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?
Mutations occur when the sequence of bases in a gene becomes altered.
The mutation results in a wrong polypeptide chain being made.
How does pre-mRNA turn into RNA?
Undergoes splicing -introns are removed and remaining exons are stuck back together.
What are histones?
are DNA-binding proteins. Strands of DNA wrap around histones to form a structure called a nucleosome - a chain of this is called chromatin
What is energy needed for?
Active transport
Exocytosis
Endocytosis
Anabolism
Cell division
Movement
What is ATP made of and used for?
three phosphate groups one nitrogenous base and one ribose sugar.
purines Vs pyramidines
purines: 2 carbon rings
pyramidines: 1 carobonring
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
