Restriction Enzymes Background Information

What are restriction enzymes?

• Proteins that cut DNA at specific sites

• Proteins that replicate DNA

• Proteins that synthesize RNA

• Proteins that repair DNA

What is a palindrome in the context of DNA sequences?

• A sequence that reads the same forward and backward

• A sequence that is only found in RNA

• A sequence that is always different on both strands

• A sequence that contains only adenine and thymine

Fill in the blank: Restriction enzymes scan the DNA code until they find a very specific sequence of nucleotides, called a ________, and make a specific cut in that point.

• restriction site

• promoter region

• exon

• telomere

Once HaeIII finds the GGCC sequence, it _______ the DNA between the GG and CC bases.

• cleaves

• joins

• replicates

• transcribes

What do scientists call the straight cuts produced by restriction enzymes like HaeIII?

• Sticky ends

• Blunt ends

• Curved ends

• Palindromic ends

Restriction enzymes come from bacteria and are named based on the type of bacteria in which the enzyme is found, as well as the order in which the restriction enzyme was identified and isolated. For example, EcoRI gets its name from the R strain of E. Coli bacteria. What does the 'I' in EcoRI stand for?

• It stands for the first restriction enzyme discovered in E. Coli

• It stands for the type of cut produced

• It stands for the sticky end

• It stands for the DNA sequence recognized

EcoRI searches for the DNA for the following palindromic sequence: 5’ GAATTC 3’ 3’ CTTAAC 5’ Where does EcoRI cut in this sequence? Fill in the blank with the correct answer. EcoRI cuts between the ___ and ___ on the top and bottom strands.

• G and A

• A and T

• T and T

• C and G

When EcoRI cuts DNA, does it produce a blunt end or a sticky end?

• Sticky end

• Blunt end

• Flat end

• Smooth end

Sticky ends are useful in recombinant DNA technology because:

• they allow DNA fragments with complementary sticky ends to combine and create new molecules, facilitating the insertion of foreign genes into plasmids.

• they prevent DNA fragments from joining together.

• they make DNA fragments more stable and resistant to enzymes.

• they ensure that DNA fragments cannot be used in genetic engineering.

EcoRI produces fragments that are uneven or staggered, resulting in sticky ends.

• True

• False