Topic D Biology

What does DNA replication do and why?

Makes an exact copy of a DNA strand for reproduction and growth

How does semi conservation replication work?

The parent strand is a template that’s used to make a new strand using complementary base pairs

Steps of Gel Electrophoresis

• DNA is put one either ends of a gel block

• Each side is charged. The DNA is on the negative charged side

• Because DNA is also negative, it’s propelled forward

• Shorter DNA strands go farther

Helicase

The enzyme that unzips DNA by breaking the hydrogen bonds

DNA polymerase

Adds the free floating nucleotides to new strands during translation

Steps of a polymerase chain reaction

• The DNA is heated to break the hydrogen bonds

• Primase is used to signal where to start the reaction

• Taq Polymerase is used because it can withstand the heat

• Ends with amplifying the DNA strands

Transcription

Creates RNA by using DNA as a template

Functions of the RNA polymerase

• Separates DNA strands

• Adds RNA nucleotides

• Creates sugar-phosphate bonds

Sense vs antisense strands

Sense strands are the strands the genetic info is copied off of,

the antisense strand is used for transcription

Translation

Goes from mRNA to a polypeptide (protein)

Codon & anticodon group

Codon is a group of 3 bases on the mRNA

Anticodon is a group of 3 bases on the tRNA

What are the components of the ribosome?

Small subunit - binds to the mRNA

Large subunit - tRNA

What is EPA?

The three sites on the EPA

A - initital binding site

P - Where the polypeptide chain grows

E - tRNA exits