Nucleic acids Flashcards
What are nucleic acids?
Molecules found in a cell’s nucleus.
What are the two types of nucleic acid?
DNA and RNA
What elements are present in nucleic acids?
Carbon, hydrogen, oxygen, nitrogen and phosphorus.
What are the monomer units of nucleic acids called?
Nucleotides
What three components make up a nucleotide?
A sugar
A phosphate group
A base
What bond holds two nucleotides together?
Phosphodiester bond
Name the sugar in
1) DNA
2) RNA
1) deoxyribose
2) ribose
What 4 bases are present in DNA?
Adenine, Thymine, Cytosine and Guanine
What 4 bases are present in RNA?
Adenine, Uracil, Cytosine and Guanine
Which, out of pyrimidines and purines, is the smaller bases?
Pyrimidines.
Which bases are purines?
Adenine and Guanine
How many hydrogen bonds form between;
1) Adenine and Thymine
2) Guanine and Cytosine
1) 2 hydrogen bonds
2) 3 hydrogen bonds
The bases are________to eachother. Complete the sentence.
Complementary
True or false?
Purines always pair with purines.
False. Purines always pair with Pyrimidines.
DNA is too big to leave the nucleus for proteins to be made in the cytoplasm. So what is done?
Information is copied into RNA, which is small enough to leave the nucleus.
True or false?
1) DNA is a double helix
2) RNA contains Thymine
3) RNA is single stranded
4) DNA has an equal amount of A,T and C,G
1) True
2) False
3) True
4) True
Put these steps for DNA Extraction in the right order.
A) Add a layer of ethanol on top so that the DNA precipitates out.
B) Mix with detergent to break cell membranes and release content.
C) Spool out white strands of DNA that form between ethanol and sample
D) Grind sample in mortar and pestle to break the cell walls
E) Add salt to break hydrogen bonds between DNA and water
F) Add protease enzyme to break down proteins in the nucleus.
1) D
2) B
3) E
4) F
5) A
6) C
What is ribose/deoxyribose?
A pentose monosaccharide
How is a phosphodiester bond broken?
Hydrolysis reaction. By adding water.
How are nucleotides linked to form polynucleotides?
In condensation reactions. They are linked by phosphodiester bonds.
What is the backbone called in a strand of DNA/RNA?
Sugar-phosphate backbone.
The 2 strands in DNA are anti parallel. What does this mean?
They run in opposite directions.
After proteins synthesis, what happens to the RNA molecule?
It is degraded and hydrolysed to be reused again.
