Biology Final Ch 16

Single strand binding proteins:

helps hold the DNA strands apart while they are being replicated

The leading and lagging strands differ in what way?

leading strand: synthesized in the same direction as the replication fork; add nucleotides to the 3' end lagging strand: opposite direction; add nucleotides to the 5' end.

Helicase:

separates DNA strands during replication

The monomers of DNA and RNA are A) amino acids B) monosaccharides C) nucleotides D) fatty acids E) nucleic acids

C) nucleotides

What is the difference between DNA & RNA?

- double stranded vs single stranded - sugars - nucleotides

DNA polymerase:

-removes RNA nucleotides from the primer, adds to the 3' end of Okazaki fragments -catalyzes the elongation of a DNA strand in the 5' --> 3'

When one DNA molecules replicates to make 2 DNA molecules, the new DNA contains what percent of the parents DNA?

50% of the parent DNA

We would expect that a 15-nucleotide sequence will direct the production of a polypeptide that consists of A) 2 amino acids D) 15 amino acids B) 5 amino acids E) 7 amino acids C) 3 amino acids

B) 5 amino acids (15 / 3 codons = 5)

Which of the following in not a function of tRNA? A) joining to only one specific type of amino acid B) recognizing the appropriate codons in mRNA C) transferring nucleotides to rRNA D) helping to translate codons into amino acids E) All of the choices are functions of tRNA

C) transferring nucleotides to rRNA

Nuclease:

DNA cutting enzymes, repair DNA damage

The stands that make up DNA are antiparallel. This means that _______

One strands runs in the 5" to 3" direction and the other strand runs in the 3" to 5" direction.

The DNA double helix has a uniform diameter because ____, which have two rings, always pair with _____ which have one ring.

Purines, pyrimidines

What is always true with regard to a DNA double helix?

adenine=thymine guanine=cytosine. A=T G=C

Ligase:

connects segments of DNA

What kind of chemical bond is found between paired bases of the DNA double helix?

hydrogen bond

Primase:

synthesizes short segments of RNA

DNA replication

uses each strand of a DNA molecule as a template for the creation of a new strand