BIO - TERMS - SUGAR Flashcards
1→4 Link
A glycoside link between the C1 -OH group of one sugar and the C4 -OH group of another sugar.
agar
A complex polysaccharide derived from a marine alga and used as a solidifying agent in culture media.
Aglycone
The nonsugar part of a glycoside (after removal of the sugar part).
Alditol
The polyalcohol resulting from reduction of the carbonyl group of a sugar.
Amino sugar
A sugar with one of its -OH groups replaced by -NH2.
aminoglycoside
An antibiotic consisting of amino sugars and an aminocyclitol ring; for example, streptomycin.
amylose
Starch consisting of straight chains of glucose. anaerobic Energy systems that do not have an oxygen requirement.
anomeric carbon
The carbon atom in a sugar at the new stereocenter formed when a sugar cyclizes to form a hemiacetal. This is the carbonyl carbon of aldehydes and ketones.
Anomeric center
The hemiacetal carbon atom in the cyclic pyranose or furanose form of a sugar.
Asialoglycoprotein
Glycoprotein that has lost the terminal sialic acid residues from its oligosaccharides; undergoes endocytosis by the liver.
b-glucan
A polysaccharide composed of d-glucose units linked by b-glycosidic bonds.
Bi-desmosidic saponins
Saponins with 2 sugar chains.
capsulated bacteria
Referring to bacteria surrounded by a polysaccharide shell that resists actions of phagocytes, resulting in pus formation at the site of infection. Also called pyogenic (pus-forming) bacteria.
Carbohydrate loading
A procedure aimed at the buildup of large muscle glycogen stores in endurance athletes.
carbohydrate response element-binding protein (ChREBP)
A transcription protein activated by a highcarbohydrate diet that upregulates genes that promote enzymes used in lipid synthesis.
carbon fixation
The synthesis of sugars by using carbons from CO2. See also Calvin-Benson cycle.
Catabolite activator protein (CAP)
A positive regulatory protein that in the presence of cyclic AMP (cAMP) binds to the promoter regions of operons and stimulates their transcription. CAP/cAMP assures that glucose is used as a carbon source when present rather than less-efficient energy sources such as lactose, arabinose, and other sugars. When glucose is present, it prevents the synthesis of cAMP and thus the activation of transcription by CAP/cAMP.
cellular respiration
Multistep metabolic pathway in which organic molecules (e.g., glucose) are disassembled in a controlled manner by a series of enzymes to eventually form ATP.
chitin
A carbohydrate that is a polymer of N-acetylglucosamine and composes the shells or exoskeletons of insects and crustacean. It is considered a type of human dietary fiber.
collectins
A family of calcium-dependent sugar-binding proteins (lectins) containing collagen-like sequences. An example is mannose-binding lectin (MBL).
complex oligosaccharides
Broad class of N-linked oligosaccharides, attached to mammalian glycoproteins in the endoplasmic reticulum and modified in the Golgi apparatus, containing N-acetylglucosamine, galactose, sialic acid, and fucose residues.
conjugate vaccines
Antibacterial vaccines made from bacterial capsular polysaccharides bound to proteins of known immunogenicity, such as tetanus toxoid.
cross-linking glycan
One of a heterogeneous group of branched polysaccharides that help to cross-link cellulose microfibrils into a complex network. Has a long linear backbone of one sugar type (glucose, xylose, or mannose) with short side chains of other sugars.
cross-over concept
Lower-intensity exercise receives its ATP primarily from the oxidation of fat and some carbohydrates.
Cyanogenic glycosides
Vacuolar glycosides where the aglycone contains labile cyanide, which is released on cleavage of the glucose moiety and may serve as a defense compound.
d Sugars
Sugars whose hydroxyl group at the chirality center farthest from the carbonyl group has the same coniguration as D-glyceraldehyde and points to the right when drawn in Fischer projection.
Deoxy sugar
A sugar with one of its -OH groups replaced by an -H.
deoxyribose
A five-carbon sugar contained in DNA nucleotides.
Entner-Doudoroff pathway
An alternative pathway for the oxidation of glucose to pyruvic acid.
