gen bio - lecture 3: biological molecules

this is a long one!!

structure equals…

function

carbon has ____ single valence electrons

FOUR (4)

organic compounds

contain carbon bonded to…

• carbon

• hydrogen

carbon chains

skeletons of organic molecules which vary in…

• length

• branching

• types of bonds

• presence of rings

definition of functional groups (R)

a set of molecules that change the function of the original molecule

hydrocarbons + characteristics (2)

• carbon and hydrogen

• characteristics

  • nonpolar/uncharged

  • hydrophobic (insoluble in H2O)

hydroxyl group (example, formula, drawing, polarity, hydrophilicity, acidity)

• example: alcohOL (end in -ol), carbs

• formula: R - OH

• polar? YES (partially -/+)

• hydrophilicity? YES (hydrophilic)

• acidity? neutral

carbonyl group (example, formula, drawing, polarity, hydrophilicity, acidity)

• example: aldehyde, ketone, sugars

• formula: CHO

• polar? YES

• hydrophilicity? YES (but hydrophilic BUT less than hydroxyl)

• acidity? normally neutral

carboxyl group (example, formula, drawing, polarity, hydrophilicity, acidity)

• example: carboxylic acids , can act as amino acids, (donates H+)

• formula: R-COOH

• polar? YES

• hydrophilicity? YES (hydrophilic)

• acidity? acidic

amino group (example, formula, drawing, polarity, hydrophilicity, acidity)

• example: amines (accept H+)

• formula: R-NH2

• polar? YES

• hydrophilicity? YES (hydrophilic)

• acidity? basic

phosphate group (example, formula, drawing, polarity, hydrophilicity, acidity)

• example: organic phosphates, lipids/fats, ATP/ADP

(- charge)

• formula: R -PO4H2

• polar? YES

• hydrophilicity? YES (hydrophilic)

• acidity? acidic

methyl group (example, formula, drawing, polarity, hydrophilicity, acidity)

• example: methyl hydrocarbons, control gene expression, sex hormones

• formula: R-CH3

• polar? NO, NONPOLAR

• hydrophilicity? NO (hydrophobic)

• acidity? neutral (not an acid or base)

monomers

• building blocks of macromolecules

• join together to form polymers

3 out of the 4 biological molecules are polymers:

• carbs

• proteins

• nucleic acids

• LIPIDS ARE NOT POLYMERS; THEY ARE BIOLOGICAL MOLECULES

dehydration synthesis

• remove water to join monomers

• enzyme: dehydrogenases

hydrolysis

• add water to break apart a polymer

• enzyme: hydrolases

carbohydrates (formula, examples, structure, monomer, polymer, bond, function)

• formula: CH2O

• examples: rice, bread, pasta

• structure: linear and ring form

• monomer: sugars/monosaccharides/glucose

• polymer: polysaccharides

• bond: covalent - glycosidic linkage

• function: energy or structural support

lipids (overall info)

• NOT polymers

• hydrophobic = mostly hydrocarbons

• 3 categories: fats, phospholipids, steroids

lipids: fats (function, examples, structure, bond)

• function: energy storage

• examples (3):

  • saturated fatty acids, butter (linear)

  • unsaturated fatty acids, oil (has kink)

  • trans fat, margarine (double carbon bond)

• structure: glycerol + 1-3 fatty acids through dehydration synthesis

• bond: covalent - ester linkage

lipids: phospholipids (one point abt polarity)

• make up cell membranes which are amphipathic (have hydrophilic and hydrophobic parts)

  • hydrophilic part: phosphate group (head)

  • hydrophobic part: glycerol + 2 fatty acids (tail)

steroids (structure + examples)

• structure: 3 rings of 6 carbons and 1 ring of 5 carbons (functional groups vary)

• examples: cholesterol in animals (communication, cell membrane structure); cortisol (stress hormone)

proteins (function, monomers, polymers, bond, STRUCTURE, denaturation)

• function: important for everything

• monomers: amino acids

• polymers: polypeptides

• bond: peptide bond

• structure: must be FOLDED into correct 3D shape to be a protein

1. primary structure: sequence of amino acids joined by peptide bonds in polypeptide chain (determined by DNA)

2. secondary structure: within a single polypeptide chain

• hydrogen bonds stick AAs together

• NO R GROUPS

• d helix/coil OR B pleated sheet

3. tertiary structure: within a single polypeptide

• R group interaction

• fold into particular 3D shape

• ALL bonds can occur

4. quaternary structure: no more folding —> multiple polypeptide chains form one molecule

• denaturation: loss of a protein’s 3rd or 4th structure

  • becomes biologically inactive

  • due to pH, salt concentration, temperature

nucleic acids (monomers, classes, function)

• monomers: nucleotides

• 2 classes: DNA + RNA

• function: transmit hereditary info + determine protein production