12th Grade > Biology
BIOMOLECULES MCQs
Total Questions : 58
| Page 4 of 6 pages
Answer: Option A. -> Carbon and hydrogen
:
A
Organic compounds are compounds of carbon and hydrogen found in biological systems. These compounds can contain other elements such as nitrogen, phosphorous and oxygen etc. But it is the presence of carbon that determines whether it is an organic molecule.
:
A
Organic compounds are compounds of carbon and hydrogen found in biological systems. These compounds can contain other elements such as nitrogen, phosphorous and oxygen etc. But it is the presence of carbon that determines whether it is an organic molecule.
Answer: Option D. -> Assertion [A] is True and Reason [R] is True but is not a correct explanation to [A].
:
D
The graph indicates the rate of enzymatic activity (Y - axis) based on increase in temperature (X- axis). As the temperature increases up to a certain level, the rate of enzymatic activity too, increases. It happens so till a certain limit is reached. This threshold is called the Optimum temperature. This is usually around 37.5∘ C which is also the normal human body temperature. But, any further increase in temperature, although should theoretically, increase the rate of activity, it does not because, the protein structure of the enzyme would start to break apart. This is also known as thermal denaturation.
Therefore, the answer is D even though the reason is true.
:
D
The graph indicates the rate of enzymatic activity (Y - axis) based on increase in temperature (X- axis). As the temperature increases up to a certain level, the rate of enzymatic activity too, increases. It happens so till a certain limit is reached. This threshold is called the Optimum temperature. This is usually around 37.5∘ C which is also the normal human body temperature. But, any further increase in temperature, although should theoretically, increase the rate of activity, it does not because, the protein structure of the enzyme would start to break apart. This is also known as thermal denaturation.
Therefore, the answer is D even though the reason is true.
Answer: Option D. -> 480
:
D
According to Chargaff's rules, the amount of adenine is always equal to that of thymine, and the amount of guanine is always equal to that of cytosine i.e A = T (120) and G = C (120), therefore, the total no. of nucleotides would be 120×4=480.
:
D
According to Chargaff's rules, the amount of adenine is always equal to that of thymine, and the amount of guanine is always equal to that of cytosine i.e A = T (120) and G = C (120), therefore, the total no. of nucleotides would be 120×4=480.
Answer: Option B. -> (i) Nuclein (ii) Miescher (iii) Nucleotides (iv) RNA
:
B
The term Nucleic acid is derived from a greek word called Nuclein, coined by Miescher. Each molecule of Nucleic acid has basic units called Nucleotides and the most abundant Nucleic acid is RNA. There is roughly eight times more RNA than there is DNA, because, although DNA stores the much important bio-info, it is RNA which brings it into use. Picture it like this, although the brain is more important than the hands, we have only one brain, but two hands to carry out the work dictated by the brain.
:
B
The term Nucleic acid is derived from a greek word called Nuclein, coined by Miescher. Each molecule of Nucleic acid has basic units called Nucleotides and the most abundant Nucleic acid is RNA. There is roughly eight times more RNA than there is DNA, because, although DNA stores the much important bio-info, it is RNA which brings it into use. Picture it like this, although the brain is more important than the hands, we have only one brain, but two hands to carry out the work dictated by the brain.
Answer: Option B. -> Hydrogen bonds
:
B
Within the long protein chains there are regions in which the chains are organised into regular structures, which forms the secondary structure of protein. The most common secondary structures arealpha-helices(alpha-helixes) and beta-pleated sheets. These secondary structures are held together by hydrogen bonds.
:
B
Within the long protein chains there are regions in which the chains are organised into regular structures, which forms the secondary structure of protein. The most common secondary structures arealpha-helices(alpha-helixes) and beta-pleated sheets. These secondary structures are held together by hydrogen bonds.
Answer: Option A. -> Glucose
:
A
Fehling's test is based on the principle that the presence of aldehydes can be detected easily due to their reducing property. The free aldehydes undergo oxidation, by reducing the deep blue solution of Fehling's reagent containing copper(II) to an easily detected red precipitate of insoluble copper oxide. Therefore this testis used only for reducing sugars, that contain the free aldehyde group, that is monosaccharides like glucose, fructose, galactose etc.
