1. Biochemistry of Life

2. Matter and Atoms Everything on Earth is made up of matter Matter: anything that has mass and takes up space All matter is made up of units called atoms Atoms are the smallest parts of matter

3. Elements and Compounds There are 118 different types of atoms called elements The six most important elements for living things (organisms) are : Carbon (C) Oxygen (O) Hydrogen (H) Nitrogen (N) Phosphorus (P) Sulfur (S)

4. Elements cannot be broken down into smaller parts Elements can combine with other elements to form a new substance called a compound Compounds are held together by chemical bonds Examples of compounds: Water (H 2 O) is two hydrogen atoms bonded to one oxygen atom Carbon dioxide (CO 2 ) is one carbon atom bonded to two oxygen atoms

5. O HH Chemical bond

6. Organic Compounds Our bodies use organic compounds to: 1. make energy 2. build new structures 3. store materials 4. repair existing structures 5. keep all chemical activities working properly These reactions are all part of metabolism

7. Organic compounds are usually very large and are called polymers Polymers are made by linking smaller parts together The smaller parts are called monomers Monomer + Monomer = Polymer The process of linking monomers together to make polymers is called condensation synthesis by removing a water (dehydration synthesis) The process of breaking down polymers into monomers is hydrolysis by adding water

8. Carbohydrates Carbohydrates are sugars Made of the elements carbon, hydrogen, and oxygen The functions of carbohydrates are: 1. to store energy 2. to provide building materials for the body The monomers of carbohydrates are simple sugars or monosaccharides Examples: glucose and fructose

9. When two simple sugars are linked together, they form a disaccharide Example: glucose + fructose = sucrose Sucrose is table sugar Lactose, the sugar found in milk, is also a disaccharide

10. C C CH 2 OH CC C HH H H H OH O Glucose C 6 H 12 O 6

12. When many simple sugars are linked together, they form a polysaccharide Polysaccharides store large amounts of energy Humans use the polysaccharide glycogen Plants use the polysaccharide starch

13. Lipids Fats and oils are lipids Lipids are made of long chains of carbon and hydrogen atoms Lipids store energy more efficiently than carbohydrates do The energy stored in lipids is for long-term use and is not used up quickly It takes a lot of exercise to burn fat

14. Lipids are made of two different parts: one glycerol molecule and three fatty acid molecules The fatty acids can be very long

15. CCCH H HH OC H H C H H C H H H CCCH H H O OC H H C H H C H H H CCCH H H OC H H C H H C H H H H O O Glycerol3 Fatty Acids

16. There are two types of fats: saturated and unsaturated Saturated fats contain as many hydrogen atoms as they can (all single bonds between the C atome) Unsaturated fats are missing some hydrogen atoms (double or triple bond between the c atome) When a fat is missing many hydrogen atoms, it is polyunsaturated Polyunsaturated fats are less likely to cause heart disease than saturated fats Vegetable oils contain polyunsaturated fats; meats and dairy contain saturated fats

17. CC H C H C H C H H O Glycerol Saturated fat Unsaturated fat CC H H C H H C H H C H H H O Glycerol

18. Steroids are also lipids Made of carbon atoms arranged in a ring Cholesterol is a steroid that is found in food and is also made in the body High levels of cholesterol can lead to hardening of the arteries (atherosclerosis) which can cause heart disease The male hormone testosterone and the female hormone estrogen are also steroids

19. Proteins (Polypeptide) Proteins are much more diverse than the other macromolecules Nitrogen containing compounds No two people except for identical twins have exactly the same proteins Proteins have many functions: 1. building materials (collagen and elastin) 2. transport other materials (hemoglobin in the blood) 3. send signals (insulin and other hormones) 4. defense against disease (antibodies) 5. control metabolism (enzymes)

20. Proteins are large polymers made of amino acid monomers There are 20 different amino acids (9 essentials) The order of the amino acids determines the protein’s properties Some amino acids are attracted to each other and others are repelled This makes the protein fold up in unique ways Each protein has its own specific shape called its conformation

21. Essential Amino Acids An essential amino acid may also be called an indispensable amino acid. (9) (peptide)essential amino acid This is an amino acid that the body cannot synthesize on its own, so it must be obtained from the diet.amino acid Because each has its own physiology, the list of essential amino acids is different for humans than it is for other organisms.

