CARBON AND MOLECULAR DIVERSITY The Structure and Function of Macromolecules

OBJECTIVES Describe properties of macromolecules important to life: Carbohydrates Nucleic acids Proteins Lipids Know how polymers are assembled and dismantled

ORGANIC MOLECULES

ATOMS & MOLECULES There are various ways to write a chemical formula

MACROMOLECULES BY WAY OF POLYMERIZATION Monosaccharides  Nucleotides  Amino acids 

GENERIC POLYMERIZATION REACTION (bonding together of monomers) Figure: 3.7 Caption: In this generalized diagram, the monomers could be amino acids, sugars, or nucleotides.

BUILDING POLYMERS Constructing Polymers: Dehydration (Condensation) Reaction

DISMANTLING POLYMERS Breaking Down Polymers: Hydrolysis Reaction:

CARBOHYDRATES Monosaccharides: Building block (monomer) for

CARBOHYDRATES Monosaccharides: Glucose as a linear, ring and abbreviated ring structure

CARBOHYDRATES: MONOSACCHARIDES

CARBOHYDRATES Disaccharides: 2 Monosaccharides hooked together

CARBOHYDRATES Polysaccharides: Many monosaccharides hooked together

NUCLEIC ACIDS Store and transmit Composed of

NUCLEIC ACIDS A String of Nucleotides Nucleotide Structure:

STRUCTURE OF THE NUCLEOTIDE

NUCLEIC ACIDS Nucleotides are connected by Result of condensation rxns.

NUCLEIC ACIDS DNA: RNA:

Base Pairing in RNA RNA Loop 3´ 5´ G C G C U A A U C G Figure: 3.15b Caption: (b) This RNA molecule has secondary structure. The double-stranded “stem” and single-stranded “loop” form a hairpin. Note that the bonded bases in the stem are oriented in the opposite 5’  3’ direction. To capture this point, researchers say that they are antiparallel.  Exercise Compare the hydrogen bonds in part (a). Which bond is stronger, the A–U bond or the C–G bond? A U Base Pairing in RNA C G 3´ 5´

PROTEIN Numerous Functions:

PROTEINS Proteins are composed of 20 possible amino acids

20 Amino Acids Note: Variable R Group

PROTEINS When Amino Acids Link, a Peptide Results: Dipeptide: Two amino acids connected

PROTEINS When Amino Acids Link, a Peptide Results: Polypeptide: Many amino acids joined together

PROTEINS Levels of Organization: Primary Secondary Tertiary Quaternary

PROTEIN STRUCTURE Primary Level:

PROTEIN STRUCTURE Secondary Level:  Helix: Pleated Sheet:

PROTEIN STRUCTURE Tertiary Level:

PROTEIN STRUCTURE Quaternary Level:

PROTEIN

PROTEIN FORM & FUNCTION Form & Function Are Correlated! The function of a protein depends on its specific conformation

LOSS OF PROTEIN FUNCTION Genetics:

LOSS OF PROTEIN FUNCTION The Environment: Denaturation: Protein denatured

LIPIDS Lipids:

LIPIDS Functions Include:

LIPIDS Lipids: Most important types found in cells:

TYPES OF LIPIDS Steroids: Includes:

TYPES OF LIPIDS Phospholipids: Play structural role Are “amphipathic”:

TYPES OF LIPIDS Fats: Serve as a source of Usually in form of Formed through

TYPES OF LIPIDS Fats: Saturated versus unsaturated fats