Bio Molecular Genetics

DNA replication

the cellular process of creating an exact copy of a DNA strand

what does DNA replication create

2 strands of DNA that are 100% identical to each other, sister chromatids

mitosis

growth

meiosis

reproduction

What is step 1 in the dna replication process

dna helicase binds to the origin of replication and unwinds the double helix

What is step 2 in the dna replication process

• RNA polymerase II

• DNA polymerase III

• DNA ligase

• DNA polymerase

rna polymerase II

used to start a process of adhering a primer to build the new change off of

dna polymerase III

adds a polymer of nucleotides to carbon 3 following the base rule

uses a phosphodiester bond

dna ligase

connects okazaki fragments (phosphodiester)

dna polymerase I

digests RNA primer into DNA

What is step 3 in the dna replication process

two identical sister chromatids

What keeps the two sister chromatids identical

polymers III

Where does DNA replication take place

nucleus

dna transcription

the process of writing a copy of DNA to form mRNA

Where does DNA transcription occur

nucleus

What are the steps of DNA transcription

RNA polymerase II will bind to the promoter on the template strand

mRNA is built following the base pairing rule until a termination signal is reached

What must happen to mRNA before it can leave the nucleus?

processed

How does DNA translation and transcription maintain accuracy?

by the base pairing rule

What is dna translation?

the process of decoding mRNA to build a protien

Steps in DNA translation

1. mRNA binds to the small subunit as well as the tRNA

2. the large subunit joins to form a complex

3. tRNA brings in amino acids in which the anticodon must match the codon

4. protein is released (must reach 3D shape)

5. packaged and sent by Golgi bodies

Step 2 of DNA translation sites

A site - accepts new tRNA

P site - makes peptide bond and holds the protein chain

E site- eject empty tRNA

Can mRNA be reused?

yes if needed

How long does mRNA stay in the body?

72 hours

Where does DNA translation take place?

ribosomes

What does DNA transcription produce?

mRNA

What does DNA translation produce?

protein chains/amino acid chain

What does DNA transcription start with?

rna polymerase II binding to the promoter

What does DNA translation start with?

mRNA binding to the small subunit

What is DNA transcription completed by?

rna polymerase II

What is DNA translation completed by?

tRNA (getting the amino acids)

large subunit (forming peptide bonds)

What does DNA translation end with?

termination signal

What does DNA translation ends with?

the stop codon

How does DNA polymersae proofread?

checks each nucleotide as it adds to it

can only go back one nucleotide

How does the mismatch repair enzymes proofread?

they will run along the dna once it is replicated and correct any single nucleotide erros

How do the nuclease proofread?

these can cut out a chunk of DNA and replace the handful of nucleotides based upon the original strand

Polymerase Chain Reaction

a biotech that simulates DNA replication on the lab

RNA processing

occurs in the nucleus before the mRNA can exit via nuclear pores