BT-202 Netaji Subhas Institute of Technology, Dwarka, New Delhi. Dr. Amita Pandey Aug 24, 2011
Syllabus for mid-term Properties of water ✔ Acids and bases and buffers ✔ Covalent bond ✔ Non-covalent interactions in biological system ✔ Carbohydrates ✔ Proteins Enzymes Lipids Nucleic acids Vitamins and Co-enzymes Separation technique for biomolecules
What is the molecular formula for glucose?
C6 H12 O6
C12 H22 O11
C12 H22 O11
Which of the following is a simple sugar or monosaccharide?
Maltose is composed of which two simple sugars?
Glucose and galactose
Glucose and fructose
Glucose and glucose
What kind of sugars are found in the disaccharide sucrose?
Fructose and galactose
Glucose and fructose
Polysaccharides are polymers of monosaccharides also called glycans.
Polysaccharides differ from each other
-identity of the recurring monosaccharide units.
-length of their chains.
-degree of branching.
Starch in plants and glycogen in animals are the most important storage polysaccharide.
Both occur as intracellular granules or large clusters.
Heavily hydrated since they have many exposed hydroxyl groups.
Homopolysaccharides as stored fuel
Starch and Glycogen
Contains amylose and amylopectin which are glucose polymers.
Amylose has long chains of D-glucose. residues connected by ( α1 4) linkage.
Amylopectin is branched ( α1 6). Branching occur every 24-30 residues.
Most abundantly found in tubers in plants.
Glycogen is more extensively branched (branch on average at every 8-12 residues). More compact than starch.
Liver (hepatocytes), skeletal muscles.
Dextran: used in Size exclusion chromatography.
Homoploysaccharides as structural biomolecules
Cellulose is fibrous, tough, and water insoluble substance found in cell walls of plant cells.
It is linear, unbranched, consisting of D-glucose monomers with ( β 1 4)-linkage.
Termites, bacteria, ruminants, cattles, and wood fungus can break down
Why animals cannot use cellulose as a fuel?
Composed of N -acetylglucosamine residues in ( β 1 4)-linkage.
Heteropolysaccharides as structural components
repeating disaccharide units
-either N-acetylglucosamnie or N- acetylgalactosamine.
-D-glucuronic acid or L-iduronic acid.
esterified sulfate groups.
Present in ECM.
( β 1 4)-linked
N -acetylglucosamine and
N -acetylmuramic acid units.
Polysaccharides as information carriers
Communication between cell and extracellular components.
Transportation of proteins.
Recognition sites for extracellular signal molecules.
Glycocalyx serves is made up of oligosaccharides.
Carbohydrate protein conjugates.
Eg. Mucins, glycophorin A, immunoglobins, and certain harmones, collagen.
Oligosaccharide chains are attached either posttranslation or cotranslation modification.
systematic characterization of all the carbohydrate component of the cell or tissue, including those attached to proteins and to lipids.
What is the biological advantage of adding oligosaccharides to proteins?
How Lysozyme kills bacteria?
What is mode of action of penicillin?
Separation techniques for Carbohydrates
Mixture dissolved in liquid or solid
Porous solid matrix
Components of mixture pass through the column at different rates based on properties
Size/molecular exclusion chromatography
Stationary phase = gels with pores of particular size
Molecules separate based on size
Small molecules caught in pores
Large molecules pass through
Matrix chemically altered to include a molecule designed to bind a particular carbohydrate
Other carbohydrates pass through
Separation is based on highly specific interactions.
Lectin affinity chromatography is when lectin is used to separate components within a mixture. Lectin binds to carbodydrates. Eg. Concanavalin A
High Performance Liquid Chromatography (HPLC)
-Stationary phase = small uniform particles, large surface area
-a solvent is forced through under high pressures of up to 400 atmospheres.
-Adapt to separate based on polarity, size, etc.
Determines the mass-to-charge ratio of charged molecules.