Chapter 4, Nucleic Acids Flashcards
What are 5 elements found in nucleic acids
Hydrogen,Carbon,Nitrogen,Oxygen,Phosphorus
What is the general term for the monomers of nucleic acid?
Nucleotides
Review: what type of reaction is used to link two monomers together
Dehydration synthesis or Condensation reaction
What is the general term for the polymers of nucleic acid?
Polynucleotides
How are polynucleotides linked together and what kind of bond (specific) do they have
Nucleotides are linked together by joining the -OH (hydroxyl) group on the 3’ carbon of one nucleotide and the phosphate group of the 5’ carbon. IT IS ALWAYS 3’ and 5’ on the carbons
They are bonded covalently, the specific name of this bond is a phosphodiester linkage
Phosphodiester bonds create a backbone of “BLANK”, with appendages made from “BLANK”
Backbone of sugar and phosphate
Nitrogenous bases as appendages
What are the three major types of nucleic acid and their respective functions
Deoxyribonucleic Acid (DNA)
- Stores genetic information, Always works as a template for the information to turn into RNA -> protein (central dogma and universal template for RNA)
Ribonucleic acid (RNA)
- Transports genetic information that is needed for protein synthesis (for ceels0
Adenosine Triphosphate (ATP)
=Transport/source of energy
What are nucleotides comprised of?
Each nucleotide consists of a nitrogenous base, a pentose sugar, and a phosphate group.
How is a nucleotide arranged
Its chemical structure
Phosphate group on the 5’ Carbon
Nitrogenous base on the 1’ Carbon
Carbon ring counted clockwise (to the right) from the oxygen (ether F.G.)
What are the two families of nitrogenous bases
Pyrimidines (cytosine, thymine/uracil)
Purines (adenine and guanine)
How do you remember the 5 nucleotides
Pyrimidines have a single 6-membered ring, Purines have a single 6-membered ring fused with a 5-membered ring.
Go in order
Thymine (Has CH3 group) -> Adenine (its complementary base)
Cytosine (other 6-membered ring) <-> Guanine (other 6 + 5 membered ring
Uracil replaces Thymine when undergoes RNA transcription
How many nucleotides does DNA have, and clarify which nitrogenous bases are found in DNA
4
Which are: Adenine, Thymine, Guanine, Cytosine
How many nucleotides does RNA have, and clarify which nitrogenous bases are found in RNA?
4
Which are: Adenine, Uracil, Guanine, Cytosine
What is the difference between DNA and RNA sugars
DNA has deoxyribose sugar
RNA has a ribose sugar
What is the difference between the two nucleic acid sugars
Ribose sugar
Deoxyribose sugar
What is a pentose sugar?
A 5-carbon ringed carbohydrate (monosaccharide)
What does 3’ and 5’ mean when referring to a nucleotide polymer?
5’ means the beginning of a nucleotide polymer
3’ means the end of a nucleotide polymer
What part of DNA forms hydrogen bonds
The nitrogenous bases pair up, via hydrogen bonds
How many combinations of nitrogenous bases can there be in DNA?
Only two. Guanine and Cytosine. Adenine and Thymine
Why can there only be a set number? What are these pairs called?
Because only Purine-Pyrmidines can have the right space to form stable H-bonds.
Adenine and Thymine form 2 hydrogen bonds based on the NH + N groups on Adeninne and NH/O groups on Thymine
Cytosine and Guanine can form 3 hydrogen bonds based on the 1 NH group + N/O of cytosine and the 2 NH groups and O group of guanine. They complement each other so they are known as complementary pairs
What condition must be met for hydrogen bonds to form between complementary pairs?
The two strands must run in opposite directions (antiparallel) to form hydrogen bonds
What shape is the DNA molecule
Spiralling around an imaginary axis, forming a double helix
If Thymine is 30% of DNA, How much % is Adenine in DNA?
30% (T=A, 30% =A)
If there’s 40% Guanine, how much Thymine is there?
10%, (40% G + 40% C = 80%, 100%-80% = 20%. 20%/2 = 10% T, 10% A)
List the 3 major types of RNA and their functions
mRNA (messenger RNA)
- RNA that is from DNA
rRNA (ribosomal RNA)
- RNA within the ribosome, is part of the structure
tRNA (transfer RNA)
- RNA that goes to the ribosome to make protein, based on the information of the messenger RNA
When an RNA strand folds over, what is its form and how?
When RNA folds over, it creates a hairpin structure, The bases on one side of the fold, align with an antiparallel RNA segment on the other side of the fold. The bases of RNA typically form hydrogen bonds with complementary bases on the same strand.
Why is DNA, rather than RNA used for long-term information storage in cells?
DNA is more stable than RNA.
DNA is made from deoxyribose sugar, which is less reactive and more stable than RNA’s ribose sugar due to one less oxygen atom. This makes DNA’s structure less reactive and less prone to degradation. Stability allows the safety/protection of generic information.
List 3 structural differences between DNA and RNA
RNA is single-stranded, DNA is double-stranded
Both have pentose sugar, RNA has ribose while DNA has deoxyribose
Nitrogenous Bases, RNA has Uracil while DNA has Thymine
