Major Organic Compounds in our body

Glucose

Carbohydrates = sugars Made out of monosaccharides. 1 sugar = Monosaccharide Monosaccharide + Monosaccharide = disaccharide E.g. Glucose + Fructose = Sucrose (table salt) Many monosaccharides linked = polysaccharide E.g. Glucose x many = starch

Glucose Sucrose Starch Fructose

Uses Produce ATP (energy) Store energy – e.g. glycogen in our liver Structure – e.g. Cellulose in plant cell walls e.g. Chitin in insect exoskeletons

Fatty acid

Lipids = fats (mostly) Fats are made out of fatty acids. Three fatty acids + glycerol combine to form a triglyceride. Molecules like Cholesterol can be lipids but not fats.

Fatty acids Glycerol backbone -> Triglyceride Cholesterol

Uses Produce ATP (energy) Store energy – e.g. liver stores triglycerides e.g. adipose tissue stores fats. Structure – e.g. phosphor’lipid’ bilayer Signaling – e.g. steroid hormones like testosterone, estrogen

Protein

Proteins Proteins are chains of amino acids Few amino acids linked together = Peptide Peptide x many = Polypeptide Proteins are chained together by a peptide bond. Different amino acids have a carbon oxygen nitrogen backbone with different R groups.

Amino Acid

Protein chain

Uses Produce ATP (energy) Enzymes – e.g. pepsin, DNA polymerase, amylase etc. Signaling – e.g. Insulin, glucagon Membrane channels, receptors Structure – e.g. collagen, tubulin, actin Locomotion – e.g. actin, myosin

DNA

Nucleic acids (in DNA and RNA) Nucleic Acids have a Sugar backbone, a Phosphate group, and a nitrogenous base. DNA and RNA are made up of nucleic acids. RNA – Ribonucleic Acid DNA – Deoxyribose Nucleic Acid The sugar backbone has one less Oxygen compared to RNA

Nucleic Acids DNA

Uses Encodes genetic information (DNA). Transmits genetic information (DNA). Expresses genetic information (RNA).

Simple Organic Compounds tests

Benedict’s test Clear blue solution When added to and heated with a simple sugars (e.g. glucose) and some disaccharides (e.g. lactose), turns red. Blue (no reaction) – no simple sugars Yellow, orange (partial reaction) – some simple sugars Red (Full reaction) – lots of simple sugars

Iodine Test Brownish Yellow solution When added to starch, turns purple black. Brown (no reaction) – no starch Somewhere in between (partial reaction) – some starch Purple black (Full reaction) – lots of starch

Biuret test Clear blue solution When added to proteins, turns Pink Purple. Blue (no reaction) – no proteins Somewhere in between (partial reaction) – some proteins Pink Purple (Full reaction) – lots of proteins

Brown paper bag test It’s a Brown paper bag? When the sample solutions is dropped onto the Brown paper bag, the paper turns translucent. No change after dryness – No lipids Turns translucent – there are lipids