Enzymes 15 September 2014

Enzymes lower the activation energy required to start a chemical reaction. Enzymes function as catalysts – a substance that speeds up the rate of chemical reaction.

Catalysts like enzymes are not changed during a reaction.

Enzymes have a specific amino acid sequence What biomolecule group do most enzymes belong to?

Most enzymes are proteins; their structure depends on amino acid sequence. Structure is influenced by temperature and pH.

The specific reactant that an enzyme acts on are called substrates. Red shapes are substrates. The blue dots are inhibitors-something that makes it more difficult for the enzyme to function.

When an enzyme binds to a substrate, together they are referred to as the enzyme-substrate complex.

Pepsinogen changes shape in low pH to become pepsin, which digests protein.

Enzyme examples: Lactase breaks down lactose – milk sugar.

Lactose has about twice as many hydrogens as carbons. What group of biomolecule does it belong to?

Enzyme examples: catalase – breaks down toxic H 2 O 2 into H 2 O and O 2.

HIV uses reverse transcriptase, which converts RNA into DNA and integrates with human DNA.

Pineapples contain bromelain which is a type of protease enzyme. These enzymes catabolize proteins.