Define RQ. What is its value for fats?
Question: Define RQ. What is its value for fats? Solution: Respiratory quotient (RQ) or respiratory ratio can be defined as the ratio of the volume of $\mathrm{CO}_{2}$ evolved to the volume of $\mathrm{O}_{2}$ consumed during respiration. The value of respiratory quotient depends on the type of respiratory substrate. Its value is one for carbohydrates. However, it is always less than one for fats as fats consume more oxygen for respiration than carbohydrates. It can be illustrated through the e...
Read More →Lifetimes of the molecules in the excited states are often measured
[question] Question. Lifetimes of the molecules in the excited states are often measured by using pulsed radiation source of duration nearly in the nano second range. If the radiation source has the duration of $2 \mathrm{~ns}$ and the number of photons emitted during the pulse source is $2.5 \times$ $10^{15}$, calculate the energy of the source. [/question] [solution] Solution: Frequency of radiation $(v)$, $v=\frac{1}{2.0 \times 10^{-9} \mathrm{~s}}$ $v=5.0 \times 10^{8} \mathrm{~s}^{-1}$ Ener...
Read More →Discuss “The respiratory pathway is an amphibolic pathway.”
Question: Discuss The respiratory pathway is an amphibolic pathway. Solution: Respiration is generally assumed to be a catabolic process because during respiration, various substrates are broken down for deriving energy. Carbohydrates are broken down to glucose before entering respiratory pathways. Fats get converted into fatty acids and glycerol whereas fatty acids get converted into acetyl CoA before entering the respiration. In a similar manner, proteins are converted into amino acids, which ...
Read More →If tan 2 A = cot (A – 18°), where 2 A is an acute angle,
[question] Question. If tan 2 A = cot (A – 18°), where 2 A is an acute angle, find the value of A. [/question] [solution] Solution: tan2A = cot(A – 18°) cot (90° – 2A) = cot (A – 18°) 90° – 2A = A – 18° 108° = 3A A = 36° [/solution]...
Read More →What are the assumptions made during the calculation of net gain of ATP?
Question: What are the assumptions made during the calculation of net gain of ATP? Solution: For theoretical calculation of ATP molecules, various assumptions are made, which are as follows. (a)It is assumed that various parts of aerobic respiration such as glycolysis, TCA cycle, and ETS occur in a sequential and orderly pathway. (b)NADH produced during the process of glycolysis enters into mitochondria to undergo oxidative phosphorylation. (c)Glucose molecule is assumed to be the only substrate...
Read More →Show that the area of the triangle contained between the vectors
[question] Question. Show that the area of the triangle contained between the vectors $\mathbf{a}$ and $\mathbf{b}$ is one half of the magnitude of $\mathbf{a} \times \mathbf{b}$. [/question] [solution] solution: Consider two vectors $\overrightarrow{\mathrm{OK}}=|\vec{a}|$ and $\overrightarrow{\mathrm{OM}}=|\vec{b}|$, inclined at an angle $\theta$, as shown in the following figure. In $\Delta \mathrm{OMN}$, we can write the relation: $\sin \theta=\frac{\mathrm{MN}}{\mathrm{OM}}=\frac{\mathrm{MN...
Read More →Write the general outer electronic configuration of s-, p-, d- and f- block elements.
Question: Write the general outer electronic configuration of $\mathrm{s}-p_{-}, d$ - and $f$-block elements. Solution:...
Read More →Distinguish between the following:
Question: Distinguish between the following: (a) Aerobic respiration and Anaerobic respiration (b) Glycolysis and Fermentation (c) Glycolysis and Citric acid Cycle Solution: (a)Aerobic respiration and Anaerobic respiration (b)Glycolysis and Fermentation (c)Glycolysis and citric acid cycle...
Read More →Show that
[question] Question. Show that (i) tan 48° tan 23° tan 42° tan 67° = 1 (ii) cos 38° cos 52° – sin 38° sin 52° = 0. [/question] [solution] Solution: (i) $\mathrm{LHS}=\tan 48^{\circ} \tan 23^{\circ} \tan 42^{\circ} \tan 67^{\circ}$ $=\tan 48^{\circ} \times \tan 23^{\circ} \times \tan \left(90^{\circ}-48^{\circ}\right)$ $\times \tan \left(90^{\circ}-23^{\circ}\right)$ $=\tan 48^{\circ} \times \tan 23^{\circ} \times \cot 48^{\circ} \times \cot 23^{\circ}$ $=\tan 48^{\circ} \times \tan 23^{\circ} \t...
Read More →Explain ETS.
Question: Explain ETS. Solution: ETS or electron transport system is located in the inner mitochondrial membrane. It helps in releasing and utilizing the energy stored in NADH+H+and FADH2.NADH + H+, which is formed during glycolysis and citric acid cycle, gets oxidized by NADH dehydrogenase (complexI). The electrons so generated get transferred to ubiquinone through FMN. In a similar manner, FADH2(complexII) generated during citric acid cycle gets transferred to ubiquinone. The electrons from ub...
Read More →In astronomical observations, signals observed from the distant stars are generally weak.
[question] Question. In astronomical observations, signals observed from the distant stars are generally weak. If the photon detector receives a total of $3.15 \times 10^{-18} \mathrm{~J}$ from the radiations of $600 \mathrm{~nm}$, calculate the number of photons received by the detector. [/question] [solution] Solution: From the expression of energy of one photon $(E)$, $E=\frac{\text { he }}{\lambda}$ Where, $\lambda=$ wavelength of radiation $h=$ Planck's constant $c=$ velocity of radiation S...
