Bio ch.14 smartbook

Lagging Strand Synthesis in correct order

1. synthesize primers using primase 2. Synthesize DNA 3. Replace RNA primers w/ DNA 4. Seal nicks in the DNA

Polymerase

Attaches a nucleotide to the 3' end of the DNA strand

Primase

Makes a 10-12 bp complementary primer to the DNA

The experiments used to distinguish between the three potential DNA replication mechanisms were performed by ______.

Meselson and Stahl

Which of these is not required for DNA replication?

NADPH

What is the name of the subunit that acts as the sliding clamp which keeps the replicating enzyme complex attached to the template in eukaryotic cells?

PCNA

During DNA replication, the enzyme _________ synthesizes RNA primers, the enzyme ___________ unwinds the double helix, and the enzyme DNA polymerase __________ joins two strands of DNA together.

RNA primase; helicase, ligase

Gyrase

Relieves coiling in DNA strands ahead of the replication fork

Consider a double stranded DNA molecule. In complementary base pairing, A pairs with ______ and C pairs with ______

T, G

Which model for DNA replication suggests that both strands of the double helix remain intact and the new DNA double helix consists of two new DNA strands?

The conservative model

As the lagging strand is being synthesized, adjacent Okazaki fragments are joined by the enzyme DNA __________

ligase

DNA replication in eukaryotic cells is complicated by the fact that eukaryotic cells have ______

linear chromosomes

Adjacent nucleotides in the same DNA strand are held together by covalent bonds known as ______ bonds.

phosphodiester

In DNA, consecutive nucleotides are linked via ________ bonds, which are made between the 5' phosphate of one nucleotide and the 3' _________ group of another nucleotide.

phosphodiester; hydroxyl (OH)

The enzyme DNA polymerase ________ covalently links nucleotides to synthesize new DNA strands together during DNA replication.

polymerase

The enzyme DNA ___________ synthesizes the RNA primers required by DNA polymerases during replication.

primase

In the replisome, the is composed of primase, helicase, and accessory proteins that prime the lagging strand.

primosome

The ability of a DNA polymerase to remain attached to its template is called the polymerase's ______

processivity

Griffith's experiments were important because they showed ______.

that the genetic material could be passed from one cell to another

The partial opening of a DNA helix to form two single strands is called ______.

the replication fork

What are some basic differences in prokaryotic and eukaryotic replication?

- Eukaryotes have linear chromosomes. Prokaryotes have single circular chromosomes - Eukaryotes have multiple, large chromosomes

Enzymes involved in DNA replication are found at the replication fork in all three types of cells (bacterial, archaeal, and eukaryotic)?

- Helicase - Primase - Polymerases - Clamp loader - Sliding clamp

Leading Strand

- Synthesized continuously - Requires a single primer

Lagging Strand

- Synthesized in small fragments that are later connected - Requires multiple primers

3 items that are required for DNA replication

- Template - Polymerase - Nucleotides

Characteristics of the transforming substance isolated by Avery, MacLeod and McCarty.

- The elemental composition of the substance was very similar to that of DNA. - RNA-digesting enzymes did not affect its transforming ability. - DNA-digesting enzymes destroyed its transforming ability. - Protein-digesting enzymes did not affect its transforming ability.

An ______ cuts DNA internally and an ______ cuts at the ends of DNA.

endonuclease; exonuclease

The primary purpose of the Meselson and Stahl experiments was to determine Blank______.

how DNA replicates

During DNA replication, the ___________ strand is synthesized continuously while the __________ strand is synthesized as small fragments that are connected to each other to form a continuous strand.

leading, lagging

A ______________ is the partial opening of a DNA helix to form two single strands.

replication fork

When the double stranded DNA helix is unwound, two single strands of DNA are formed. These strands have to be stabilized because their hydrophobic bases are exposed to water. The proteins that stabilize the two single strands are called ______.

single-strand binding proteins

Which enzymes did Avery, MacLeod, and McCarty use in order to identify the genetic material?

- DNA digesting enzymes - Carbohydrate digesting enzymes - RNA digesting enzymes

Part of the Watson-Crick model of the structure of DNA molecules

- Each DNA molecule is composed of two strands that run antiparallel. - Each DNA molecule is composed of 2 phosphodiester strands.

Components of a nucleotide

- Phosphate group - Nitrogenous base - Sugar

Features of the Watson and Crick model include ________

- a helical structure - a double stranded structure - a sugar phosphate backbone

The DNA structure proposed by Watson and Crick involves ______.

- a helical structure - a sugar phosphate backbone - two grooves (major and minor)

DNA primase ______

- makes a primer of RNA complementary to the DNA. - makes a primer about 10 -20 nucleotides in length.

The function & characteristic of telomeres:

- protect the ends of chromosomes - Short, repeated sequences of DNA are characteristic of

The DNA backbone is composed of ______.

- sugars - phosphate groups

Which enzyme covalently links nucleotides together?

DNA polymerase

In which of the following chromosomal entities are an individual's traits specified?

Genes

The experiments with radioactively labeled phage that showed that DNA was the genetic material were performed by ______.

Hershey and Chase

What provides the energy for the addition of nucleotides to a newly synthesized strand of DNA?

High energy bonds in the nucleotides used to synthesize the strand

Helicase

Unwinds the double helix

A bacterial chromosome is typically replicated as _____.

a single replicon

DNA's phosphodiester _______ is composed of alternating sugars and phosphates.

backbone

Viruses that infect bacteria are known as ______.

bacteriophages

Nucleotides contain a sugar, a phosphate, and a nitrogenous ______

base

The enzymes in the replisome are active on

both the leading and the lagging strand

Genes, which contain trait specifying information, are located on _______.

chromosomes

During DNA synthesis, each nucleotide used as a building block provides the _________ for its own incorporation into the new strand as its two terminal _________ are cleaved.

energy; phosphates

Franklin used x-ray _______ to suggest that DNA has a helical structure.

diffraction

This model of DNA replication suggests that newly synthesized strands of DNA have mixtures of parental and newly synthesized portions is called ______.

dispersive

The level of DNA structure that resembles a spiral staircase is the ______.

double helix

E. coli polymerases I, II, and III have 3' to 5' ___________ activity, which provides them with a proofreading function, i.e. they can remove a mispaired base.

exonuclease

The enzyme _________ uses ATP to unwind the DNA template.

helicase

A phage is a type of _______ that infects ______ cells.

viruses; bacterial

During semiconservative DNA replication, ______.

one of the strands in each new double helix comes from the original molecule, and one is newly synthesized

The DNA polymerase III enzyme of E. coli contains a subunit called the β subunit, which dramatically increases the enzyme's _______

processivity (an enzyme's ability to catalyze "consecutive reactions without releasing its substrate")

The results of the Hershey and Chase experiments suggested that DNA was the genetic material because ______.

radioactive bacteriophage DNA was found in the cytoplasm of bacterial cells

The DNA controlled by an origin is called a

replicon

DNA replication that leads to the production of double helices with one parental strand and one newly synthesized strand is consistent with ______.

semiconservative replication

Griffith's studies were instrumental in the discovery of DNA as the genetic material because his experiments demonstrated ______.

transformation in bacteria

Which type (or types) of cells has more than one origin of replication per chromosome?

Eukaryotes

Which of the following bonds, while individually weak, are numerous enough to hold the two strands of a double-stranded DNA molecule tightly together?

Hydrogen bonds between basepairs

Franklin determined that the structure of DNA was helical based on ______.

x-ray diffraction analysis