4 Macromolecues

Carbohydrate

-Amylopectin

-Monomer: glucose

-1° Bonding: glycosidic
-Function: energy source

 

-contains carbon, hydrogen, oxygen atoms in 1:2:1 ratio

-contain an aldehyde (functional group at the end) or a ketone (functional group inside)group and one or more hydorxyl group

-simplest carbohydrates are monosaccharides

            Examples: galactose, glucose, fructose 

            -glucose is an energy source

            -sugars are linear with five or more carbons but are readily to form cyclic structures when           dissolved in water

-disaccarides have two covalently linked monosaccharides

         Example: sucrose (glucose and fructose), Lactose (galactose and glucose), Maltose (glucose+ glucose)

-polysaccharides are composed of thousands of monosaccharide subunits held together by glycosidic linkages

           Examples: amulopectin, amylose

          -some are straight chains, others are branched

          -two important functions are energy storage and structural support

             Cellulose (polymer b-glucose)top holding hands; Starch (polymer a-glucose) bottom holding hands

Lipids

-Triglycerid

-Monomer: glycerol + fatty acid

-Hydrophilic vs. Hydrophobic(tail)

-1°  Bonding: ester

-Function: energy storage, membrane structure, hormones, vitamins

-hydophobic molecules composed of carbon, hydrogen, and oxygen

-insoluable in water but soluble in other nonpolar substances

-used for energy storage, building membranes, and other cell parts, chemical signalling molecules

-fatty acids with many carbon-carbon double bonds are called polyunsaturated fatty acids        

Divided into four families:

 fats

-most common fat in plants and animals are triglycerides

               -contans three fatty acids and a molecule of glycerol

-saturated fatty acids have single bonds – more stable

-unsaturated fatty acids have one ore more double bond – less stable – break more easily 

  phospholipids

-composed of a glycerol molecule attached to two fatty acid (hydrophobic), and a highly polar phosphate group (hydrophilic)

-tail and head, respectively

- form spheres, micelles, when added to watter (heads dissolve in watter, tails mix with one another in the center)

Steroids

-compact hydrophobic molecules, four hydrocarbon rings, several functional roups

Eg. Cholestrol, testosterone, estrogens

Protein

-Four-stranded parallel  ß-sheet (gold), for a helicaes (red) and a single 316 helix (purple)

-Low molecular wight

-Monomer: 157 amino acid

-1°  Bonding: peptide

-Function: signal transduction, cell cycle regulation, differenciation

-variety of roles, strctural building blocks, involved in almost everything the cell do

-amino acid polymers folded into specific 3-D shapes

-contains carboxyl and amino group 

-proteins have four levels of structure

Primary structure

-the sequence of amino acidss in the polypeptide strand

Secondary Structure

-portions of polypeptide chain forms coil due to hydrogen bond between oxygen of the carboxyl group and hyrogen of an amino group  

-Beta sheets – two parts of the polypeptide chain lie parallel to one another

Tertiary Structure

-contains both beta sheets and helix

Quaternary Structure

-composed of more that one tertiary protein

A change in 3-D shape of proteins caused by changes in temperature, pH, ionic concentration, or other environmental factors is called denaturation (cannot carry out is biological functions)

 

 

Nucleic Acid

-deoxyribonuleic acid

-Monomer: nucleotides

-N-Base: A, T, G, C

-1°  Bonding: phosphodiester

-Function: inheritance, genetic, protein synthesis

 

DNA

-contains sugar deoxyribose, phosphate group, nucleotides (A,C,G,T)

-hydrogen bond between the two strands between nitrogenous bases

-phosphodiester linkage between phosphate group of one nucleotide and the sugar of the next

RNA  

-contains ribose instead of deoxyribose, nucleotide U instead of T