Module 2.3 Nucleotides +nucleic Acids Flashcards
What are the monomers of nuclei acids
Nucleotides
What bond joins the two nucleotides
Phospodiester bond
What are similarities between DNA and RNA
Both contain
A, G,C
Phosphate group
Nitrogenous base
What bases are found in the RNA
Adenine
URACIL
Guanine
Cytosine
What are two types of bases ?
Purines
Pyrimidines
State difference between purines and pyrimidines
Purines are large with 2 carbon ring
Pyrimidines : are small with one carbon ring
Give examples of purines
Adenine
Guanine
How many hydrogen bonds are found between T and A
2
Why do we crush the piece of fruit in DNA extraction using mortar and pestle
Help to break cellullose cell wall in plants
Why is detergent added to sample
Dissolve the surface membrane
Why is protease enzyme added to sample ?
Breaks down the histone proteins associated with DNA
Why is salt added to the sample
To help the DNA clump together
And break the hydrogen bond
Between DNA and water molecules
Why is ethanol added
DNA insoluble in the alcohol
Precipate forms
Why is the stage one of DNa replication
Unwinding and unzipping
DNA helicase causes the DNA double helix to unwind and the strands to unzip
- breaking of hydrogen bond between the nitrogenous bases
exposes both strands
both of the STANDS ACTS AS TEMPLATES
OUTLINE STAGES two of DNA replication ?
- FREE DNA nucleotides align with the exposed bases using hydrogen bonds
- following the complementary base pairing
what happens in the stage 3 of DNA replication
new nucleotides are joined together by DNA POLYMERASE .
Phosphodiester bonds forms producing sugar phosphate backbone of the new strand of dna
what is the term given to the strands that are arranged in opposite directions ?
anti parallel
which enzyme joins the okazaki fragments ?
DNA LIGASE
Define a gene
A section of DNA that contains sequnce of bases to code for an entire protein
how many codons code for a amino acid
3
what are the 3 features of genetic code ?
Universal
Non overlapping
Degenerative
