Unit 6 - Gene Expression and Regulation Flashcards
(81 cards)
What is the chemical composition of nucleic acids?
CHONP
What are examples of nucleic acids?
RNA and DNA
What is the function of nucleic acids?
store and transmit genetic information and are the primary source of inheritable information
Where is the genetic information actually stored in nucleic acids?
its stored in the sequence of nucleotides
How is the continuity of genetics in cells ensured?
through complimentary base pairs
Whats a nucleotide?
monomer of nucleic acids
What is the composition of nucleotides?
a nitrogenous base, a sugar molecule (either ribose or deoxyribose), and a phosphate group
What is the shape of DNA and RNA
DNA is double stranded and RNA is single stranded
What do DNA and RNA have in common?
- both made of nucleotides
- both have 5 and 3 prime
- both have a sugar phosphate backbone
How do nucleotide monomers join together to form a polymer?
through hydrogen bonds at the bases
Purines
A and G and these are double ringed
Pyrimadines
C and T these are single ringed
When C and G bond how many bonds are there?
3
When A and T bond how many bonds are there
2
What are the bonds between the sugar and phosphate?
covalent bonds called phosphodiester bond
What does it mean that DNA is antiparallel?
DNA strands run in opposite directions
How is DNA built and how do we add bases to a DNA strand?
bases are added 5’ to 3’ so the new nucleotide is added to the 3’ end
How do we build our nucleic acids?
1) nucleotides arrive with 3 phosphate groups
2) DNA polymerase 3 uses the energy from phosphates to bind nucleotides
DNA Polymerase 3 in building nucleic acids
uses the energy from phosphates to bind nucleotides together (through energy coupling the exergonic reaction powers the endergonic reaction)
How does energy coupling work with DNA Polymerase 3?
when the 2 phosphate groups are broken off, that is an exergonic reaction. That energy is used to build the phosodiester bond and power the endergonic reaction
DNA Polymerase 3 definiton
is the enzyme that adds nucleotides to the growing strand (must be 5’ to 3’)
What about when you get to the last phosodiester bond?
then an enzyme called ligase is used
Ligase
an enzyme that comes and builds the phosphodiester bond between the 2 nucleotides
Why does DNA replicate?
DNA replicates for reproduction, to make new cells, for repair, and for growth