Which one of the following statements is correct?
All enzymes that utilise ATP in phosphate transfer require Ca as the cofactor
The bone in human body is an inert and unchanging substance
The daily requirement of Mg and Ca in the human body is estimated to be 0.2-0.3 g
Mg plays roles in neuromuscular function and interneuronal transmission
The correct answer is Option 4: Mg plays roles in neuromuscular function and intraneuronal transmission.
Magnesium (Mg) is an essential mineral and cofactor that plays a critical role in various biochemical reactions in the human body. It is especially important in the functioning of the nervous and muscular systems. Mg helps regulate neurotransmitter release, muscle contraction, and nerve signal transmission, making it vital for both neuromuscular function and intraneuronal communication.
Explanation of all options:
Option 1: "All enzymes that utilise ATP in phosphate transfer require Ca as the cofactor" – This statement is incorrect. Although calcium (Ca) does act as a cofactor for certain enzymes, most ATP-dependent reactions actually require magnesium (Mg) as the true cofactor. Mg stabilizes ATP molecules by binding to the phosphate groups, making it essential for enzyme catalysis involving ATP.
Option 2: "The bone in human body is an inert and unchanging substance" – This is a misconception. Bone is a living tissue that continuously undergoes remodeling. It actively participates in mineral storage, blood cell formation (hematopoiesis), and responds to mechanical and metabolic stress. Therefore, it is not inert or unchanging.
Option 3: "The daily requirement of Mg and Ca in the human body is estimated to be 0.2–0.3 g" – This statement is incorrect. The daily recommended intake for calcium in adults is around 1000–1200 mg (1–1.2 g), and for magnesium, it ranges between 300–400 mg. The combined requirement of 0.2–0.3 g is a significant underestimation.
Option 4: "Mg plays roles in neuromuscular function and interneuronal transmission" – This is the correct statement. Magnesium is vital for regulating ion channels, especially calcium and potassium, which are crucial for proper muscle contractions and nerve signal propagation. A deficiency in Mg can lead to muscle cramps, spasms, and neurological issues.
In conclusion, magnesium's crucial role in both neuromuscular and neuronal functions makes Option 3 the best and most scientifically accurate choice among the given options. Understanding the physiological significance of minerals like Mg and Ca is essential for mastering human biology, especially for competitive exams like NEET.
Which of the following statements are true?
A. Unlike Ga that has a very high melting point, Cs has a very low melting point.
B. On Pauling scale, the electronegativity values of N and C are not the same.
C. $Ar, K^{+}, Cl^{–}, Ca^{2+} and S^{2–}$ are all isoelectronic species.
D. The correct order of the first ionization enthalpies of Na, Mg, Al, and Si is Si $>$ Al $>$ Mg $>$ Na.
E. The atomic radius of Cs is greater than that of Li and Rb.
Choose the correct answer from the options given below:
For the reaction A(g) $\rightleftharpoons$ 2B(g), the backward reaction rate constant is higher than the forward reaction rate constant by a factor of 2500, at 1000 K.
[Given: R = 0.0831 atm $mol^{–1} K^{–1}$]
$K_p$ for the reaction at 1000 K is:
Among the following, choose the ones with an equal number of atoms.
Choose the correct answer from the options given below:
Identify the suitable reagent for the following conversion: $Ph-C(=O)-OCH_3$ $\longrightarrow$ $Ph-CHO$
Some tranquilizers are listed below. Which one from the following belong barbiturates?
Given below are two statements:
A constant voltage of 50 V is maintained between the points A and B of the circuit shown in the figure. The current through the branch CD of the circuit is :
Which of the following statements are true?
A. Unlike Ga that has a very high melting point, Cs has a very low melting point.
B. On Pauling scale, the electronegativity values of N and C are not the same.
C. $Ar, K^{+}, Cl^{–}, Ca^{2+} and S^{2–}$ are all isoelectronic species.
D. The correct order of the first ionization enthalpies of Na, Mg, Al, and Si is Si $>$ Al $>$ Mg $>$ Na.
E. The atomic radius of Cs is greater than that of Li and Rb.
Choose the correct answer from the options given below:
AB is a part of an electrical circuit (see figure). The potential difference \(V_A - V_B\), at the instant when current \(i = 2\) A and is increasing at a rate of 1 amp/second is:
An essential part of every cell in our body, protein is one of the three macronutrients which is required by our body in larger amounts. Proteins are made up of linear chains of smaller units called amino acids. Every biochemical process that takes place inside our bodies is possible because of these proteins. Proteins are 3-dimensional structures that are assembled with different amino acid sequences.
Proteins are used in many ways. Some of their functions are:
Proteins are classified on the basis of:
A protein molecule is made from a long chain of amino acids, each linked to its neighbor through a covalent peptide bond. The structure of proteins are divided into four types: