DNA vs. RNA
Which of the nucleic acids stay inside of the nucleus of the cell?
DNA
What nucleotide does "A" stand for?
Adenine
Define a nucleic acid.
A nucleic acid is a polymer and more importantly, the fundamental genetic material within a living thing. In the case of humans, DNA is the genetic material. RNA is also considered a nucleic acid.
Why are both nucleic acids and proteins compatible with water?
Both DNA and proteins are polar, and what's more...both DNA and proteins can engage in hydrogen bonding.
What are three differences between DNA and RNA?
(i)There is a difference in the sugar in the backbone of DNA and RNA;
(ii) RNA has uracil, DNA has thymine;
(iii)RNA is single stranded, DNA is double stranded
If one part of a DNA strand has the nitrogenous bases A C G T, find the nitrogenous bases in the corresponding part of the second DNA strand.
T G C A
Define a nucleotide.
The monomer making up the polymer nucleic acid. A nucleotide contains phosphate, a sugar, and a nitrogenous base.
Why is it necessary to separate the double stranded DNA during the early stage of transcription?
Only one DNA strand is read; it is necessary to separate the double helix in order for that strand to be read.
How is the bond formed between phosphate and sugar in both DNA and RNA?
In the dehydration process, an O-H is lost from the sugar and the H is lost from monohydrogen phosphate, resulting in the formation of water and a bond between sugar and phosphate.
If a portion of the mRNA strand has the nitrogenous bases U A C G, find the nitrogenous bases on the corresponding portion of the original DNA strand.
A T G C
Define a phosphate
A polar, negatively charged, inorganic substance with one phosphorus atom and four oxygen atoms.
If a protein has 327 amino acids, how many nitrogenous bases were read in the original DNA molecule?
Since three nucleotide bases translates to one amino acid (3 x 327 = 981), the original DNA strand read had 981 nitrogenous bases.
Which is more stable, DNA or RNA? Why?
DNA is more stable than RNA because there is hydrogen bonding between the base pairs in DNA. There is no hydrogen bonding between base pairs in RNA since RNA is single stranded.
Why is the melting point higher for DNA molecules with a greater percentage of guanine and cytosine compared to thymine and adenine?
There are three hydrogen bonds between cytosine and guanine compared to two hydrogen bonds between adenine and thymine. The connection between cytosine and guanine is therefore stronger.
Why is a sugar often referred to as a carbohydrate?
Why are proteins bound with DNA within a chromosome?
Since both proteins and DNA are polar, they are compatible with each other. Proteins can condense DNA so it can fit inside the tiny nucleus of a cell.
Why can RNA sometimes fold into complex three dimensional structures?
Although RNA is single stranded, RNA has nitrogenous bases which allows folding due to the hydrogen bonding between the different nitrogenous bases in the RNA strand.
Why is the percentage of only one nitrogenous base in DNA necessary to find the percentages of all the other bases?
If, for example the percentage of cytosine is 30%, we know that the percentage of guanine is therefore 30% too since cytosine always pairs with guanine. This means that the combined percentage of adenine and thymine is 40%, meaning that the percentages of adenine and thymine are 20 % each since adenine always pairs with thymine.
Define transcription
Transcription is the first step of protein synthesis in which mRNA is assembled using one of the two strands of DNA as a template.
Why can it potentially be a serious problem if one of the DNA bases being read is transcribed incorrectly ?(i.e. instead of the A base in DNA being transcribed to a U base in mRNA, the A base in DNA is transcribed to a C base in mRNA).
One of the three nitrogenous bases making up one particular amino acid is not correct. The wrong amino acid may result from that faulty sequence of nitrogenous bases in mRNA. Even one wrong amino acid in a protein can be a disaster in terms of function.