Biology 2 (Dna/rna)

Front 1

Purines

Back 1

A, G

Front 2

Pyrmidine

Back 2

C, T

Front 3

What Aromatic Base has...
2 Hydrogen Bonds?

Back 3

A, T

Front 4

What Aromatic Base has...
3 Hydrogen Bonds?

Back 4

C, G

Front 5

What are Aromatic Bases?

Back 5

A, G, C, T

Front 6

Nucleoside

Back 6

Ribose + Aromatic Base

Front 7

Nucleotide

Back 7

- Aromatic Base + Ribose + 1-3 Phosphates
- also known as dNTP
- There are 4 different for each aromatic base

Front 8

Phosphodiester Bonds

Back 8

- Covalently link nucleotides
- High Energy Bond
- The bond is between the 3' Hydroxy and the 5' Phosphate

Front 9

Polymerization

Back 9

Increase chain through mass linkage

Front 10

Where are the aromatic bases on DNA? Inside or outside?

Back 10

- They're interior, because they don't want to be near the exterior's acidic environment

Front 11

Chargoff's Rule

Back 11

[A] = [T]
[G] = [C]

Front 12

Annealing/Hybridization

Back 12

- Binding of two strands of complimentary DNA into ds-DNA
- Basically how long it takes

Front 13

Denaturization/Melting

Back 13

Separation of DNA

Front 14

Tm

Back 14

- Time taken to denature 50% of DNA
- This is proportional to the number of H bonds in the strand

Front 15

Prokaryotic Chromosome

Back 15

- Single, circular
- Can be DNA or RNA based

Front 16

Histone

Back 16

- Proteins that eukaryotic DNA wraps around
- Mostly basic, need to be attracted to DNA's acidic nature/exterior
- 8 Histones make up a NUCLEOSOME

Front 17

Genes

Back 17

- What DNA is ultimately coding for
- "Template" for the production of RNA

Front 18

Transcription

Back 18

- Reads DNA to RNA
- This is done purely in the nucleus

Front 19

Translation

Back 19

- RNA to Protein
- Happens in the cytoplasm

Front 20

Stop Codons (3)

Back 20

UAA, UAG, UGA

Front 21

What does degenerate but ambiguous mean?

Back 21

- Degenerate: two or more codons can code for the same AA
- Ambiguous: codon only codes for one AA

Front 22

Mutagen

Back 22

Any agent causing mutations

Front 23

Point Mutation - Transitions

Back 23

- Purine to Purine (A-G)
- Pyrimidine to Pyrimidine (T-C)

Front 24

Point Mutations - Transversions

Back 24

- Purine to Pyrimidine (A-T)
- Pyrimidine to Purine (G-C)

Front 25

Missense Mutation

Back 25

Change in protein code

Front 26

Nonsense Mutation

Back 26

Coding for a stop codon instead of another AA in the chain

Front 27

Silent Mutation

Back 27

No change is made in the protein code

Front 28

Conservative Mutation

Back 28

- Missense only
- Little change in structure or function of protein
- Changes the primary structure, but not the secondary or quaternary

Front 29

Frame Shift

Back 29

- Caused by insertions or deletions
- Serious because DNA is now read differently
- Can lead to premature termination of translation
- Not ALL insertions/deletions lead to it

Front 30

How is DNA Replication semiconservative?

Back 30

- Half of the DNA comes from the parental strand, and the other half is new.

Front 31

In what direction does polymerization occur?

Back 31

- 5'----3'
- Existing chain lengthened by adding nucleotides to the end

Front 32

DNA Polymerase III

Back 32

- Main enzyme that catalyzes the elongation of daughter strand from parental strand
- Needs a primer to start (RNA Primase)

Front 33

Helicase

Back 33

- Unwinds DNA's coiled helix
- Uses ATP to break H bonds
- Binds at a specific sequence of nucleotides

Front 34

DNA Ligase

Back 34

Joins fragments

Front 35

DNA Translation
Steps

Back 35

- Replication starts at the fork
- Occurs from 5'--3' on the leading strand (which is the 3'---5' strand)
- Problem is that it can't go backwards. So uh, what do we do about the other strand?

