Enzymes and Hormones Questions in English

(B) The class of enzymes that catalyze the oxidation of one substrate with the simultaneous reduction of another substrate is known as $Oxidoreductases$.

(N/A) The active sites of enzymes hold the substrate molecule in a specific orientation or suitable position. This allows the reagent to attack the substrate effectively,thereby increasing the rate of the biochemical reaction.

(A-4, B-3, C-5, D-1, E-2) The correct matches are:
$A$ (Invertase) catalyzes the hydrolysis of cane sugar $(4)$.
$B$ (Maltase) catalyzes the hydrolysis of maltose into glucose $(3)$.
$C$ (Pepsin) catalyzes the hydrolysis of proteins into peptides $(5)$.
$D$ (Urease) catalyzes the decomposition of urea into $NH_3$ and $CO_2$ $(1)$.
$E$ (Zymase) catalyzes the conversion of glucose into ethyl alcohol $(2)$.
Therefore,the correct sequence is $A-4, B-3, C-5, D-1, E-2$.

(B) Some drugs do not bind to the enzyme's active site.
These bind to a different site of the enzyme,which is known as the allosteric site.

(D) The primary function of an enzyme in its catalytic activity is to hold the substrate for a chemical reaction. Active sites of enzymes hold the substrate molecule in a suitable position so that it can be attacked by the reagent effectively.
Substrates bind to the active site of the enzyme through a variety of interactions,such as $ionic \ bonding$,$hydrogen \ bonding$,$van \ der \ Waals' \ interactions$,or $dipole-dipole \ interactions$.

(B) When a strong covalent bond is formed between an enzyme and an inhibitor,it cannot be broken easily.
As a result,the enzyme is blocked permanently.
The body then degrades this enzyme-inhibitor complex and synthesizes a new enzyme to restore biological function.

(N/A) Enzymes catalyze reactions by providing a binding site for the substrate. The substrate binds to the active site of the enzyme through various interactions such as ionic bonding,hydrogen bonding,van der Waals interactions,or dipole-dipole interactions. This binding lowers the activation energy of the reaction,thereby increasing the rate of the reaction.
Drug-target interaction: Drugs often act as enzyme inhibitors. They can interact with the active site of the enzyme in two ways:
$1$. Competitive Inhibition: The drug competes with the natural substrate for the active site of the enzyme. Since the drug is structurally similar to the substrate,it binds to the active site,preventing the substrate from binding.
$2$. Non-competitive (Allosteric) Inhibition: The drug binds to a different site on the enzyme,known as the allosteric site. This binding changes the shape of the active site,making it impossible for the substrate to bind effectively.

(N/A) Enzyme inhibitors are foreign substances that bind to the active site of an enzyme and inhibit its catalytic activity.
They are classified into two types based on their mode of attachment:
$1$. Competitive Inhibitors: These compete with the natural substrate for the active site of the enzyme. They resemble the substrate in molecular shape.
$2$. Non-competitive (Allosteric) Inhibitors: These bind to a site other than the active site of the enzyme,known as the allosteric site. This binding changes the shape of the active site so that the substrate cannot bind to it.
Diagrammatic explanation:
$(a)$ Competitive inhibition: The inhibitor occupies the active site,preventing the substrate from binding.
$(b)$ Non-competitive inhibition: The inhibitor binds to the allosteric site,causing a conformational change in the enzyme's active site,rendering it ineffective.

(A) . Zymase converts glucose into $Ethanol$ $(iv)$.
$B$. Invertase hydrolyzes $Sucrose$ $(iii)$.
$C$. Anaerobic condition refers to the $Absence \ of \ air$ $(i)$.
$D$. Denaturation of ethanol is achieved by adding $Copper \ sulphate \ and \ pyridine$ $(ii)$.
Therefore,the correct matching is $A-iv, B-iii, C-i, D-ii$.

(C) The hydrolysis of sucrose into glucose and fructose is catalyzed by the enzyme $Invertase$.
The fermentation of glucose into ethanol and carbon dioxide is catalyzed by the enzyme $Zymase$.
Therefore,the reactions are:
$C_{12}H_{22}O_{11} + H_2O \stackrel{\text{Invertase}}{\longrightarrow} C_6H_{12}O_6 + C_6H_{12}O_6$
$C_6H_{12}O_6 \stackrel{\text{Zymase}}{\longrightarrow} 2C_2H_5OH + 2CO_2$
Thus,enzyme $A$ is $Invertase$ and enzyme $B$ is $Zymase$.

