DNA
Define semiconservative DNA replication
this means that one polynucleotide chain of DNA is conserved when it is replicated
what is cytosine and thymine
pyrimidines (double ring structures)
what is the function of DNA
responsible for genetic information from cell to cell
what advantages do I get of the DNA is coiled
store more genetic information in a small amount of space in the nucleus
describe what a DNA nucleotide structure has
it is made from a phosphate group and pentose/dexoyribose sugar and a nitrogen containing base (nitrogenous group)
what are polynucleotides
long chains of nucleotides bonded together
A polynucleotide structure
many nucleotides Bond together to form long chains of polynucleotide by a condensation reaction to form a phosphodiester bond chain a chain of phosphate group and pentose sugar is called a sugar phosphate backbone
what is the difference between nucleic acids and nucleotides
nucleotides are the monomers of nucleic acids
describe the structure of the nucleoside
pentose sugar molecule is bonded to a phosphate group with a Easter bond and bonded to a nitrogenous group with a glycosidic bond
what are adenine and guanine
purines (2 rings)
what is the structure of mRNA
single stranded made from nucleotides bonded together (consists of phosphate group/ pentose group and nitrogenous base) it is used to make protein found in cytoplasm made in nucleus
How does tRNA work?
tRNA has an anticodon and is charged with a specific amino acid. it finds the specific codon so that the anticodon can pair with it and then drops off the amino acid
Describe DNA replication
- DNA double helix is unwound and the hydrogen bonds between the nitrogenous bases to form 2 long polynucleotide chains by DNA helicase - the polynucleotide chains act as templates for the free nucleotides to bond to its complementary base - free nucleotides that is made in the cytoplasm moves to its complementary nitrogenous group (A GOES TO T) ( AND G GOES TO C) - The base pairing occurs between the free nucleotides and the exposed bases of the long chain polynucleotides - The DNA polymerase bonds the free nucleotides by forming covalent bonds which forms a sugar phosphate backbone. - the free nucleotides forms hydrogen bonds to its complementary base - 2 daughter DNA molecules are formed.
Why is DNA stable?
1. the phosphodiester backbone protects the more chemically reactive organic bases inside the double helix 2. many hydrogen bonds link the base pairs together, so it adds strength overall. C-G have
What does DNA consist of?
2 long chain nucleotides wound together to form a double helix
what is the difference between DNA and RNA
DNA is double stranded and RNA is single stranded DNA contains deoxyribose sugar RNA contains ribose sugar DNA stores genetic information RNA makes protein RNA has uracil instead of Thymine DNA is long and RNA is short
how does the DNA polymerase only bond the free nucleotides
Each stand end is different on the 2 DNA strands the free nucleotides goes from 5' (5 prime) to 3' ( 5 prime) The active site is complimentary to the 3' end so it bonds the nucleotides on the 3' end of the parents strand so the DNA polymerase moves from 3' to 5' on the DNA parents strand and 5' to 3' on the daughter strand since the parent strands in double helix are antiparrellel the DNA polymerase works on the 2 DNA strands in opposite directions in binding the templates
Describe the structure of DNA
It has a double helix as the molecules in sugar phosphate backbone from hydrogen bonds to the adjacent molecule in the phosphate sugar backbone which makes the molecule coil. there is also hydrogen bonds between the nitrogenous base pairs. ( C to G with 3 hydrogen bonds and A to T with 2 hydrogen bonds) which forms a double polynucleotide structure this also makes the 2 polynucleotide molecules antiparallel to each other
what are the main parts of a nucleotide
Phosphate group, deoxyribose (or Pentose) sugar, nitrogen containing base (nitrogenous group)
what is the difference between a phosphodiester bond and an ester Bond
a phosphodiester bond is 2 ester bonds between one nucleotides
Describe the structure of RNA
a type of nucleic acid that consist of long chain of nucleotides each nucleotide consists of nitrogenous base/ ribose sugar (Pentose sugar) / phosphate group
what are the different types of nitrogen base groups
adenine which bonds to thymine it has two hydrogen bonds between the two nitrogen base cytosine and guanine three hydrogen bonds between nitrogen containing base there are always equal amounts of adenine thymine cytosine and guanine
what is stronger covalent bonds or hydrogen bonds
covalent bonds
describe the DNA structure
double helix which is made from two polynucleotide chains which are wind around each other to form a spiral the DNA is then coiled up which makes it compact able to store more genetic information in small spaces in the nucleus