AP Bio DNA Replication

What type of bond do you see between DNA?

Hydrogen bonds

How does replication differ from translation/transcription?

Replication is for cell division and growth + repair.

How is DNA Replication semi-conservative?

Each copy will have one half new and one half original strand.

DNA Poly III reads in…

3’ to 5’ direction.

DNA Poly synthesizes in…

5’ to 3’ direction.

What is transcription/translation?

Gene to protein.

DNA Lang > Transcription > Pre-mRNA Lang > Post-Transcriptional Controls > Mature mRNA

What is DNA Splicing?

When spliceosomes cut pre mRNA and remove introns (junk) to replace with exons (coding regions)

With one transcript you can get multiple mature mRNA strands.

Where does all transcription to mRNA and mRNA splicing take place?

The Nucleus

What are histone proteins?

Are positively charged and can coil around the DNA bc of different charges (DNA is neg)

What is Helicase?

Breaks H-Bonds to unwind DNA

What is DNA Poly I?

Removes RNA Primer and replaces with DNA nucleotide

What is DNA Poly III?

Adds the correct nucleotide to the DNA strand

What is Ligase?

Joins the okazaki fragments of the lagging strand

What is a Primase?

Places an RNA Primer

What is a topoisomerase?

Helps relieve tension of the DNA

What is a telomerase?

Extends telomeres by repeating nucleotides

What are SSBP’S (Single Stranded Binding Proteins)?

They help hold the DNA open and stabilize it

What do histone proteins create and what will happen without it?

Two forms of DNA — Euchromatin and Heterochromatin

DNA will not fit in the Nucleus without it.

What is Euchromatin?

Loosely packed DNA

Genes ON

What is Heterochromatin?

DNA is tightly coiled around histone

Genes OFF

Where does translation happen?

In the cytoplasm

What are the ribosome points?

A-Site (Attachment)

P-Site (Peptidle Site)

E-Site (Exit Site)

What are the three steps of translation?

1. Initiation

2. Elongation

3. Termination

The codon is always specific to what?

mRNA, has 3 mRNA bases

What is the third base of a codon?

A wobble point

What makes up an okazaki fragment?

RNA Primer and nucleotides

Anything being synthesized..

Anything being synthesized is 5’ to 3’ direction

Anything being read..

Anything being read is 3’ to 5’

What is an “ON” lac operon?

Inactive repressor WITH lac, transcription ON

What is an “OFF” lac operon?

Active repressor WITHOUT lac, no transcription

What is “ON” trp operon?

Inactive Repressor WITHOUT trp, transcription on

What is “OFF” trp operon?

Active repressor WITH trp, no transcription

What is the promoter site?

TATA Box

What is an operon?

A sequence of specific genes in prokaryotes. WE DON'T HAVE IT

What does methylation of DNA do?

Silences genes

What is the role of acetyl groups in DNA?

Unpacks the DNA and bonds to nucleosome (histone+DNA)

What does DNA Poly bond to?

The promoter region

In PROKARYOTES, Translation occurs..

The same time transcription occurs.

In eukaryotes, where does transcription and translation occur?

Nucleus and the cytoplasm