1 UNIT 1 PART 3:CHEMICAL COMPOUNDS OF LIFE The most common elements in living things are: –Carbon (C) –Hydrogen (H) –Oxygen (O) –Nitrogen (N)

2 2 Types of Chemical Compounds A.Inorganic compounds DO NOT contain carbon and hydrogen, Ex: O 2, H 2 O, NaCl, CO 2, HCl, H 2 SO 4 B.Organic compounds contain both carbon and hydrogen. Ex: C 6 H 12 O 6, NH 2 C 4 H 8 COOH, C 17 H 35 COOH Water is the most important inorganic compound.

3 Organic Compounds Organic Compounds always contain Carbon and Hydrogen. The 4 biologically important types are: –Carbohydrates –Lipids –Proteins –Nucleic acids Lipid Protein Carbohydrate Nucleic Acid

4 Carbohydrates: Sugars & Starches Contain C, H & O The H’s & O’s are in a 2:1 ratio as in C 6 H 12 O 6 Usually end in –ose Usually have a 5 or 6 sided ring structure. Used for Energy Most common one is glucose, C 6 H 12 O 6.

5 Types of Carbohydrates Simple sugars, (glucose, fructose, ribose) Found in fruits, used as quick energy because they digest quickly Double sugars, ( maltose, lactose, sucrose) 2 simple sugars combined to form one molecule. They are table sugars, and also found in fruits and vegetables. Starches, (glycogen, cellulose-plant cell walls) String of many simple sugars combined in repeating chains They are used as storage for large sources of energy and are found in pastas, cereals, breads, vegetables

6 Dehydration synthesis is the joining of molecules with the release of water (Dehydration) in a process that forms a bigger molecule. (Synthesis = To make or build) 2 simple sugars into a double sugar C 6 H 12 O 6 + C 6 H 12 O 6  C 12 H 22 O 11 + H 2 O + + H 2 O Dehydration synthesis OH HO O

7 Hydrolysis – is the opposite of dehydration synthesis. This is the breaking apart of complex molecules into simpler ones, by adding water. This is part of digestion. Changing starches back to simple sugars. C 18 H 32 O H 2 O  3 C 6 H 12 O 6 + 2H 2 O  Hydrolysis - Digestion + OHHOO OHOHO OH

8 Lipids: fats, oils, and waxes Contain C, H & O but not a 2:1 hydrogen and oxygen ratio (H 2 O), they have many H’s & few O’s (C 51 H 98 O 6 ) The basic structure of the lipid is 3 fatty acids and a glycerol molecule. Glycerol 3 Fatty Acids

9 Lipids are used as long term energy sources because they have about twice as much energy (calories) as carbohydrates. They are used as part of membrane structures in cells. Types of lipids: 1. oils- liquid at room temperature and come from plants usually, ex: corn oil 2. fats- semisolid at room temperature, and come from animals usually, ex: butter 3. waxes- solid at room temperature 4. steroids- hormones (chemical messengers) They are also formed by dehydration synthesis. Lipids: fats, oils, and waxes

10 NUCLEIC ACIDS: DNA AND RNA Contain N and P as well as C, H, and O Controls all cell activities Building blocks are nucleotides:

11 PROTEINS Proteins always contain C,H,O, N and sometime S a. Amino Acids are the building blocks of protein. b. An amino acid is made of 1. a carboxyl group (acid) (COOH) 2. an amino group (NH 2 ) 3. a side group, ( R ) c. The R group makes each amino acid different Carboxyl group Amino group

12 Common Amino Acids

13 Dehydration synthesis of Proteins Dehydration synthesis combines many amino acids together to form a protein molecule. –The bond between amino acids is called a peptide bond –A dipeptide contains 2 amino acids, a polypeptide, many –Proteins are one or more polypeptides bonded together

14 SHAPE = FUNCTION Amino acids can be joined in any order. Every sequence makes a different protein. These chains can twist and fold into many different shapes. The sequence of amino acids determines the shape of each protein. The shape of the protein determines its function.

15 Important Proteins Proteins are used as: 1.Hormones - chemical messengers 2. Antibodies - fight diseases 3. Receptor molecules – cellular communication 4. Enzymes - control chemical reactions in cell

16 Characteristics of Enzymes Enzymes are Specific (do 1 reaction). Enzymes help reactions to occur Faster Enzymes are used over and over Enzymes are not changed by reactions

Characteristics of Enzymes Enzyme reactions are reversible. Enzyme names end in –ase. (protease, lipase) Enzymes are helped by coenzymes (vitamins). Enzymes are affected by temperature, pH, & concentration. 17

18 Lock and Key Theory Each chemical reaction requires a specific enzyme, shaped in a specific way. The substrate is the substance acted upon by the enzyme. The enzyme molecule joins temporarily with the substrate (forming an enzyme- substrate complex) The enzyme helps a reaction to take place in the substrate. Upon completion of the reaction, the enzyme releases the new products.

19 Lock & Key Theory Enzyme- Substrate Complex Substrate Enzyme Products

20 Effect of temperature on enzymes Every enzyme works best at a specific temperature (called optimum temperature). An enzyme is denatured at high temperatures (loses its shape) and will not work At low temperatures the enzyme lacks the energy to work, but its shape is not denatured.

21 Effects of pH on enzymes Enzymes work best at a specific pH level. –Stomach enzymes work best at low pH 2 levels. –In your intestine, enzymes work at pH 8. Outside of the optimum pH the enzyme is denatured, (loses its shape) and will not work

22 Effect of Concentration on Enzyme Action If the amount of enzyme remains constant and you add substrate, the rate of reaction will increase. Eventually all of the enzyme is being used so the reaction rate will level off. If the amount of substrate remains constant and you add enzyme, the rate of reaction will increase. Eventually all of the substrate is being used so the reaction rate will level off.

23 Key to ID Organic Compounds 1a: Has both C and H’s…………….……..…....…Goto 2 1b: Does not have both C and H’s………….…Inorganic 2a: Has N in it…………………..……………..Goto 3 2b: No N in it………..….……………………..Goto 4 3a: Has P in it…….………………......Nucleic acid 3b: No P in it………………………....….…Protein 4a: H’s and O’s in a 2:1 ratio…….Carbohydrate 4b: No 2:1 ratio………………...…………Lipid