Essential monosaccharide
One of eight simple sugars that is best obtained in the diet rather than by biosynthesis.
ethanol fermentation
The anaerobic conversion of glucose to ethanol via glycolysis; also called alcohol fermentation. See also fermentation.
euglycemia
Achievement of an optimal fasting blood glucose level by hormonal regulation.
exogenous pyrogen
Any substance originating outside the body that can induce fever, such as the bacterial lipopolysaccharide LPS. Cf. endogenous pyrogens.
fast glycolysis
One of the two ways in which glycolysis proceeds. Fast glycolysis results in the formation of lactic acid from the breakdown of glucose and has a faster rate of energy supply when compared to slow glycolysis.
fermentation test
Method used to determine whether a bacterium or yeast ferments a specific carbohydrate; usually performed in a peptone broth containing the carbohydrate, a pH indicator, and an inverted tube to trap gas.
ficolins
Carbohydrate-binding proteins that can initiate the lectin pathway of complement activation. They are members of the collectin family and bind to the N-acetylglucosamine present on the surface of some pathogens.
fructose
Monosaccharide found in fruits and honey and as half of the disaccharide sucrose.
Fructose-2,6-bisphosphate
A regulatory metabolite that mediates hormonal effects on phosphofructokinase and fructose-1,6-bisphosphatase.
Furanose
The five-membered-ring form of a simple sugar.
Furanose ring
Five-member ring in monosaccharides.
galactose
Monosaccharide found, to a limited degree, in foods and as half of the disaccharide lactose.
glucosamine
A basic building block of glycosaminoglycans; consists of glucose with an attached amine group.
Glucose oxidase test
An enzymatic method for the selective determination of glucose in the clinical laboratory.
glucose tolerance
The ability to appropriately reestablish euglycemia following meal-induced hyperglycemia.
Glucose tolerance test
A laboratory test that determines the effect of glucose ingestion on the blood glucose level.
glucose transporter 5 (GLUT5)
A family of transport proteins that shuttle fructose across cell membranes.
glucose-6-phosphate
Created in the first reaction of glycolysis; can be used to make glycogen, to enter the pentose phosphate pathway, or to continue glycolysis.
Glycal
An unsaturated sugar with a C1–C2 double bond.
Glycal assembly method
A method for linking monosaccharides together to synthesize polysaccharides.
glycan
A polymer of monosaccharide units joined by glycosidic bonds; polysaccharide.
glycemia
The level of glucose in the blood.
glycemic load
The glycemic index of a food normalized for a standard serving size for a food.
glycemic response
The degree and duration of elevation of blood glucose level that is produced by eating a specific food.
Glycoforms
The total set of forms of a protein that differ in the number, location, and nature of oligosaccharide chains. ( Chapter 12)
glycogenin
The protein that both primes the synthesis of new glycogen chains and catalyzes the polymerization of the first few sugar residues of each chain before glycogen synthase continues the extension.
glycolytic system
The energy system that provides energy via the breakdown of glucose; also known as glycolysis. It generally supplies energy for higher-intensity activities lasting 20 s to 2 min.
glycome
The full complement of carbohydrates and carbohydrate-containing molecules of a cell or tissue under a particular set of conditions.
Glycosidic bond
Bond formed by the anomeric carbon of a monosaccharide.
glycosidic linkage
A bond between carbohydrates that results from a dehydration reaction.
glycosuria
(glı̄-kō-sū′rē-ă) Presence of glucose in urine; symptom of diabetes mellitus (also called glucosuria).
glyoxylate cycle
A variant of the citric acid cycle, for the net conversion of acetate into succinate and, eventually, new carbohydrate; present in bacteria and some plant cells.
GPI-anchored protein
A protein held to the outer monolayer of the plasma membrane by its covalent attachment through a short oligosaccharide chain to a phosphatidylinositol molecule in the membrane.
Haworth perspective formulas
A method for representing cyclic chemical structures so as to define the configuration of each substituent group; commonly used for representing sugars.
hemicellulose
A fiber component composed of pentose and hexose sugars covalently bonded in a b1–4 linkage with branching side chains.
Hemoglobin A1c
Hemoglobin A modified by a reaction between terminal amino groups and glucose.
Hereditary fructose intolerance
Inherited defect in hepatic fructose metabolism.
heteropolysaccharide
A polysaccharide containing more than one type of sugar.
high-mannose oligosaccharides
Broad class of N-linked oligosaccharides, attached to mammalian glycoproteins in the endoplasmic reticulum, containing two N-acetylglucosamine residues and many mannose residues.
HPV
Human papillomavirus; infects the cervical epithelium and is important as a cause of carcinoma of the uterine cervix. hyaluronan (hyaluronic acid) Type of nonsulfated glycosaminoglycan with a regular repeating sequence of up to 25,000 identical disaccharide units, not linked to a core protein. Found in the fluid lubricating joints and in many other tissues.
hyaluronan
A high molecular weight, acidic polysaccharide typically composed of the alternating disaccharide GlcUA(1n3)GlcNAc; a major component of the extracellular matrix, forming larger complexes (proteoglycans) with proteins and other acidic polysaccharides. Also called hyaluronic acid.
hyperglycemia
Elevated blood glucose level.
hyperglycinemia
Increased blood levels of the amino acid glycine.
hyperinsulinemia
Elevation of the level of insulin in circulation in response to an increase in blood glucose.
