Why is it important to eat protein? Your body needs 20 different amino acids to make all the necessary proteins Your body is only able to produce 12 of these amino acids on its own The other 8 amino acids come from foods you eat that contain protein (meat, nuts, dairy products, beans, etc.) – These are called essential amino acids because you cannot survive without eating them

The bottom line about DNA… No DNA = No Protein = No Cells = No Life Reproduction is all about passing DNA from one cell to another and from one generation of organisms to the next

Note Sheet 14 - Enzymes

What is an enzyme? Enzyme – a type of protein that helps chemical reactions in a living thing start and happen quickly Catalyst – something that makes things happen and/or speeds things up Enzymes are catalysts, they catalyze chemical reactions (they make reactions happen)

Enzyme Facts Almost all processes in a cell need enzymes to occur at significant rates Most enzyme reaction rates are millions of times faster than those of comparable un-catalyzed reactions Enzymes are known to catalyze about 4,000 biochemical reactions Many drugs and poisons are enzyme inhibitors

Reactions happen faster with enzymes

Pepsin Ex. Pepsin is an enzyme in your stomach that helps you break down proteins into amino acids

Lactase Ex. Lactase is an enzyme that breaks down the sugar lactose into more easily digestible substances

Helicase Ex. Helicase is an enzyme that “unzips” DNA by breaking the hydrogen bonds in between the base pairs

What is an enzyme? Since enzymes are proteins, the instructions to build all enzymes are in an organism’s DNA Organisms could not survive without enzymes – they make things happen

How does an enzyme work? Each enzyme is specially built to either bring specific substances together making a new substance, or to break substances apart

How does an enzyme work? Each enzyme is specially built to either bring specific substances together making a new substance, or to break substances apart

How does an enzyme work? Each enzyme is specially built to either bring specific substances together making a new substance, or to break substances apart

How does an enzyme work? Each enzyme is specially built to either bring specific substances together making a new substance, or to break substances apart

Lysozyme splitting a large molecule into smaller molecules

The Importance of Enzymes Since the tight control of enzyme activity is essential for maintaining a balanced environment inside cells, any malfunction (mutation, overproduction, underproduction or deletion) of a single critical enzyme can lead to a genetic disease The importance of enzymes is shown by the fact that a lethal illness can be caused by the malfunction of just one type of enzyme out of the thousands of types present in our bodies

Enzyme Inhibiting Poison Alpha-amanitin, which is found in relatives of the death cap mushroom, is a potent enzyme inhibitor It prevents the RNA polymerase II enzyme from transcribing DNA which brings about cell death

Enzyme Inhibiting Poison Individuals who have ingested mushrooms with alpha-amanitin may not be aware for some time that they have eaten a poison mushroom because symptoms may not appear until 6 to 12 hours, or even as late as 48 hours First symptoms include sharp abdominal pain, nausea, vomiting and watery diarrhea or bloody stools. There is usually great thirst. By the 3rd or 4th day, jaundice, renal shutdown, convulsions, and coma occur. Symptoms such as dilated pupils, stiffness of neck, and twitching of facial muscles precede convulsions and death