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All questions of Biomolecules for EmSAT Achieve Exam

Which is true about enzymes?a)All enzymes are proteins.b)All proteins are enzymes.c)All enzymes are not proteins.d)All enzymes are vitamins.Correct answer is option 'C'. Can you explain this answer?

Gaurav Kumar answered
Enzymes are known to catalyze more than 5,000 biochemical reaction types. Most enzymes are proteins, although a few are catalytic RNA molecules. The latter are called ribozymes. Enzymes' specificity comes from their unique three-dimensional structures.

The turnover of biomolecules is together called
  • a)
    Anabolism
  • b)
    Bioenergetics
  • c)
    Catabolism
  • d)
    Metabolism
Correct answer is option 'D'. Can you explain this answer?

Hansa Sharma answered
All the biomolecules are constantly being changed into some other biomolecules and also made from some other biomolecules. The turnover of biomolecules takes place continuously. All these reactions are together called metabolism.

Cellulose is made up of
  • a)
    Fructose
  • b)
    Glucose
  • c)
    Sucrose
  • d)
    Ribose
Correct answer is option 'B'. Can you explain this answer?

Ayush Chauhan answered
Cellulose is a third polymer made from beta glucose molecules and the polymer molecules are straight cellulose serves a very different purpose in nature to starch and glycogen it make up the cell walls in plant cell.

The number of amino acids found in proteins are
  • a)
    20
  • b)
    21
  • c)
    18
  • d)
    16
Correct answer is option 'A'. Can you explain this answer?

Rohan Singh answered
Proteinogenic amino acids are amino acids that are incorporated biosynthetically into proteins during translation. ... Throughout known life, there are 22 genetically encoded (proteinogenic) amino acids, 20 in the standard genetic code and an additional 2 that can be incorporated by special translation mechanisms.

Which of the following is a catabolic pathway?
  • a)
    Photosynthesis
  • b)
    Formation of proteins from amino acids
  • c)
    Conversion of acetic acid to cholesterol
  • d)
    Conversion of glucose to lactic acid
Correct answer is option 'D'. Can you explain this answer?

Ankit Patel answered
Catabolic pathways are metabolic pathways that involve the breakdown of complex molecules into simpler ones with the release of energy. The correct answer is option D, which states the conversion of glucose to lactic acid.

Explanation:

• Glucose is a simple sugar that is an important source of energy for living organisms.
• The breakdown of glucose into simpler molecules is called glycolysis, which is the first step in cellular respiration.
• During glycolysis, glucose is converted to pyruvate, which can be further metabolized to produce energy.
• In the absence of oxygen, pyruvate is converted to lactic acid through a process called fermentation.
• This process releases a small amount of energy and regenerates NAD+ for further glycolysis.

Therefore, the conversion of glucose to lactic acid is a catabolic pathway as it involves the breakdown of glucose into simpler molecules with the release of energy.

The most abundant organic molecule present on earth is
  • a)
    Protein
  • b)
    Lipid
  • c)
    Steroids
  • d)
    Cellulose
Correct answer is option 'D'. Can you explain this answer?

The most abundant organic molecule present on earth is cellulose.

What is Cellulose?

Cellulose is a complex carbohydrate that is found in the cell walls of plants. It is composed of repeating units of glucose molecules that are linked together to form long chains. These chains are then arranged in a way that gives cellulose its characteristic strength and rigidity.

Why is Cellulose Abundant on Earth?

Cellulose is abundant on earth for several reasons:

1. It is found in the cell walls of plants - Plants are the most abundant form of life on earth, and cellulose is a major component of their cell walls. This means that there is a huge amount of cellulose present on earth.

2. It is resistant to degradation - Unlike other organic molecules, cellulose is highly resistant to degradation by enzymes and other biological processes. This means that it can persist in the environment for a long time, contributing to its abundance.

