macromolecules

Organic Chemistry - 

Inorganic molecules 

• Very small amounts of carbon 

• Cations + anions 

• Ionic 

• Few atoms 

• Abiotic

Organic molecules

• Significant amounts of carbon 

• Always has CHO(N) 

• Covalent bonds

• Large, many atoms (macromoles) 

• Biotic 

Carbon - 

• Carbon is essential to life because it can form strong, nonpolar bonds and it can have up to 4 chemical bonds

• Carbon has 6 electrons - and it often bonds with other carbons (hydrocarbons) 

• Carbon can either be linear (hydrocarbons) or rings 

• Covalent bonds store a LOT of energy 

Macromolecules - macromolecules or biomolecules → large 

• Made of repeating units or polymers 

*Lipids - fat

*Carbohydrates - polysaccharides → monosaccharides

*Proteins - polypeptide → amino acids 

*Nucleic Acids - DNA, RNA, ATP → nucleotide 

• Most large molecules in living things are macromolecules called polymers 

• Polymers are long chains of smaller molecular units called monomers 

Dehydration synthesis - how to make a polymer 

• Dehydration – removal of water molecule 

• Used to connect monomers together to make polymers 

• The removal of water causes carbons to want to bond with each other 

Hydrolysis - how to break a polymer 

• Hydrolysis - addition of water molecule

• Used to disassemble polymers into monomer parts 

Chemical Reactions: the making or breaking of bonds 

• Bonds store energy that is released when a bond is broken

• Exergonic Reaction → more energy is released than used 

→ breaking polymers into monomers using hydrolysis 

• Ex: fireworks 

• Endergonic Reaction → more energy is stored than released 

→ joining monomers into polymers 

• Ex: photosynthesis

Carbohydrates 

Carbohydrates - molecules that contain carbon, hydrogen, and oxygen in a 1:2:1 ratio

• Monosaccharides = simple sugar (monomer) 

• Dissaccherides - 2 monosaccharides joined covalently 

• Polysaccharides - many monosaccharide sub units 

• Glucose = C₆H₂O₆ - keeps the 1:2:1 ratio

Monossacherides (simple) 

• Single unit sugars 

• Makes ATP (fuel for cellular work) 

• Multiples of CH₂O 

• Soluble and sweet to taste 

Examples: 

glucose, fructose, galactose 

• Hexoses (6 carbon atoms) 

• Isomers of C₆H₂O₆

Ribose and deoxyribose (nucleotides) 

• Pentoses (5 carbon atoms) 

•  C₅H₂O₆  (ribose) & C₅H₂O₄  → Notice there are 4 oxygens which is why we call it “deoxy” 

Isomers - same atoms, different arrangements 

• Form rings because oxygen needs 2 bonds (2 carbon) 

Monosaccaride + monosaccaride = disaccaride

• Sucrose + maltose   (which would come from dehydration synthesis) 

Disaccharides - contain 2 monosaccharides joined by dehydration reaction forming covalent bonds 

• Sucrose (glucose + fructose) 

• Maltose (glucose + glucose) 

Lactose - disaccharide found in milk (milk sugar) 

• Made of glucose and galactose 

**Lactase (enzyme) breaks these apart  

→ this is one cause of being lactose intolerant - if you lack lactase you can’t break down milk) 

******not sweet

Polysaccharide: polymers of hundreds of thousands of monosaccharides linked by dehydration synthesis. 

• Used to store energy + structural support 

- structural: cellulose (plants) and chitin (fungi) 

• Ex: glycogen – extra sugar in body stored 

Lipids 

Lipids do not form polymers and are hydrophobic 

• Hydrophobic: have little or no affinity to water 

Ex of lipids: fats, oils, phospholipids, steroids, waxes 

Fats - 

• Used as storage molecules

• Separate from water because water molecules form hydrogen bonds with each other and exclude the fats 

• Made from glycerol + fatty acids 

* Structure:

• Glycerol: 3 carbon alcohol with a hydroxyl group attached to each carbon 

• Fatty Acid: carboxyl group attached to a long carbon skeleton 

** Triglyceride - 3 fatty acids are joined to glycerol by ester linkage 

Fatty Acids - vary in length 

1. Saturated → maximum number of hydrogen atoms and no double bonds between carbons 

• Saturated fats - made from saturated fatty acids 

• To many can cause cardiovascular disease 

• Solid at room temperature 

• Animal fats 

2. Unsaturated → one or more double bonds 

• Unsaturated fats - made from unsaturated fatty acids 

• Plant and fish fats 

• Liquid at room temperature are oils 

3. Polyunsaturated → 2 or more double bonds 

Trans- unsaturated fats - produced artificially by partial hydrogenation 

• Semi solid at room temperature 

• Less likely to spoil 

• High consumption is associated with many diseases and cancer so it was banned by the FDA 