Sucrose and starch do not contain a free aldehyde group and is a non-reducing sugar and therefore not reactive to Fehlings reagent. Fats also do not contain free aldehyde groups and cannot reduce Fehling's solution.
:
A
Fehling's test is based on the principle that the presence of aldehydes can be detected easily due to their reducing property. The free aldehydes undergo oxidation, by reducing the deep blue solution of Fehling's reagent containing copper(II) to an easily detected red precipitate of insoluble copper oxide. Therefore this testis used only for reducing sugars, that contain the free aldehyde group, that is monosaccharides like glucose, fructose, galactose etc.
Sucrose and starch do not contain a free aldehyde group and is a non-reducing sugar and therefore not reactive to Fehlings reagent. Fats also do not contain free aldehyde groups and cannot reduce Fehling's solution.
Answer: Option D. -> P > N > L > C
:
D
In animals, by percentages of composition of cellular mass, Proteins (P) occupy the major portion in forming living matter. Most structural and functional units of life, is made up of proteins. This is followed by the genetic material, which is formed by Nucleic acids (N). Lipids forming the membrane layer of cells and cell organelles come third. And lastly, Carbohydrates (C) are found as structural and functional support to proteins, and is stored in the cell as glycogen.
:
D
In animals, by percentages of composition of cellular mass, Proteins (P) occupy the major portion in forming living matter. Most structural and functional units of life, is made up of proteins. This is followed by the genetic material, which is formed by Nucleic acids (N). Lipids forming the membrane layer of cells and cell organelles come third. And lastly, Carbohydrates (C) are found as structural and functional support to proteins, and is stored in the cell as glycogen.
Question 38. Match the classes of lipids listed under column I with the examples mentioned under column II and select the right answer indicating the correct combination of alphabets of the two columns.
Column IColumn IClasses of lipidsExamplesACompound lipidseWaxesBSteroidsfPhospholipidsCSimple lipidsgPantothenic acidhCholesterol
Column IColumn IClasses of lipidsExamplesACompound lipidseWaxesBSteroidsfPhospholipidsCSimple lipidsgPantothenic acidhCholesterol
Answer: Option D. -> A= f, B = h, C =e
:
D
Compound lipids - phospholipids that is lipids containing an phosphate group.
Steroids - cholesterol is a modified steroid, that is a sterol or a steroid alcohol
Simple lipids - Waxes are fatty acid esters with alcohol
Pantothenic acidalso called vitamin B5 (a B vitamin), is a water-soluble vitamin.Pantothenic acidis an essential nutrient.
:
D
Compound lipids - phospholipids that is lipids containing an phosphate group.
Steroids - cholesterol is a modified steroid, that is a sterol or a steroid alcohol
Simple lipids - Waxes are fatty acid esters with alcohol
Pantothenic acidalso called vitamin B5 (a B vitamin), is a water-soluble vitamin.Pantothenic acidis an essential nutrient.
Answer: Option A. -> They are permanently bound to the apoenzyme
:
A
Most enzymes are made up of a protein part, which is conjugated to a non-protein group called cofactor by covalent or non-covalent interactions. The protein part of the enzyme, which is inactive without the cofactor is called an apoenzyme. It binds to the cofactor, which may be metal ions, or a coenzyme, which are non-proteinaceous simple molecules such as NADH, FADH etc. The apoenzyme and the cofactor together forms the catalytically active enzyme called the holoenzyme.
:
A
Most enzymes are made up of a protein part, which is conjugated to a non-protein group called cofactor by covalent or non-covalent interactions. The protein part of the enzyme, which is inactive without the cofactor is called an apoenzyme. It binds to the cofactor, which may be metal ions, or a coenzyme, which are non-proteinaceous simple molecules such as NADH, FADH etc. The apoenzyme and the cofactor together forms the catalytically active enzyme called the holoenzyme.
Answer: Option A. -> Guanine
:
A
Apurineis a heterocyclicaromaticorganic compoundthat consists of a pyramidinering fused to an imidazolering. Adenine and guanine are the purine bases and thymine and cytosine are the pyramidine bases in nucleic acids.
:
A
Apurineis a heterocyclicaromaticorganic compoundthat consists of a pyramidinering fused to an imidazolering. Adenine and guanine are the purine bases and thymine and cytosine are the pyramidine bases in nucleic acids.
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