1. MACROMOLECULES SBI 3C: SEPTEMBER 2012

2. MACROMOLECULES  Macromolecules:  Very large molecules containing many carbon atoms  4 major groups of macromolecules: 1. Carbohydrates 2. Lipids 3. Proteins 4. Nucleic acids

4. WHAT IS A CARBOHYDRATE?  Molecules that contain carbon, hydrogen, and oxygen  Used mainly by living organisms for energy  Produced by plants by photosynthesis

5. WHAT DOES A SIMPLE CARBOHYDRATE LOOK LIKE?  Glucose:  Formula: C 6 H 12 O 6 Hydroxyl group (OH)

6. WHAT DOES A SIMPLE CARBOHYDRATE LOOK LIKE?  Fructose  Formula: C 6 H 12 O 6 Hydroxyl group (OH)

7. MONOSACCHARIDES:  Also known as simple sugars  What are they?  Carbohydrates that contain 6 carbon atoms and hydroxyl groups  Examples and Information:  Glucose (C 6 H 12 O 6 )  Fructose (C 6 H 12 O 6 )  Both are water soluble

8. DISACCHARIDES  Also known as double sugars  What are they?  2 monosaccharides linked together  Examples and information:  Sucrose is glucose + fructose  Formed by bonding two sugars together  Occurs when hydroxyl groups react with each other  Sucrose is water soluble

9. MAKING SUCROSE + H2OH2O

10. POLYSACCHARIDES  Also known as complex carbohydrates  What are they?  Sugars attached together in a chain  Examples and information:  Insoluble in water  Polymer:  Molecule composed of many linked subunits  Monomer:  Individual subunits of a polymer

11. EXAMPLES OF POLYSACCHARIDES  Starch (polymer of glucose)  Used by plants for energy  Glycogen (polymer of glucose)  Used by animals for energy  Cellulose (polymer of glucose)  Makes up plant cell walls  Humans cannot digest  Chitin (polymer of type of glucose)  Hard exterior of insects, fungi and crustaceans

12. MACROMOLECULES - LIPIDS  What is a lipid?  A molecule made up of carbon, hydrogen, and oxygen  Used by animals as energy storage molecules  Soluble (dissolves) in oils and other non-polar solvents  Insoluble (does not dissolve) in H 2 O

13. TRIGLYCERIDES  Also known as oils and fats  What are they?  Lipids consisting of 4 parts (glycerol and 3 fatty acids)  Examples and Information  Butter, oil glycerol 3 fatty acids

14. TRIGLYCERIDE STRUCTURE  Glycerol is a 3 carbon molecule with a hydroxyl group attached to each carbon atom  Fatty acid is a long chain of carbon and hydrogen atoms with a carboxyl group at the end Hydroxyl groups (OH) Carboxyl group (COOH)

15. TYPES OF LIPIDS  Waxes:  Used by plants and some animals as waterproof-coating  Steroids  Composed of 4 carbon rings  Ex. Testosterone and cholesterol  Phospholipids  Similar to triglyceride with additional phosphate group  Found in cell membrane

16. SATURATED FATTY ACIDS  Saturated Triglycerides:  Single bonds between the carbon atoms  Animal fats  Causes clogging of arteries

17. UNSATURATED FATTY ACIDS  Unsaturated Triglycerides:  Double bonds between some carbon atoms  more than one double bond = polyunsaturated  Low melting points, liquids at room temperature  Ex. Plant oils – olive oil, canola oil

18. MACROMOLECULES: PROTEINS  What is a protein?  Unbranched chain of amino acids  Most diverse and important molecule in living organisms  Produced by protein synthesis

19. AMINO ACIDS:  How many are there?  20  Common examples:  Leucine, serine, cytsteine, phenylalanine  Other facts:  Small molecules that contain a central carbon atom attached to an amino group, a carboxyl group, a hydrogen, and a side chain (R group)  R groups distinguish the amino acid  20 amino acids are in food we eat, 8 are essential because our body cannot make them

20. POLYPEPTIDE  What is it?  Chain of amino acids  Formed by a reaction between the amino group and carboxyl group on adjacent amino acids  Forms bond called peptide bond  Polypeptides can fold up into different shapes.  For example: fold into a sheet or wrap into coils

21. DENATURING  What is it?  When proteins lose their shape due to high temperatures, high salt or pH  What happens?  Changes the 3D shape of the protein  What happens to a protein if it is done?  Can’t carry out its function  Will return to normal if no bonds are broken  Examples:  Fever can denature enzymes in the brain  Curing meats with salt denatures enzymes, preserving meat  Heat denatures protein in the hair making it straight

22. MACROMOLECULES: NUCLEIC ACIDS  What is a nucleic acid?  Where organisms store information about the structures of their proteins  Polymers of nucleotides  Each nucleotide is made up of:  A five-carbon sugar (ribose in RNA; deoxyribose in DNA)  A phosphate group  An nitrogen containing component (nitrogenous base)

23. DNA  Stands for:  Deoxyribonucleic acid  Looks like:  Double helix  Helix held together by hydrogen bonds  Contains which base pairs?  A – T  C – G  A – adenine, T – thymine  C – cytosine, G – guanine

24. RNA  Stands for:  Ribonucleic acid  Looks like:  Single stand  Contains which base pairs?  A – U (uracil)  C – G  Types of RNA…  mRNA – carries info to ribosomes  tRNA – transfers amino acid to mRNA

25. DIFFERENCES BETWEEN DNA AND RNA RNADNA Single strandedDouble stranded Has uracilHas thymine Decodes hereditary infoStores hereditary info Sugar is a riboseSugar is deoxyribose

26. DNA DETAILS  What does the code in DNA specify?  The order of amino acids in proteins  What is a gene?  Instructions to code a protein  How many genes are in the human genome?  30,000 – 35,000  How many base pairs are in the human genome?  3 billion