3. It is a major component of biomass - Cellulose is a major component of the biomass of plants. When plants die and decompose, the cellulose in their cell walls is broken down into smaller molecules that can be used by other organisms. This means that there is a constant supply of cellulose being produced and broken down on earth.

Conclusion:

In conclusion, cellulose is the most abundant organic molecule present on earth due to its presence in the cell walls of plants, its resistance to degradation, and its role as a major component of biomass.

The bacterial cell wall is formed of
  • a)
    Cellulose
  • b)
    Hemicellulose
  • c)
    Peptidoglycan
  • d)
    Glycogen
Correct answer is option 'C'. Can you explain this answer?

Pooja Shah answered
Bacterial cell walls are made of peptidoglycan (also called murein), which is made from polysaccharide chains cross-linked by unusual peptides containing D-amino acids. Bacterial cell walls are different from the cell walls of plants and fungi which are made of cellulose and chitin, respectively.

Can you explain the answer of this question below:

The energy content in kcal/g of carbohydrate:protein:triglycerol is approximately in the ratio of

  • A:

    1:2:1

  • B:

    2:2:1

  • C:

    1:1:2

  • D:

    1:2:2

The answer is c.

Shreya Gupta answered
Carbohydrates supply energy at the physiological rate of 4 kcal/g (caloric value 4.1), fats are the source of energy with a physiological rate of 9 kcal/g (caloric value 9.45), while proteins may yield energy at 4.65 kcal/g caloric value or 4.0 kcal/g physiological fuel value.

 Chemical reactions require energy for
  • a)
    Entropy
  • b)
    Activation
  • c)
    Oxidation
  • d)
    Enthalpy
Correct answer is option 'B'. Can you explain this answer?

Sounak Saini answered
Chemical reactions require energy for Activation.

Explanation:
Activation energy is the minimum amount of energy required to start a chemical reaction. It is the energy required to break the bonds of the reactant molecules so that they can rearrange to form the product molecules.

During a chemical reaction, the reactant molecules collide with each other. However, not all collisions lead to a successful reaction. Only those collisions in which the reactant molecules possess sufficient energy to overcome the activation energy barrier lead to the formation of the product molecules.

Thus, energy is required for activation so that the reactant molecules can possess enough energy to overcome the activation energy barrier and form the product molecules.

An ester bond is present between
  • a)
    Amino acids
  • b)
    Nucleoside
  • c)
    Nucleotide
  • d)
    Monosaccharides
     
Correct answer is option 'C'. Can you explain this answer?

Syed Hussain answered
Phosphodiester bond definition. A bondbetween a two sugar groups and a phosphate group; such bonds form the sugar-phosphate-sugar backbone of DNA and RNA. A diester bond (between phosphoric acid and two sugar molecules) linking two nucleotides together to form the nucleotide polymers DNA and RNA.

Double hydrogen bond occurs in DNA between
  • a)
    Adenine and guanine
  • b)
    Thymine and cytosine
  • c)
    Adenine and thymine
  • d)
    Uracil and thymine
Correct answer is option 'C'. Can you explain this answer?

Gaurav Kumar answered
The complementary base pairs of guanine with cytosine and adenine with thymine connect to one another using hydrogen bonds. In addition to holding the DNA strands together, the hydrogen bonding between the complementary bases also sequester the bases in the interior of the double helix. Since, the option of Guanine and Cytosine is not provided. Hence, the correct option is Option C. 

Which of the following is an anabolic pathway?
  • a)
    Conversion of glycogen to carbon dioxide and water
  • b)
    Conversion of glucose to lactic acid
  • c)
    Hydrolysis of sucrose
  • d)
    Formation of proteins
Correct answer is option 'D'. Can you explain this answer?

Preeti Iyer answered
Anabolic pathways require an input of energy to synthesize complex molecules from simpler ones.
Example: Synthesis of large proteins from amino acid building blocks, and the synthesis of new DNA strands from nucleic acid building blocks.
These biosynthetic processes are critical to the life of the cell, take place constantly, and demand energy provided by ATP and other high-energy molecules like NADH (nicotinamide adenine dinucleotide) and NADPH.

