9.1 Manipulating DNA•Set up Cornell Notes on pg. 13

•Topic: 9.1 Manipulating DNA

•Essential Question:

1.Suppose you cut DNA. You know that you should find four DNA fragments on a gel, but only three appear, and one fragment is very large. Explain what happened?

2.1 Atoms, Ions, and Molecules

9.1 Manipulating DNA

1. Suppose you cut DNA. You know that you should find four DNA fragments on a gel, but only three appear, and one fragment is very large. Explain what happened?

KEY CONCEPT Biotechnology relies on cutting DNA at specific places

9.1 Manipulating DNA

Points to Ponder

A natural disaster strikes. Families are separated. How can they be reunited?

If a body is found and the person cannot be identified by looks, how can we identify them?

What types of identifiers do we have?

9.1 Manipulating DNA

A natural disaster strikes. Families are separated. How can they be reunited?

If a body is found and the person cannot be identified by looks, how can we identify them?

What types of identifiers do we have?

• DNA- skin, sperm, saliva, blood

• Fingerprinting

• Teeth

9.1 Manipulating DNA

Sydney Leslie Goodwin 1910-1912

•Died in the sinking of the RMS Titanic

•Known as “The Unknown Child”

•The Goodwins and their 6 children were third class passengers and all perished

•Finally identified in 2007 using DNA

9.1 Manipulating DNA

KEY CONCEPT Biotechnology relies on cutting DNA at specific places.

Baby 81 was rescued after the 2004 Indian Ocean tsunami. He was reunited with his parents by using DNA fingerprinting technology

9.1 Manipulating DNA

Biotechnology allows us to

• Produce transgenic organisms• Clone• Study diseases and evolution• Produce medical treatments for people with illnesses

9.1 Manipulating DNA

• DNA cannot be picked up and rearranged by hand

• Therefore, scientists must be able to work with DNA without being able to see it, or handle it directly

9.1 Manipulating DNA

Scientists use several techniques to manipulate DNA.

• Chemicals, computers, and bacteria are used to work with DNA.

• Scientists use these tools in genetics research and biotechnology.

9.1 Manipulating DNA

• Restriction enzymes act as “scissors” by cutting DNA

– allow scientists to more easily study and manipulate genes

– cut DNA at a specific nucleotide sequence called a restriction site

DNA Restriction enzyme

9.1 Manipulating DNA

• Different restriction enzymes cut DNA in different ways.

– each enzyme has a different restriction site

9.1 Manipulating DNA

– some cut straight across and leave “blunt ends”

– some make staggered cuts and leave “sticky ends”

Sticky ends

9.1 Manipulating DNA

Between what nucleotides does this restriction enzyme cut between?

T and C or C and T

9.1 Manipulating DNA

ATTACGACCTAGGACG

Restriction enzyme: cuts between T and A

1. How many fragments are produced?

2. Are all the fragments the same length?

3. Please organize the fragments from biggest to smallest.

4. How many nucleotides in each segment when organized?

9.1 Manipulating DNA

ATTACGACCTAGGACG

Restriction enzyme: cuts between T and A

How many fragments are produced? 3

Are all the fragments the same length? No

Please organize the fragments from biggest to smallest. ACGACCT/AGGACG/ATT

How many nucleotides in each segment when organized? 7, 6, 3

9.1 Manipulating DNA

• Restriction Enzyme Video

9.1 Manipulating DNA

• After DNA has been cut, several different things can be done with it– The gene can be studied– The gene can be placed in another organism

• But first, the DNA fragments have to be separated from one another• Sorted according to their size

9.1 Manipulating DNA

• Gel electrophoresis is used to separate DNA fragments by size.– A DNA sample is cut with restriction enzymes– Electrical current pulls DNA fragments through a gel

9.1 Manipulating DNA

– Smaller fragments move faster and travel farther than larger fragments

– Fragments of different sizes appear as bands on the gel

9.1 Manipulating DNA

• A restriction map shows the lengths of DNA fragments between restriction sites.

– only indicate size, not DNA sequence

– useful in genetic engineering

– used to study mutations

9.1 Manipulating DNA

ATTACGACCTAGGACG

Restriction enzyme: cuts between T and A

Please organize the fragments from biggest to smallest.

ACGACCT (7)

AGGACG (6)

ATT (3)

9.1 Manipulating DNA

Grab 3 colors. Please organize the fragments from biggest to smallest.

ACGACCT (7)

AGGACG (6)

ATT (3)

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109876543210

---Draw and

complete this restriction map on pg. 12

9.1 Manipulating DNA

“Who Ate the Cheese?” Warm-Up

• Please complete the warm-up by yourself

9.3 DNA Fingerprinting

Who Ate the Cheese?Practice Gel Electrophoresis-Restriction Enzyme Lab

• Get into pairs– Each pair needs a Bio book– Read the Royal Incident Report– The restriction enzyme used will always cut between

CCGG – Create you DNA Fingerprint restriction map

Objective: You will examine crime evidence and model the process of gel electrophoresis and DNA fingerprinting to identify the person who ate the Queen’s cheese.

CC GG