Fatty acids - 

• Eladic - trans 

• Oleic - unsaturated 

• Stearic - Saturated 

Phospholipids - make up a cell membrane and internal membrane of eukaryotic cells 

• Made of hydrophobic head and hydrophobic tails 

• Cell membrane - the structure of phospholipids results in a bilayer arrangement found in cell membranes 

• Head has a phosphate group attached to glycerol tails have 2 fatty acids 

**When added to water the hydrophobic tails point away from water 

Great emulsifiers - phospholipids are soluble both in water and oil allowing the 2 to mix and making phospholipids emulsifiers 

Steroids - have a carbon skeleton consisting of 4 fused rings 

• Can be hormones 

**Cholesterol - 

• Made by your body (nonessential) 

• Maintains fluidity of cell membranes

• High levels in blood contribute to cardiovascular disease 

Lipoproteins - proteins and lipids tangled together  

• Carry lipids around in our blood 

2 - 

• LDL (low density lipoprotein - cause cholesterol on artery walls) 

• HDL (high density lipoprotein - carry cholesterol out of blood) 

Waxes - fatty acid connected to long chain hydroxyl with ester linkage 

• Repel water 

• High melting point 

• Resistant to degradation 

Proteins

Protein functions - 

• Enzymes (catalyst - speeds up reactions) 

• Defense (immune system)  

• Transport 

• Structural support 

• Motion 

• Regulation 

• Storage 

Proteins are structurally sophisticated: 

• Shape determines their function and is crucial to the job of a protein  

• Made of amino acids joined by peptide bonds

• 20 types

• Made at ribosomes in a cell 

Amino acids - monomer of proteins 

• All have a central carbon, amino group (NH₂), carboxyl group (COOH), and hydrogen 

• The difference is the R groups which change the look and function and makes the 20 different amino acids 

Polypeptide - characteristics are determined by composition and sequence of amino acids 

• polypeptide : one linear amino acid chain 

• Protein: made of one or more polypeptides 

Shape determines function - driven by noncovalent interaction (hydrogen bonding, ionic interactions) and hydrophobic packing [going towards the middle to avoid water] 

Structures: 

1. Primary - the order of the amino acids sequence coded by DNA 

• A change in DNA could change structure and therefore function 

2. Secondary - interactions between atoms of backbone (amino and carboxyl groups) 

• Does not include R group 

• Held together by hydrogen bond 

• Helix and pleated sheet 

3. Tertiary - R groups interact with one another - all proteins will reach this 

• Hydrogen, ionic, or covalent bonding 

• Polar R groups create hydrogen bonds 

• Hydrophobic interaction → goes to middle inside to avoid water 

• Leaving anything attracted to water on outside 

4. Quaternary - 2+ tertiary structured proteins come together to create complex proteins 

Unfolding Proteins - 

• Denature → protein losing its higher structure, but never primary structure 

• Causes: salt, heat, pH (once this happens proteins are nonfunctional) 

Nucleic Acids 

3 types: 

• DNA (deoxyribonucleic acid) - codes to assemble proteins 

• RNA (ribonucleic acid) - carries DNA coded messages 

• ATP (adenosine triphosphate) - energy 

Structure - composed of long polymers of repeating 

• Subunits (nucleotides – monomer) 

• 5-carbon sugar

• Phosphate 

• Nitrogenous base 

• Purines: adenine + guanine 

• Pyrimidines: cytosine + thymine + uracil 

DNA - double stranded molecules 

• Genetic info - coded for by order of nucleotides 

• Double helix 

• Complementary base pairing: A - T, C - G 

• Hydrogen bonding 

RNA - single strand 

• Contains ribose instead of deoxyribose 

• Contains uracil in place of thymine 

• A, U, G, C 

Purines - 2 rings 

Pyrimidine - 1 ring 

*these always bond together (A - T) 

ATriP - adenine + ribose 

• 3 phosphates 

ADiP - breaks bond of the last phosphate 

• Lots of energy stored in bond broken