Q. Which one is absent in wood?
NTA AbhyasNTA Abhyas 2020
Solution:
A plant cell wall is made up of cellulose, hemicellulose, lignin, and pectin, all of which are polymeric. Among them, cellulose is the most abundant organic polymer seen on Earth.
During primary and secondary growth, new walls are formed, the primary wall which encloses the newly formed cell, and the middle lamella or intercellular layer separates adjoining cells. Middle lamella or intercellular layers are rich in pectic material. The secondary wall is deposited onto the primary wall composed of cellulose and hemicellulose towards protoplasm. Simultaneously deposition of lignin starts at the cell corners and spread along the primary wall and intercellular layer. After the lignification, the cell dies, and the remaining cytoplasmic debris is deposited on the lumen walls in the form of a terminal lamella.
Thus, wood is made up of cellulose, hemicellulose, lignin, and pectin.
Fats are generally liquid at room temperature, and their melting points are low, hence referred to as oils. This nature of molecule cannot provide rigidity, that's why fats can not be a part of the wood.
During primary and secondary growth, new walls are formed, the primary wall which encloses the newly formed cell, and the middle lamella or intercellular layer separates adjoining cells. Middle lamella or intercellular layers are rich in pectic material. The secondary wall is deposited onto the primary wall composed of cellulose and hemicellulose towards protoplasm. Simultaneously deposition of lignin starts at the cell corners and spread along the primary wall and intercellular layer. After the lignification, the cell dies, and the remaining cytoplasmic debris is deposited on the lumen walls in the form of a terminal lamella.
Thus, wood is made up of cellulose, hemicellulose, lignin, and pectin.
Fats are generally liquid at room temperature, and their melting points are low, hence referred to as oils. This nature of molecule cannot provide rigidity, that's why fats can not be a part of the wood.