Nucleotides and Nucleic acids Flashcards
semi-conservative replication of DNA
- Double Helix unzips the DNA strand
- Hydrogen bonds are broken
- free nucleotides are attached to the template strand via complementary base pairing
- DNA polymerase creates phosphodiester bonds via condensation reaction
define Semi conservative replication?
each new DNA molecule is made up of one parent strand (see next point) from the original DNA molecule, and one new, daughter strand.
What is DNA made up of?
A phosphate group,
deoxyribose sugar
4 bases (A,C,T,G) that connect the two strands in DNA
What is RNA made up of?
Single stranded
Ribose sugar
Uracil instead of thymine
Where is the phosphodiester bonds?
Between the phosphate group and the sugar molecule.
What is the genetic code?
- non-overlapping
- degenerate
- universal
Summarise the process of transcription.
DNA molecule is separated by RNA polymerase.
free nucleotides bind to the single strand that acts as a template
splicing - introns are removed and exons remain
mRNA leaves via the nuclear pore
Summarise the process of translocation.
mRNA attaches to the ribosome in the cytoplasm
tRNA anticodon region binds to ribosome
rRNA catalyses peptide bond between 2 AA
process continues till stop codon
polypeptide chain formed
mRNA, tRNA and polypeptide chain detach from ribosome
What is a mutation?
change in the DNA sequence
How does pre-mRNA turn into RNA?
Undergoes splicing -introns are removed and remaining exons are stuck back together.
What are histones?
- wrap DNA around them and form chromatids
What is energy needed for?
Active transport
Exocytosis
Endocytosis
Anabolism
Cell division
Movement
What is ATP made of
three phosphate groups one nitrogenous base and one ribose sugar.
purines Vs pyramidines
purines: 2 carbon rings e.g A and G
pyramidines: 1 carobon ring e.g T and C
how many H-bonds between each base pairs
2 between A and T
3 between G and C
importance of DNA replication
conserve genetic information
precipitation reaction
- add detergent - breaks down cell membrane
- add salt- clumps DNA
- add protease enzyme- breaks down histone proteins
- add ethanol- form the ppt
what elements does a nucleotide have
C,H,O,N,P
DNA and RNA are polymers of?
nucleotides
