Question

Evaluate whether each statement below is correct or incorrect. Then, in a phrase or two, explain why. In either case, the explanation is important. See example.

EXAMPLE: An atomic nucleus contains protons and neutrons.

Two valid answers: 1) Correct, with the exception of hydrogen, which has only a proton. 2) Incorrect, because, while most nuclei contain both, hydrogen does not have a neutron.

1. The cell nucleus is surrounded by a double membrane.

2. All atoms of the same element have the same number of neutrons.

3. Hydrogen bonds are weak and can be broken by thermal energy, yet they contribute significantly to the specificity of interactions between macromolecules

4. Proteins are so remarkably diverse because each is made from a unique mixture of amino acids that are linked in random order.

5. Nucleic acids contain sugar groups.

6. DNA contains the four different bases A, G, U, and C.

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Thank you!

Answer 1

The cell nucleus is surrounded by a double membrane.

correct, because only the eukaryotic cells have a well-defined nucleus which is surrounded by a double membrane called nuclear membrane. prokaryotic cells do not have nucleus, their genetic material is localized into the cytoplasm and hence they do not have a double membrane layer (because no well-defined nucleus).

DNA contains the four different bases A, G, U, and C.

incorrect, DNA has four different bases A, G, C, and T. thymine is present in DNA while Uracil is present in RNA.

Nucleic acids contain sugar groups.

correct, whether DNA or RNA both have pentose sugar called deoxyribose sugar and ribose sugar respectively.

All atoms of the same element have the same number of neutrons.

incorrect, for example - hydrogen is having 3 different forms called isotopes. protium, deuterium, and tritium. all are having a different number of neutrons in them which are 0, 1, and 2 respectively.

Proteins are so remarkably diverse because each is made from a unique mixture of amino acids that are linked in random order.

incorrect, type of protein depends on the unique mixture of amino acids and in a well-defined order.

Hydrogen bonds are weak and can be broken by thermal energy, yet they contribute significantly to the specificity of interactions between macromolecules

correct, Individually hydrogen bonds are weak and easily broken down by thermal energy but interactions between two macromolecules involve a large number of such bonds, therefore, the overall binding is strong, and because hydrogen bonds form only between correctly positioned groups on the interfacing macromolecules, they are extremely specific