Front 36

Leading Strand

Back 36

- Where DNA Polymerase can happily replicate DNA without interruptions.
- 3'----5' direction

Front 37

DNA Polymerase I

Back 37

- Works the same as DNA Polymerase III, but is slower
- Uses its exonuclease activity to remove the RNA Primer and replace it with DNA to link the okazaki fragments together

Front 38

Exonuclease

Back 38

- Cuts nucleic acids at the end of a chain
- Need them to do editing work, without which we get more point mutations

Front 39

Transcription

Back 39

- Synthesis of mRNA, tRNA, or rRNA using DNA as a template

Front 40

Gene Expression

Back 40

- Process by which information contained in genes begins to have effects in the cell

Front 41

Basics of RNA

Back 41

- Single Stranded
- U instead of T
- Ring is ribose (not deoxy)
- Less stable, but it doesn't matter because it is transient, made and broken down

Front 42

Monocistronic

Back 42

- One gene, one protein
- Holds true for eukaryotes, but not in prokaryotes (who are polycistronic)

Front 43

mRNA

Back 43

- Carries genetic info from nucleus to cytoplasm
- Constantly made and degraded according to cells need for protein

Front 44

rRNA

Back 44

Components of the ribosome

Front 45

tRNA

Back 45

- Translate genetic code
- Carry AA from cytoplasm to ribosome to be added to growing polypeptide change
- Between 20-61 types

Front 46

Does RNA Polymerase require a primer?

Back 46

- No, because it's already made of RNA!
- RNA Polymerase lacks exonuclase ability (contributed to proofreading)
- This makes mutations occur more frequently here

Front 47

What is the strand that is transcribed in translation?

Back 47

- "Template"
- "Anti-sense"

Front 48

What is the strand that is NOT coded in translation called?

Back 48

- "Coding"
- "Sense strand"

Front 49

Repressible

Back 49

- Anabolic
- Enzymes whose transcription is inhibited in the presence of excess amounts of product

Front 50

Inducible Enzyme

Back 50

- Catabolic
- Enzymes whose transcription can be stimulated by an abundance of a substrate

Front 51

Operon Components (3)

Back 51

- Coding sequence for enzymes
- Genes encoding for regulatory enzymes
- Upstream regulatory sequences

Front 52

Eukaryotic RNA Poly I

Back 52

Transcribs rRNA

Front 53

Eukaryotic RNA Poly II

Back 53

- Transcribes mRNA
- Makes hn-mRNA strand (with introns+exons) before it is shipped out of the nucleus

Front 54

Eukaryotic RNA Poly III

Back 54

Transcribes tRNA

Front 55

Intron

Back 55

- Noncoding
- Spliced out in the nucleus before it is shipped to the cytoplasm

Front 56

What do the 5' Cap, and 3'-Poly AAA tail do?

Back 56

- Help the mRNA to not be digested by free floating exonucleases
- Exonucleases are free floating to help degrade the transient mRNA, and destroy viruses

Front 57

Prokaryotic Ribosome

Back 57

70S
(50S+30S components)

Front 58

Eukaryotic Ribosome

Back 58

80S
(60S+40S components)

Front 59

What are the A, P, E sites for?

Back 59

A - tRNA delivers new AA here
P - Growing polypeptide chain is here
E - Exit Site

Front 60

Translation
What happens during elongation?

Back 60

- tRNA enters A site, hydrogen bonds using 1GTP
- Enzyme catalyzes peptide bond between Met and new AA.
- Nucleophilic reaction displaces tRNA.

Front 61

Translation
What happens during Translocation?

Back 61

- In elongation, the tRNA-AA was added to the growing polypeptide chain
- The tRNA is now lonely and not carrying anything, so it moves to the E site to get out of the ribosomal complex
- A new tRNA-AA enters A.

Front 62

Translation
What happens during Termination?

Back 62

- Stop codon enters A site
- Enzymes catalyzes hydrolysis to complete polypeptide