Molybdenum is a mineral ion present in the soil solution. It enters the cell as molybdate ions via membrane transport proteins. These proteins can bind to, and hydrolyse, ATP. Name and describe the transport mechanism by which molybdate ions enter the cell.
State the structures in the bacterial cell where the protein components of nitrogenase are made.
A section of the reaction catalysed by nitrogenase in A. vinelandii is shown below. Complete the equation by stating the product of the reaction. atmospheric nitrogen ($N_2$) $\xrightarrow{\text{nitrogenase, ATP and hydrogen}}$ ................
Using data from Table 3.1, calculate the percentage of nitrogen fixation carried out worldwide by nitrogen-fixing organisms, such as A. vinelandii, in agricultural land. Show your working and give your answer to the nearest whole number.
Explain why the proportion of nitrogen gas in the atmosphere stays stable at $78\%$, even though nitrogen fixation removes nitrogen gas from the atmosphere.
Describe and explain the benefits to humans of the presence of nitrogen-fixing bacteria, such as A. vinelandii, in agricultural land.