LET'S LEARN PLANTS
Thursday 14 January 2021
Sunday 22 November 2020
Lipid Biochemistry (Part II)
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PhosphoglyceridesPhosphoinositidesPhosphosphingosides
Lecithins (Phosphatidyl cholines)Cephalins (Phosphatidyl ethanolamine and phosphatidyl serine)Plasmalogens (Phosphoglyceracetals)
Phosphatidyl ethanolaminePhosphatidyl serine
Phosphatidal cholinePhosphatidal ethanolaminePhosphatidal serine
Tuesday 17 November 2020
Lipid Biochemistry (Part I)
To access and download PowerPoint presentation on 'Lipid Biochemistry' click on the link below:
Lipids
Lipids are water-insoluble biomolecules that are highly soluble in organic solvents like chloroform.
Lipids are a heterogeneous group of compounds related to fatty acids and include fats, oils, waxes, and other related substances.
Lipids are hydrophobic in nature.
The term ‘lipid’ was first coined by a German biochemist, Bioor, in 1943.
Chemically fats are defined as the esters of glycerol and fatty acids or triglycerides of fatty acids.
Functions of lipids
A diverse range of functions in biological systems:
Important constituents of diet because of their high energy value
Serve as a source of fat-soluble vitamins and essential fatty acids in natural foodstuffs.
Serve as a stored form of energy in adipose tissues.
Serve as an insulating material in subcutaneous tissues and around certain organs.
Lipoproteins are important constituents of biological membranes.
enzyme cofactors,electron carriers,light absorbing pigments,emulsifying agent in digestive tracts,hormones and intracellular messengers
Simple lipids or homolipidsCompound lipids or heterolipidsDerived lipids
Acyl glycerolsWaxesPhospholipidsSphingolipidsGlycolipidsTerpenoid lipids including carotenoids and steroids
Example-α-Linolenic acid (ω-3 fatty acid), Linoleic acid (ω-6 fatty acid)
NutsSoybeansWalnut oilCanola oilFlaxseed oilCold water fatty fish such as salmon, herring, cod, flounder, tuna, bluefish, and shrimp
Leafy vegetablesSeedsNutsGrainsVegetable oils (corn, safflower, soybean, cottonseed, sesame, sunflower)
- Help with cellular development and the formation of healthy cell membranes.
- Blocks tumor formation and growth of cancer cells
- Assist in the development and function of the brain and nervous system.
- Regulates proper thyroid and adrenal activity.
- Plays a role in thinning your blood, which prevents blood clots, heart attacks and stroke.
- Regulates blood pressure, immune responses and liver function.
- Deficiency causes skin problems, including eczema, dandruff, split nails and brittle hair.
- Forms Lipid rafts which affects cellular signalling.
- Acts on DNA, activates or inhibits transcription factors.
Thursday 5 November 2020
Carbohydrate Biochemistry (Part II)
To access and download PowerPoint presentation on 'Carbohydrate Biochemistry' click on the link below:
Disaccharides
Disaccharides consist of two monosaccharides joined covalently by an O-glycosidic bond, which is formed when a hydroxyl group of one sugar reacts with the anomeric carbon of the other.
Example: maltose, lactose, and sucrose
Glycosidic bonds are readily hydrolyzed by acid but resist cleavage by base. Thus disaccharides can be hydrolyzed to yield their free monosaccharide components by boiling with dilute acid.
N-glycosyl bonds join the anomeric carbon of a sugar to a nitrogen atom in glycoproteins and nucleotides.
General formula: Cₙ(H2O)ₙ₋₁
The oxidation of a sugar’s anomeric carbon by cupric or ferric ion (the reaction that defines a reducing sugar) occurs only with the linear form, which exists in equilibrium with the cyclic form(s).
It is composed of two monosaccharides: glucose and fructoseRing type: Glucose is pyranose and fructose is furanoseLinkage: oxygen on C1 of α-D-glucose is linked to C2 of β-D-fructoseSuffix '–oside' and '⟺' indicates that the anomeric carbons of both the monosaccharides participate in glycosidic bond formation
Structural roleStorage of energy
Homopolysaccharides (Homoglycans): They, on hydrolysis, yield only one type of monosaccharide. They are named based on the nature of the monosaccharide unit.
Example: Glucan (polymer of glucose), Fructosan (polymer of fructose)
Heteropolysaccharides (heteroglycans): They, on hydrolysis, yield a mixture of a few types of monosaccharide units or their derivatives.
Example: Peptidoglycan (polymer of N-acetylglucosamine and N-acetylmuramic acid residues)
Water soluble amylose (15-20%)Water insoluble amylopectin (80-85%)