Manipulating DNA

DNA Technology

Lesson 1

New Vocabulary

genetic engineering

genome

transformation

restriction enzyme

DNA ligase

cloning

gel electrophoresis

polymerase chain reaction

recombinant DNA

transgenic organism

plasmid

Review Vocabulary

DNA: the genetic material of all organisms,
composed of two complementary chains of
nucleotides wound in a double helix

Genetic Engineering

•

By about 1970, researchers had discovered
the structure of DNA and determined the
central dogma that information flowed from
DNA to RNA to proteins.

•

However, scientists did not know much about
the function of individual genes.

•

The situation changed when scientists began
using genetic engineering, technology that
involves manipulating the DNA of one
organism in order to insert exogenous DNA
(the DNA of another organism).

3.1.1 Differentiate, using examples, between genetic engineering and biotechnology

DNA Tools

•

Genetic engineering can be used to increase or
decrease the expression of specific genes in
selected organisms. It has many applications
from human health to agriculture.

•

An organism’s genome is the total DNA present
in the nucleus of each cell.

•

In order to study a specific gene, DNA tools can
be used to manipulate DNA and to isolate genes
from the rest of the genome.

3.1.2 Summarize the roles of DNA tools (Include: restriction enzymes and gel electrophoresis)

DNA Tools

Restriction Enzymes
•

Restriction enzymes are proteins that recognize
and bind to specific DNA sequences and cleave
the DNA within that sequence.

•

Restriction enzymes are used as powerful tools
for isolating specific genes or regions of the
genome.

DNA Tools

EcoRI
•

EcoRI is a restriction
enzyme that specifically
cuts DNA containing the
sequence GAATTC.

•

Sticky ends are single
stranded DNA sequences
at the end of fragments.

•

They can be joined
together with
complementary sticky
ends.

Multiple Choice

Which of the following is a protein that acts as DNA scissors?

• plasmid

• ligase

• restriction enzyme

• protein expression

DNA Tools

Gel Electrophoresis
•

In gel electrophoresis, an electric current is used
to separate DNA fragments according to the size
of the fragments.

•

When an electric current is applied, the DNA
fragments move toward the positive end of the
gel.

•

The unique pattern created based on the size of
the DNA fragments can be compared to known
DNA fragments for identification.

3.1.3 Interpret data collected from the process of gel electrophoresis

Multiple Choice

Gel electrophoresis enables scientists to

• separate DNA fragments.

• count the genes in DNA

• combine DNA fragments

• insert DNA in cells

Multiple Choice

Based on these results whose blood was found in the blood stain at the crime scene?

• Bob

• John

• Sue

• Lisa

Recombinant DNA Technology

•

DNA fragments from different sources can be
combined to make new DNA molecules.

•

The newly generated DNA molecules with DNA
from different sources is called recombinant DNA.

•

Recombinant DNA is placed into bacterial cells for
study via a vector.

3.1.4 Sequence, using diagrams and models, how recombinant DNA is made and manipulated

Recombinant DNA Technology

•

Common vectors include viruses and plasmids.
Plasmids are small, circular, double-stranded DNA
molecules that occur naturally in bacteria and
yeasts.

•

DNA ligase, a cellular repair enzyme, attaches the
recombinant DNA to the plasmid.

3.1.5 Explain the role of plasmids and DNA ligase in recombinant DNA technology

Multiple Choice

 

Which of the following is a circular piece of DNA from bacteria that can hold a foreign gene?

• plasmid

• ligase

• restriction enzyme

• protein expression

Multiple Choice

When human DNA is inserted in bacterial DNA to create insulin it is called

• viral DNA

• bacterial DNA

• recombinant DNA

• transcribed DNA

Recombinant DNA Technology

Draw

Label the diagrams missing labels

Multiple Choice

Which of the following tools or processes is NOT involved in genetic engineering?

• restriction enzymes

• the human genome

• gene cloning

• DNA sequencing

​Stem Cells

Open Ended

Explain how adult stem cells and embryonic stem cells are different.

Open Ended

Explain how cloning techniques can be beneficial.