Unit 3 Summary 3

Question 1

Helicase

Answer 1

The enzyme that uncoils the DNA by breaking the weak hydrogen bonds between two strands, resulting in unpaired/exposed bases. Each strand can now act as a template to build new strands.

Question 2

RNA Primers

Answer 2

Short pieces of RNA that bind to each DNA strand; the “starting point” from which the the DNA polymerase is able to bond the free nucleotides in a 5’->3’ direction.

Question 3

DNA Polymerase

Answer 3

Attracts a complementary DNA nucleotide (from the nucleoplasm) to each unpaired base on each separated strand, then binds the added nucleotides into a second chain.

Question 4

Semi conservative

Answer 4

The process of DNA replication is _____ _________, because each new DNA molecule consists of one new and one old strand.

Question 5

5’ to 3’

Answer 5

The new DNA strands are made in the ____ to ____ direction.

Question 6

Leading strand

Answer 6

The strand that is made by adding one nucleotide at a time, beginning at the 3’ end of the original strand. This occurs in a continuous manner as the DNA molecule unzips.

Question 7

Lagging strand

Answer 7

The strand made by constructing short pieces of the new strand (okazaki fragments) from the location of RNA primers. When the the fragments have been completed, the RNA primer is replaced by DNA nucleotides.

Question 8

DNA ligase

Answer 8

A linking enzyme essential for DNA replication; joins DNA fragments together.

Question 9

Enzymes