1. Nucleic Acids and Gene Expression Flashcards
1
Q
Types of nucleic acids
A
- DNA
- RNA
2
Q
DNA
A
Deoxyribonucleic acid
3
Q
RNA
A
Ribonucleic acid
4
Q
Components of nucleotides
A
- 5-carbon/pentose sugar (ribose or deoxyribose)
- nitrogenous base (A,T,G,C,U)
- phosphate group
5
Q
Ribose vs Deoxyribose
A
Ref. to carbon 2 carrying hydroxyl group (-OH) or hydrogen atom
6
Q
Types of nitrogenous bases
A
- purines
- pyrimidines
7
Q
Purines
A
- A, adenine
- G, guanine
8
Q
Pyrimidines
A
- T, thymine
- C, cytosine
- U, uracil
9
Q
Number of C in PURINES
A
5 carbon atoms
10
Q
Number of C in PYRIMIDINES
A
4 carbon atoms
11
Q
Which C is the nitrogenous base attached to?
A
Carbon 1
12
Q
Which C is the phosphate group attached to?
A
Carbon 5
13
Q
Formation of nucleotides
A
- 3 components joined through condensation reactions involving removal of water molecules
- nitrogenous base attached to C1 through a glycosidic bond, forming a NUCLEOSIDE
- pentose sugar attached to C5 through a phosphoester bond, forming a NUCLEOTIDE
14
Q
Formation of nucleic acids from nucleotides
A
- nucleotides added as deoxyribonucleoside triphosphates (dNTPs) / ribonucleoside triphosphates (rNTPs)
- lose 2 phosphate groups (pyrophosphate) in the process
- condensation between 5’ phosphate group of incoming nucleotide and free 3’ -OH group of growing polynucleotide chain; phosphodiester bond
15
Q
Structure of DNA
A
- 2 strands of deoxyribonucleotide chains twisted to form double helix; held by hydrogen bonds between complementary nitrogenous bases (2 in A-T, 3 in G-C)
- uniform diameter of 2.0nm between the 2 sugar-phosphate backbones (as purine always paired with pyrimidine)
- one complete turn of helix consists of 10 base pairs spanning 3.4 nm
- anti-parallel
