Dna technology 2
Download
1 / 26

DNA Technology - 2 - PowerPoint PPT Presentation


  • 77 Views
  • Uploaded on

DNA Technology - 2. What are plasmids?. Small, circular DNA molecules. (Found in bacteria). They are separate from the bacterial chromosome. Why are plasmids useful?. They are used to manipulate genes in the lab. They are small. Contain genes useful to the bacteria.

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

PowerPoint Slideshow about 'DNA Technology - 2' - mora


An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript

Dna technology 2

What are plasmids?

Small, circular DNA molecules

(Found in bacteria)

They are separate from the bacterial chromosome


Dna technology 2

Why are plasmids useful?

They are used to manipulate genes in the lab

They are small

Contain genes useful to the bacteria

And, are easily taken up by bacterial cells

When they are taken up they are called vectors

What happens when the bacterial cell replicates its chromosome?

It also replicates the plasmid DNA

(including any foreign DNA as well)

vector A DNA carrier that move genes from one cell to another


Dna technology 2

What does cutting and pasting of DNA mean?

  • Enzymes are involved

e.g., A T C G

For cutting, what are they called?

Restriction enzymes

They recognize specific sequence of: A T C G

Hundreds have been isolated from bacteria

For pasting, what are they called?

DNA ligases

Its the last step to make recombinant DNA

They bind cut ends back together

(by covalent bonds between adjacent nucleotides)


Dna technology 2

So, this cutting and pasting of DNA is used to:

Cut gene sequence of interest (e.g., from human DNA)

Enzyme name?

Cut a plasmid (from a bacterium)

Enzyme name?

Create a recombinant DNA molecule

By using the plasmid

And ‘pasting’ a human gene sequence into it

Enzyme name?


Polymerase chain reaction
Polymerase Chain Reaction

Or PCR

  • PCR is a technique

  • In which any segment of DNA can be copied

  • Quickly and precisely

Why is it so important?

Use minute amounts of blood or other tissue

To generate enough DNA for analysis

e.g., DNA from the follicle of ONE stand of hair


Dna technology 2

How does PCR work?

Make a mixture of:

  • the DNA sample,

  • some nucleotides,

  • an enzyme, DNA polymerase

Treat the mixture to:

  • cycles of heating

Allows separation of DNA strands

  • cycles of cooling

Allows DNA strands to re-form duplexes

DNA Replication occurs during cooling cycle


Dna technology 2

In each cycle, the DNA is DOUBLED

How many copies of DNA after each cycle?

How many copies after a 5th cycle?

___1st cycle

Within a few hours:

___2nd cycle

PCR can generate billions of copies

From a SINGLE DNA molecule

___3rd cycle

___4th cycle

Enough to do extensive analyses


The human genome project
The Human Genome Project

1990 - 2003

What was the goal of HGP?

To determine the nucleotide sequence all the DNA

In any given human cell

To identify the location & sequence of every gene

What was discovered?

Our DNA contains ~ 2.9 billion nucleotide pairs

About 25,000 genes

There is a LOT of DNA that isn’t made up of genes

About 97% is non-coding DNA


Learning check
Learning check

1. Why is only the slightest trace of DNA at a crime scene often sufficient for forensic analysis?

2. A carrier that moves DNA from one cell to another, such as a plasmid, is called a ________

3. What features of a DNA fragment causes it to move through a gel during electrophoresis?

  • Its nucleotide sequence

  • The hydrogen bonds between its base pairs

  • Its double helix shape

  • The electrical charges of its phosphate groups


Dna technology 2

4. A paleontologist has recovered a bit of organic material from the 400 year old preserved skin of an extinct dodo. She would like to compare DNA from the sample with DNA from living birds. The most useful method for increasing the amount of dodo DNA available for testing is __________

5. Why is golden rice pale yellow in color?


Dna technology 2

What does this figure show? from the 400 year old preserved skin of an extinct dodo. She would like to compare DNA from the sample with DNA from living birds. The most useful method for increasing the amount of dodo DNA available for testing is __________

2

4

7

3

1

8

6

5

What does each ‘band’ consist of?


Some review
Some Review from the 400 year old preserved skin of an extinct dodo. She would like to compare DNA from the sample with DNA from living birds. The most useful method for increasing the amount of dodo DNA available for testing is __________


Dna technology 2

Structure and Function? from the 400 year old preserved skin of an extinct dodo. She would like to compare DNA from the sample with DNA from living birds. The most useful method for increasing the amount of dodo DNA available for testing is __________


Dna technology 2

8 from the 400 year old preserved skin of an extinct dodo. She would like to compare DNA from the sample with DNA from living birds. The most useful method for increasing the amount of dodo DNA available for testing is __________

5

6

4

7

2

1

3


Dna technology 2

7 from the 400 year old preserved skin of an extinct dodo. She would like to compare DNA from the sample with DNA from living birds. The most useful method for increasing the amount of dodo DNA available for testing is __________

3

4

2

6

8

1

5

  • Name of molecule

  • What does the arrow refer to?

  • Name of molecule

  • Name of molecule

  • Where does this take place?

  • Name molecule

  • Name molecule

  • Name molecule

  • Name the reaction


Dna technology 2

15 from the 400 year old preserved skin of an extinct dodo. She would like to compare DNA from the sample with DNA from living birds. The most useful method for increasing the amount of dodo DNA available for testing is __________

10

4

7

11

1

6

9

14

2

3

12

8

16

17

13

5

18