The Molecules of Life

1. The Molecules of Life

2. Organic Compounds • What does organic mean? • No pesticides? • Environmentally friendly farming? • In biology, organic = carbon based molecules.

3. Hydrocarbons • Hydrocarbons are long chains of carbons bonded to hydrogen atoms • C-H bond = high energy • Hydrocarbons are a good energy source Fats are mostly hydrocarbons Octane is a hydrocarbon. It is one of the main components of gasoline.

4. Hydrocarbons • Why does our body store fat? • C-H bonds are high energy • Fat is an efficient way to store a lot of energy in a small molecule (9 Calories/gram) • Excess calories  fat

5. Functional Groups • Functional groups are common groupings of atoms that give molecules predictable properties Carboxyl group -makes molecules acidic Amino group -makes molecules basic

6. Alcohol! • All alcohols are carbon based compounds with a hydroxyl group hydroxyl group ethanol (drinking alcohol) Is sugar an alcohol?

7. Carbonyl group • A carbonyl group consists of a carbon atom double bonded to an oxygen atom Acetone Have you ever used acetone?

8. Carboxyl group • A carboxyl group is a carbonyl group + an alcohol group • Carboxyl groups make many molecules acidic. • Molecule with carboxyl group = carboxylic acid Ethanoic acid = vinegar

9. Amino group • Nitrogen bonded to two hydrogens • Makes molecules basic (opposite of acidic) Amino acid Building block of proteins

10. Phosphate group • Phosphate group = phosphorus bonded to four oxygen atoms • Used in DNA backbone • Used in ATP ATP

11. Methyl group • Methyl group = carbon bonded to three hydrogens • Sometimes written CH3 How many methyl groups does acetone have?

12. Testosterone v. Estradiol • A few functional groups can make a big difference! testosterone estradiol (estrogen) Can you spot the differences?

13. Polymers • A polymer is a large molecule made of many similar building blocks strung together • Each building block is called a monomer Proteins are polymers made of amino acids DNA is a polymer of nucleic acids

14. Building Polymers • Polymers are put together by dehydration synthesis • Dehydration = lose water • Synthesis = putting together

15. Dehydration Synthesis • Proteins are made by dehydration synthesis • Building blocks = amino acids Synthesizing proteins from amino acids

16. Dehydration Synthesis • Starches are polymers of simple sugars • Sugars are joined by dehydration synthesis

17. Hydrolysis • Hydrolysis is the disassembly of polymers by adding water back in • It is the opposite of dehydration synthesis Hydrolysis of proteins Hydrolysis of starches

18. Lactose Intolerance • Lactose intolerance is the inability to digest milk and dairy products • Consumption leads to nausea, abdominal discomfort, flatulence, diarrhea • 75% of adults worldwide have partial or full lactose intolerance lactose

19. Lactose Intolerance • Why are some people lactose intolerant? • Their bodies are incapable of hydrolyzing lactose • Lactose cannot be absorbed by the body unless broken up into simple sugars • It accumulates in the intestines where bacteria digest it and release gas (which makes you sick and bloated)