Unit 4: Carbohydrates and Lipids

monosaccharide

a single carbohydrate unit that can vary in functional groups, number of carbons, and stereochemistry

sterioisomers

having the same chemical formula and connectivity, but differ in orientation

pentose

a carbohydrate that has 5 carbons

hexose

a carbohydrate that has 6 carbons

aldose

a carbohydrate with a aldehyde present at carbon 1

ketose

a carbohydrate with a ketone present at carbon 1

enantiomers

stereoisomers that are non-superimposable mirror images

chiral

a molecule that cannot be superimposed on its mirror image

to assign D or L configuration, we look at the chiral carbon ________ the carbonyl group

farthest from

D carbohydrate

OH on right

L carbohydrate

OH on left

diasteomer

cannot form a mirror image of a molecule

anomeric carbon

the electrophilic carbon after the carbohydrate forms a ring

beta carbon

cis (up)

alpha carbon

trans (down)

_____ determines whether a sugar forms a five-membered or six-membered ring

stability

reduced sugar

has a free aldehyde group

monosaccharides form ____ bonds with other sugars

glycosidic

glycosidic bond

connection of the hemiacetal of one sugar with the hydroxyl group of another

disaccharide

connection of two monosaccharides

polysaccharides

connection of multiple carbohydrates

_____ carbons make the carbon reactive during the formation of glycosidic bonds

anomeric

fatty acids

a type of lipid consisting of a long hydrocarbon chain with a carboxylic acid group

saturated fatty acid

no double bonds, straight structure

unsaturated fatty acid

one or more double bonds,

triacylglycerol

made by attaching three fatty acids to a glycerol backbone through ester bonds

saturated fatty acids are most likely to be ___

solid (butter)

unsaturated fatty acids are most likely to be ____

liquid (oil)

saturated has _____ boiling/melting point

increased

unsaturated has ____ boiling/melting point

decreased

phospholipid

type of lipid made by attaching two fatty acids and a phosphate-containing group to a glycerol backbone

if unsaturated fatty acids were added to the phospholipid bilayer what would result?

more rigid/less fluid, less uniform

integral membrane proteins

proteins that span or embed within the bilayer

nonpolar

peripheral proteins

proteins that are attached to bilayers surface

polar

Thin Layer Chromatography (TLC)

measures polarity

polar molecules travel _____ on a TLC plate

less far

nonpolar molecules travel _____ on a TLC plate

farther

molecular exclusion chromatography

separated by size, with larger molecules eluting first

ion-exchange chromatography

separates based on charge

oppositely charged proteins bind to the beads and are eluted by changing the ionic strength or pH

affinity chromatography

separate based on binding

high-Performance Liquid Chromatography (HPLC)

separates based on polarity

gas chromatography

separated based on boiling point