A segment of DNA has 120 adenine and 120 cytosine bases. The total number of nucleotides present in the segment is
  • a)
    480
  • b)
    240
  • c)
    60
  • d)
    120
Correct answer is option 'A'. Can you explain this answer?

Pooja Shah answered
According to Chargaff’s rule, the amount of adenine is always equal to that of thymine and the amount of guanine is always equal to that of cytosine.
A = T(120), G = C(120)
The total number of nucleotides would be 120 × 4 = 480.

 A living state is in
  • a)
    Equilibrium always
  • b)
    Sometimes in equilibrium and sometimes in non-equilibrium
  • c)
    Constant stable state
  • d)
    Non-equilibrium always
Correct answer is 'D'. Can you explain this answer?

Rohan Singh answered
Living State : The living state is a non-equilibrium steady-state to be able to perform work.(a) The living process is a constant effort to prevent falling into equilibrium and is achieved by energy input.(b) The metabolism provides a mechanism for the production of energy.The living state and metabolism are synonymous, without metabolism there cannot exist a living : state.(d) A living organism works continuously so it cannotafford to reach equillibrium because a system at equilibrium cannot perform the work

Process in which activation or inhibition of an enzyme by a small regulatory molecule is called
  • a)
    enzyme control
  • b)
    allosteric control
  • c)
    Specificity control
  • d)
    Enzyme action
Correct answer is option 'B'. Can you explain this answer?

Rajat Kapoor answered
Allosteric control refers to a type of enzyme regulation involving the binding of a non-substrate molecule, known as the allosteric effector, at locations on the enzyme other than the active site.

 Which one is true for ATP?
  • a)
    ATP is organic ions of enzyme.
  • b)
    ATP is a coenzyme.
  • c)
    ATP is an enzyme
  • d)
    ATP is a prosthetic part of an enzyme.
Correct answer is option 'B'. Can you explain this answer?

Hitakshi HTG answered
Adenosine triphosphate, also known as molecular unit of currency, is a coenzyme of vast importance in the transfer of chemical energy derived from biochemical oxidations and it also transports energy within cells for metabolism. Thus, option 'B' is the right answer.

Enormous diversity of protein molecules is due to
  • a)
    R groups of amino acids
  • b)
    Sequence of amino acids
  • c)
    Peptide bonds
  • d)
    Amino groups of amino acids
Correct answer is option 'B'. Can you explain this answer?

Rajat Kapoor answered
The third is tertiary; this is the folding of the secondary structures into the final 3D structure of a protein. Amino acids have properties that guide this; some interact easily with water (hydrophilic) and these orient themselves on the outside of a protein, while others don't interact well with water (hydrophobic) and will try to get themselves on the inside of the folded structure where they will be protected. Hydrophobicity/philicity is the major driving force in protein folding but other bonds will also be formed between amino acids like S-S linkages, other ionic bonds and HYDROGEN BONDS (tons of these are made). These smaller interactions generally stabilize the protein and keep it folded in the most ideal conformation possible. 

The enzyme which cuts DNA is
  • a)
    DNA polymerase
  • b)
    DNA ligase
  • c)
    Restriction endonucleases
  • d)
    DNA lyase
Correct answer is option 'C'. Can you explain this answer?

Baby Ghosh answered
Restriction Endonucleases are enzyme which scan DNA molecules for a particular nucleotide sequence. These are called Recognition Sequences.Once the Endonuclease finds this sequence it halts ans cuts the strand.Thus,the correct option is "C".

 The enzyme found functional in lysosome is
  • a)
    Acid phosphatase
    Lyases
  • b)
    Lyases
  • c)
    Oxidoreductase
  • d)
    Basic phosphatase
Correct answer is option 'B'. Can you explain this answer?

