1.5.1: Nucleic acid structure Flashcards
state 2 functions of the DNA
1 - replication for cell division
2 - Carry genetic code for protein synthesis
State the 3 types of RNA and their full forms too
1 - mRNA - messenger RNA
2 - tRNA - transfer RNA
3 - rRNA - ribosomal RNA
What are the two types of nucleic acids
DNA and RNA
how many polynucleotides does a molecule of DNA contain and where is it found
2 - nucleus
how many polynucleotides does a molecule of RNA have and where is it found
1 - cytoplasm and nucleus
Describe the structure of a general nucleotide
pentose sugar (ribose or deoxyribose), nitrogenous base attached to carbon-1, phosphate group attached to carbon-5
what is the full form of ATP
adenosine triphosphate
what are the 2 types of nitrogenous bases
purine bases, pyrimidine bases
List the purine bases
adenine
guanine
list the pyrimidine bases
thymine
cytosine
uracil
what are 2 main differences between purine and pyrimidine bases
purine bases are always bigger than pyrimidine bases, purine bases are double ring whereas pyrimidine bases are single ring
which bases have complementary base pairing and how many h-bonds are there between each pair
A-T (2 H bonds)
C-G (3 H bonds)
A -U (2 H bonds)
What is the relation between purine and pyrimidine bases
they complementary base pair to each other
Describe the process of the formation of a DNA molecule
When a condensation reaction occurs between the pentose sugar of one nucleotide and the phosphate group of another, a strong covalent bond called a phosphodiester bond forms.
Repeated condensation reactions results in a single chain of repeating nucleotides which has a strong sugar-phosphate backbone with bases protruding from it. The second polynucleotide chain forms antiparallel to the first running from 5’ to 3’. Hydrogen bonds form between exposed bases that are complementary to each other joining the 2 polynucleotide chains together.
how is the feature of the DNA having a sugar-phosphate backbone related to its function
gives strength to the DNA molecule
how is the feature of the DNA being two chains held together by weak hydrogen bonds related to its function
chains can be separated for transcription and replication
how is the feature of the DNA having a coiled structure related to its function
protects hydrogen bonds therefore reducing corruption of genetic code
how is the feature of the DNA having many weak hydrogen bonds related to its function
makes DNA a stable molecule
how is the feature of the DNA having a sequencing of DNA bases related to its function
allows information to be stored
how is the feature of the DNA being a long molecule related to its function
can store a lot of genetic information
what is the difference in the nitrogenous bases present in DNA and in RNA
RNA has uracil instead of thymine
Name the 2 scientists who proposed models of the chemical structure of DNA
Watson and Crick
