Carbohydrates Flashcards
Carbs
Most abundant organic molecule in nature
Function of Carbs
Energy, Cell membrane components for intercellular communication, and bacterial cell walls
6-C Structures prefer…
to be in an aromatic shape C6H1206
Carbs most common configuration in body…
D configuration
Racemases
enzymes that conver simple sugars between the L and D forms
Monosaccharides
Glyceraldehyde –> Arabinose –>Glucose & Mannose
Glyceraldehyde –> Lyxose –> Galactose
Dihydroxyacetone –> Ribulose –> Fructose
Isomers
Compounds with the same chemical formula
EX: Glucose, Fructose, Galactose
Epimers
Monosaccharide differ around a specific C.
EX: Galactose and glucose around C4
Mannose and Glucose around C2
Enantiomers
Non-super imposable mirror images. They are chiral.
Anomers
Cyclization creates an anomeric C. This creates an alpha and beta configuration. They can spontaneously switch forms which is called mutarotation. They help maintain the equilibrium in the body.
EX: alpha-D-glucopyranose: synthesizes glycogen
beta-D-glucopyranose: synthesizes cellulose
Glycosidic Bonds
Link monosaccharides. C1 Galactose, C4 Glucose
a config = a bond, B config = b bond
Glycosyltransferase
enzyme that forms Glycosidic Bonds
Lactose bond type
galactosyl- B (1-4) glucose
Asparagine & Sugar bond type
N-glycosidic bond (due to NH)
Serine & Sugar bond type
O-glycosidic bond (due to OH)
Disaccharide
2 Monosaccharides
Oligosaccharide
3-12 Monosaccharides
Polysaccharide
12 or more Monosaccharides
Sucrose
Glucose and Fructose.
1a-2B bond
Broken down by Sucrase.
Lactose
Galactose and Glucose.
1B-4 bond
Broken down by Lactase.
Maltose
Glucose and Glucose
1a-4 bond.
Broken down by Maltase.
Cellobiose
Glucose and Glucose
1B-4 bond.
a-amylase
Breaks down Starches
Hydrolysis
Glycosidase and H2O help to add OH on to seperate.
Starch Breakdown
- -> isomaltose (isomaltase or a-dextrinase) –> Glucose
- -> imaltose &imaltotriose (maltase) –> Glucose
Mouth Digestion
salivary a-amylase breaks starch into a-dextrins
Stomach Digestion
low pH stops salivary amylase - NO CARB DIGESTION
Small Intestine Digestion
Acid neutralized by bicarbonate secreted by pancrease. Pancreatic a-amylase continues. Final, enzymes synthesized by intestinal mucosal cells.
Glucose, Galactose, & Fructose–>liver via portal circulation.
Tri & oligosaccharides broken down in SI.
Lactase Deficiency
in the large intestine, lactose is broken down by bacteria into 2C metabolites, 3C metabolites and CO2
Portal Circulation
Small Intestine lactose uses B-galactosidase to go to galactose & glucose
Glycosaminoglycans (GAG)
Long unbranched repeating disaccharide units.
Compose: Catilage, Tendons, Skin, Blood vessels, Collagen, & Elastin.
Hyaluronate
Makes up the Synovial Fluid and Hyaluronic Acid
Chondriotin-4-sulfate & Chondroitin-6-sulfate
Makes up tendons and Ligaments
Dermatan sulfate & Keratan sulfate & Heparin
Makes up Connective Tissue
Proteoglycans
Found in the cartilage, they are the core protein that linear GAG chains covalently attach to. (Bottle Brush form)
Common GAG: chondroitin sulfate & keratan sulfate
Glycopoteins
Proteins attached to oligosaccharides covalently.
Branches instead of linear. Attaches to amino acids.
Used in Cell phenomena: surface antigenicity, surface recognition & mucins in GI tract & urogenital tract.