Vijay Bansal answered
A lysosome is a membrane-bound organelle found in nearly all animal cells. They are spherical vesicles that contain hydrolytic enzymes that can break down many kinds of biomolecules.

Enzyme amylase belongs to
  • a)
    Hydrolases
  • b)
    Transferases
  • c)
    Isomerases
  • d)
    Oxidoreductases
Correct answer is option 'A'. Can you explain this answer?

Ragini Shukla answered
Hydrolase are the enzyme which breaks down the large molecules into smaller ones with the help of hydrogen and hydroxyl groups of water molecule this phenomena is known as hydrolysis. Amylase is the enzyme produced by the salivary gland and helps in breaking down the starch into glucose. Amylase catalysis the hydrolysis of starch into sugar (glucose).
Amylase is also found in germinating seeds.

Which enzyme is concerned with the transfer of electrons?
  • a)
    Dehydrogenase
  • b)
    Transaminase
  • c)
    Hydrolase
  • d)
     Desmolase
Correct answer is option 'A'. Can you explain this answer?

Leelu Bhai answered
Transaminase are the enzymes concerned with transfer of atoms or group of atoms or electrons.. so, option B is correct not A

DNA nucleotides are attached by
  • a)
    Hydrogen bond 
  • b)
    Covalent bond
  • c)
    Van der Waals bond
  • d)
    Electrovalent bond
Correct answer is option 'A'. Can you explain this answer?

Gopikas S answered
Explanation: DNA nucleotides are attached by the Hydrogen bond. A nucleotide is the basic unit of polynucleotide chain of DNA (deoxyribonucleic acid) or RNA (Ribonucleic acid). 
The nitrogenous bases are found in the strand's inward direction.  The nitrogenous bases of the two antiparallel strands form hydrogen bonds, resulting in the formation of two helical strands. 
The nitrogenous bases used in DNA (double-stranded helical structure) are adenine (A), cytosine (C), guanine (G), and thymine (T). 
Adenine is joined to thymine with two hydrogen bonds, whereas guanine is joined to cytosine by three hydrogen bonds. 
Thus, DNA nucleotides are attached by Hydrogen bond.

The nucleotide chemical components are
  • a)
    Heterocyclic compounds, sugar and phosphate
  • b)
    Sugar and Phosphate
  • c)
    Heterocyclic compounds and sugar
  • d)
    Phosphate and heterocyclic compounds
Correct answer is option 'A'. Can you explain this answer?

Akshat Chavan answered
The nucleotide has three chemically distinct components. One is a heterocyclic compound, the second is a monosaccharide and the third a phosphoric acid or phosphate.

Which one is not a denaturing factor for protein?
  • a)
    High energy radiation
  • b)
    High pressure
  • c)
    Drastic change in pH
  • d)
    High temperature
Correct answer is option 'B'. Can you explain this answer?

Protein molecules get denatured due to high temperature, very high or low pH and high energy radiation but there is no effect due to high pressure.

Which of the following is not a conjugated protein?
  • a)
    Peptone
  • b)
    Glycoprotein
  • c)
    Chromoprotein
  • d)
    Lipoprotein
Correct answer is option 'A'. Can you explain this answer?

Suyash Jain answered
A conjugated protein is a protein that functions in interaction with other (non-polypeptide) chemical groups attached by covalent bonding or weak interactions.

Peptones are linear chains of amino acids and do not contain other molecules. Phosphoproteins contain phosphorous, lipoproteins contain lipids and chromoprotein are flavoproteins which contain FMN and FAD, in addition to amino acids. 

. __________ is a globular protein of 6 kDa consisting of 51 amino acids arranged in 2 polypeptide chains held together by a disulphide bridge
  • a)
    Fibrinogen
  • b)
    Keratin
  • c)
    Insulin
  • d)
    Glucagon
Correct answer is option 'C'. Can you explain this answer?

Pooja Mehta answered
Human insulin is a peptide hormone composed of 51 ammo acids and has a molecular weight of 5805 Da.(∼6 Kda). In this molecule, there are two polypeptide chains (A and B) held together by disulphide bridge.

