(3.1.5.1) structure of DNA Flashcards
what is DNA called?
deoxyribonucleic acid.
what is DNA?
a polymer of nucleotides chemically joined together by condensation reactions forming phosphodiester bonds.
what is the function of DNA?
DNA holds genetic information, making it an important information-carrying molecule
what is the structure of a single DNA nucleotide?
includes a phosphate group linked to a deoxyribose sugar, which is then linked to a nitrogen-containing base
- the possible bases can be thymine, adenine, guanine and cytosine.
how is a phosphodiester bond formed between two nucleotides in a DNA molecule?
condensation reactions join the phosphate group of one nucleotide to the deoxyribose sugar of another nucleotide
* this forms a dinucleotide which join to form polynucleotides!
what is DNA’s structure?
- a polynucleotide
- each nucleotide formed from deoxyribose, a phosphate group and a nitrogenous base;
- phosphodiester bonds between nucleotides
- double helix/two polynucleotide strands joined by hydrogen bonds
*complementary base pairing - strands are anti-parallel
what are the bonds between nitrogen-containing bases known as?
complementary base pairing:
* adenine forms 2 hydrogen bonds with thymine
* cytosine forms 3 hydrogen bonds with guanine
what are DNA’s two jobs?
- DNA replication - to create more copies so that when cells divide they have exact copies of DNA
- protein synthesis - contains genes (order of bases) which codes for the order of amino acids in a protein
what are structural features and advantages of DNA?
- long with a helical shape so it can store lots of information compactly
- double stranded making each strand act as a template for accurate replication
- weak hydrogen bonds to easily unzip for DNA replication and protein synthesis but lots to keep molecule stable
- sugar-phosphate backbone which provides strength and stabillity and protects the bases within helix
