GATE Overflow for GATE BT - Recent questions and answers in Fundamentals of Biological Engineering

GATE BT 2026 | Question: 18

Mon, 23 Feb 2026 14:21:44 +0000

Which of the following drugs inhibit(s) $\text{ATP-ADP}$ translocase?

Oligomycin
Atractyloside
Amytal
Bongkrekic acid

GATE BT 2026 | Question: 24

Mon, 23 Feb 2026 14:21:34 +0000

Given below is the Gibbs free energy change ( $\Delta \mathrm{G}$ ) in kilo Joules per electron equivalent ( $\mathrm{kJ} \mathrm{e}^{-} \mathrm{eq}^{-1}$ ) at pH $7.0$, of organic and inorganic half reactions.

Acetate synthesis:
\[
\frac{1}{8} \mathrm{CO}_{2}+\frac{1}{8} \mathrm{HCO}_{3}^{-}+\mathrm{H}^{+}+\mathrm{e}^{-} \rightarrow \frac{1}{8} \mathrm{CH}_{3} \mathrm{COO}^{-}+\frac{3}{8} \mathrm{H}_{2} \mathrm{O} \quad \Delta \mathrm{G}=27.4 \mathrm{~kJ} \mathrm{e}^{-} \mathrm{eq}^{-1}
\]

Reduction reaction:
\[
\frac{1}{4} \mathrm{O}_{2}+\mathrm{H}^{+}+\mathrm{e}^{-} \rightarrow \frac{1}{2} \mathrm{H}_{2} \mathrm{O} \quad \Delta \mathrm{G}=-78.72\mathrm{~kJ} \mathrm{e}^{-} \mathrm{eq}^{-1}
\]

The free energy change of acetate oxidation to $\mathrm{CO}_{2}, \mathrm{H}_{2} \mathrm{O}$ and $\mathrm{HCO}_{3}^{-}$ is $\_\_\_\_$ $\mathrm{kJ} \mathrm{e}^{-} \mathrm{eq}^{-1}$. (rounded off to two decimal places)

GATE BT 2026 | Question: 35

Mon, 23 Feb 2026 14:20:59 +0000

For a Newtonian fluid, a plot of shear stress (on $\text{Y}$ axis) against shear rate (on $\text{X}$ axis) will result in a straight line $\_\_\_\_$.

parallel to the $\text{X}$ axis
parallel to the $\text{Y}$ axis
with a negative slope
with a positive slope

GATE BT 2026 | Question: 37

Mon, 23 Feb 2026 14:20:54 +0000

For a liquid flowing in a circular cross section pipe, the transition from laminar to turbulent flow will NOT depend on which of the following factor(s)?

The diameter of the pipe
The length of the pipe
The linear velocity of the liquid
The viscosity of the liquid

GATE BT 2026 | Question: 40

Mon, 23 Feb 2026 14:20:45 +0000

An enzyme-catalyzed reaction is found to have $\Delta \mathrm{G}=-100 \mathrm{~kJ} \mathrm{~mol}^{-1}$. Which of the following statements about this reaction is/are true?

The rate of the reaction cannot be predicted
The rate of the reaction is high
The rate of the reaction is low
The reaction is irreversible

GATE BT 2025 | Question: 19

Thu, 06 Mar 2025 17:05:40 +0000

For a mechanically reversible isobaric process taking place in a closed system involving $5$ moles of an ideal gas, the temperature increases from an initial value of $300 \: K$ to a final value of $450 \: K$. If the specific heat capacity at constant volume $\left(C_{\mathrm{v}}\right)$ is given as $12.5 \mathrm{~J} \mathrm{~mol}^{-1} \mathrm{~K}^{-1}$ and gas constant is $8.314 \mathrm{~J} \mathrm{~mol}^{-1} \mathrm{~K}^{-1}$, the amount of heat transferred to the system will be $\_\_\_\_\_$ $\mathrm{J}$.

(Round off to the nearest integer)

Answered: GATE BT 2024 | Question: 3

Mon, 23 Dec 2024 19:46:40 +0000

Answer: D
In a closed system, only energy can be transferred across the system boundary not mass.

GATE BT 2024 | Question: 47

Mon, 25 Mar 2024 19:16:13 +0000

The free energy change of ATP hydrolysis at $25^{\circ} \mathrm{C}$ is $-32.2 \mathrm{~kJ} \mathrm{~mol}^{-1}$. The free energy change for hydrolysis of $\alpha$-glycerophosphate to glycerol is $-8.2 \mathrm{~kJ} \mathrm{~mol}^{-1}$ at $25^{\circ} \mathrm{C}$. Using the above information, the free energy change for the formation of $\alpha$-glycerophosphate from glycerol and ATP is $\_\_\_\_\_\_\_\_$ $\mathrm{kJ} \mathrm{mol}^{-1}$ (Answer in integer).

