Carbohydrates and Lipids Flashcards
What are carbohydrates?
Organic molecules composed of carbon, hydrogen, and oxygen
Chemically defined as polyhydroxy aldehydes or ketones
What are three physiological functions of carbohydrates?
Energy source and storage
Cellular communication in cell membrane
Structural
What are four monosaccharides of physiological importance?
d-glucose
d-mannose
d-galactose
d-fructose
What are the key physiological functions of glucose?
Energy
Storage
Glycosylation reactions
Precursor for other molecules
What are the key physiological functions of fructose?
Energy source
Storage
Fatty acid synthesis
What is the key physiological function of mannose?
Protein glycosylation
What are the key physiological functions of galactose?
Energy source - converted to glucose
Milk production during lactation
Protein glycosylation in nerves
What are the disaccharides of physiological importance?
Sucrose - glucose and fructose
Lactose - glucose and galactose
Maltose - glucose and glucose
What are the polysaccharides of physiological importance?
Cellulose
Starch
Glycogen
What are isomers?
Compounds with the same molecular formula, but different structures
What are epimers?
Differ in configuration around 1 carbon
What bonds to monosaccharides form and with what enzyme?
Glycosidic bonds
Glycosyltransferases
What are glycosaminoglycans (GAGs)?
Complex heteropolysaccharide chains
Associated with proteoglycans to form gel-like matrix
Form mucous secretions and synovial fluids
What are the key properties of lipids?
Hydrophobic
Compartmentalized in cells and body fluids
What are the key functions of lipids?
Partitioning cellular compartments
Cofactors
Fat-soluble vitamin absorption
Energy
Cell communication - hormonal function
