Question 1 of 34
Cellulose does not form blue colour with lodine because
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Biomolecules PYQs
Class XI Biology โข NCERT Based โข NEET Practice
Question 2 of 34
Melonate inhibits the growth of pathogenic bacteria by inhibiting the activity of:
Explanation:
Melonate inhibits the activity of succinic dehydrogenase, a key enzyme in the TCA cycle and electron transport chain of many bacteria. Blocking this enzyme disrupts aerobic respiration and energy production, thereby hindering bacterial growth. Among the options, succinic dehydrogenase (option 2) is the correct target. Dinitrogenase (nitrogenase) is involved in nitrogen fixation, amylase breaks down starch, and lipase breaks down fats; these are not the primary targets of melonate in NCERT-based bacterial physiology.
๐ง Did You Know?Succinic dehydrogenase also functions as complex II of the mitochondrial/ bacterial electron transport chain, linking citric acid cycle to energy production.
๐ก NCERT Memory Line:Enzymes of respiration like succinic dehydrogenase are essential for energy release in bacteria and play a role in inhibiting growth when blocked.
Question 3 of 34
Given below are two statements:
Statement I: Low temperature preserves the enzyme in a temporarily inactive state whereas high temperature destroys enzymatic activity because proteins are denatured by heat. Statement II: When the inhibitor closely resembles the substrate in its molecular structure and inhibits the activity of the enzyme, it is known as competitive inhibitor.
In the light of the above statements, choose the correct answer from the options given below:
Statement I: Low temperature preserves the enzyme in a temporarily inactive state whereas high temperature destroys enzymatic activity because proteins are denatured by heat. Statement II: When the inhibitor closely resembles the substrate in its molecular structure and inhibits the activity of the enzyme, it is known as competitive inhibitor.
In the light of the above statements, choose the correct answer from the options given below:
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Question 4 of 34
Given below are two statements:
Statement I: A protein is imagined as a line, the left end represented by first amino acid (C-terminal) and the right end represented by last amino acid (N-terminal)
Statement II: Adult human haemoglobin, consists of 4 subunits (two subunits of ฮฑ type and two subunits of ฮฒ type.)
In the light of the above statements, choose the correct answer from the options given below:
Statement I: A protein is imagined as a line, the left end represented by first amino acid (C-terminal) and the right end represented by last amino acid (N-terminal)
Statement II: Adult human haemoglobin, consists of 4 subunits (two subunits of ฮฑ type and two subunits of ฮฒ type.)
In the light of the above statements, choose the correct answer from the options given below:
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Question 5 of 34
Exoskeleton of arthropods is composed of :
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Question 6 of 34
Read the following statements on lipids and find out correct set of statements:
A. Lecithin found in the plasma membrane is a glycolipid
B. Saturated fatty acids possess one or more c = c bonds
C. Gingely oil has lower melting point, hence remains as oil in winter
D. Lipids are generally insoluble in water but soluble in some organic solvents
E. When fatty acid is esterified with glycerol, monoglycerides are formed
Choose the correct answer from the option given below:
A. Lecithin found in the plasma membrane is a glycolipid
B. Saturated fatty acids possess one or more c = c bonds
C. Gingely oil has lower melting point, hence remains as oil in winter
D. Lipids are generally insoluble in water but soluble in some organic solvents
E. When fatty acid is esterified with glycerol, monoglycerides are formed
Choose the correct answer from the option given below:
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Question 7 of 34
A dehydration reaction links two glucose molecules
to produce maltose. If the formula for glucose is
C6H12O6 then what is the formula for maltose ?
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Question 8 of 34
Match List-I with List-II.
Choose the correct answer from the options given below:
| List-I (Biological Molecules) | List-II (Biological functions) |
|---|---|
| (A)Glycogen | (I)Hormone |
| (B)Globulin | (II)Biocatalyst |
| (C)Steroids | (III)Antibody |
| (D)Thrombin | (IV)Storage product |
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Question 9 of 34
Which of the following are not secondary
metabolites in plants?
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Question 10 of 34
Match List-I with List-II.
Choose the correct answer from the options given below:
| List-I | List-II |
|---|---|
| (A)Protein | (I)C = C double bonds |
| (B)Unsaturated fatty acid | (II)Phosphodiester bonds |
| (C)Nucleic acid | (III)Glycosidic bonds |
| (D)Polysaccharide | (IV)Peptide bonds |
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