Photosynthesis in Higher Plants Test - 3

The use of radioactive C-14 by him in algal photosynthesis studies led to the discovery that the first CO² fixation product was a 3-carbon organic acid.

Other thylakoid pigments like chlorophyll b, xanthophylls and carotenoids, which are called accessory pigments, also absorb light and transfer the energy to chlorophyll a. Indeed, they not only enable a wider range of wavelength of incoming light to be utilized for photosynthesis but also protect chlorophyll a from photo-oxidation.

The ATPase enzyme consists of two parts: one called the F₀ is embedded in the membrane and forms a transmembrane channel that carries out facilitated diffusion of protons across the membrane. The other portion is called F₁ and protrudes on the outer surface of the thylakoid membrane on the side that faces the stroma.

Hydrophytes are those plants that grow in water. Hydrophytes can absorb Bicarbonates through their general body surface.

The photosynthetic pigment Beta-carotenes can be converted to Vitamin A. carrot contain large quantity of carotenes that can be converted into vitamin A.

As chlorophyll is a complex compoumd, Magnesium(Mg) is found in the centre of the structure of this compond.

Separation of leaf pigments of any green plant through paper chromatography. A chromatographic separation of the leaf pigments shows that the colour that we see in leaves is not due to a single pigment but due to four pigments: Chlorophyll a (bright or blue greenin the chromatogram), chlorophyll b (yellow-green), xanthophylls (yellow) and carotenoids.

Living organisms have the capability of extracting energy from oxidisable substances and store this in the form of bond energy. Special substances like ATP, carry this energy in their chemical bonds.

In stroma, enzymatic reactions incorporate CO₂ into the plant leading tothe synthesis of sugar, whichare not directly light driven but are dependent on the products of light reactions (ATP and NADPH). Hence, to distinguish the latter they are called, by convention, as dark reactions. However, this should not be construed to mean that they occur in darkness or that they are not lightdependent.

The key features of plant photosynthesis were known, namely, that plants could use light energy to make carbohydratesC₆H₁₂O₆from CO₂ and water, where C₆H₁₂O₆ represents glucose.