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All questions of Biomolecules for ACT Exam

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 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.

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.

The most abundant mineral of the animal body is
  • a)
    Potassium
  • b)
    Sodium
  • c)
    Calcium
  • d)
    Iron
Correct answer is option 'C'. Can you explain this answer?

Hansa Sharma answered
Calcium is the most abundant mineral in our body. It is essential for the development and maintenance of strong bones and teeth, where about 99% of the body's calcium is found. Calcium also helps the heart, nerves, muscles, and other body systems work properly. 
Therefore, the correct answer is option C.

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?

Vijay Bansal answered
The most abundant organic compound on Earth is cellulose, which is made up of many, many glucose molecules all linked together. Cellulose is found in the cell walls of every plant, which is why it is the most abundant organic molecule.

Ester linkages occur in
  • a)
    Proteins
  • b)
    Lipids
  • c)
    Nucleic acids
  • d)
    Carbohydrates
Correct answer is option 'B'. Can you explain this answer?

Anjali Iyer answered
Lipids are actually triglycerides. A triglyceride consists of glycerol and fatty acids which are held together by ester linkages.

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.

A nucleoside differs from a nucleotide in not having a
  • a)
    Phosphate group
  • b)
    Glucose
  • c)
    Sugar
  • d)
    Nitrogen base
Correct answer is option 'A'. Can you explain this answer?

Aliya Agrawal answered
Phosphate group...
because nucleoside = sugar + nitrogen base...
while nucleotides = sugar + nitrogen base + phosphate group.....

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. 

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.

Which is a reducing sugar?
  • a)
    Cellulose
  • b)
    Maltose
  • c)
    Starch
  • d)
    Sucrose
Correct answer is option 'B'. Can you explain this answer?

Prem Darade answered
The sugar that is capable of acting as a reducing sugar because it has free aldehyde group or a free ketone group ...

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.

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 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 of the following carbohydrates is not a disaccharide?
  • a)
    Lactose
  • b)
    Maltose
  • c)
    Sucrose
  • d)
    Galactose
Correct answer is option 'D'. Can you explain this answer?

Gaurav Kumar answered
Galactose is a monosaccharide. When combined with glucose (monosaccharide), through a condensation reaction, the result is the disaccharide lactose. The hydrolysis of lactose to glucose and galactose is catalyzed by the enzymes lactase and β-galactosidase.
Chemical formula: C6H12O6
Solubility in water: 650 g/L (20 °C)

Lactose is made of
  • a)
    Glucose + Fructose
  • b)
    Fructose + Fructose
  • c)
    Glucose + Glucose
  • d)
    Glucose + Galactose
Correct answer is option 'D'. Can you explain this answer?

Ciel Knowledge answered
 Glucose+Galactose
  1. Lactose is a disaccharide that breaks down into two saccharides, glucose and galactose on hydrolysis.
  2. Both saccharides are joined by a beta glycosidic link.
  3. It is a natural sugar found in milk in amounts ranging from 2 to 8%.
  4. Lactose is a reducing sugar because it contains one free hemiacetal hydroxide.
  5. Hence, it is the correct option.

Fehling’s solution is used for the detection of
  • a)
    Fats
  • b)
    Starch
  • c)
    Glucose
  • d)
    All carbohydrates
Correct answer is option 'C'. Can you explain this answer?

Fehling is a chemical reagent used to test for the presence of aldehyde functional groups. It consists of two separate solutions, Fehling's A and Fehling's B, which are mixed together before use. When an aldehyde is added to Fehling's solution and heated, a red precipitate of copper(I) oxide is formed, indicating the presence of the aldehyde. Fehling's reagent is commonly used in organic chemistry laboratories to identify and distinguish aldehydes from other types of compounds.

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.

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.

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?

Nandini Patel answered
A conjugated protein is a protein that functions in interaction with other (non-polypeptide) chemical groups attached by covalent bonding or weak interactions. Many proteins contain only amino acids and no other chemical groups, and they are called simple proteins.

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.

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.

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.

. __________ 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.

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.

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.

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.

An immediate source of cellular energy is
  • a)
    Pyruvic acid
  • b)
    NADH
  • c)
    Glucose
  • d)
    ATP
Correct answer is option 'D'. Can you explain this answer?

Because during cellular respiration, Glucose undergoes oxidation through various enzymatic machinery to produce energy which is stored as the ATP( energy currency of cell ) , ATP is further utilized by the different cell for their activities.

Which of the following nitrogenous base produces nucleoside only with ribose sugar?
  • a)
    Thymine
  • b)
    Guanine
  • c)
    Uracil
  • d)
    Adenine
Correct answer is option 'C'. Can you explain this answer?

Uracil nitrogenous base is produces nucleoside only with ribose sugar. This nucleoside is present only inside the RNA and absent in DNA.

Lipids that are found in the cell membrane are
  • a)
    Triglycerides
  • b)
    Simple lipids
  • c)
    Diglycerides
  • d)
    Phospholipids
Correct answer is option 'D'. Can you explain this answer?

Aniket Chawla answered
Some lipids have phosphorous and a phosphorylated organic compound in them. These are phospholipids. They are found in cell membrane.

The amino acids are linked together serially by
  • a)
    Peptide bonds
  • b)
    Hydrogen bonds
  • c)
    Covalent bonds
  • d)
    Ionic bonds
Correct answer is option 'A'. Can you explain this answer?