(D) Enzymes are highly specific both in the reactions that they catalyze and in their choice of reactants,which are called substrates. Therefore,the statement that enzymes are non-specific is incorrect.

(B) The correct answer is $B$.
$1$. Like chemical catalysts,enzymes reduce the activation energy of bio-processes. This is a correct statement.
$2$. Enzymes are polysaccharides. This is an incorrect statement because enzymes are proteinaceous in nature (they are globular proteins).
$3$. Enzymes are very specific for a particular reaction and substrate. This is a correct statement.
$4$. Enzymes are biocatalysts. This is a correct statement.

(B) The correct matches are:
$a$. Zymase is an enzyme obtained from $ii$. Yeast.
$b$. Diastase is an enzyme obtained from $iii$. Malt.
$c$. Urease is an enzyme obtained from $iv$. Soyabean.
$d$. Pepsin is an enzyme found in $i$. Stomach.
Therefore,the correct sequence is $a-ii, b-iii, c-iv, d-i$.

(C) The correct matches are:
$A$. Invertase: Catalyzes the hydrolysis of cane sugar (sucrose) into glucose and fructose $(IV)$.
$B$. Zymase: Catalyzes the conversion of glucose into ethanol and $CO_2$ $(III)$.
$C$. Diastase: Catalyzes the conversion of starch into maltose $(I)$.
$D$. Maltase: Catalyzes the hydrolysis of maltose into glucose $(II)$.
Therefore,the correct sequence is $A-IV, B-III, C-I, D-II$.

(C) Enzyme inhibitors are classified into two main types:
$1$. Competitive inhibitors: These drugs compete with the natural substrate for the active site of the enzyme.
$2$. Non-competitive inhibitors: These drugs bind to a different site known as the allosteric site,which changes the shape of the active site so that the substrate cannot bind.
Therefore,statement $A$ is correct because it identifies the two types.
Statement $B$ is correct because competitive inhibitors bind to the active site,while non-competitive inhibitors bind to the allosteric site.
Statements $C$ and $D$ are incorrect because they swap the definitions of competitive and non-competitive inhibitors.
Thus,only $A$ and $B$ are correct.

(C) The correct matches are as follows:
$A$. Sucrose $\rightarrow$ Glucose and Fructose is catalyzed by Invertase $(III)$.
$B$. Glucose $\rightarrow$ Ethyl alcohol and $CO_2$ is catalyzed by Zymase $(I)$.
$C$. Starch $\rightarrow$ Maltose is catalyzed by Diastase $(IV)$.
$D$. Proteins $\rightarrow$ Amino acids is catalyzed by Pepsin $(II)$.
Therefore,the correct sequence is $A-III, B-I, C-IV, D-II$.

(C) $1$. Statement $A$ is correct: Enzymes are biological catalysts that speed up biochemical reactions.
$2$. Statement $B$ is incorrect: Enzymes are highly specific in their action and usually catalyse only one type of reaction.
$3$. Statement $C$ is correct: Most enzymes are globular proteins.
$4$. Statement $D$ is incorrect: The enzyme that catalyses the hydrolysis of maltose into glucose is maltase,not oxidase. Oxidase enzymes are involved in oxidation-reduction reactions.
Therefore,statements $B$ and $D$ are incorrect.

(D) The enzyme $Glucose \ isomerase$ is responsible for the conversion of $glucose$ into $fructose$.

(B) $Glucose$ $(xylose)$ $isomerase$ catalyzes the reversible isomerization of $glucose$ to $fructose$ and that of $xylose$ to $xylulose$.
It is an important enzyme used in the industrial production of high-$fructose$ corn syrup.

(B) The synthesis of adipic acid from renewable resources was developed by $Drath$ and $Frost$ using an engineered strain of $Escherichia \text{ } coli$. The process utilizes $Glucose$ as the primary carbon source to produce adipic acid through a microbial fermentation pathway.

(A) The enzyme that converts maltose into glucose is $Maltase$.
During digestion,starch is partially transformed into maltose by pancreatic or salivary enzymes called amylases.
$Maltase$,secreted by the intestine,then converts maltose into glucose.
The glucose so produced is either utilised by the body or stored in the liver as glycogen.

(A) $ \text{Amylase}$ is the enzyme responsible for the hydrolysis of $ \text{starch}$ into simpler sugars like $ \text{maltose}$ and $ \text{glucose}$.
$ \text{Proteases}$ hydrolyze proteins.
$ \text{Glucose isomerase}$ converts $ \text{glucose}$ to $ \text{fructose}$.
$ \text{Insulin}$ is a hormone.

