DNA structure - lesson one Flashcards
(10 cards)
what is the structure of DNA
- DNA: deoxyribonucleic acid
- Double helix
- Composed of sub-units called nucleotides (sugar, phosphate, nitrogenous bases)
- four bases
what are the different nitrogenous bases
- adenine
- thymine
- guanine
- cytosine
what are the corresponding nitrogenous base pairs
- adenine pairs with thymine
- guanine pairs with cytosine
how many hydrogen bonds pair adenine and thymine together
two
how many hydrogen bonds pair cytosine and guanine together
three
what is the structure of the deoxyribose sugar
Deoxyribose sugar is composed of a chain of five carbon atoms, making it a pentose sugar.
what is the 5’ to 3’ strand? Use a diagram to support your answer
One of the strands will start with the 5’ carbon and finish with a 3’ carbon
what is a 3’ to 5’ strand? Use a diagram to support your answer
The second strand is an upside-down version. This strand starts with a 3’ carbon and ends with a 5’ carbon.
what carbon will phosphate attach to
5’
what carbon will the nitrogenous base attach to
1’
