Untitled

Other cell products

 some of the cell products like vitamins , hormones and enzymes play an important role in physiology of cells Tannins

Mineral crystal

Volatile oils

Latex

Resins

Organic acids

gums

alkaloid

1.Tannins  Occur dissolved in cell sap, cell wall , abundantly in certain dead tissues as bark and heart wood  Young and old of leaf, many unripe fruits  Disappear in the fruits ripen ,become converted into glucose and other substance  Contain in tea leaves, areca nut

 Taste bitter and aseptic, i.e. free from the attacks of parasitic fungi and insects  Presence of tannin makes the wood hard and durable  Mixed with iron salts, they are used in the manufacture of ink

2.Volatile oils Known as essential or ethereal oil and occur mostly in oil glands Transparent spots in the rind of orange, lemon are all oil glands Present in the petals of flowers as in rose and jasmine Fragrant odor of flower is due to the presence of essential oils

A substance of oily containing volatile aroma compounds are obtained from plants It evaporates when exposed to the air, are usually obtained by distillation of the plant part containing the oil, some obtained by expression or extraction Many volatile oil, identical to or closely resembling the natural oil can be made synthetically

Used in medicine as stimulants, stomachaches, carminative, in perfumes and cosmetics and for purposes of flavoring

3. Resins • Mostly found in the stems of conifers, abundantly occur in special canals ,resin ducts • When present in the wood, resins add to its strength and durability

4.Gums  Are formed in various kinds of plants as a result of the break down of cell wall contents ( Gummosis)  Acacia species yields the best gum Arabic of commerce

5.Mineral crystals  Common forms of crystals consists of silica, calcium carbonate, calcium oxalate  Occur in the cell cavity or cell wall  Crystal of calcium oxalate are most common and are very widely distributed among various plants

a. Salica  Occurs as an incrustation on the cell wall or lies embedded in it  Abundantly found in the leaves and stems of horsetail ( Equisetum ) and several grasses

b. Calcium carbonate  Occurs in the form a crystalline mass of pear shaped crystals ( cystoliths), like a bunch of grape  Found in the leaf of Ficus, remain enclosed in a large cell

c. Calcium oxalate  Occurs as crystal of various forms ( i ) Raphide needle like crystals Single raphide e.g water hyacinth

Bundle raphide e.g Colocasia

( ii ) Conglomerate crystals • Clusters of crystals which radiate from a common center • More or less star-shaped appearance

( iii ) Octahedral, cubical, prismatic and rod like crystals  Common in plant  Readily seen in the dry scales of onion

6. Latex  Milkny juice found in latex cells and latex vessels

 Contains some salts, enzymes and often some poisonous substance  Function- is associated with nutrition, healing of wounds and protection against parasites and animals

Carica papaya

7. Organic acids • Living cells give an acid reaction • The sour taste of mainly fruits, particularly of unripe ones • Due to the presence of some kinds of such acids in them • Are formed as a result of respiration, both anaerobic and aerobic

8. Alkaloid  Alkaloids are a group of naturally occurring chemical compounds that mostly contain basic nitrogen atoms.  This group also includes some related compounds with neutral and even weakly acidic properties  the earliest isolated pure compounds with biological activity  Have diverse and important physiological effects on humans and other animals

 Intensely bitter taste and many of them are extremely poisonous  A few of them are liquids but the majority of them are crystalline solid  Over 200 known alkaloids found in plants  Many alkaloid are poisonous in nature  Some are used medicinally as analgesics ( pain relievers) or  Anaesthetics and for other uses

Atropine Atropa belladonna

Caffeine Coffee

Tea

Cocaine Erythroxylum spp

Colchicine Colchicum autumnale

Daturine Datura

Ergotamine ,Ergometrine

Claviceps purpurea

Ephedrine Ephedra spp

Morphine opium poppy

Nicotine Tobacco

Quinine & Cinchonine

Cinchona

Reserpine Rauwolfia serpentina

Strychnine Nux-vomoca

Vincristine, vinblastine Catharanthus roseus