GATE BT 2023 | Question: 53

Sun, 21 May 2023 02:58:13 +0000

An evaporator is insulated using glass wool material of $0.15 \mathrm{~m}$ thickness. The inner most surface and the outer surface of the insulation are at $700{ }^{\circ} \mathrm{C}$ and $80^{\circ} \mathrm{C}$, respectively. The mean thermal conductivity of the glass wool under these conditions is $0.29 \mathrm{~W} . \mathrm{m}^{-1} . \mathrm{K}^{-1}$. The rate of heat loss (in $W$ ) through $1.2 \mathrm{~m}^2$ of the evaporator wall surface (rounded off to the nearest integer) is ______________.

GATE BT 2022 | Question: 25

Sun, 20 Mar 2022 16:16:28 +0000

For a pure species, the slope of the melting line
$$\frac{dP}{dT} \; \text{at} \; -2 \; ^{\circ} \textrm{C} \; \text{is} -5.0665 \times 10^{6} \text{Pa K}^{-1}.$$
The difference between the molar volumes of the liquid and solid phase at $-2 ^{\circ} \text{C}$ is $-4.5\times 10^{6} \; \text{m}^{3} \text{mol}^{-1}.$

The value of the latent heat of fusion (rounded off to nearest integer) is __________ $\text{J} \; \text{mol}^{-1}.$

GATE BT 2022 | Question: 51

Sun, 20 Mar 2022 16:16:25 +0000

Consider a piston-cylinder assembly shown in the figure below. The walls of the cylinder are insulated. The cylinder contains $1$ mole of an ideal gas at $300 \; \text{K}$ and the piston is held initially at the position $\text{z}_{1}$ using a stopper. After the stopper is removed, the piston suddenly rises against atmospheric pressure $(1.013\times 10^{5} \; \text{Pa})$ to the new position $\text{z}_{2}$ where it is held by another stopper.

The heat capacity $(C_{v})$ of the gas is $12.5 \; \text{J mol}^{-1} \text{K}^{-1}.$ The cross-sectional area of the cylinder is $10^{-3} \text{m}^{2}.$ Assume the piston is weightless and frictionless.

If $\text{z}_{2} – \text{z}_{1} =1\; \text{m},$ the final temperature of the gas (rounded off to nearest integer) is _____________$\text{K}.$

Answered: GATE BT 2021 | Question: 24

Wed, 07 Apr 2021 15:42:58 +0000

Final Equilibrium Pressure of the system = (P1V1+P2V2)/V1+V2 which comes out to be 7atm.

GATE BT 2021 | Question: 50

Mon, 01 Mar 2021 03:19:46 +0000

A feed stream $(F_1)$ containing components $A$ and $B$ is processed in a system comprising of separation unit and a mixer as shown below in the schematic diagram. The mole fractions of the components $A$ and $B$ are $x_A$ and $x_B$, respectively. If $F_1+F_2=100 \textit{ kg h}^{-1}$, the degrees of freedom of the system is _________.

GATE2020: 26

Tue, 03 Nov 2020 11:16:27 +0000

A block of ice at $0 \:^{\circ}C$ is supplied heat at a constant rate to convert ice to superheated steam. Which one of the following trajectories correctly represents the trend of the temperature of the system with time? Assume that the Specific heat of $H_{2}O$ is not a function of temperature.

GATE2020: 14

Tue, 03 Nov 2020 11:02:13 +0000

Which of the following are energy transducing membranes?

Plasma membrane of bacteria
Inner membrane of chloroplasts
Inner membrane of mitochondria

$P$ and $Q$ only
$P$ and $R$ only
$Q$ and $R$ only
$P, Q$ and $R$

GATE2019: 16

Tue, 03 Nov 2020 04:04:44 +0000

Which one of the following is the unit of heat transfer coefficient?

$W\:m^{2}K^{-1}$
$W\:m^{-2}K$
$W\:m^{-2}K^{-1}$
$W\:m^{2}K$

GATE2016-16

Mon, 26 Mar 2018 16:59:51 +0000

Prandtl number is the ratio of

thermal diffusivity to momentum diffusivity
mass diffusivity to momentum diffusivity
momentum diffusivity to thermal diffusivity
thermal diffusivity to mass diffusivity

GATE BT 2015 | Question: 60

Mon, 26 Mar 2018 15:10:43 +0000

The standard free energy change $(\Delta G' ^\circ)$ for ATP hydrolysis is $-30 kJ \cdot \text{mole}^{-1}$. The $\textit{in vivo}$ concentrations of ATP, ADP and $P_i$ in $E \textit{.coli}$ are $7.90, 1.04$ and $7.90$ mM, respectively. When $E\text{.coli}$ cells are cultured at $37 ^\circ C$, the free energy change $(\Delta G)$ for ATP hydrolysis $\textit{in viva}$ is _______ $kJ \cdot \text{mole}^{-1}$.