(B) Pepsin is a digestive enzyme that catalyzes the hydrolysis of proteins into $\alpha$-amino acids in the stomach.

(A) Amylase,an enzyme present in saliva,hydrolyzes starch into maltose.

(D) The correct answer is Carbonic anhydrase.
In the human body,the enzyme carbonic anhydrase catalyses the hydration of $CO_{2}$.
It facilitates the reaction that converts $CO_{2}$ and water into carbonic acid $(H_{2}CO_{3})$,which subsequently dissociates into protons $(H^{+})$ and bicarbonate ions $(HCO_{3}^{-})$.
This enzyme is primarily found in red blood cells and is essential for the transport of $CO_{2}$ from tissues to the lungs.
The reaction is: $CO_{2} + H_{2}O \xrightarrow{\text{Carbonic anhydrase}} H_{2}CO_{3}$

(C) The given reaction is the decomposition of hydrogen peroxide $(H_2O_2)$ into water and oxygen.
This reaction is biologically catalyzed by the enzyme $Catalase$ in living organisms to prevent the accumulation of toxic $H_2O_2$ in cells.
Therefore,the enzyme '$X$' is $Catalase$.

(A) Many enzymes require metal ions as cofactors to function. Among the given options,$Mn^{2+}$,$Cu^{2+}$,and $Fe^{2+}$ are all known to act as essential cofactors for various enzymes. However,in the context of standard biochemical textbooks,$Mn^{2+}$ is frequently cited as a cofactor for enzymes like glycosyltransferases and decarboxylases. Since multiple options are technically correct in biological systems,the question is often context-dependent. Given the standard curriculum,$Mn^{2+}$ is the most common example provided for metal ion cofactors.

(D) $Testosterone$ is the primary male sex hormone and an anabolic steroid.
It plays a key role in the development of male reproductive tissues such as the testes and prostate,as well as promoting secondary sexual characteristics such as increased muscle and bone mass,and the growth of body hair and deepening of the voice.
Therefore,the correct option is $D$.

(C) Hypothyroidism is caused due to the deficiency of thyroxine.
Thyroxine is a hormone secreted by the thyroid gland,which regulates the metabolism of carbohydrates,lipids,and proteins in the body.

(B) Estradiol is the primary female sex hormone. It is responsible for the development of secondary female characteristics and plays a crucial role in the regulation of the menstrual cycle.

(D) Oxytocin is a peptide hormone,not an enzyme.
Silk is a natural polyamide (protein).
Lipase is an enzyme.
Butter is a fat (lipid).
Therefore,the incorrect match is $D$.

(B) The hormone that contains iodine is $Thyroxine$. It is secreted by the thyroid gland.

(A) In reaction $I$,the hydrolysis of sucrose into glucose and fructose is catalyzed by the enzyme $\text{Invertase}$.
In reaction $II$,the fermentation of glucose into ethanol and $CO_2$ is catalyzed by the enzyme $\text{Zymase}$.
Therefore,$x = \text{Invertase}$ and $y = \text{Zymase}$.

(C) The conversion of sucrose into glucose and fructose is catalyzed by the enzyme $\text{invertase}$,not $\text{zymase}$.
$\text{Zymase}$ is the enzyme responsible for the conversion of glucose or fructose into ethanol and carbon dioxide.
Therefore,the pair in option $C$ is incorrectly matched.

(C) Both $Pepsin$ and $Trypsin$ are proteolytic enzymes that break down proteins into amino acids. $Pepsin$ acts in the stomach,while $Trypsin$ acts in the small intestine. Given the options,$Trypsin$ is a standard answer for pancreatic protein digestion. $Pepsin$ is also a correct answer in biological contexts. However,in many academic contexts,$Trypsin$ is highlighted for its role in the final breakdown of proteins into amino acids in the small intestine.

(A) $1$. $Addison's$ disease is caused by the hyposecretion of hormones from the $Adrenal \text{ } Cortex$ (specifically glucocorticoids and mineralocorticoids).
$2$. Estradiol is the primary estrogen hormone responsible for the development and maintenance of secondary female sexual characteristics.
$3$. Therefore,'$X$' is the $Adrenal \text{ } Cortex$ and '$Y$' is estradiol.
$4$. The correct option is $A$.

(A) The correct matching is as follows:
$A$. Glucocorticoids: $I$. Control the carbohydrate metabolism.
$B$. Mineralocorticoids: $II$. Control the level of excretion of water and salt by the kidneys.
$C$. Progesterone: $III$. Prepares the uterus for implantation of fertilised egg.
$D$. Estradiol: $IV$. In the control of menstrual cycle.
Therefore,the correct sequence is $A-I, B-II, C-III, D-IV$.

