Lecture 3: Biological Macromolecules

rutgers gen bio

tetravalent

four single valence electrons

organic compounds

contain carbon bonded to C or H

carbon chains

skeletons of organic molecules

functional group

group of atoms in molecule that dictates characteristic chemical behavior and properties

hydrocarbons

consist of carbon and hydrogen and are nonpolar & uncharged, and thus are hydrophobic and insoluble in water

example of a hydrocarbon

CH₄

hydroxyl group 

r-OH

components of hydroxyl group

ex. alcohol (name ends in -hol); polar; hydrophilic; neutral (pH)

carbonyl group

CHO

components of carbonyl group

ex. aldehyde/ketone (depend on location of C=O); polar; hydrophilic (less than OH); neutral (pH)

carboxyl group

R-COOH

components of carboxyl group

ex. carboxylic acids (H+ easily released); polar; hydrophilic; acidic (pH)

amino group

R-NH₂

components of amino group

ex. amines (H+ easily accepted); polar; hydrophilic; basic (pH)

phosphate group

R-PO₄H₂

components of phosphate group

ex. organic phosphate; polar; hydrophilic; acidic (pH); often contain negative charge; phospholipids and nucleic acids (DNA and RNA)

methyl group

R-CH₃

components of methyl group

ex. methyl hydrocarbon; nonpolar; hydrophobic; neutral (pH); control of gene expression, shape, and function of sex hormones

monomers

building blocks of macromolecules

polymers

monomers joined together

which biological molecules are polymers?

carbohydrates, proteins, and nucleic acids

dehydration synthesis

remove H₂O and joins enzymes; monomer→polymer

dehydrogenoses

enzymes used in dehydration synthesis

hydrolysis 

add H₂O and breaks enzymes; polymer→monomer

hydrolyses

enzymes used in hydrolysis

carbohydrates

CH₂O; fuel and building material

monomers in carbs

sugars (monosaccharides) and glucose (C₆H₁₂O₆₎

polymer in carbs

polysaccharides

glucose forms

linear and ring

glucose in ring form

formed in two ways—alpha (α) or beta (β)

glycosidic linkage

covalent bond between monosaccharides

disaccharide

just two monomers (ex. glucose + fructose)

polysaccharides

more than two monomers in a chain → sugar polymers

what purpose do carbohydrates serve?

depending on the types of monomers and glycosidic linkages, it can function as energy or structural support

lipids

not polymers; hydrophobic; mostly hydrocarbonds

families of lipids

fats, phospholipids, steroids

function of fats

energy storage

what do fats consist of?

glycerol and 1-3 fatty acids

glycerol

3 carbon alcohol with three -OH

ester linkage

dehydration synthesis → covalent bond

triglyceride

storage form of fat

what does the presence of double bonds determine for fats?

if the fat is saturated, unsaturated, or trans-oleic

phospholipid

cell membrane

amphipathic

glycerol + 2 fatty acids; hydrophobic

what group are phospholipids part of?

phosphate group

steroids

three rings of 6 carbon and one ring of 5 carbon

what do z in animals lead to 

communication and cell membrane structure

cortisol

stress hormone

proteins

peptide bonds between amino acids (monomers)

what type of reaction do proteins undergo?

dehydration synthesis

polypeptide

sequence of amino acids; each amino acid is bound to the next with a peptire bond BUT must be folded into the correct 3D shape to become a protein

primary structure

sequence of amino acids joined by peptide bonds in polypeptide chain; determined by DNA

secondary structure

within a single polypeptide, hydrogen bonds stick amino acids together; amino group carboxyl group; R- groups do not participate; alpha helix = coil, beta pleated sheet

tertiary structure

within a single polypeptide, R-groups interact; folds into a particular 3D shape; any/all types of bonds

quaternary structure

multiple polypeptide chains from one macromolecule (not more folding); ex. collagen

denaturation

loss of a protein’s third or fourth structure

is a denatured protein biologically active or inactive?

biologically inactive

what causes denaturation?

pH, salt concentration, and temperature; ex. frying egg

nucleotides

monomers in nucleic acids

classes of nucleotides

DNA and RNAw

what does DNA stand for?

deoxyribonucleic acidw

what does RNA stand for?

ribonucleic acid

what do nucleic acids do?

transmit hereditary information and determine protein production