Lecture+2

You need however to recognize the hydrophobic

Info iconThis preview shows page 1. Sign up to view the full content.

View Full Document Right Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: - Table of amino acid structure No need to memorize any specific structure. You need, however, to recognize the hydrophobic, hydrophylic, acidic properties of the amino acid by the structure. from NEB.com -5- Polysaccharides • Sugars are the monomers that build polysaccharides (the polymer). A sugar consists of a carbon chain (typically 3-7 C) with one OH on most carbons. The sugar molecule can be either linear or circularized. • monosaccharides: one-sugar, glucose • coh-coh-coh-coh-coh-ch=o == coh-c(ring)-o-c(ring) <-ring formation • common sugars exist in 3 to 7 carbon chains: pentose for 5, hexose for 6 • glycosidic linkage (a covalent bond) attaches two sugars: glucose + fructose • • • function: • storage (remove water by polymerization and packing). Starch in seed or storage organs (rice, bread, potato) • structure (cell wall of plants; paper; crab skeleton) Lipids • Fatty acids • saturated, unsaturated • triglyceride (storage unit) R-OH (glycerol) + COOH-R (f.a.). 2: diglycerides, 3: triglycerides -6- • saturated fatty acids free or as glycerides become solid at higher temperatures than the corresponding unsaturated compounds. This is because the kinks introduced by the unsaturated (=double) bonds prevent good cohesion between fatty acid chains. An industrial process called lipid hydrogenation is used to convert natural, unsaturated lipids to saturated ones because these are more desirable as foods (such as margarine). In the process of hydrogenation, H are added to the fatty acid chain to convert double bonds to single bonds. This conversion is not complete in most cases. The double bond left after hydrogenation are changed in their nature. Instead of having the H- on the same side (cis) they have them on opposite sides (trans). Trans-fats are thought to be bad for human health. • Phospholipids: polar head, hydrophobic tail • phosphatidylcholine: N+(CH3)4-C-O-PO(neg)-O-C[glycerol]-2FA • function of P'lipid - lipid...
View Full Document

Ask a homework question - tutors are online