The amino acids are linked together one after the other by peptide bonds. This bond is formed between NH3 of one amino acids with carboxyl end of another amino acids to release water.

Metal ions required for functioning of enzyme is
  • a)
    Holoenzyme
  • b)
    Co-enzyme
  • c)
    Prosthetic group
  • d)
    Co-factor
Correct answer is option 'D'. Can you explain this answer?

Mahi Shah answered
A number of enzymes require metal ions for their activity which form coordination bonds with side chains at the active site and at the same time form one or more cordination bonds with the substrate, e.g., zinc is a cofactor for the proteolytic enzyme carboxypeptidase.

Read the following passage to answer the following questions:
Proteins are polypeptide chains made up of amino acids. There are 20 types of amino acids joined together by peptide bond between amino and carboxylic group. There are two kinds of amino acids, Essential amino acids and Non-essential amino acids. The Primary structure of protein is the linear sequence of amino acids in a polypeptide chain. The first amino acid of sequence is called N-terminal amino acids and last amino acid of peptide chain is called C-terminal amino acids. The secondary structure proteins forms helix. There are three types of secondary structure: a helix, P pleated and collagen helix. In tertiary structure long protein chain is folded upon itself like a hollow woollen ball to give three-dimensional view of protein. In quaternary structure, each polypeptide develops its own tertiary structure and function as subunit of protein.
Q. The smallest amino acid is
  • a)
    Phenol
  • b)
    Formic acid
  • c)
    Glycine
  • d)
    Methane
Correct answer is option 'C'. Can you explain this answer?



The smallest amino acid is Glycine



Explanation:

- Glycine is the smallest amino acid because it has the simplest structure among all the amino acids.
- It has a hydrogen atom as its side chain, making it the smallest molecular weight amino acid.
- Glycine is a non-essential amino acid, which means that the body can synthesize it on its own and it does not need to be obtained from the diet.
- Despite its small size, glycine plays important roles in the body such as being a component of proteins and helping in the synthesis of other molecules.

By understanding the characteristics of glycine, we can see why it is considered the smallest amino acid.

Which of the following statements given above is/are correct?
i. In the absence of any enzyme, the formation of H2CO3 is very slow, with about 200 molecules produced in an hour.
ii. Carbonic anhydrase accelerates the reaction rate by approximately 10 million times, producing about 600,000 molecules of H2CO3 every second.
iii. The metabolic pathway from glucose to pyruvic acid involves ten enzyme-catalyzed reactions.
iv. Under anaerobic conditions in skeletal muscle, pyruvic acid is formed instead of lactic acid.
  • a)
    i and ii
  • b)
     i, ii and iii
  • c)
    i, iii and iv
  • d)
    ii and iii
Correct answer is option 'B'. Can you explain this answer?

Mansi Ahuja answered
Analysis of Statements
To evaluate which statements are correct, let’s break down each one:
i. Formation of H2CO3 without Enzyme
- The statement claims that in the absence of any enzyme, the formation of H2CO3 is very slow, with about 200 molecules produced in an hour.
- This statement is correct. The formation of carbonic acid (H2CO3) from carbon dioxide (CO2) and water (H2O) occurs slowly without enzymes.
ii. Role of Carbonic Anhydrase
- This statement asserts that carbonic anhydrase accelerates the reaction rate by approximately 10 million times, producing about 600,000 molecules of H2CO3 every second.
- This statement is also correct. Carbonic anhydrase is a highly efficient enzyme that dramatically increases the rate of H2CO3 formation.
iii. Metabolic Pathway from Glucose to Pyruvic Acid
- This statement indicates that the pathway involves ten enzyme-catalyzed reactions.
- This statement is correct. The glycolytic pathway, which converts glucose to pyruvate, consists of ten distinct enzymatic steps.
iv. Anaerobic Conditions in Skeletal Muscle
- This statement claims that under anaerobic conditions in skeletal muscle, pyruvic acid is formed instead of lactic acid.
- This statement is incorrect. Under anaerobic conditions, pyruvic acid is converted to lactic acid.
Conclusion
Based on the analysis, statements i, ii, and iii are correct. Therefore, the correct answer is option 'B', which includes statements i, ii, and iii.
- Correct Statements: i, ii, and iii
- Incorrect Statement: iv

Tertiary structure of protein is formed by __________
  • a)
    Sulphide linkages between different amino acids
  • b)
    Multiple chains of polypeptides held together by hydrogen bonds
  • c)
    Peptide linkages between two amino acids
  • d)
    Hydrogen bond formed by helical or pleated structure
Correct answer is option 'A'. Can you explain this answer?

Ashwin Saini answered
Formation of Tertiary Structure in Protein
Formation of tertiary structure in proteins is a crucial step in their folding process. This structure is primarily determined by the interactions between different amino acid residues within the protein chain.

Sulphide linkages between different amino acids
- Tertiary structure is primarily formed by disulphide linkages between different amino acids. These covalent bonds are formed between the sulfur atoms of two cysteine residues, stabilizing the overall structure of the protein.
- Disulphide bonds are important for maintaining the conformation of proteins, especially in extracellular environments where they can provide structural stability.

Importance of Sulphide Linkages
- Sulphide linkages play a crucial role in stabilizing the tertiary structure of proteins, allowing them to adopt specific shapes and functions.
- These bonds can also be important for protein-protein interactions and the overall stability of protein complexes.
Therefore, the correct answer is option A) Sulphide linkages between different amino acids.

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