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Flashcards in Nucleic Acids & Nucleotides Deck (21)
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1

DNA

STORE and TRANSMIT genetic information
Antiparallel double strand helix
Offset pairing of the 2 strands creates major and minor grooves

2

DNA Ribose Structure

PENTOSE (sugar) defines whether a molecule is DNA or RNA
2'-deoxy-D-ribose (2 H groups on 2' pentose)

3

Types of RNA and Their Functions

mRNA- carries information from nucleus-->cytoplasm
tRNA (cytoplasm)- Translate information in mRNA; link between mRNA and AAs
rRNA (cytoplasm) - Structural component of ribosomes carries out syn of proteins

4

RNA Ribose Structure

PENTOSE (sugar) defines whether a molecule is DNA or RNA
D-ribose (one H group and one OH group on 2')

5

Pyrimidine

One of the 2 nitrogenous base groups
Single Ring
Cytosine
Thymine
Uracil (RNA only)
Pyramids CUT

6

Purine

One of the 2 nitrogenous base groups
Double Ring
Adenine
Guanine
*Green Apples are Pure*

7

Nucleotide

Must have 3 things to be an actual nucleotide
1. Nitrogenous Base (Pyrimidine or Purine)
2. Sugar (pentose)
3. Phosphate (one or more)

8

RNA

Single Strand of Genetic Information
Can form hairpin loops (double back on itself) and bulges which gives it secondary structure

9

Methylation of Bases

Purine and Pyrimidine bases can be methylated
(Add a CH3 group)
Methylation can help REGULATE or PROTECT genetic information

10

Linkage of DNA and RNA

Phosphodiester linkage in a 5'--> 3' Direction
One phosphate bonds to the 5' of a base (below ring)
and the 3' of a second base (above ring)

11

Backbone of DNA/RNA

Sugar, Phosphate, Sugar 5'--->3'
Hydrophilic

12

Base Pairing

Hydrogen bonding of a purine and a pyrimidine via amine and carbonyl groups
G=C form 3 Hydrogen bonds
A=T form 2 Hydrogen bonds
A=U (RNA only) form 2 Hydrogen bonds
Bases are HYDROPHOBIC

13

Variations of Watson and Crick Form

A form - Right Handed, favored in absence of water, shortest
B form - Right Handed
Z form - Left Handed looks crazy, longest

14

mRNA for Polypeptide Chains

1. Monocistronic - codes for a single gene
2. Polycistronic - codes for more than one gene
Both have noncoding regions (parts that mean nothing) but Polycistronic has noncoding regions between each gene segment

15

Non-Enzymatic Transformations of Nucleotides and Nucleic Acids

1. Mutation - alters DNA structure and causes permanent changes
2. Deamination/Depurination
3. Pyrimidine dimers caused by UV
4. Reactive Chemical Interactions
5. Methylation of Bases

16

Denaturing DNA

Heat the DNA til the H-bonds break between bases and cause the two strands to separate

17

Annealing DNA

Cool the DNA so that it knits back together

18

PCR

Polymerase Chain Reaction
1. Denature DNA (heat until separation at ~95*C)
2. Anneal a new primer (cool ~68*C)
3. Elongate new strand (~72*C)

19

Genetic recombination experiments depend heavily upon the action of which enzymes?

1. DNA Ligase - facilitates the joining of DNA strands
2. Restriction Endonuclease - recognizes specific DNA sequences and cuts DNA where needed

20

Which N on Purine bonds with the Pentose?

N in the bottom right ring (9)

21

Which N on Pyrimidine bonds with the Pentose?

Bottom N (1)