The energy currency of cell is—
  • a)
    GDP
  • b)
    ATP
  • c)
    ADP
  • d)
    NAD
Correct answer is option 'B'. Can you explain this answer?

Rohan Singh answered
When the ATP converts to ADP, the ATP is said to be spent. he molecule is used like a battery within cells and allows the consumption of one of its phosphorous molecules.The energy currency used by all cells from bacteria to man is adenosine triphosphate (ATP).

A peptide bond is formed by the process of
  • a)
    Amination
  • b)
    Rehydration
  • c)
    Deamination
  • d)
    Dehydration
Correct answer is option 'D'. Can you explain this answer?

Preeti Iyer answered
A peptide bond is a chemical bond formed between two molecules when the carboxyl group of one molecule reacts with the amino group of the other molecule, releasing a molecule of water (H2O). This is a dehydration synthesis reaction (also known as a condensation reaction), and usually occurs between amino acids.

 In a DNA molecule, two strands are held by
  • a)
    Nitrogen bonds
  • b)
    Phosphate bonds
  • c)
    Carbon bonds
  • d)
    Hydrogen bonds
Correct answer is option 'D'. Can you explain this answer?

Pooja Mehta answered
By hydrogen bonds between the two bases. Basically, the bases are ‘polar’, meaning they have slight differences in electrical charge at certain points. This allows them to attract one another like a balloon sticking to your hair.
Hydrogen bonds are weaker than the covalent bonds that hold the rest of the molecule together, making them easier to break and re-form.

The rate of energy metabolism is equivalent to the
  • a)
    Rate of carbon dioxide consumption
  • b)
    Rate of nitrogen consumption
  • c)
    Rate of hydrogen consumption
  • d)
    Rate of oxygen consumption
Correct answer is option 'D'. Can you explain this answer?

Anjana Sharma answered
The energy equivalent for converting rate of oxygen consumption into rate of heat production (Qox cal mg-1 oxygen consumed) is 3.53 cal mg-1 for carbohydrate oxidation, 3.28 cal mg-1 (range 3.22–3.32) for fat oxidation. Qox values for the respiration of standard protein are the same at 3.25 cal mg-1 for ureotelic and uricotelic animals, and about 2% less at 3.20 cal mg-1 for ammoniotelic animals. The energy equivalent for converting rate of oxygen consumption into rate of energy loss in excreta (Qex cal mg-1) varies considerably with different excretory products. Values for standard protein are 0.62 cal mg-1 for ammonioteles, 0.58 cal mg-1 for ureoteles, and 0.94 cal mg-1 for uricoteles.

Which one of the following is fibrous protein?
  • a)
    Collagen
  • b)
    Ribozymes
  • c)
    Haemoglobin
  • d)
    Hemicellulose
Correct answer is option 'A'. Can you explain this answer?

Shanaya Rane answered
Collagen is a fibrous protein. It is the main structural protein in the extracellular space in thevarious connective tissues. It is the most abundant protein in mammals.

A polysaccharide present as storehouse of energy of plant tissues
  • a)
    Chitin
  • b)
    Starch
  • c)
    Hemi cellulose
  • d)
    Cellulose
Correct answer is option 'B'. Can you explain this answer?

Jyoti Kapoor answered
Polysaccharide 
A polysaccharide is a large molecule made of many smaller monosaccharides. Monosaccharides are simple sugars, like glucose. Special enzymes bind these small monomers together creating large sugar polymers, or polysaccharides. A polysaccharide is also called a glycan. A polysaccharide can be a homopolysaccharide, in which all the monosaccharides are the same, or a heteropolysaccharide in which the monosaccharides vary. Depending on which monosaccharides are connected, and which carbons in the monosaccharides connects, polysaccharides take on a variety of forms. A molecule with a straight chain of monosaccharides is called a linear polysaccharide, while a chain that has arms and turns is known as a branched polysaccharide.

