Is adenine a tautomer of thymine?

Commonly, adenine in its amino form (non-tautomeric) binds to thymine by means of two hydrogen bonds, and guanine in its non-tautomeric keto form binds to cytosine by means of three hydrogen bonds between them.

What is a tautomer in DNA?

Tautomers are isomers of a molecule that exist in solution or in a cell. They are interchangeable forms because chemical bonds are rearranged many times spontaneously. This is different from chirality, where molecules are mirror images (or enantiomers) of each other (d- and l-glucose, etc.).

What is another name for thymine?

Thymine is also known as 5-methyluracil, a pyrimidine nucleobase.

Which can show tautomerism?

Option A is nitromethane. The structure of nitromethane is, Here, alpha hydrogen is present. So, nitromethane shows tautomerism.

How do you identify a tautomer?

Tautomers are distinct chemical species and can be identified as such by their differing spectroscopic data, whereas resonance structures are merely convenient depictions and do not physically exist.

What is the main function of thymine?

In DNA, thymine (T) binds to adenine (A) via two hydrogen bonds, thereby stabilizing the nucleic acid structures. Thymine combined with deoxyribose creates the nucleoside deoxythymidine, which is synonymous with the term thymidine.

What are examples of thymine?

Cytosine. Thymine, cytosine, and uracil are pyrimidine nucleobases. Thymine has two keto groups at positions 2 and 4, and a methyl group at position 5 in its heterocyclic aromatic ring. Thymine complementary base pairs with adenine by two hydrogen bonds.

Which is a tautomer of adenine and cytosine?

Tautomers of Adenine, Cytosine, Guanine, and Thymine. The four bases of DNA can exist in at least two tautomeric forms as shown below. amino or imino forms, and guanine, thymine, and uracil (which are cyclic amides) can exist in either lactam (keto) or lactim (enol) forms.

Why does adenine always pair with thymine and guanine?

In base pairing, adenine always pairs with thymine, and guanine always pairs with cytosine. Why does adenine always pair with thymine and guanine with cytosine in DNA quizlet? Adenine and Guanine are purines, and Thymine and Cytosine are pyrimidines. So, for a uniform diameter, a purine must always bond with a pyrimidine.

Where are the hydrogen acceptors located in thymine?

In thymine, the groups at C-4 and C-2 are hydrogen acceptors, and N-3 is a hydrogen donor. (Only two of these sites, C-4 and N–3, are used to form base pairs in DNA.)

Which is more stable amino or lactam tautomer?

The tautomeric forms of each base exist in equilibrium but the amino and lactam tautomers are more stable and therefore predominate under the conditions found inside most cells. The rings remain unsaturated and planar in each tautomer.