Nucleic Acids Flashcards
What is DNA
A nucleic acid
What are nucleic acids
Chains of repating monomers called nucleotides
How do Nucleotides form a nucleic acid polymer
by a condensation reaction called polymerisation
What are the two types of nucleic acids in living organisms
DNA - (deoxyribonucleic acid)
RNA (ribonucleic acids)
What are the three components of a nucleotide
- A phosphate
- A sugar
- A base
What is a pentose sugar
a simple sugar made up of five carbon atoms
What is a base
a molecule that contains nitrogen and acts as a base
What is a phosphate
a functional group made up of phosphorus and oxygen
How do nucleotide units link together
covalent bond
Name the five bases
Cytosine
Guanine
Adenine
Thymine
Uracil
What are the two types of bases
Purines (two rings in their structure)
Pyrimidines (one ring in their structure )
What bases are example of Pyrimidines
Thymine
Cytosine
Uracil
What bases are examples of Purines
Adenine
Guanine
what does the sequences of bases form
genetic code
What is the pentose sugar in DNA and RNA called
deoxyribose
ribose
How are the two strands linked in DNA
by complementary base pairing
Why is base pairing important
to stabilise the double helix structure
What bond is held between the two strands
hydrogen
What bonds bond the bases
hydrogen
Explain gene expressions
the process by which the genetic code in the DNA is translated into a protein
What does DNA stand for
deoxyribonucleic acid
What are nucleotides
building blocks of nucleus acid
viruses are not
living organisms
What are nucleotides made up of
pentose sugar (pentagon ) , phosphate (circle) and base (rectangle)
What is the pentose sugar molecule called in RNa
ribose
What is connected in the pentagon
4 carbons
1 oxygen on top
What is the chemical symbol for a phosphate
PO4 3-
What is the backbone of DNA mad RNa
repeating phosphate and sugar bonds
What is the order of bases
the genetic code
The two strands of the DNA molecule are always
parallel
in opposite directions
What bonds connect the bases
hydrogen
What is the difference between strands of Rna And Dna
DNA has two strands
RNA has one strand
What bases does RNA have
Adenine
Cytosine
Guanine
Uracil
What is RNA
A nucleic acid polymer formed by the condensation of nucleotide monomers
How many bonds does Adenine pair with Thymine
two hydrogen bonds
How many bonds does Guanine pair with Cytosine
three hydrogen bonds
benefits of dna
high base sequence diversity
limits storage capacity
What type of bond is formed between a pentose sugar and phosphate
covalent
Identity a similarity between DNA and RNA
covalent bonds between adjacent nucleotides
What is the process in which the genetic code is translated into a protein
gene expression
What does dna replication and gene expression have in common
complementary base pairing
ATP is a type of nucleotide
distinguish between ATP and DNA
ATP contains 3 phosphate groups , DNA only one
ATP only has adenine for a base whereas DNA can contain A, T,C and G
ATP has ribose DNA has deoxyribose
ATP stores energy DNA transmits genetic information
ATP found throughout the cell DNA found in nucleus
Outline the role of different types of RNA involved in translation
mRNA carries the genetic information from DNA to the ribosome
Codons on the mRNA specify the positioning of amino acids along the polypeptide chain. Each tRNA molecule has a specific anticodon sequence that is complementary to a codon on the mRNA . Base pairing allows tRNA to bring the corresponding amino acid to the correct position to form the polypeptide. The rRna catalysed the formation of peptide bonds between adjacent amino acids
Describe the structure of the DNA double helix
- each strand has a sugar phosphate backbone
- four nitrogenous bases
- strands are parallel but are in opposite directions
- covalent bond between phosphate and sugar
- complementary base pairing
- A to T C to G
One problem if there were two parallel strands and no anti-parallel
no hydrogen bonding (two strands not held together)