DNA differs from RNA in having
  • a)
    Thymine but no uracil
  • b)
    Uracil but no thymine
  • c)
    Thymine but no cytosine
  • d)
    Cytosine but no guanine
Correct answer is option 'A'. Can you explain this answer?

Om Desai answered
Uracil is energetically less expensive to produce than thymine, which may account for its use in RNA. In DNA, however, uracil is readily produced by chemical degradation of cytosine, so having thymine as the normal base makes detection and repair of such incipient mutations more efficient.

Which of the following carries the hereditary information from parents to progeny?
  • a)
    Nucleotides
  • b)
    Nucleoside
  • c)
    Nucleic acids
  • d)
    Proteins
Correct answer is option 'C'. Can you explain this answer?

Pooja Mehta answered
Nucleic acid is the chemical name for the molecules RNA and DNA. The name comes from the fact that these molecules are acids – that is, they are good at donating protons and accepting electron pairs in chemical reactions – and the fact that they were first discovered in the nuclei of our cells.

The part of enzyme bound to the protein part by a covalent bond is called
  • a)
    Holoenzyme
  • b)
    Cofactor
  • c)
    Prosthetic group
  • d)
    Apoenzyme
Correct answer is option 'C'. Can you explain this answer?

Imk Pathsala answered
A prosthetic group is a tightly covalently bound, specific non-polypeptide unit required for the biological function of some proteins. The prosthetic group may be organic (such as a vitamin, sugar, or lipid) or inorganic (such as a metal ion), but is not composed of amino acids.

Assertion (A): Competitive inhibitors bind to the active site of an enzyme, preventing substrate binding.
Reason (R): Competitive inhibition can be overcome by increasing the concentration of the substrate.
  • a)
    If both Assertion and Reason are true and Reason is the correct explanation of Assertion
  • b)
    If both Assertion and Reason are true but Reason is not the correct explanation of Assertion
  • c)
    If Assertion is true but Reason is false
  • d)
    If both Assertion and Reason are false
Correct answer is option 'A'. Can you explain this answer?

Sreemoyee Iyer answered
Understanding Competitive Inhibition
Competitive inhibitors play a crucial role in enzyme activity and regulation. Let's break down the assertion and reason provided.
Assertion (A): Competitive inhibitors bind to the active site of an enzyme, preventing substrate binding.
- Competitive inhibitors are molecules that resemble the substrate and compete for binding at the enzyme's active site.
- When a competitive inhibitor occupies the active site, the actual substrate cannot bind, leading to decreased enzyme activity.
Reason (R): Competitive inhibition can be overcome by increasing the concentration of the substrate.
- Increasing substrate concentration effectively outcompetes the inhibitor for the active site.
- As the substrate concentration rises, more substrate molecules can bind to the enzyme, thereby restoring enzyme activity and overcoming the inhibition.
Conclusion: Why Option A is Correct
- Both the assertion and reason are true. Competitive inhibitors indeed bind to the active site, and their effects can be mitigated by increasing substrate concentration.
- The reason provided correctly explains the assertion, as the mechanism of competitive inhibition directly relates to the ability to overcome it by increasing substrate levels.
Summary
- Competitive inhibitors block substrate binding at the active site.
- Increased substrate concentration can alleviate the effects of competitive inhibition.
- Therefore, both assertion and reason are true, with the reason serving as the correct explanation for the assertion.
In conclusion, option 'A' is the correct choice as it reflects the relationship between competitive inhibition and substrate concentration effectively.

Proteins are made up of
  • a)
    Monomers
  • b)
    Amino acids
  • c)
    Homopolymers
  • d)
    Nucleosides
Correct answer is option 'B'. Can you explain this answer?

