Module 1.2 Review: DNA Replication II

Ligase

Enzyme that “binds and seals together the new base pairs to the original strands."

Repair

General term for fixing DNA when “other proteins identify inappropriately mismatched nucleotides and replace them.”

Template

The strand named again in repair, used as the standard for correct pairing.

Template

The strand used to “determine the correct complementary pairs.”

Daughter cell

Cell that would inherit errors if repair fails.

Covalent

Type of bond joined the intended, correct base.

Nuclease

Enzymes that “cut DNA” by cleaving out a short stretch on the new strand (plural).

Mismatch

The problem “even though proofreading is deployed,” where bases pair inappropriately.

Polymerase

Class of enzymes that “patrol newly added nucleotides,” compare to the template, and remove incorrect bases.

Complementary

How bases are paired when they’re matched correctly.

Excision

Mechanism deployed “when entire stretches of the newly synthesized strand may be erroneous.” (first word only)

Polymerase

Class of enzymes that “patrol newly added nucleotides" (plural)

3’

Nucleotides can only be added to the ____ end of a preexisting strand.

5’

As nucleotides are added, the newly synthesized strand moves toward the ____ end of the parental strand.

shorter

When the initial RNA primer is removed from the newly made lagging fragment’s 5’ end, new DNA nucleotides cannot be added. As a result, daughter strands have a ______ length compared to the parent strand.

tail

Telomeres are specialized nucleotide sequences that act as a protective ____ on the ends of DNA strands.

TTAGGG

In humans, the specific nucleotide sequence of a telomere is ____

error repairs

Proteins associated with telomeres prevent the cell from deploying _____ within telomeric DNA.

genetic

Telomeres are short, repeating sequences that do not hold any relevant _____ information.

apoptosis

If error-detection machinery mistook a telomere for damage, the cell might fail its cycle checkpoints and undergo _______.

aging

The gradual shortening of telomeres in somatic cells is thought to underlie the predictable process of ______.

Germ

______ cells are shielded from telomere shortening to preserve genetic information across generations.

telomerase

A specialized enzyme called _______ lengthens telomeres in germ cells.

RNA

Telomerase has its own unique ____ molecule that serves as a template to extend telomeres.