Biomolecules Presented by Amelia McCutcheon
Fats Carbohydrates Proteins Vitamins
Fats Also known as lipids Fats are solids (high mel=ng point) ils are liquids (low mel=ng point) Mainly consist of Carbon and ydrogen and small amounts of xygen The two types of fats we will look at are: FaFy Acids Triglycerides
Fatty Acids Non- polar end Fa3y Polar end Acid
Fatty acids Saturated fats contain all C- C single bonds within the fafy acid 0 degrees of unsatura=on all s present Palmi=c acid; C 16 32 2 Mono- unsaturated fat is when there is one double bond within the fafy acid 1 degree of unsatura=on; 2 s less than C n 2n+2 rule leic acid; C 18 34 2
Fatty acids Poly- unsaturated fat is when there is more than one double (or triple) bonds within the fafy acid 1 degree of unsatura=on for every double bond (or 2 for every triple bond); 2 s less than C n 2n+2 rule for every degree of unsatura=on Linoleic acid; C 18 32 2
Essential fatty acids Essen=al fafy acids: fafy acids that the body requires for good health but cannot synthesise These MUST be consumed in the diet There are two essen=al fafy acids: alpha- linolenic acid (an omega- 3 fafy acid) linoleic acid (an omega- 6 fafy acid)
Essential fatty acids alpha- linolenic acid (an omega- 3 fafy acid) C 3
Essential fatty acids linoleic acid (an omega- 6 fafy acid) C 3
Fatty acids and melting point 3 C 3 C 3 C 3 C 3 C 3 C Can pack more closely together, increasing the strength of intermolecular bonding (dispersion forces) Therefore, saturated fats have a higher mel=ng point
Fatty acids and melting point C 3 C 3 C 3 C 3 Can t pack as closely together, decreasing the strength of intermolecular bonding (dispersion forces) Therefore, unsaturated fats have a lower mel=ng point
Triglycerides FaFy acid Glycerol FaFy Acid Triglyceride FaFy acid
Triglycerides Ester linkage R R R R R R + 3 2
Carbohydrates Made from C, and Simple sugars: Mono- and di- saccharides Monosaccharides: Glucose, fructose, galactose Disaccharides: sucrose, lactose, maltose Polysaccharides: Glycogen, starch, cellulose
Monosaccharides Mono = one Saccharides = sugar Glucose Fructose Galactose
Formation of disaccharides + - 2 Glucose Glucose Maltose Glycosidic linkage (ether)
Formation of disaccharides + - 2 Glucose Fructose Sucrose Di = two Saccharides = sugar
Polysaccharides Poly = many Saccharides = sugar Branched/unbranched Glycogen: Glucose storage in animals (when in excess) Starch: Glucose storage in plants Cellulose: 50,000 to 2,500,000 long glucose chains used as structural material in plants
Chemical structures of Glucose common sugars Sucrose Fructose 2 N N C 3 Aspartame Methyl L- α- aspartyl- L- phenylalaninate
Energy content of common sugars Sugar Energy content (kj/g) RelaMve Sweetness Glucose ~16 0.7 Sucrose ~16 1 Fructose ~16 1.8 Aspartame ~16 200
Proteins Long chains of amino acids (polypep=des) Shape determines func=onality Structure (ligaments, car=lage, skin, bone, etc) Enzymes (diges=on) ormones (insulin) Protec=on (an=bodies) Transport (haemoglobin) Lock and key
What are amino acids? Amine 2 N R Acid Side chain Can contain: alkyl chain ((C 2 ) n C 3 ) Acids (C) Amines (N 2 ) Thiols (S) Rings (e.g. benzene)
Some amino acid examples
Formation of peptides and proteins 2 N R - 2 PepMde linkage (amide) DipepMde
Levels of structure of proteins Primary structure: sequence of amino acids Secondary structure: three dimensional shapes/ structures (folding, plea=ng, coiling into helices) formed by hydrogen and other bonds Ter=ary structure: the overall shape of the protein Quaternary structure: arrangement of 2 or more protein molecules which acts as one func=onal structure (e.g. haemoglobin)
Enzymes A type of protein which acts as a biological catalyst Faster reac=on rates Allow reac=on to proceed under milder condi=ons Sensi=ve Selec=ve Lock and key model Ac=ve site Cofactors: non- protein parts of the enzyme in the ac=ve site which allow or enhance enzyme ac=on
Amino Acids in the diet Essen=al amino acids: Amino acids that the body cannot synthesise These MUST be consumed in the diet Non- essen=al amino acids: Amino acids that the body can synthesise readily. No nutri=onal supplementa=on is required Condi=onally essen=al amino acids: Amino acids that the body can synthesise but can be limited in certain circumstances. Nutri=onal supplementa=on is advised.
Amino Acids in the diet Nine essen=al amino acids: his=dine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan, and valine Six condi=onally essen=al amino acids: arginine, cysteine, glycine, glutamine, proline, and tyrosine Five non- essen=al amino acids: alanine, aspar=c acid, asparagine, glutamic acid and serine
Vitamins The only vitamin humans can synthesise is Vitamin D All others must be provided via the diet 3 C C C 3 3 C 3 C 3 C 3 Vitamin A1 ReMnol 3 C N P Vitamin B6 Pyridoxal phosphate C 3 C 3 C 3 3 C C 3 C 3 Vitamin E Tocopherol C 3
Vitamins C & D 3 C C 3 3 C C 3 Vitamin C Water soluble C 2 Vitamin D3 Fat soluble
Biomolecules Presented by Amelia McCutcheon