Rohan Singh answered
Proteins are heteropolymers usually made of amino acids. While a nucleic acid like DNA or RNA is made of of only 4 types of nucleotide monomers, proteins are made of 20 types of monomers. Ans: (d) Proteins perform many physiological functions. ... Ans: (a) Glycogen is a homopolymer made of glucose units.

Which of the following is not obtained on hydrolysis of nucleic acid?
  • a)
    Purine
  • b)
    Phosphoric acid
  • c)
    Pyrimidine
  • d)
    Pentose sugar
Correct answer is option 'B'. Can you explain this answer?

Ruchi Chopra answered
Hydrolysis of nucleic acid (DNA and RNA) produces pentose sugar (ribose or deoxyribose) purine and pyrimidine. Phosphoric acid is not released on hydrolysis of DNA or RNA.

Enzymes with slightly different molecular structure but performing identical activity are
  • a)
    Isoenzymes
  • b)
    Apoenzymes
  • c)
    Holoenzyme
  • d)
    Coenzymes
Correct answer is option 'A'. Can you explain this answer?

Mira Tiwari answered
Enzymes with slightly different molecular structure but performing identical activity are called isoenzymes.

Explanation:
Enzymes are biological catalysts that facilitate and speed up biochemical reactions in living organisms. They are usually proteins with a specific three-dimensional structure that allows them to bind to specific substrates and convert them into products. However, enzymes can also have slightly different molecular structures while performing the same catalytic activity. These enzymes are called isoenzymes.

Definition of Isoenzymes:
Isoenzymes, also known as isozymes, are enzymes that catalyze the same chemical reaction but have slightly different amino acid sequences or molecular structures. They are encoded by different genes but perform identical functions in the same organism or different tissues. Isoenzymes are often found in multiple forms and can be distinguished from each other through various methods such as electrophoresis or immunoassay.

Reasons for Different Molecular Structures:
1. Genetic Differences: Isoenzymes are encoded by different genes, which can result in variations in the amino acid sequence and overall structure of the enzyme.
2. Post-translational Modifications: Isoenzymes may undergo different post-translational modifications, such as phosphorylation or glycosylation, which can alter their structure and function.
3. Tissue-Specific Expression: Different tissues within an organism may require slightly different versions of an enzyme to perform the same activity optimally. These tissue-specific isoenzymes may have distinct molecular structures.

Importance of Isoenzymes:
1. Diagnostic Tool: Isoenzymes can be used as diagnostic markers for certain diseases or conditions. For example, the measurement of different forms of creatine kinase isoenzymes can help diagnose heart attacks.
2. Tissue-Specific Function: Isoenzymes may have different kinetic properties or substrate specificities, allowing them to perform specialized functions in specific tissues.
3. Evolutionary Adaptation: Isoenzymes can evolve to perform similar functions under different conditions or in different organisms, allowing for adaptation and survival in diverse environments.

In conclusion, isoenzymes refer to enzymes with slightly different molecular structures but identical catalytic activities. They play important roles in various biological processes and have diagnostic and evolutionary significance.

Allosteric modulation is due to the inhibitory action of enzyme by
  • a)
    Enzyme concentration
  • b)
    Products of reaction
  • c)
    Substrate concentration
  • d)
    Non-competitive inhibition
Correct answer is option 'B'. Can you explain this answer?

Sarita Gayan answered
It is an enzyme regulatory mechanism , where product of a simple or chain reaction can function as temporary allosteric inhibitor. An allosteric inhibitor combines with a regular or allosteric site other than active sites if it's concentration crosses the threshold value . For example , excess of glucose -6- phosphate
stops the activity of enzyme hexokinase that helps in it's formation from glucose and ATP.

How many subunits are there in human adult haemoglobin?
  • a)
    4
  • b)
    5
  • c)
    3
  • d)
    2
Correct answer is option 'A'. Can you explain this answer?

Rajat Roy answered
Proteins human haemoglobin consists of 4 subunits. Two of these are identical toeach other. Hence, two subunits of αα type and two subunits of ββ type together constitute the human haemoglobin (Hb).

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