22. H H O NOHC R H C Side chain (different in every amino acid) Amine group Carboxyl group Basic Amino Acid Structure

23. Nucleic Acids Nucleic acids consist of deoxyribonucleic acid (DNA) and ribonucleic acid (RNA) DNA and RNA store genetic information DNA and RNA are made up of many nucleotide monomers linked together Nucleotides consist of a sugar, a phosphate, and a nitrogenous base The sequence of nucleotides in DNA determines the sequence of nucleotides in RNA

24. The sequence of nucleotides in RNA determines the sequence of amino acids in a protein DNA  RNA  Protein P Phosphate 5-Carbon sugar Nitrogenous base

25. Building Blocks and polymer Building blocksStructure Amino acidsProteins, enzymes, hormones SugarsStarches carbohydrates Glycerol and fatty acidsLipid Nucleotides(phosphate, sugar, base)Nucleic acids DNA :RNA

26. Differences between DNA and RNA DNARNA DeoxyriboseRibose A;T;C;GA;U;C;G Double stranded for cell reproductionSingle stranded for protein synthesis

27. Enzymes Enzymes: proteins that speed up reactions in organisms Organic catalysts Enzymes work on substances called substrates Substrates are turned into products Enzymes have an area called the active site that matches the shape of the substrate Enzymes are specific for their substrates

28. The names of enzymes usually end in –ase and refer to their substrate Ex: maltase breaks down the disaccharide maltose Lipases break down lipids Proteases break down proteins Co-Enzyme is a vitamin they are sometimes needed by the enzyme to complete the job.

29. Lock and Key Model The active site and substrate are said to fit together just as a key fits in a lock In reality, the active site changes shape slightly to accommodate the substrate Like a glove molding to a hand Called the induced-fit model The substrate fits into the active site of the enzyme to make an enzyme-substrate complex Enzymes change the substrate, but the enzyme itself is not changed The same enzyme can be reused many times

30. Enzyme-substrate complex Products Enzyme breaks the bond holding the substrate together 3 2 1 4

31. How Enzymes Work An enzyme works by lowering the energy a reaction needs to change a substrate All reactions require a “push” to get started This push is called the activation energy The more activation energy a reaction needs, the slower the reaction Enzymes lower the amount of activation energy needed

32. REACTION ENERGY Activation energy without an enzyme Activation energy with an enzyme

33. Enzymes and Temperature All enzymes have a temperature at which they work best This is called its optimum temperature Enzymes that function in humans will have optimum temperatures close to normal body temperature (37°C) If the temperature gets too high, the enzyme can denature When an enzyme denatures, its active site loses its shape it cannot do its job

34. Sometimes, the active site will go back to its normal shape if the temperature is lowered Denaturation can be permanent

35. TEMPERATURE ENZYME ACTIVITY Optimum temperature = highest activity Enzyme is denatured

36. Enzymes and pH pH is a measure of how acidic or basic a substance is The pH scale ranges from 0 to 14 0-6 = acidic 7 = neutral 8-14 = basic For most enzymes in humans, the optimum pH is around neutral because most of the body is neutral

37. Salivary amylase, which breaks down sugars as we chew, works best around pH 7 Pepsin, an enzyme that works in the stomach, has an optimum pH around 2 The stomach is an acidic environment If the pH becomes too low or too high, the enzyme will denature

38. pH ENZYME ACTIVITY 1234567890 Pepsin Salivary amylase

39. Substrate Concentration Increasing the substrate’s concentration makes the enzyme’s rate increase After a point, the enzyme is working as fast as it can Adding more substrate at this point will not increase the rate any more. The enzyme can be reused. It will complete its function and attach to another substrate.

40. ENZYME ACTIVITY SUBSTRATE CONCENTRATION Enzyme is working as fast as it can