Read More →The increasing order of reactivity among group 1 elements is Li < Na < K < Rb <Cs whereas that among group
Question: The increasing order of reactivity among group 1 elements is Li Na K Rb Cs whereas that among group 17 elements is F CI Br I. Explain. Solution: The elements present in group 1 have only 1 valence electron, which they tend to lose. Group 17 elements, on the other hand, need only one electron to attain the noble gas configuration. On moving down group 1, the ionization enthalpies decrease. This means that the energy required to lose the valence electron decreases. Thus, reactivity incre...
Read More →A child sits stationary at one end of a long trolley moving uniformly
[question] Question. A child sits stationary at one end of a long trolley moving uniformly with a speed V on a smooth horizontal floor. If the child gets up and runs about on the trolley in any manner, what is the speed of the CM of the (trolley + child) system? [/question] [solution] solution: No change The child is running arbitrarily on a trolley moving with velocity v. However, the running of the child will produce no effect on the velocity of the centre of mass of the trolley. This is becau...
Read More →Why is mitosis called equational division?
[question] Question. Why is mitosis called equational division? [/question] [solution] Solution: Mitosis is the process of cell division wherein the chromosomes replicate and get equally distributed into two daughter cells. The chromosome number in each daughter cell is equal to that in the parent cell, i.e., diploid. Hence, mitosis is known as equational division. [/solution]...
Read More →Use the periodic table to answer the following questions.
Question: Use the periodic table to answer the following questions. (a) Identify an element with five electrons in the outer subshell. (b) Identify an element that would tend to lose two electrons. (c) Identify an element that would tend to gain two electrons. (d) Identify the group having metal, non-metal, liquid as well as gas at the room temperature. Solution: (a) The electronic configuration of an element having 5 electrons in its outermost subshell should be $n s^{2} n p^{5}$. This is the e...
Read More →Evaluate :
[question] Question. Evaluate : (i) $\frac{\sin 18^{\circ}}{\cos 72^{\circ}}$ (ii) $\frac{\tan 26^{\circ}}{\cot 64^{\circ}}$ (iii) $\cos 48^{\circ}-\sin 42^{\circ}$ (iv) $\operatorname{cosec} 31^{\circ}-\sec 59^{\circ}$ [/question] [solution] Solution: (i) $\frac{\sin 18^{\circ}}{\cos 72^{\circ}}=\frac{\sin 18^{\circ}}{\cos \left(90^{\circ}-18^{\circ}\right)}=\frac{\sin 18^{\circ}}{\sin 18^{\circ}}=1$. $\left\{\because \cos \left(90^{\circ}-\theta\right)=\sin \theta\right\}$ (ii) $\frac{\tan 26^...
Read More →Give the schematic representation of an overall view of Krebs cycle.
Question: Give the schematic representation of an overall view of Krebs cycle. Solution:...
Read More →What is G0 (quiescent phase) of cell cycle?
[question] Question. What is $\mathrm{G}_{0}$ (quiescent phase) of cell cycle? [/question] [solution] Solution: $\mathrm{G}_{0}$ or quiescent phase is the stage wherein cells remain metabolically active, but do not proliferate unless called to do so. Such cells are used for replacing the cells lost during injury. [/solution]...
Read More →What are the main steps in aerobic respiration? Where does it take place?
Question: What are the main steps in aerobic respiration? Where does it take place? Solution: The major steps in aerobic respiration and the sites where they occur are listed in the given table....
Read More →What are the major differences between metals and non-metals?
Question: What are the major differences between metals and non-metals? Solution:...
Read More →State whether the following are true or false. Justify your answer
[question] Question. State whether the following are true or false. Justify your answer. (i) sin (A + B) = sin A + sin B (ii) The value of $\sin \theta$ increases as $\theta$ increases. (iii) The value of $\cos \theta$ increases as $\theta$ increases. (iv) $\sin \theta=\cos \theta$ for all values of $\theta$. (v) $\cot \mathrm{A}$ is not defined for $\mathrm{A}=0^{\circ}$. [/question] [solution] Solution: (i) False. When A = 60°, B = 30° LHS = sin (A + B) = sin (60° + 30°) = sin 90° = 1 RHS = si...
Read More →Give the schematic representation of glycolysis?
Question: Give the schematic representation of glycolysis? Solution:...
Read More →Describe the events taking place during interphase.
[question] Question. Describe the events taking place during interphase. [/question] [solution] Solution: Interphase involves a series of changes that prepare a cell for division. It is the period during which the cell experiences growth and DNA replication in an orderly manner. Interphase is divided into three phases. (i) $G_{1}$ phase (ii) $S$ phase (iii) $\mathrm{G}_{2}$ phase $\mathrm{G}_{1}$ phase $-$ It is the stage during which the cell grows and prepares its DNA for replication. In this ...
Read More →What are respiratory substrates? Name the most common respiratory substrate.
Question: What are respiratory substrates? Name the most common respiratory substrate. Solution: The compounds oxidised during the process of respiration are called respiratory substrates. Carbohydrates,especially glucose, act as respiratory substrates. Fats, proteins, and organic acids also act as respiratory substrates....
Read More →Would you expect the first ionization enthalpies for two isotopes of the same element to be the same or different?
Question: Would you expect the first ionization enthalpies for two isotopes of the same element to be the same or different? Justify your answer. Solution: The ionization enthalpy of an atom depends on the number of electrons and protons (nuclear charge) of that atom. Now, the isotopes of an element have the same number of protons and electrons. Therefore, the first ionization enthalpy for two isotopes of the same element should be the same....
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