Hatch Slack pathway

Plants are divided into two groups for the fixing mechanisms of carbon dioxide plants of one group use the Calvin-Benson cycle, while those of the other group 

As a result, oxaloacetate (OAA, C4-compound) is formed unlike the case of the Calvin-Benson cycle in which 3-phosphoglycerate (C3-compound) is formed. The pathway in the fixation of carbon dioxide by the catalysis of PEP-carboxylase is observed in sugar cane, corn, etc., and is called the Hatch-Slack pathway (Hatch et al., 1967). The plants having the Hatch-Slack pathway have chloroplasts both in mesophyll cells and in vascular bundle sheath cells, and the Hatch-Slack pathway occurs in the mesophyll cells. Oxaloacetate formed by the fixation of carbon dioxide in the mesophyll cells is reduced to malate. Malate thus formed moves to the vascular bundle sheath cells and releases carbon dioxide there. Carbon dioxide released is fixed by the catalysis of Rubisco, and the organic compounds are formed through the Calvin-Benson cycle. (Fig. 6.3). 

The plants producing organic compounds from carbon dioxide through the Calvin-Benson cycle are called C3-plants, while the plants producing organic compounds from carbon dioxide through the Hatch-Slack pathway are called C4-plants. 

Examples of plants Spinach, soybean, rice plant Sugar cane, corn, Japanese millet 

Effect of light intensity on photosynthetic rate Saturated at 1-2 x 104 lux Proportional limitlessly to the intensity of natural light 

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The lithoautotrophs have to form cellular materials from carbon dioxide. The process to change carbon dioxide into organic compounds is called fixation of carbon dioxide. On the basis of the knowledge to date, all algae and cyanobacteria, and many of the plants, fix carbon dioxide through the Calvin-Benson cycle (or reductive pentose phosphate cycle) (Bassham et al., 1954), while the plants of 20 families and 1200 species have been known to fix carbon dioxide through the Hatch-Slack pathway (or C4 dicarboxylate pathway) (Hatch et al., 1967). 

C4 plants are found primarily in the tropics. Such plants include sugar cane and maize (com). They have been assigned the name C4 plants because a four-carbon molecule (oxaloacetate) plays a prominent role in a biochemical pathway that avoids photorespiration. This pathway is called the C4 pathway or the Hatch-Slack pathway (after its discoverers). 

Plant leaves e.g. spinach cycle or Hatch-Slack pathway) ... 

In tropical plants, there is a G4 pathway (Figure 22.18), so named because it involves four-carbon compounds. The operation of this pathway (also called the Hatch-Slack pathway) ultimately leads to the Gg (based on 3-phosphoglycerate) pathway of the Galvin cycle. (There are other G pathways, but this one is most... 

C4 plants Plants that employ the Hatch-Slack pathway during photosynthesis. C4 plants are named such because they employ an intermediate compound, oxaloacetic acid that contains four carbon atoms. These plants moderately discriminate (8 to 14% ) against C during carbon incorporation. C4 plants are usually higher land plants that are specially adapted to dry and low-/JCO2 conditions. 

Stable isotope ratio analysis (SIRA, GC-IRMS [Gas Chromatography-Isotope Ratio Mass Spectrometry], and Site Specific Isotope Fractionation — Nuclear Magnetic Resonance [SNIF-NMR]) have proven useful in many adulteration situations. In nature, and exist at relative proportions of 1.11 98.89 [27]. The photosynthetic process selectively enriches the plant in dependent upon the type of photosynthetic process used by the plant. Plants using the Hatch-Slack pathway (e.g., com, sugar cane, millet, and lemon grass) give 8 C values the closest to the standard, i.e., 5 C values of ca. -10. The 5 C value is calculated as ... 

The ecophysiological significance of the C4 dicarboxylic acid pathway is still a matter of discussion. It is striking, though, that it is also found in a large number of halophytes. This has led to the assumption that the C4 dicarboxylic acids formed via the Hatch-Slack pathway might play a role in osmoregulation in these species. However, this is only one of several possibilities. 

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