Chapter 8 & 9: Carbohydrates and Lipids Terms

Monosaccharide

single sugar molecule, building blocks or monomer of carbohydrates or sugars

Dissaccharide

two sugar molecules, polymer of carbohydrates or sugars

Glycan

polysaccharide (large sugar molecule composed of multiple carbohydrates via glycosidic bonds)

Glyconjugates

sugar molecules that are covalently attached to proteins, lipids, or amino acids (peptides)

ketose

a sugar molecule that contains a ketone

aldose

a sugar molecule that contains a aldehyde

enantiomer

isomers that are mirror images of each other, nonsuperimposable

epimer

a single chiral carbon atom differentiation between sugar molecules

anomeric carbon

the carbon that determines if the sugar molecule is in the alpha or beta orientation (6 sugar rings is 1C, 5 sugar rings is 2C)

anomer

isomers that differentiate between alpha and beta orientations (only found in cyclic structures)

reducing sugar

a sugar molecule that has a free aldehyde or ketone (a free anomeric carbon)

non-reducing sugar

a sugar molecule that is participating in chemical reactions at its anomeric carbon (no free anomeric carbons)

glycosidic bond

a covalent bond between sugars

oligosaccharide

a small chain of polysaccharides (2-10 monosaccharides)

polysaccharide

a long chain of monosaccharides (+10 monossaccharides)

glycogen

Energy sugar storage in animals that are formed via alpha-1,4 linkages and several alpha-1,6 branch linkages

cellulose

parallel glucose molecules that form a sheet via beta-1,4 linkages and hydrogen bonding between chains that are used to form plant cell walls

Chitin

parallel N-acetylglucosamine molecules that form a sheet via beta-1,4 linkages and hydrogen bonding between chains that are used to form fungal cell walls (& exoskeletons of anthropods)

Amylose

a linear polymer of glucose molecules connected by alpha-1,4 linkages that form a helical structure and sever as a starch in plants for energy storage

Amylopectin

a branched polymer of glucose molecules connected by both alpha-1,4 and alpha-1,6 linkages, serving as a major component of starch in plants, allowing for rapid energy release

Proteoglycan

a large sugar molecule composed of a glycosaminoglycan (GAGs) and proteins used for linkages; features disaccharide repeating units, highly modified sugar groups, and a jelly-like texture that is used in the extracellular matrix of connective tissues

Peptidogylcans

long sugar chain molecules that are connected to small peptides/amino acid residues that are used in building plant cell walls

Glycoproteins

large globular proteins that are attached to sugar proteins via glycosylation to N- or O-glycosides to amino residues that contain a -OH group (Asn, Ser, Thr) that are responsible for cell-to-cell signaling/communication

Lectins

any protein that binds to sugar groups; a type of glycoprotein that is secreted through the membrane that features a binding site (no chemistry happens) that is highly specific about the isomer it binds via extensive hydrogen bonding that facilitates cell-to-cell communication

Fatty Acids

a type of lipid that contains a polar COOH head and a non-polar hydrocarbon tail

Triglycerols

a type of lipid that contains a glycerol backbone formed by three carbons with -OH groups that are connected to three fatty acid tails via condensation/dehydration reactions between the -OH groups and the carboxyl groups of the fatty acids

Phospholipids

a type of lipid that consists of a glycerol backbone, two fatty acid tails, and a phosphate group, which form lipid bilayers in cell membranes

Phosphoglycerides

a type of phospholipid that has a glycerol backbone, with two fatty acids, a phosphate group, and an amino-alcohol group

Sphingomyelins

a type of phospholipid that contains a sphingosine backbone that features a 3C chain connected to 2 -OH groups and a single -NH3 group and a trans C=C that leads into a fatty acid tail

Glycolipids

a type of lipid that connects a sugar molecule to a sphingosine or glycerol backbone (sugar is always connected to the primary alcohol of the sphingosine)

Cerebrosides

a type of glycolipid that contains a single sugar molecule bonded to a ceramide backbone

Gangliosides

a type of glycolipid that contains a branched chain of multiple sugars attached to a ceramide backbone, that rest on cell surfaces and act as receptors for recognition

Steroid

a type of lipid that contains a ABCD core structure that features 3 6-membered rings and a single 5-membered ring followed by a hydrocarbon tail

Cholesterol

a type of steroid that serves as the precursor to all steroid hormones

Steroid hormones

molecules derived from cholesterol that are highly modified to assist in regulating various physiological processes, including metabolism, immune function, and sexual characteristics

Waxes

a type of lipid that contains long fatty acid chains connected via ester linkages

Isoprenoids

a type of lipid that contains repeating units of isoprene that is found mostly in plants

Eicosinoid

a type of lipid derived from arachidonic acid, which is converted into PGH2 that serves as a precursor to all eicosanoids that are faster acting than hormones in assisting pain, fever, blood pressure and clotting regulation via localized on-site production and signaling

lipid membranes

sheet-like structures that contain two phospholipids that form closed boundaries via hydrophobic aggregation