Introduction on Kranz Anatomy
Kranz Anatomy is one structure within the leaves of the C4 plants that are specialized in nature. This is where the spongy mesophyll cells are found bundled up. They are seen in a ring-like shape that surrounds the veins of a leaf.
Kranz Anatomy Definition
Kranz anatomy is a unique structure observed in C4 plants. In these plants, the mesophyll cells cluster around the bundle-sheath cell in a wreath formation (Kranz means ‘wreath or ring). Also, the number of chloroplasts observed in bundle sheath cells is more than that in the mesophyll cell. This entire structure is densely packed and plays a major role in C4 photosynthesis.
Advantage of Kranz Anatomy
We have established with the help of the above definitions that Kranz Anatomy is a significant part of C4 plants. Thus, this has several advantages to the respective plants. Some of those advantages can be found below:
It provides a perfect site for CO2 to be concentrated within the plants, around the RuBisCO.
It helps in preventing photorespiration
It enables the carbon dioxide fixation twice within the C4 plants with the help of the bundle sheath cells found in them
Different Between C3 Plants And C4 Plants
When we talk about C3 Plants And C4 Plants, there is a good difference that exists between the two. While in C3 plants, the carbon dioxide fixation happens only once, in C4, the same happens twice. This is all because of the presence of the Kranz Anatomy in the latter and the absence in the former.
FAQs on Kranz Anatomy
1. What is the Advantage of Double Carbon Fixation in C4 Plants?
A double carbon fixation offers C4 plants with better photosynthetic efficiency. In a hot and dry climate, when excess water vapour diffuses out of the stomata in C3 plants, in C4 plants it’s relatively less because of the C4 cycle taking place in the bundle sheath cells of these plants.
The stomata will be closed and the concentration of gases within cells will change. As photosynthesis takes place, CO2 will be consumed and oxygen will be generated and eventually, CO2 levels will reduce. However, because of Kranz anatomy, the CO2 levels around RUBISCO in Bundle sheath cells will always be more and it will continue to fix carbon and not give rise to photorespiration.
This is because initially CO2 was fixed in a C4 acid by an enzyme called phosphoenolpyruvate carboxylase enzyme or PEPcase which is not inhibited by O2. The organic acid breaks down in the bundle sheath cells releasing CO2 which is used by RUBISCO.
2. What are the Differences between Bundle Sheath Cells and Mesophyll Cells?
Mesophyll Cells | Bundle Sheath Cells |
Mesophyll cells are thin-walled and gas permeable | Bundle sheath cells are thick-walled and gas impermeable, |
The chloroplast in mesophyll cells is randomly arranged. | The chloroplast in bundle sheath cells is centrifugally arranged. |
There are no starch grains present in mesophyll cells. | Starch grain can be observed in bundle sheath cells. |
Large amounts of reduced coenzymes and ATPs are produced in Mesophyll cells. | Bundle cells produce very low or no amount of ATPs and reduced coenzymes |
C3 cycle does not take place in mesophyll cells due to the absence of RuBP carboxylase. | RuBP carboxylase is available in high concentrations in bundle sheath cells which assists in the C3 cycle. |
CO2 fixation does not take place in the chloroplast of mesophyll cells. It takes place in the cytoplasm of the cell with the help of PEP carboxylase. | CO2 fixation takes place in the bundle sheath cells as it is released by oxaloacetate and accepted by RuBP to enter in the C3 cycle. |
3. Which Plants Show Krantz Anatomy?
All C4 plants show Krantz anatomy. Some examples are sugarcane, sorghum, maize, millets, switchgrass which is used as a source of biofuel.
4. What is the importance of Kranz Anatomy?
The main role, as well as the point of the importance of the Kranz Anatomy, is that it provides the perfect site for CO2 or carbon dioxide to be concentrated. This happens to surround the RuBisCO. This helps in the continuous fixation of the carbon dioxide that keeps the levels of the CO2 more at any given point in time. The function that makes it all the more significant is that it helps in avoiding photorespiration. This is one such advantage that helps the C4 plants to store the carbon dioxide more than others, like C3 plants.
5. Why do C4 plants display Kranz anatomy?
There are many reasons why C4 plants show Kranz anatomy. We have a few main ones listed out below:
It helps with preventing photorespiration.
C4 plants have a high level of CO2 that can be absorbed and stored within them.
The efficiency of carbon fixation is increased due to Kranz anatomy. This helps with carrying out the process of photosynthesis even when the concentration of carbon dioxide is at a lower level.
When it comes to the C4 plants, they tend to have a greater photosynthetic ability than the C3 plants.
6. Where can I get the in-detail information about the Kranz Anatomy?
Kranz Anatomy is an important as well as an interesting topic that every science enthusiast or a student must know about. That being said, anybody can get more information about it with the help of Vedantu. On the online platform, you can get to know all the information you need or want, from its definition to advantages, importance to features, and much more. It is all explained in such detail, that one can do nothing but simply understand the concept.
7. Which Plants Show Kranz Anatomy?
The plants in which Kranz anatomy is evident are mainly C4 plants. These have 2 types of photosynthetic cells. They are called bundle sheath cells and mesophyll cells. While the former type of cells are the ones that go around the vascular bundles, on the other hand, the latter are the ones that essentially surround the bundle sheath cells. The whole process helps them in the fixation of carbon dioxide, and that too twice. The process is also meant to help with preventing photorespiration.
8. What function does Kranz anatomy play in C4 leaves?
When it comes to the primary function of the Kranz anatomy, it has been determined to be offering a proper site for CO2 concentration. Here CO2 is concentrated surrounding the RuBisCo which in turn results in preventing photorespiration. This also enables the C4 leaves, or the whole plants to save up or store the carbon dioxide within them for longer. The process is also one that allows the C4 plants to have a greater photosynthetic ability than the C3 plants.
