Biological compounds The chemistry of living organisms Biochemistry Biological compounds The chemistry of living organisms

Chapter 20 Read and Outline …Major headings Pay careful attention to summary notes and terms in bold print. KEY TERMS (you will be tested on these!)

Classification Proteins Carbohydrate Lipids Nucleic Acid A long chain hydrocarbon containing amino acids Simple sugars and their polymers Fats, waxes and oils also steroids Polymers composed of sugars, a base and phosphoric acid Lipids Nucleic Acid

General Properties Important Are they water soluble or fat soluble? Why is this important? Proteins, Carbohydrates and Nucleic Acids are soluble to some degree Fats are insoluble in aqueous solution Vitamins A,D,E, and K are fat soluble… While C, B complexes are not

Hydrocarbon Chemistry Functional groups help us understand solubility…. Amides (-CONH2) lower chains are soluble larger chains and aryl-amides not so much! Acids, Aldehydes, Ketones the same… check tables in Chapter 19. Check for patterns.

Special Features What link joins amino acids in proteins? Peptide bonds (amide bond) What does the term “polypeptide refer to?” What are enzymes? What does the lock and key model refer to?

Carbohydrates Usually contains an aldehyde or ketone group Bond between sugars is called a glycoside linkage sugar – O - sugar

Lipids Water insoluble Contains an alcohol and one or more carboxylic acid molecules Fats and oils 3 Carboxylic acids are linked by an ester and joined to a glycerol

Nucleic acid Biochemical polymer Contains a sugar attached to nitrogen base and phosphate group Units linked by phosphate linkage Base- sugar- phosphate- sugar - base

Nucleic Acids Base Sugar Phosphoric acid

Nucleic acids Contain genetic information DNA- deoxyribonucleic acid RNA- ribonucleic acid Different functions – only difference is a hydroxyl group (-OH)

Structure Proteins are made up of amino acid structures that are linked together by a PEPTIDE BOND. Proteins have a primary, secondary and tertiary structure

Enzymes Enzyme- a protein that catalyzes a biochemical reaction Lock and key – an enzyme molecule has a specific shape that fits perfectly into the shape of the reacting molecule known as the substrate

Nomenclature of proteins Important features R- group refers to the hydrocarbon side chain attached to the a–carbon. R- groups may be neutral, acidic or basic.

Lipids Oils…..unsaturated (plant source) Fats….saturated (animal) Waxes are lipids…think about candles and the “old days” Steroids are lipids -ol endings or –one ending Read about vitamins (p. 585)

DNA and RNA What are the differences? What is the same?

Other Patterns Nomenclature Endings are important Check the endings of functional groups… Ex: R-OH alcohol, ending –ol Ex: R-CHO aldehyde, ending –al Lets try # 93, 94,95 (p. 566) How about the biomolecules…. Make a list for yourself to study…

Hydrocarbon Chains Alkanes Alkenes Alkynes Cn H 2n-2 C n H 2n+ 2

Check out the Patterns Name longest consecutive chain Prefixes Meth Prop But Pent Hex Hept Oct Non Dec

Alkanes Saturated compounds Carbon in chain contains all single bonds Must be four bonds around each Carbon Saturated compounds

Alkenes Unsaturated (contains double bond…at least one) Carbon with lowest number between double bonds names the bond.

Alkynes Carbon chain contains a triple bond Acetylene lowest chain Highly unsaturated Triple bonds > double >single in bond strength Makes chemical properties different

Isomers Carbon chain with same molecular formula but different structural formula

Look for patterns in the names How are carbohydrates named? What about steroids that are hormones? What family of biochemistry do steroids belong to? What is the general form of a fatty acid? Try # 1 and 2 on p. 591!