Indirectly anchored proteins
Proteins that are indirectly bound to the plasma membrane by interacting with either integral membrane proteins or the charged sugars of membrane glycolipids. (Chapter 2)
inflammatory inducers
Chemical structures that indicate the presence of invading microbes or cellular damage, such as bacterial lipopolysaccharides, extracellular ATP, or urate crystals.
informational macromolecules
Biomolecules containing information in the form of specific sequences of different monomers; for example, many proteins, lipids, polysaccharides, and nucleic acids.
Kiliani–Fischer synthesis
A method for lengthening the chain of an aldose sugar.
L Sugar
A sugar whose hydroxyl group at the chirality center farthest from the carbonyl group points to the left when drawn in Fischer projection.
light-independent (dark) reactions
The process by which electrons and energy from ATP are used to reduce CO2 to sugar. See also Calvin-Benson cycle.
malting
The germination of starchy grains resulting in glucose and maltose production.
maltodextrin
A polysaccharide that consists of small links of glucose with a branch point. Can be produced by partially digesting starch.
mannose receptor (MR)
A receptor on macrophages that is specific for mannose-containing carbohydrates that occur on the surfaces of pathogens but not on host cells.
Mucopolysaccharidoses
Lysosomal storage diseases caused by deficiencies of glycosaminoglycan (GAG)- degrading enzymes.
N-Acetylneuraminic acid
Sialic acid; an acidic sugar derivative in glycolipids and glycoproteins.
N-Linked oligosaccharides
Oligosaccharides bound to asparagine side chains in glycoproteins.
O-glycosidic bonds
Bonds between a sugar and another molecule (typically an alcohol, purine, pyrimidine, or sugar) through an intervening oxygen.
O-linked glycosylation
Addition of one or more sugars to a hydroxyl group on a protein.
O-linked oligosaccharides
Oligosaccharides bound to hydroxyl groups in proteins.
oligomer
A short polymer, usually of amino acids, sugars, or nucleotides; the definition of “short” is somewhat arbitrary, but usually fewer than 50 subunits.
Polyol pathway
A pathway that synthesizes fructose from glucose.
protein glycosylation
Process of transferring a single saccharide or preformed precursor oligosaccharide to proteins.
Pyranose
The six-membered, cyclic hemiacetal form of a simple sugar.
Pyranose ring
Six-member ring in monosaccharides.
reducing end
The end of a polysaccharide having a terminal sugar with a free anomeric carbon; the terminal residue can act as a reducing sugar.
Saccharide
A sugar.
shikimic acid pathway
A biochemical pathway where simple carbohydrate intermediates of glycolysis and the pentose phosphate pathway (PPP) are converted to the aromatic amino acids phenylalanine, tyrosine, and tryptophan. Further chemical modifications lead to the synthesis of phenolic compounds such as flavones, isoflavones, and flavanols.
simple sugars
Carbohydrates that cannot be broken down into smaller sugars by hydrolysis.
slow glycolysis
One of the two ways in which glycolysis proceeds. Slow glycolysis results in the formation of pyruvate from the breakdown of glucose and proceeds with a rate slower than fast glycolysis.
Sorbitol
A sugar alcohol formed by aldose reductase; intermediate in fructose biosynthesis.
sulfated sialyl-LewisX
A sulfated tetrasaccharide carbohydrate structure attached to many cell surface proteins, it binds the P-selectin and E-selectin molecules on the surface of cells, such as neutrophils, that mediate interactions with the endothelium.
teichoic acid
A polysaccharide found in gram-positive cell walls.
TLR-4
Cell-surface Toll-like receptor that, in conjunction with the accessory proteins MD-2 and CD14, recognizes bacterial lipopolysaccharide and lipoteichoic acid.
von Gierke disease
Deficiency of glucose-6-phosphatase, causing hepatomegaly and severe fasting hypoglycemia.
Wohl degradation
A method for shortening the chain of an aldose sugar by one carbon.
α-Anomer
The cyclic hemiacetal form of a sugar that has the hemiacetal -OH group cis to the -OH at the lowest chirality center in a Fischer projection.
β-Anomer
The cyclic hemiacetal form of a sugar that has the hemiacetal -OH group trans to the -OH at the lowest chirality center in a Fischer projection.
