins: Enzymes

Links to simulations watched in class:

Enzymes combining molecules 
Amylase enzyme from saliva breaking down amylose (starch) sugars 

Enzymes are a class of protein molecules that catalyze chemical reactions. Each enzyme has a unique shape based on the number, order, and types of amino acids that make it up. Along with its unique shape comes a unique function—each enzyme is specific to a particular chemical reaction. All enzymes end in the suffix -ase.

Some enzymes combine two molecules into one, such as the enzymes DNA and RNA polymerase, which link new nucleotides onto a growing strand to make a longer nucleic acid. Some enzymes do the opposite—they break a molecule into two smaller pieces. One example of this is the enzyme lactase, which helps us digest the sugar lactose by breaking lactose into two monosaccharides, glucose and galactose, which our mitochondria can then burn for energy.

Catalase Enzyme Lab:

The enzyme catalase plays an essential role in the cells of our body, as well as in the cells of yeast, the single-celled fungus that we are using in this lab. Catalase breaks apart the harmful chemical hydrogen peroxide (H2O2) into harmless water (H2O) and oxygen gas (O2), which bubbles off. Hydrogen peroxide builds up in cells as a result of metabolism (breaking down food for energy), and it must be destroyed or it damages the cell. Luckily, all organisms have a catalase enzyme to help rid the cell of hydrogen peroxide.

2 H2O2     —>      2 H2O     +     O2 (g)