Micro Exam 3 : Lecture 9-11

Central Dogma

How genetic info is passed.
DNA → RNA → Proteins

Translation

mRNA → Proteins
Occurs in the ribosomes

Transcription

DNA → RNA
RNA Synthesis

Fredrick Griffith

Discovered DNA’s role in heredity using mice

Erwin Chargaff

Created base pairing rules (A with T, C with G)

Watson, Crick, and Wilkins

Discovered the structure of DNA (won nobel prize)

Into chromosomes

How is DNA organized?

True

T/F all cells have dsDNA (double stranded DNA)

Eukaryotic chromosomes

Diploid
Supercoiled
Histones
Linear
NO plasmids
dsDNA
Chromosomes in nucleus

Prokaryotic chromosomes

Haploid
Supercoiled
Histone LIKE proteins
Circular
dsDNA
Chromosomes stores in NUCLEOID

Semi-Conservative Replication

DNA is copied so each new DNA helix consists of an original strand and a new one.

Anti-parallel replication

Where DNA replicates in opposite directions
Leading and Lagging strands (Okazaki Fragments)
5’ to 3’

Okazaki fragments

Short DNA segments that are created during DNA replication

Sugar, Phosphate, Nitrogen Base

Nucleotides are made up of ______, ______, and a ______ ______

Phosphodiester bonds

What type of bond links nucleotides?

Hydrogen bond

What type of bond links nitrogen bases together

Uracil, Thymine, Cytosine

3 Pyrimidines

Adenine, Guanine

2 Purines

Circular

What shape are Prokaryotic cells?

Linear

What shape are eukaryotic cells?

oriC

Where does bacterial DNA replication begin?

The replication bubble, which consists of 2 replication forks

What forms at the oriC?

5’ to 3’

Which way does bacteria replicate?

Ter sites

What ensures replication ends at the right spot?

2 daughter chromosomes

What are the results of bacteria DNA replication?

Helicase

unzips H+ bonds

Primase

Synthesize RNA primers

DNA Polymerase

Synthesizes new DNA strands by adding more nucleotides
Builds DNA

Ligase

Links the phosphate to the 3’ OH group
Links DNA

Topoisomerase

Relieves DNA supercoiling by cutting and rejoining

A, U, G, C

What are RNA’s base pairs?

Ribose

What sugar does RNA have?

Single

RNA are ______ stranded

Transcription

RNA undergo ____________

A, T, G, C

What are DNA’s base pairs

Deoxyribose

What sugar does DNA have?

Double

DNA is ______ stranded

Replication

DNA undergo _________

Linear

mRNA shape

Genetic code

mRNA is responsible for the _____ ____

Codons (3 nucleotides)

mRNA contains ______

Single

mRNA are ______ stranded

Single

tRNA are ______ stranded

Amino Acid

tRNA brings the ____ ____

Anticodon

tRNA carries an _________

Secondary folding

tRNA is responsible for ______ _______

23S

Bacteria need ___ rRNA for peptidyl transferase

1. Initiation

2. Elongation

3. Termination

Steps of bacterial Transcription

Promoter

Where does initiation begin?

Synthesizing RNA from DNA

Elongation

Rho dependent and Rho independent

2 methods of termination

1. 5’ cap added

2. 3’ poly A tail added

3. Introns spliced out via splicesome

4. Exons are joined together

Steps of Eukaryotic processing

Chromatin

DNA stabilized with proteins

Transcription and Translation

What processes can be coupled in a prokaryotic/bacterial cell?

Sigma Factor

protein subunit that recognizes the promoter and allows RNA polymerase to bind

U

When asked to find an anticodon, A pairs with _

Secondary folding

tRNA shape

RNA polymerase

Breaks the hydrogen bonds to allow for access to the strand of DNA