Chemical Building blocks of life Raven Chp 3 Biochemistry

Biological molecules Molecules that are only made by living things Most are macromolecules

Types

Bio molecules all based on CARBON Carbon has 4 unpaired electrons, makes 4 covalent bonds Hydrocarbon chain carbon-hydrogen chains

Shorthand for Carbon hydrogen chain

Functional groups attach to carbon chain Determine specific functions

Isomers Organic molecules exist in different forms but have same chemical formula Stereo isomers are mirror images

Chiral molecules Mirror image isomers of carbon D form – Dextrorotary (right handed) L form – Levorotary (left handed) Biological molecules usually only are one or other L- Amino acids D - sugars

2 forms for all biomolecules Polymer form – chains Monomer form – single unit

Types of biomolecules Carbohydrates – starch, glycogen, cellulose Nucleic acids – DNA and RNA Proteins – structure, function Lipids – fats, phospholipids, steroids

Carbohydrates

Carbohydrates Monomer = monosaccharide Sugars and Starches and cellulose Function - Store energy and cell structure Easily available energy Made of Carbon, Hydrogen and Oxygen

Monosaccharides = One Simple sugars C6H12O6 (ratio 1:2:1) Ex. Glucose, fructose and galactose

Each type sugar has formula C6H12O6 1:2:1 ratio

Sugars are found in RING shape in nature

Structural Isomers Have same formula, but different molecular structure

Other sugars

Alcohol sugars – sugar substitute Contain calories, but metabolized differently Ex. Xylitol

Other alcohol sugars

Ingredient Sweetness GI Cal/g Sucrose (sugar) 100% 60 4 Maltitol Syrup 75% 52 3 Hydrogenated Starch Hydrolysate 33% 39 2.8 Maltitol 36 2.7 Xylitol 13 2.5 Isomalt 55% 9 2.1 Sorbitol 60% Lactitol 35% 6 2 Mannitol 1.5 Erythritol 70% 0.2

Disaccharides = two Double sugar Ex. Sucrose = glucose + fructose Dehydration synthesis – Water byproduct during bond formation

Other disaccharides Glucose + Glucose = maltose Glucose + Fructose = Sucrose (table sugar) Glucose + galactose = Lactose (milk sugar)

Polysaccharide = many Chain of simple sugars Fiber = polysaccharides Ex. Starch, cellulose, glycogen

Starch In plants Straight chains of glucose digestible

Starch types Amylose – long chains w/ no branches Amylopectin – Starch with branches

Glycogen = “animal starch” (Liver cells) glucose Branches

Cellulose Glucose bonds in opposite directions. Forms fiber, cell walls Human indigestible

Structure compare

Chitin Forms shells in arthropods

Nucleic Acids = DNA and RNA Very large complex organic molecules that store and carry information in a cell. NOT required nutrient DNA – contains Genetic code RNA – copies code and makes proteins

Nucleic acids are made of Nucleotides linked together Nucleotide = monomer

Nucleotides contain 1 – Sugar 2 – Phosphate 3 – Nitrogen Base

DNA backbone Made of sugar and phosphates

DNA has 4 nitrogen bases A = Adenine T = Thymine G = Guanine C = Cytosine This is the 4 letter alphabet for DNA

DNA (DeoxyRibonucleic Acid) Forms Double helix Contains all the information a cell needs to reproduce and grow Contained in nucleus Must be replicated prior to cell division

RNA (RiboNucleic Acid) 3 different types. Has uracil instead of thymine Has ribose instead of deoxyribose RNA reads the DNA and then builds proteins for the body

Proteins

Proteins C + H + O + N Building blocks of cells. Contain Nitrogen as well as Carbon, Hydrogen and Oxygen C + H + O + N

Protein functions Enzymes – catalyze reactions Defense – antibodies , toxins (venom) Transport – membrane transport and hemoglobin Support – fibers such as hair keratin Motion – muscles and contraction of cell Regulation – hormones

Proteins are made of chains of Amino Acids There are 20 different Amino Acids Each have: - Amino group (-NH2) - Carboxyl (-COOH) - R group (other)

Peptide bonds link amino acids Also Dehydration synthesis. Water is formed at each bond

Hydrolysis is the breaking of a peptide bond Water added

Shape of protein determines function Primary structure – sequence of amino acids Secondary structure – alpha helix, beta pleated sheets Tertiary structure – Hydrogen bonds hydrophobic interactions, ionic bonds Quaternary structure – 2 or more poly peptides together

H bonds form secondary structure

Tertiary structure forms from other bonds

Denaturing proteins Heat etc. will break bonds of protein tertiary structure. reversible

Lipids (Fats)

C + H > O Lipids (Fats) Store energy, Form cell membranes. Hydrophobic -Do not dissolve in water. Lipids have much more Carbon and Hydrogen than Oxygen C + H > O

Fats are made of fatty acids Have a Hydrocarbon chain Hydrocarbons are hydrophobic

Triglycerides = fats Fatty acids attach to glycerol

Saturated fats Are filled up with hydrogen and tend to be solid Ex: butter Animal fats

Unsaturated fats Are not filled up with hydrogen (double bonds) and tend to be liquid Ex. Plant fats, corn oil, olive oil

Saturated vs. Unsaturated Saturated = straight, fit tight together Unsaturated = bent, fit loose together

TRANS FATS =Unsaturated but act like saturated Should they be banned?

Trans fats Unsaturated Trans fat Saturated Unsaturated has one Trans double bond. Hydrogens on opposite sides. Acts like saturated Saturated Has no double bonds Straight Unsaturated Has one Cis double bond. Hydrogens on same side of bond. bends

Phospholipids Main building blocks of cell membrane Heads (glycerol and phosphate groups) hydrophilic (polar) 2 Fatty acid tails hydrophobic

Steroids Hydrophobic hormones and cholesterol Have 4 carbon rings

vitamin D Sunlight turns cholesterol to vitamin D

Terpenes Pigment lipids Chlorophyll in plants Retinol in eye retina