DNA and RNA Flashcards
what are DNA and RNA both types of ?
nucleic acid
where are DNA and RNA both found ?
both found in living cells
what do both RNA and DNA carry ?
information
what is the function of RNA ?
to transfer genetic info from DNA to ribosomes
what are ribosomes made up of ?
RNA and proteins
what is the function of ribosomes ?
read the RNA to make
polypeptides (proteins) in a process called translation
what is the structure of RNA?
similar to DNA(double helix)
what is the structure of DNA ?
double helix
what is the functions of DNA?
store genetic information
what does DNA stand for ?
deoxyribnucleic acid
what does RNA stand for ?
ribonucleic acid
what are DNA and RNA to nucleotides ?
the molecules of RNA and DNA are polymers of nucleotide.there nucleotide are the monomers that make up RNA and DNA
what is a nucleotide ?
is a type of biological molecule which is made from three different components:
a pentose sugar (that’s a sugar with 5 carbon atoms), a nitrogen-containing
organic base (organic means that it contains carbon), and a phosphate group
many nucleotide join together to form what ?
polynucleotide strands
how do the nucleotide join to form polynucleotide strands ?
a condensation reaction between the phosphate group of one nucleotide and the sugar of
another.This forms a phosphodiester bond (consisting of the phosphate group and two ester bonds).
The chain of phosphates and sugars is known as the ….
sugar-phosphate backbone
what are the strands in DNA made of?
The strands are polynucleotides. They’re made up of lots of nucleotides joined together
in a long chain.
how is a DNA molecule fit for it’s function ?
DNA molecules are really long and are coiled up very tightly, so a lot of genetic information can fit into a small space in the cell nucleus.
what is the structure of a DNA nucleotide ?
made from a phosphate group, the pentose sugar deoxyribose and a nitrogen-containing organic base. Each DNA nucleotide has the same sugar and phosphate. The base on each nucleotide can vary though. There are four possible bases
what are the four possible bases in a DNA nucleotide ?
adenine (A), thymine (T), cytosine (C) and guanine (G)
how do two DNA polynucleotide strands join together ?
by hydrogen bonds between
the bases.
explain complementary base pairing in DNA polynucleotide strands ?
Each base can only join with one particular partner. Adenine always pairs with thymine (A - T) and guanine always pairs with cytosine (G - C)
explain the bonding in complementary base pairing in DNA polynucleotide strands ?
Two hydrogen bonds form between A and T, and three hydrogen bonds form between C and G.
how do you tell what direction a strand is running?
The two ends of a polynucleotide strand are different — one end has a phosphate group and the other has a hydroxyl (OH) group
attached to the sugar.
what from of direction does two DNA polynucleotide strands run to form a DNA double helix ?
antiparallel
describe the structure of RNA?
nucleotides that contain a sugar, a phosphate group and one of four different bases. The nucleotides also form a polynucleotide strand with a sugar-phosphate backbone
how does the structure of RNA differ from DNA ?
The sugar in RNA nucleotides is a ribose sugar (not deoxyribose).
It’s still a pentose sugar though.
Uracil (U, a pyrimidine) replaces thymine as a base.
Uracil always pairs with adenine in RNA.
The nucleotides form a single polynucleotide strand (not a double one).
RNA strands are much shorter than most DNA polynucleotides.
how do DNA and RNA differ ,give the shape ,pentose sugar ,Base and Size ?
DNA RNA
Shape: Double-stranded —twisted into a double helix
and held together by hydrogen bonds /Single-stranded
Pentose sugar : Deoxyribose sugar /Ribose sugar
Bases :A, T, C, G/ A, U, C, G
Size : long Relatively /short
when was DNA first observed ?
1880’s
what was the issue a lot of scientists had when DNA was first observed ?
lots of scientists at the time doubted that it could carry the genetic code because it has a relatively simple chemical
composition. Some argued that genetic information must be carried by proteins — which are much more chemically varied.
what happened in 1953?
, experiments had shown that DNA was the carrier of the
genetic code.This was also the year in which the double helix structure, which helps DNA to carry out its function, was determined by scientists
James Watson and Francis Crick
What is a phosphodiester bond ?
Strong and covalent
