Glycosaminoglycans and Proteoglycans
Covers the structure and function of glycosaminoglycans, proteoglycans, glycoproteins, and lectins in biochemistry
Questions
Which glycosaminoglycan does not contain uronic acid and their sulphate content is variable?
- Hyaluronate
- Keratan sulfate
- Laminin
- Dermatan sulfate
- Chondrotin sulfate
Which is the only glycosaminoglycan that is exclusively nonsulfated?
Glycosaminoglycans have high degrees of heterogeneity with regards to molecular weight, disaccharide construction and sulfation due to the fact that GAG synthesis, unlike proteins or nucleic acids, is not template driven, and dynamically modulated by processing enzymes. Members of the glycosaminoglycan family vary in the type of hexosamine, hexose or hexuronic acid unit they contain.
- Hyaluronan
- Heparin
- Keratan sulfate
- Heparan sulfate
- Dermatan sulfate
What is the main function of heparin?
- Electrostatically retains and stores histamine
- Regulation of cell growth and proliferation
- Maintenance of tissue hydration
- Inhibition of axonal growth
- Major component of synovial tissues and fluid
Which of the following is not a glycoprotein?
- Thyroid stimulating hormone
- Immunoglobulin
- Syndecan
- Glycophorin A
- Luteinizing hormone
Which of the following proteoglycans are included in the small leucine - rich proteoglycan family?
Small leucine-rich proteoglycan (SLRP) family consists of a protein core containing leucine repeats with a glycosaminoglycan (GAG) chain consisting of either chondroitin sulfate (CS) or dermatansulfate (DS).
- Versican
- Decorin
- Aggrecan
- Perlecan
- None of these
Which heteropolysaccharide serves as lubricant in the synovial fluid of the joints?
- Heparin
- Peptidoglycan
- Hyaluronate
- Heparan sulphate
- Proteoglycans
Which of the following is a mannose - binding lectin?
Lectins are carbohydrate-binding proteins that are highly specific for sugar moieties, particularly, the high specificity of plant lectins for foreign glycoconjugates. Lectins serve a wide variety of cell-cell recognition, signalling and adhesion processes and intracellular targeting of newly syntheisized proteins. Most lectins do not possess enzymatic activity and are not produced naturally by the immune system. They may bind to a soluble carbohydrate or to a carbohydrate moiety that is a part of aglycoproteinor glycolipid. They typically agglutinate certain animal cells and/or precipitate glycoconjugates.
- Peanut agglutinin
- Wheat germ agglutinin
- Concanavalin A
- Jacalin
- Elderberry lectin