Question

Which of the following is not correctly matched?

• A. Calcium - middle lamella
  
• B. Magnesium - component of nitrogenase
  
• C. Potassium - opening and closing of stomata
  
• D. Sulphur - present in amino acids

Answer 1

The correct option is B Magnesium - component of nitrogenase


The enzyme complex nitrogenase consists of two proteins, a molybdenum-iron protein and a smaller iron protein. Alternatively, it may also contain vanadium or only iron but not magnesium as an enzyme constituent.
The middle lamella which cements two adjoining cells is made up of calcium and magnesium pectates.

Potassium ion, which is responsible for the turgidity of guard cells, is also responsible for causing the opening and closing of stomata.

Sulphur is present in some amino acids, such as methionine and cysteine.