BIOCHEMISTRY

Chemistry – study of what substances are made of and how they change and combine A. Atom – fundamental unit of matter 1. Subatomic particles: no = neutron p+ = proton e- = electron   B. Element - each different kind of atom is a different element. Pure substance consisting of one type of atom 1. Examples: C = carbon H = hydrogen O = oxygen N = nitrogen C. Compound - two or more elements chemically combined in definite proportions 1. Examples: CO2 H2O NaCl C6H12O6

D. Chemical reactions – process leading to changes in matter 2 H2 + O2 2 H2O (reactants) (products)

E. Compounds are classified into two broad groups: 1. Inorganic Compounds – come from nonliving substances ( in = not organic = living) 2. Organic Compounds – come from living substances

II. Biochemistry – chemistry of living organisms (text pages 44 – 53) A. Organic compounds – compounds made by cells and containing carbon 1. Example: C6H12O6 Glucose 2. Exception: CO2 Carbon Dioxide

DRAw picture to remember 3. Organic compounds in living cells are usually complex compounds that are so large they are called macromolecules (giant molecules) or biomolecules 4. Macromolecules are formed by process called polymerization – smaller units called monomers join together to form polymers DRAw picture to remember

5. Four kinds of organic compounds: a. carbohydrates b. proteins c. lipids d. nucleic acids  

III. Carbohydrates A. Provides energy for all organisms — main source of energy for cells B. Most carbohydrates are manufactured by plants C. Structure: contains the elements C, H and O usually in ratio of 1C : 2H : 1O C6H12O6 = Glucose

D. Three groups of carbohydrates: 1. Monosaccharides = single sugar; basic structural unit from which larger carbohydrates are built ( mono = one sacchar = sugar) Examples: sugars usually end in -ose a. glucose – C6H12O6 -- most common, in every cell – produced by green plants b. fructose -- C6H12O6 -- sugar in fruits c. galactose -- C6H12O6 -- sugar in milk d. isomers – same molecular formula; different structural formula  

2. Disaccharide – double sugar (di = two) a. sucrose - cane sugar (table sugar) b. chemical reaction: 2 monosaccharides joined together to make a disaccharide glucose + fructose sucrose + water C6H12O6 + C6H12O6 C12H22O11 + H2O (when water is released in a chemical reaction = dehydration synthesis)  

3. Polysaccharide – many sugars (poly = many) a. starch – polysaccharide stored in plants potatoes, pasta, grains (bread, rice) b. glycogen – polysaccharide stored in animals – stored in liver and muscles c. cellulose – polysaccharide that gives support and structure to plant cells (fiber) most abundant organic chemical on earth  

What is the purpose of storing sugars as polysaccharides in plant and animal tissues? Plants: Animals:

E. Monomers/Polymers 1. General term for any small compounds that can be joined together to make larger compounds – monomer example: glucose = monomer many glucose molecules can be added together by dehydration synthesis to make a polysaccharide 2. General term for any large compound formed by combining monomers - polymer example: starch = polymer starch is a polymer made when many glucose molecules are chemically combined  

Take 5: Complete concept map for carbohydrates Function: Examples: Structure:

IV. Proteins (also called peptides) A. Needed for growth, maintenance and repair of living materials 1. cell membrane, skin, nails, hair, bones and muscles made of protein B. Fight disease – antibodies made of proteins C. Control rate of chemical reactions in cells – enzymes made of proteins D. Food source – lean meat, fish, eggs, cheese, nuts, beans, dairy  

1. proteins are polymers of molecules called amino acids E. Structure: 1. proteins are polymers of molecules called amino acids monomer = amino acid polymer = protein 2. contain the elements C, H, O and N   Dehydration Synthesis of Proteins F. 20 different amino acids combine in different ways to make up thousands of different proteins

Take 5: Complete concept map for Proteins Function: Examples: Structure:

V. Lipids A. Functions: 1. energy storage – twice as much energy / g. as carbohydrates 2. makes up part of the cell membrane 3. hormones are lipids – estrogen and testosterone B. Examples: 1. Fats – solid at room temperature – butter, lard (animal fat) 2. Oils – liquid at room temperature – corn oil, olive oil (plant fats)

3. Phospholipids and cholesterol – makes up cell membranes 4. Steroids – type of hormone that can cross cell membrane directly into cells. Function: chemical messengers 5. Waxes – on leaves of plants to make them waterproof  

C. Structure: fats and oils 1. composed of glycerol and 3 fatty acids 2. contain the elements C, H and O When glycerol + 3 fatty acids combine to form 1 fat molecule, H2O is released = dehydration synthesis

D. Dietary importance 1. Saturated fats – generally come from animal fats a. Bad for you – deposited in arteries – cause heart disease   Saturated with hydrogens (H) No double bonds in fatty acid chain

2. Unsaturated fats – generally from plant oils a. Better for you Have one or more double bonds

3. Cholesterol – 2 sources a. your body produces it – essential to life: helps produce certain hormones and part of cell membranes in animals b. you consume it in food 1. bad cholesterol – LDL (low density lipoprotein) – goes to cells, excess deposited in arteries 2. good cholesterol – HDL (high density lipoprotein) – gets rid of excess LDL’s in arteries

Take 5: Complete concept map for Lipids Function: Examples: Structure:

VI. Nucleic Acids A. Function is to store and transmit genetic information from parent to offspring B. Examples: DNA and RNA (Nucleotide)

VI. Nucleic Acids C. Monomer- Nucleotides - A: Adenine - T: Thymine - C: Cytosine - G: Guanine - U: Uracil D. Nucleotide Structure: 5 carbon sugar, phosphate group, and a nitrogenous base

Take 5: Complete concept map for nucleic acids Function: Examples: Structure:

VII. Enzymes Take 5 – read pages 51 – 53 in text A. Enzymes are catalysts in living organisms catalyst – substance that speeds up a chemical reaction B. Most enzymes are made of proteins C. Enzymes are not changed in a reaction and can be reused D. Enzymes are specific – speed up only one type of chemical reaction E. Lock and Key hypothesis – an explanation of how an enzyme works

F. Substrate – substance upon which a certain enzyme acts G. Naming enzymes – add “ase” to substrate a. maltose is substrate – maltase is enzyme b. protein is substrate – protease is enzyme H. One important function of enzymes is speeding up digestion of food