DNA base pairs

Base pairs in DNA

DNA (Deoxyribonucleic acid), is a chemical found primarily in the nucleus of cells. DNA carries the instructions for making all the structures and materials the body needs to function.

DNA is organized as two complementary strands, head-to-toe, with bonds between them that can be "unzipped" like a zipper, separating the strands.

Why does Adenine pair with Thymidine and Cytosine pair with Guanine?

A critical feature of DNA is the ability of the nucleotides to make specific pairs: . Adenine pairs with Thymine and Cytosine pairs with Guanine. We say A is complementary to T (and U) and C is complementary to G

ADENINE PAIRS WITH THYMIDINE

The complementary nucleotides are held together by weak hydrogen (H) bonds. Note that there are 2 H bonds between A and T.

TO VIEW THE HYDROGEN BONDS --

Click right mouse button over image
Select -->All
Style --> Hydrogen Bonds --> Calculate
Shift -- Left Mouse Button (drag) to Zoom In
Color ---> Hydrogen Bonds --> Yellow (for better viewing)

CYTOSINE PAIRS WITH GUANINE

The complementary nucleotides are held together by weak hydrogen (H) bonds. Note that there are 3 hydrogen bonds between Cand G

TO VIEW THE HYDROGEN BONDS --

Click right mouse button over image
Select -->All
Style --> Hydrogen Bonds --> Calculate
Shift -- Left Mouse Button (drag) to Zoom In
Color ---> Hydrogen Bonds --> Yellow (for better viewing)

Base pairs in DNA

DNA (Deoxyribonucleic acid), is a chemical found primarily in the nucleus of cells. DNA carries the instructions for making all the structures and materials the body needs to function.

DNA is organized as two complementary strands, head-to-toe, with bonds between them that can be "unzipped" like a zipper, separating the strands.

The complementary nucleotides are held together by weak hydrogen (H) bonds. However, the sum of the strength of these weak bonds allows DNA to maintain its double-stranded structure.

TO VIEW THE HYDROGEN BONDS --

Click right mouse button over image

Style --> Hydrogen Bonds --> Calculate

NOTE: Use Shift -- Left Mouse Button (then drag) to Zoom In

Color ---> Hydrogen Bonds --> Yellow (for better viewing)