Lipids

 A class of molecules that is hydrophobic  Hydrophobic= water fearing Ex.  Fats  Oils  Steroids

Fat  Made up of Glycerol and fatty acids  Glycerol-3 carbon backbone  Fatty acid= long hydrocarbon chain Glycerol Fatty acid

Saturated Fat  Saturated Fat= a fat that has all three fatty acid chains contain the maximum number of hydrogen atoms  Only single bonds  Found in most animal fat Lard butter

Saturated Fat

Unsaturated Fat  Unsaturated Fat= A fat that has less than the maximum number of hydrogen's bonded.  Some Carbon atoms are double bonded. Corn Oil Olive Oil Vegetable oil

Unsaturated Fat

Steroids  Steroid= a lipid molecule made up of four fused rings  Are lipids because they are hydrophobic  Chemical messenger Estrogen Testoterone

Steroids

Cholesterol  Cholesterol= an essential cell membrane lipid.  Starting point of steroids  Good and bad uses

Proteins

Protein  Protein= a polymer made up of amino acids  20 different amino acids  Uses Hair Muscles Nutrient storage

Amino Acids  Amino Acid= a monomer made up of a central carbon and four partners  Three are the same and one changes to create 20 different amino acids

Amino Acid Carboxyl (acid) group Amino group

Building Proteins  Proteins are made by connecting amino acids into a chain called a polypeptide  Each amino acid is linked by a dehydration reaction  Linked between the amino group and carboxyl group

Building a Protein Amino acid Dipeptide Amino acid Peptide bond Dehydration reaction Amino group Carboxyl group

Protein Shape  A protein consists of one or more polypeptide precisely folded into a unique shape  The shape is influenced by the environment  Temperature and pH change will change the shape of a protein = denaturation

Protein Shape Levels of Protein Structure Amino acids Basic structure of protein is a long chain of amino acids.

Secondary Shape  Secondary Shape folds the amino acid chain into two shapes Alpha Helix Beta Pleated Sheet

Secondary Shape Levels of Protein Structure Amino acids Hydrogen bond Alpha helix Pleated sheet

Tertiary Shape  Brings multiple polypeptides together and continues to fold them

LE 3-14c Levels of Protein Structure Amino acids Hydrogen bond Alpha helix Pleated sheet Polypeptide (single subunit of transthyretin)

Quaternary Shape  Multiple polypeptides are folded together into a useable shape held together by hydrogen bonds

LE 3-14d Levels of Protein Structure Amino acids Hydrogen bond Alpha helix Pleated sheet Polypeptide (single subunit of transthyretin) Transthyretin, with four identical polypeptide subunits

Enzymes

Catalyst  A compound that speeds up chemical reactions

Enzymes  A biological catalyst  A specialized protein that lowers the activation energy of chemical reactions

Activation Energy  Amount of energy needed to start a chemical reaction

Reactants Net change in energy E A without enzyme Products Progress of the reaction Energy E A with enzyme

Substrate Enzyme Active site Normal binding of substrate Enzyme

LE 5-6 Enzyme available with empty active site Active site Glucose Fructose Products are released Enzyme (sucrase) Substrate (sucrose) H2OH2O Substrate is converted to products Substrate binds to enzyme with induced fit

b. a. f. c. d. e.