GROUP I GROUP II P. Nitrobacter 1. $NO_3^-$ $\rightarrow$ $NO_2^-$ Q. Nitrite reductase 2. $N_2$ $\rightarrow$ $2NH_3$ R. Nitrogenase 3. $NO_2^-$ $\rightarrow$ $NH_4^+$ S. Nitrate reductase 4. $NO_2^-$ $\rightarrow$ $NO_3^-$
P-4, Q-3, R-2, S-1
Nitrogen Fixation and Assimilation Matching
This question requires matching specific components involved in nitrogen fixation and assimilation (Group I) with their corresponding biochemical reactions (Group II).
Analyzing Group I Components and Reactions
We analyze each item in Group I to determine its role and match it with the correct reaction from Group II:
- P. Nitrobacter: This bacterium performs nitrification, specifically oxidizing nitrite ($NO_2^-$) to nitrate ($NO_3^-$). This matches reaction 4: $NO_2^- \rightarrow NO_3^-$.
- Q. Nitrite reductase: This enzyme catalyzes the reduction of nitrite ($NO_2^-$) to ammonium ($NH_4^+$), which is part of nitrate assimilation. This matches reaction 3: $NO_2^- \rightarrow NH_4^+$.
- R. Nitrogenase: This enzyme complex is responsible for biological nitrogen fixation, converting atmospheric nitrogen ($N_2$) into ammonia ($NH_3$). This matches reaction 2: $N_2 \rightarrow 2NH_3$.
- S. Nitrate reductase: This enzyme catalyzes the reduction of nitrate ($NO_3^-$) to nitrite ($NO_2^-$), the initial step in assimilating nitrate. This matches reaction 1: $NO_3^- \rightarrow NO_2^-$.
Summary of Correct Matches
The determined correct matches are:
| P | 4 |
| Q | 3 |
| R | 2 |
| S | 1 |
Therefore, the correct set of matches is P-4, Q-3, R-2, S-1.
Important Questions from Plant Biochemistry Enzymes Reactions
- Match the following digestive enzymes in Column I with their respective functions in Column II.
Column I Column II P. Erepsin (i) converts proteins to peptides Q. Steapsin (ii) activates trypsinogen to trypsin R. Pepsin (iii) converts fat into fatty acid and glycerol S. Enterokinase (iv) converts polypeptides to amino acids - Match the proteins in Column I with the organs in which they are maximally expressed in Column II.
Column I Column II P. Keratin (i) Liver Q. Surfactants (ii) Pancreas R. Pro-carboxypeptidase (iii) Lung S. Albumin (iv) Skin Identify the free radicals (marked as '?') in sequence from the inter-conversion of reactive oxygen species as shown below.
$O_2\rightarrow? \rightarrow H_2O_2 \rightarrow? \rightarrow H_2O$
P. $\mathrm{O}_2^{\bullet -}$
Q. $OH^-$
R. $HO_2^{-}$
S. $\ {}^{1}\mathrm{O}_2$
- Select the CORRECT combination by matching Group-I with Group-II.
Group-I Group-II P. Photorespiration 1. Glutamate $\rightarrow$ 2-Oxglutarate Q. Respiration 2. Acetyl-CoA $\rightarrow$ Malonyl-CoA R. Amino acid degradation 3. 2-Oxglutarate $\rightarrow$ Succinyl-CoA S. Fatty acid synthesis 4. Glycine $\rightarrow$ Serine - During cellular respiratory process, pyruvate must be oxidized to acetyl CoA and $CO_2$ before it enters the citric acid cycle. The corresponding simplified equation is
Pyruvate + $NAD^+$ + CoASH $\longrightarrow$ Acetyl-S-CoA + NADH + $CO_2$
This oxidation reaction occurs in mitochondria and is carried out in presence of the enzyme
