nucleic acids Flashcards
What are nucleic acids?
Nucleic acids are biopolymers essential for all known forms of life, primarily DNA and RNA.
What is the structure of DNA?
DNA has a double helix structure composed of two strands of nucleotides.
What are the four nitrogenous bases in DNA?
Adenine (A), Thymine (T), Cytosine (C), and Guanine (G).
True or False: RNA contains Thymine.
False. RNA contains Uracil (U) instead of Thymine.
Fill in the blank: The sugar in DNA is called _____ .
deoxyribose.
What is the primary function of DNA?
The primary function of DNA is to store and transmit genetic information.
What is the role of RNA in cells?
RNA plays several roles, including coding, decoding, regulation, and expression of genes.
Which type of RNA carries amino acids to the ribosome?
Transfer RNA (tRNA).
What is the process of copying DNA into RNA called?
Transcription.
What is the process of translating RNA into a protein called?
Translation.
True or False: DNA replication is a conservative process.
False. DNA replication is semi-conservative.
What enzyme is primarily responsible for DNA replication?
DNA polymerase.
What are the building blocks of nucleic acids?
Nucleotides.
What three components make up a nucleotide?
A phosphate group, a sugar, and a nitrogenous base.
Which nitrogenous bases are purines?
Adenine (A) and Guanine (G).
Which nitrogenous bases are pyrimidines?
Cytosine (C), Thymine (T), and Uracil (U).
Fill in the blank: The two strands of DNA are held together by _____ bonds.
hydrogen.
What is the role of messenger RNA (mRNA)?
mRNA carries the genetic code from DNA to the ribosome for protein synthesis.
True or False: RNA is usually double-stranded.
False. RNA is usually single-stranded.
What is the significance of the 5’ and 3’ ends of a DNA strand?
They indicate the directionality of the DNA strand, with 5’ being the start and 3’ the end.
What is a codon?
A codon is a sequence of three nucleotides that codes for a specific amino acid.
What is the function of ribosomal RNA (rRNA)?
rRNA forms the core of the ribosome’s structure and catalyzes protein synthesis.
True or False: All organisms use the same genetic code.
True, with few exceptions.
What is a mutation?
A mutation is a change in the nucleotide sequence of DNA.
What is the term for the regions of DNA that do not code for proteins?
Non-coding regions or introns.
What is the significance of the genetic code being degenerate?
It means that multiple codons can code for the same amino acid, providing redundancy.
Fill in the blank: The process of modifying RNA after transcription is called _____ .
RNA splicing.
what elements are nucleic acids made of
carbon,hydrogen,oxygen,phosphorous and nitrogen
what are the two nucleotides we study
dna and rna nucleotides
tell me the structure of an dna nucleotide
-pentose sugar-deoxyribose as well as a phosphate group and a nitrogenous base
what are the four possible nitrogenous bases for a dna nucleotide
-adenine
-thymine
-guanine
-cytosine
what is the structure of a rna nucleotide
-pentose sugar-ribose,phosphate group and a nitrogenous base
what are the four possible nitrogenous bases for a rna nucleotide
-uracil,adenine ,cytosine and guanine
compare a dna nucleotide with a rna nucleotide
similarities
-both have a nitrogenous base
-both have a pentose sugar
-both have one phosphate group
Difference
in a dna nucleotide the pentose sugar is deoxyribose ,in rna nucleotide its ribose
-in an rna nucleotide the thymine nitrogenous base is replaced by uracil
how does deoxyribose differ from ribose
missing an oxygen on the second carbon
how does a polynucleotide form
in a condensation reaction,the phosphate group of one nucleotide interacts with the deoxyribose sugar on of the next to form a polydiester bond ,releasing a water molecule in the process
what are the two classes of nitrogenous bases
purines and puramidines
describe the structure of dna
-phosphate groups and deoxyribose sugars form the sugar phosphate backbone
-phosphodiester bonds form ,results in a polynucleotide chain
-dna concists of two antiparallel polypetide chains bonded by h bonds that occur between complimentary base pairs
to form the dna molecule
-the polynucleotide chains are twisted to form a double helix
how do you distinguish between a purine and a pyramidine
a purine has a two carbon ring structure whereas a pyramidine has a one carbon ring structure
what nitrogenous bases are purines
adenine and guanine
what nitrogenous bases are pyramidines
cytosine thymine and uracil
what forms the sugar phosphate backbone
phosphate groups and pentose sugars
role of dna
stores genetic information
describe how the sugar phosphate backbone is formed
in a condensation reaction between the phosphate group of one nucleotide,the deoxyribose sugar of the the next where phosphodiester bonds are formed
what hold the double helix structure of dna
the h bonds that form between complimentary base pairs
which bases form h bonds
adenine with thymine in dna and adenine with uracil in rna
cytosine and guanine
how many h bonds does a and t or a and u form
2
how many h bonds does c and g form
3
is it true that adenine amouns always qual thymine aand that cytosine amounts always equal guanine
yes
role of messeger rna
-transfers gentic onformation from thr dna molecule to the ribosome
role of transfer rna
brings specific amino acids to the ribosome- what a codon codes for
role of ribosomal rna
part of the ribosome itself along with proteins
explain the base pairing rule
explain how the dna structure is adapted for its role
explain dna extraction
why do you grind the sample
why do you add detergent
why do you add alcohol
why should the temp be kept low
