OLI AP Unit 3 Module 5 Macromolecules

macromolecules

at least 1000 atoms

made of monomers

basis of complex cellular life

not intrinsically stable

polymer

very large molecule made of smaller units joined by covalent bonds using a common set of chemical reactions

4 major macromolecules

nucleic acids

proteins

lipids

carbohydrates

monomers of macromolecules

protein- amino acids joined by peptide bonds

polysaccharides- monosaccharides joined by glycosidic bonds

nucleic acids- nucleotides joined by phosphodiester bonds

carbohydrates general formula

(C(H2O))n

2:1 ratio of hydrogen to oxygen all attached to carbon backbone

carbohydrate functions

energy storage

structure

cell recognition and signaling

monosaccharides

simple sugars

glucose, fructose

3-7 carbon atoms

used for energy

polysaccharides

long polymers covalently bonded

store energy of monosaccharide

starch, glycogen

structure in plants

component in DNA backbone

glycosylations

carbohydrate modifications

on lipid membranes and proteins for specialized function and recognition

glucose

most common carbohydrate in nature

(C(H2O))6

common source of energy

protein

linear molecule comprised of amino acids

20 dif amino acids

protein structures

primary structure- sequence of amino acids

secondary structure- sequence folds to form a shape

tertiary structure- functional form

quaternary structure- several separate proteins combine

a protein’s size, shape and reactive properties depend on the

number, type and sequence of amino acids

protein functions

enzymes- rate of reactions

cell signaling and recognition

support

amino acids

monomers of proteins

sequence of amino acids in a protein is encoded in

the DNA of the cell

amino acid backbone structure

amino group

carboxyl group

alpha-hydrogen

functional/R-group

all amino acids have same main chain atoms but differ in

side chains

glycine gly

alanine ala

valine val

leucine leu

isoleucine ile

histidine his

tyrosine tyr

tryptophan trp

phenylalanine phe

serine ser

threonine thr

methionine met

asparagine asn

glutamine gln

aspartic acid asp

glutamic acid glu

lysine lys

arginine arg

cysteine cys

proline pro

functional groups

groups of atoms in a side-chain of amino acids

commonly polar

can be neutral or charged

can be acidic, neutral or base

bond between amino acids

peptide bonds

covalent

amino acids are joined together by a

condensation reaction that yields a molecule of water

nitrogen of an amino group joins with carbonyl carbon of a carboxyl group

each amino acid in polymer is known as a

residue

peptide chains

linear with defined ends

peptide

short polymer- less than 50 residues

polypeptide

longer polymer- more than 50 residues

main chain atoms are

polar functional groups

primary sequence of a protein

N-terminus on left

C-terminus on right

name of N-terminal residue is always first amino acid

nucleic acid

replicating macromolecule

in cell nucleus

DNA and RNA are most important

nucleic acid code is made of sequences of 4 bases

adenine

cytosine

guanine

thymine or uracil

bases are arranged in sets

of 3 called triplets

each triplet specifies an amino acid

chromosomes

structures of organized nucleic acids

DNA is organized into a

linear polymer in a double helix

nucleotide

DNA monomer

phosphate group

5-sided sugar

nitrogenous base

nucleotides are linked

by bridging phosphate molecules btwn 2 hydroxyl groups

by phosphodiester bonds

main difference in polymer backbone between DNA and RNA is

sugar used in formation of polymer

DNA sugar

2’ position of furanose has a hydrogen

RNA sugar

2’ position of furanose has an OH and sugar is ribose in furanose conformation

DNA/RNA polymer backbone sequence

phosphate

ribose/deoxyribose

phosphate

ribose/deoxyribose

DNA double helix is held in place with

hydrogen bonding of purines to pyrimidines

when cell divides

all DNA of genome is duplicated

protein production sequence

DNA replication

DNA transcription

RNA translation

DNA transcription

DNA is transcribed into RNA to make a protein

RNA translation

RNA is translated from a nucleic acid code into amino acid sequence of a protein

lipids

fats and waxes

form membranes of cells and organelles

enable isolation and control of chemical processes

long-term energy storage

cell signaling

lipids accumulate in

adipose cells

excess carbohydrates can be

converted into lipids which are stored in fatty tissue

lipid soluble vitamins

A, D, E, K

lipid structure

hydrophilic head

hydrophobic tail

membrane interior is

hydrophobic and attracts hydrophobic materials in it

proteins with hydrophobic regions

float inside lipid bilayer

transport charged or lipophobic molecules in and out of cell

carbohydrates attached to lipids jutting out of membrane are important for

cell recognition