Nucleic Acids and Chromosomes Flashcards
List all the purine bases
Guanine Adenine
List all the Pyrimidines
Cytosine Thymine Uracil (RNA only)
What does a nucleotide consist of
Nitrogenous base Sugar Phosphate Group add pic
What is the difference between a deoxyribose and a ribose
Deoxyribose lacks an oxygen atom that is present in the ribose add pic
In the image below indicate which carbon is linked to the base and which one is linked to the phosphate? add pic
The 1’ C is linked to the base; the 5’ C is linked to the phosphate.
What is the difference between purines and pyrimidines?
Purines have two rings whilst pyrimidines have one ring add pic
Define nucleoside
Base + (deoxy)ribose = nucleoside NO PHOSPHATE
Name the corresponding Nucleoside for the bases listed below. Adenine Guanine Cytosine Uracil Thymine
(deoxy)adenosine (deoxy)guanosine (deoxy)cytidine (deoxy)uridine (deoxy)thymidine Pyrimidines end with dine Purines end with sine add pic
What is a nucleotide?
Base + ribose + phosphate = nucleotide add pic
Name the nucleotide which consists of a adenine base bonded to 3 phosphate groups and a ribose
Adenosine triphosphate add pic
Name the nucleotide which consists of a cytosine base bonded to 3 phosphates and a deoxyribose sugar.
deoxycytidine triphosphate (dCTP) add pic
Explain the structure of DNA?
A long chain of deoxyribonucleotide units linked by phosphodiester links. The bases point inwards and the flat planes are perpendicular to the helix. The 3’-OH of sugar of one nucleotide is linked to phosphate group, which in turn is joined to 5’-OH of adjacent sugar. The chain has two ends, the 5’ end and the 3’ end. It is not symmetrical. The two chains are held togethere by hydrogen bonds between bases A and T C and G The secondary stricture of DNA is a right handed Double Helix, with the negative charges outside Phosphate sugar backbone add pic
What bonds link nucleotides togethere
phosphodiester bond
What is the primary sequence
linear sequence of the bases. by convention, the nucleotide sequence is specified in the 5’ to 3’ direction
What is the secondary structure of DNA
right-handed double helix
What does “ the chains are antiparallel” mean?
The chains are antiparallel - they run in opposite directions.
Lable in the diagram below the minor and major groves? add pic
add pic
Name ways of melting or disassociating the two strands of DNA.
High temperature or low salt concentration
Name ways of re-annealing or hybridise two DNA strands?
Cool or high salt concentration
Define karyotype
A karyotype is an organised profile of someone’s chromosomes
What does chromatin condense into?
Chromosomes
What is the lowest level of packing?
nucleosome
What does a nucleosome consits of?
consists of DNA wrapped around histone proteins. add pic
