CHAPTER ONE 

INTRODUCTION

CHLOROPHYLL (also chlorophyI) is a green pigment found in cyanobacteria and the chloroplast of algae and plants. Its name is derived from the Greek words chloros (Green) and phyllon (leaf). chlorophyIl is an extremely important bimolecular, critical in photosynthesis, which allows plants to absorbed energy from light. chlorophyIl absorb light most strongly in the blue portion of the electromagnetic spectrum, followed by the red portion. However, it is a poor absorber of green and near-green portion of the spectrum hence the green colour of chlorophylI containing tissues. CholorophyIl was first isolated by Joseph Bienaime, Caventou and Pierre, Joseph Pelletier in 1817.

ChlorphylI gives leaves their green colour and absorbed light that is also used in photosynthesis.

Chlorophyll is found in high concentrations in chloroplasts of plant cells. ChlorophyIl is vital for photosynthesis, which allows plants to absorb energy from light.

The two currently accepted photosynthesis units are photosystem II and photosystem I, which have their own distinct reaction center chlorophyIls, named p680 and p700, respectively. These pigments are named after the wavelength (in nanometers) of their red-peak absorption maximum. The identity function and spectral properties of the types of chlorophylI in each photosystem are distinct and determined by each other and the protein structure surrounding them. Once extracted from the protein into a solvent (such as acetone or methanol), (4) (5) (6) these chlorophyII pigments can be separated in a sample paper chromatography experiment and, based on the number of polar group between chlorophyII a  and chlorophyII b, will chemically separate out on the paper.

The function of the reaction center cholorophyII is to use the energy absorbed by and transferred to it from the other chlorophyII pigments in the photosystem to undergo a change separation, a specific redox reaction in which the chlorophyII donates an electron into a series of molecular intermediate called an electron transport chain. The charge reaction center chlorophyII (P680+) is then reduced back to its ground state by accepting an electron. In photosystem II, the electron that reduces P680+ ultimately comes from the oxidation of water into O2 and H+ through several intermediate. This reaction is how photosynthetic organism such as plants produce O2 gas, and is the source for practically all the O2 in earth’s atmosphere. Photosystem I typically work in series with photosystem II, thus the P700+ of photosystem I is usually reduced, via many intermediates in the thylakoid membrane, by electron ultimately from photosystem II. Electron transfer reactions in the thylakoid membrane are complex, however, and the source of electrons used to reduce P700+ can vary.

The electron flow produce by the reaction center chlorophyII pigments is used to shuttle H+ ions across the thylakoid membrane, setting up a chemiosmotic potential used mainly to produce ATP chemical energy’s and those electrons ultimately reduce NADP+ to NADPH, a universal reductant used to reduce CO2 into sugars as well as for other biosynthetic reduction.

Reaction center chlorophyII – protein complexes are capable  of directly absorbing light and performing charge separation events without other chlorophyII pigments, but the absorption cross section (the likelihood of absorbing a photon under a given light intensity) is small. Thus, the remaining chlorophyII in the photosystem and antenna pigment protein complexes associated with the photosystem all cooperatively absorb and funnel light energy to the reaction center. Beside chlorophyII a, there are other pigment, called accessory pigments, which occur in these pigment- protein antenna complexes.

A green sea slug, elysia chlorotica, has been found to use the chlorophyII it has eaten to perform photosynthesis for itself. This process in known as kleptoplasty, and no other animal has been found to have this ability.

LEGUMES

A legumes is a plant in the family fabaceae (or leguminosea), or the fruit or seed of such a plant. Legumes are grown agriculturally, primarily for their food grain seed (e.g beans and lentils or general pulse), for livestock forage and silage, and as soil enhancing green manure. Legumes are notable in that most of them have symbiotic nitrogen –fixing bacteria in structures called root nodules. Well known legumes include alfalfa, clover, peas, beans, lentils, lupins, mesquite, carob soyabeans, peanuts and the woody climbing vine wisteria. Legumes trees like the locust trees (aleditsia, Robinia) or the Kentucky coffee tree (cymnocladus dioicus) can be used in permaculture food forests.

A legume fruit is a simple drug fruit that develops from a simple carpel and usually dehisces (open along a seam) on two sides. A common name for this type of fruit is a pod, although the term “Pod” is also applied to a few other fruit types such as vanilla and radish.

USES BY HUMANS

Farmed legumes can belong to many agricultural classes including forage, grain, blooms, pharmaceutical/industrial, fallow/green manual, and timber species. Most commercially farmed species fill two or more role simultaneously, depending upon their degree of maturity when harvested.

Forage legumes are of two broad types. Some, like alfalfa, clover, vetch (vicia), stylo (stylosanthes) or Arachis are sown in pasture and grazed by livestock. Other forage legumes such as leucaena or Albizia are woody shrub or tree species that are either broken down by livestock or regularly cut by human to provide livestock feed.

Grain legumes are cultivated for their seeds, and are also called pulses. The seeds are used for human and animal consumption or for the production of oils for industrial uses. A grain legume includes beans, lentils lupins, peas and peanuts.

Legume species grown for their flowers include lupins, which are formed commercially for their blooms as well as being popular in garden worldwide. Industrially farmed legumes include Indigofera  and acacia specie, which are cultivated for dye and natural gum production. Various legume species are formed for timber production worldwide.