(B) The reaction $Starch \longrightarrow Maltose$ is catalyzed by the enzyme $Diastase$,not $Zymase$.
$Zymase$ is an enzyme complex that catalyzes the fermentation of sugar into ethanol and carbon dioxide.
Therefore,the match in option $B$ is incorrect.

(B) Glucocorticoids are steroidal hormones that control carbohydrate metabolism,modulate inflammatory reactions,and help the body react to stress.

(B) Progesterone is an endogenous steroid and progestogen sex hormone involved in the menstrual cycle,pregnancy,and embryogenesis of humans and other species. It plays a crucial role in preparing the endometrium (lining of the uterus) for the implantation of a fertilised egg.

(D) The correct matching is:
$A$. Hydrolysis of starch to maltose is catalyzed by $I$. Diastase.
$B$. Conversion of proteins to peptides is catalyzed by $II$. Pepsin.
$C$. Hydrolysis of sucrose to glucose and fructose is catalyzed by $III$. Invertase.
$D$. Conversion of glucose to ethanol is catalyzed by $IV$. Zymase.
Therefore,the correct sequence is $A-I, B-II, C-III, D-IV$.

(B) Intracellular messengers are chemical substances that transmit signals within a cell. Hormones,such as cyclic $AMP$ $(cAMP)$,$Ca^{2+}$ ions,and $IP_3$,act as intracellular messengers to regulate various metabolic processes.

(B) Hypothyroidism is a condition caused by the deficiency of iodine in the diet,which leads to the enlargement of the thyroid gland (goiter).
Thus,both $B$ and $C$ are correct.

(C) Addison's disease is caused by the deficiency of glucocorticoids and mineralocorticoids.
It is characterized by symptoms such as muscle weakness,fatigue,weight loss,low blood pressure (hypotension),and increased susceptibility to stress.
Therefore,the correct characteristics are $B$ (Weakness) and $C$ (Increased susceptibility to stress).

(B) The correct matches are as follows:
$A$. Invertase catalyzes the hydrolysis of sucrose into glucose and fructose: $Sucrose \xrightarrow{Invertase} Glucose + Fructose$ $(II)$.
$B$. Pepsin is a proteolytic enzyme that breaks down proteins into peptides: $Proteins \xrightarrow{Pepsin} Peptides$ $(III)$.
$C$. Diastase is an enzyme that catalyzes the breakdown of starch into maltose: $Starch \xrightarrow{Diastase} Maltose$ $(IV)$.
Therefore,the correct matching is $A-II, B-III, C-IV$.

(B) Hormones have several functions in the body. They help to maintain the balance of biological activities in the body.
The role of insulin in keeping the blood glucose level within the narrow limit is an example of this function. Insulin is released in response to the rapid rise in blood glucose level.
On the other hand,the hormone $Glucagon$ tends to increase the glucose level in the blood. The two hormones together regulate the glucose level in the blood.
$Epinephrine$ and $norepinephrine$ mediate responses to external stimuli.
$Estrogen$ is a category of sex hormone responsible for the development and regulation of the female reproductive system and secondary sex characteristics.
In terms of chemical nature,some of these are steroids,e.g.,$estrogens$ and $androgens$; some are polypeptides,for example,$insulin$ and $endorphins$; and some others are amino acid derivatives,such as $epinephrine$ and $norepinephrine$.

(B) Zymase is an enzyme complex that catalyzes the fermentation of glucose into ethanol and carbon dioxide.
This process occurs naturally in yeast.
The chemical reaction is as follows:
$C_6H_{12}O_6 \xrightarrow{\text{Zymase}} 2 C_2H_5OH + 2 CO_2$
Therefore,glucose is converted into ethanol.

(B) $Insulin$ is a peptide hormone composed of $51$ amino acids arranged in two polypeptide chains,making it a classic example of a polypeptide hormone.
$Epinephrine$ is a catecholamine derived from amino acids.
$Estrogen$ and $Androgen$ are steroid hormones.

(B) Insulin and glucagon are peptide hormones secreted by the pancreas that regulate blood glucose levels.
Insulin lowers blood glucose by facilitating its uptake into cells,while glucagon raises blood glucose by stimulating the breakdown of glycogen into glucose in the liver.

(B) Insulin is a peptide hormone secreted by the pancreas.
It regulates blood glucose metabolism by signaling the liver,muscles,and fat cells to take up excess glucose from the blood,thereby maintaining the level within the normal limit.