Question 1

Nucleic acids were discovered by

Accepted Answer

Miescher discovered nucleic acids from pus cells in discarded surgical bands. He observed that these were acidic in nature. The two types of nucleic acid were DNA and RNA. These are considered as the hereditary unit of the cell. These carry characters from one generation to the other.So, the correct answer is option D.

Question 2

One picogram (pg) is equal to how many base pairs (bp)?

Accepted Answer

The weight of nucleotide bases can be calculated from the chemical formula and relative weights can be used to correlate the weight with the number of bases expected in a given sample of DNA. Using this technique it has been estimated that the mean weight of one nucleotide pair would be 1.023 x 10$^9$ pg, and 1 pg of DNA would represent 978000000 base pairs. Some workers have reported a lower value (965000000). The correct formula for converting the picograms of DNA into number of nucleotide pairs will be (978000000) x (DNA content in picograms).Thus, the correct answer is option B.

Question 3

Which of the following statements is incorrect about amino acids?

Accepted Answer

Usually living systems comprise of D amino acids and L sugars. It is not that only some antibiotics have D-amino acids. The $\alpha$-amino acids have an $\alpha$-carbon atom to which four different groups are attached like R or substituent or variable group, amino group, carboxylic group and hydrogen. So, all the $\alpha$-amino acids have an asymmetric carbon and they are optically active. But glycine is different, in glycine the R is hydrogen. Hence, glycine is not optically active and lacks an asymmetric carbon atom. As far as optical isomerism is concerned, we can safely say that if an amino acid has more than one asymmetric carbon atom it will be optically active.

Question 4

Which among the following statement is incorrect?

Accepted Answer

Correct Option: FExplanation:Proteins are heteropolymers as they are made up of different amino acids. They have a three-dimensional arrangement. They have amino acid, hydrogen, nitrogen and COOH groups attached to it. They can be acidic or basic.Rubisco is the most abundant protein in the whole of the biosphere and Collagen is the most abundant proteins in animal world.

Question 5

Nucleic acid is a polymer of...................

Accepted Answer

AnswerNucleic acid is a polymer of nucleotides or nucleoside triphosphate.Nucleotides are made up of 3 units:1. Nitrogenous bases e.g adenine (A), thymine(T), cytosine(C), guanine (G) and uracil(U) 2. Pentose sugar having 5 carbon atoms in a ring e.g ribose sugar. (in RNA) or deoxyribose sugar (in DNA)3. Phosphate group Nucleotides= Nitrogenous base+ Sugar+ phosphate group.Nucleosides= Nitrogenous base + Sugar

Question 6

The active site of an enzyme is situated in its amino acids _________ .

Accepted Answer

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Question 7

Germinated barley seeds, called malt, are the source of which enzyme?

Accepted Answer

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Question 8

Which of the following are the characteristics of P-proteins?

Accepted Answer

In the dicots, the sieve tubes are comprised of the protein called as phloem or P protein. This protein is rarely found in the monocot plants. In immature cells, P protein appears to function in sealing off damaged sieve elements by plugging the sieve plate pore. When a sieve tube is cut, the release of pressure causes the content of sieve element to surge towards the cut end from which the plant could lose sugar rich phloem sap if some sealing mechanism is not there.Thus, the correct answer is option C.

Question 9

Select the correct statement for a protein.

Accepted Answer

Proteins are the most dynamic biomolecules performing a variety of structural and functional roles. The proteins have a high turn over and constantly old or worn out molecules are broken down and newer molecules are synthesized. Sprinson and Rittenberg (1949) estimated that in man, the average half life of the proteins of whole body is of the order of 80 days. Total body protein synthesis is 400 gram per day, establishing an equilibrium between bodily proteins and circulating plasma proteins.

Question 10

........... was coined by Berzelius.

Accepted Answer

Swedish chemist Berzelius had devised the chemical symbols, the first accurate list of atomic weights and experiments confirming Daltons theory that all elements must be made of distinct atoms. He also coined the words &#34;catalyst&#34;, &#34;protein&#34;, &#34;isomer&#34;.

Biomolecules

Biology
4485 Views

Nucleic acids were discovered by

One picogram (pg) is equal to how many base pairs (bp)?

Which of the following statements is incorrect about amino acids?

Which among the following statement is incorrect?

Nucleic acid is a polymer of...................

The active site of an enzyme is situated in its amino acids _________ .

Germinated barley seeds, called malt, are the source of which enzyme?

Which of the following are the characteristics of P-proteins?

Select the correct statement for a protein.

........... was coined by Berzelius.

Biomolecules

Biology 4485 Views

Nucleic acids were discovered by

One picogram (pg) is equal to how many base pairs (bp)?

Which of the following statements is incorrect about amino acids?

Which among the following statement is incorrect?

Nucleic acid is a polymer of...................

The active site of an enzyme is situated in its amino acids _________ .

Germinated barley seeds, called malt, are the source of which enzyme?

Which of the following are the characteristics of P-proteins?

Select the correct statement for a protein.

........... was coined by Berzelius.

Biology
4485 Views