Nucleic Acids Flashcards
What are nucleus acids
Large molecules
Discovered in cell nucleus
2 types of nucleic acid- dna and rna
Both roles in the storage and transfer of genetic information and synthesis of polypeptide ( proteins)
What elements do nucleic acids contain
Carbon Hydrogen Oxygen Phosphorus Nitrogen
What are nucleic acids
They are large polymers formed from many nucleotides linked together in a Chain
What are nucleotides made up of
A pentose monosaccharide sugar containing 5 carbon atoms
A phosphate group (po4 2-) , an inorganic molecule that’s acidic and negatively charged
A nitrogenous organic base - a complex organic molecule containing 1 or 2 carbon rings in its structure as well as nitrogen
How are nucleotides linked together
Condensation reactions
Form a polymer called a polynucleotides
The phosphate group at the 5th carbon of the pentose sugar of one nucleotide forms a covalent bond with the OH group at the 3rd carbon of the pentose sugar of the adjacent neuckoritde
DNA
Sugar group in dna is deoxyribose - a sugar with one fewer oxygen atoms than ribose
The nucleotides in DNA each have 1 of 4 different bases
This means that there are 4 different DNA Nucletotides
What are the 2 groups of 4 bases
Pyrmidines- smaller bases, contain carbon which have single carbon ring structure = thymine and cytosine
Purines- the larger bases, which contain double carbon ring structure - adenine and guanine
How are the 2 strands of the double helix held together
Hydrogen bonds between bases
Antiparallel??
Each strand has a phosphate group at one end and hydroxyl at the other
The 2 parallel strands are arranged so they run in opposite directions- antiparallel
Which bases bond together ??
Adenine and thymine form 2 hydrogen bonds
Cytosine and guanine form 3
How is therea constant distance created between the dna backbones ??
Small
Pyrmidine bade always binds to larger purine
CONSTANT distance
Parallel
why is RNA used ? R
Transfer genetic info from dna to the plate is that make up enzymes and tissues
Dna is very long molecule , compromising of many gems and is unable to leave the nuclear pore - so short section of long dna molecule corresponding to a single gene is transcribed into mRNA m
Why can’t dna leave the nuclear pore
Too big
Could get damaged- mutation
What is RNA formed of
Pentose sugar = ribose
Nucleotide from ribonuclease acid
Phosphate group
Thymine in RNA
Uracil
