BIO106 Ch. 12 Molecular Biology of the Gene

Separates double-stranded DNA into single strands

DNA helicase

The enzyme responsible for separating double-stranded DNA into single-stranded DNA is

DNA helicase

Attaches DNA fragments

DNA ligase

Synthesizes DNA, removes RNA and proofreads DNA

DNA polymerase

The enzyme that is used to proofread DNA as it is being synthesized

DNA polymerase

Synthesizes shirt RNA strands

DNA primase

The process of copying a DNA molecule so that there are two copies of the same DNA is called

DNA replication

The synthesis of a new DNA double helix prior to mitosis and meiosis in eukaryotic cells and during prokaryotic fission in prokaryotic cells is called

DNA replication

There is a point on a replicating prokaryotic or eukaryotic DNA strand at which separation of the strands occurs to allow for enzyme activity. What is it called?

Replication fork

The double helix model of DNA resembles a twisted ladder in which the rungs of the ladder are

a purine paired with a pyrimidine

During the final stage of translation, a release factor binds to

a stop codon

Three-base sequence in a transfer RNA molecule base that pairs with a complementary codon in mRNA

anticodon

DNA replication is said to be semiconservative because

both of the new DNA molecules contain one new strand and one old strand

`pre-mRNA is modified or processed before leaving the eukaryotic nucleus by receiving

caps at 5' and 3' end and poly-A tail

In prokaryotes, replication can occur in two directions at once because the DNA molecule is

circular

Prokaryotic cells have _________________ DNA and their DNA replications proceeds in a ________________ direction.

circular, 5' to 3'

Three base sequence in mRNA that during translation directs the addition of a particular amino acid into a protein or directs termination of the process

codon

The hydrogen bonding between particular purines and pyrimdines; responsible for the structure of DNA, and some RNA, molecules is called

complementary base pairing

Middle stage of translation in which additional amino acids specified by the mRNA are added to the growing polypeptide

elongation

What facilitates the binding of tRNA anticodon to mRNA codons?

elongation factors

What are the three tRNA binding sites on ribosomes?

exit, peptide, amino acid

segment of mRNA containing the protein coding portion of a gene that remains within the mRNA after splicing has occurred

exon

The production and usage of a gene's product

gene expression

First stage of translation in which the translational machinery binds an mRNA and assembles

initiation

The first stage of translation, during which ribosomes assemble around mRNA is called

initiation

Intervening sequence found between exons in mRNA; removed by RNA processing before translation, non protein coding regions

intron

A spliceosome uses a ribozyme to cut and remove __________ from pre-mRNA.

introns

The portion of the mRNA transcript that gets removed during RNA processing is the

introns

Eukaryotic organisms have _____________ DNA and DNA replication occurs _________________.

linear; bidirectionally

Type of RNA formed from a DNA template and bearing coded information for the amino acid sequence of a polypeptide

mRNA

Type of nucleic acid bearing codons for the amino acid sequence

mRNA

A modified and finished form of a messenger RNA molecule is called an

mRNA transcript

During protein synthesis, an anticodon on transfer RNA pairs with

messenger RNA nucleotide bases

Transformation occurs when

organisms receive foreign DNA and thereby acquire a new characteristic

facilitates the transport of mRNA out of the nucleus, helps initiate loading of ribosomes and the start of translation and delays degradation of mRNA by hydrolytic enzymes

poly-A tail

How can you increase the efficiency of translation?

polyribosomes

In an operon, a sequence of DNA where RNA polymerase binds prior to transcription, first step in transcription

promoter

Study of the structure, function, and interaction of the complete collection of proteins in a cell

proteomics

Adenine and guanine are

purines

RNA molecule associated most closely with both ribosomes and translation

rRNA

Structural form of RNA found in the ribosomes

rRNA

The process in which DNA is used as a template to produce duplicate molecules of DNA

replication

RNA molecule that functions as an enzyme that can catalyze chemical functions

ribozyme

DNA replication be described as ___________________, because the resulting daughter DNA consists of one parent strand and one daughter strand.

semiconservative

Process of DNA replication that results in two double helix molecules, each having one parental and one new strand

semiconservative replication

Keeps single stranded DNA apart

single stranded binding protein (SSB)

During translation initiation, the small ribosomal subunit and initiator tRNA attach in the vicinity of the

start codon

The central dogma of molecular biology

states that DNA is a template for all RNA production

The process in which DNA is used as a template to produce RNA

transcription

What is the source of particular sequences of tRNA, mRNA and rRNA?

transcription from DNA

Polyribosomes are strings of ribosomes simultaneously

translating an mRNA strand

Polypeptides are created during which process?

translation

The process in which RNA is used to produce a protein

translation

Why must the genetic material be a stable molecule?

-so genetic material can pass from generation to generation - so replication can be accurate

Place the steps of DNA replication in the correct sequence

1. Unwinding the DNA double helix 2. Complementary base pairing 3. Joining nucleotides to the growing DNA strand

List the steps of translation in the correct order

1. initation 2. elongation 3. termination

List the events of termination in order

1. releases factor binds to stop codon 2. protein product is released 3. ribosomal subunits dissociate

List the sequential steps of DNA replication

1. the double helix is separated and unwound 2. DNA polymerase begins the copying process 3. DNA polyermerase meet at the termination region

If 30% of an organism's DNA is thymine, then

20% is guanine

How many different types of DNA nucleotides are there?

4

If each codon were composed of only 1 nucleotide, how many amino acids are possible?

4

The information stored within DNA must be read and is replicated in a

5' to 3' direction

The following rules explain what 1. the amount of A,T,G, and C in DNa varies from species to species 2. In each species the amount of A=T and the amount of G=C

Chargaff's Rules

Who first demonstrated that DNA was the genetic material

Avery, MacLeod, McCarty

Which bacteriologist jump-started the search For DNA in the 1920s

Frederick Griffith

Allow a cell to pick and choose which exons will go into a particular mRNA.

Introns

Which scientists determined that sugars and phosphates formed backbones in the DNA, discovered the double helix shape of deoxyribonucleic acid, determined that nucleotides were paired inside the double helix

James Watson and Francis Crick

Which scientist(s) figured out that the shape of a DNA molecule is a double helix?

Rosalind Franklin

T/F: is it possible to transfer genes from one type of organism to another type of organism?

True

When researchers began their work, they knew that genetic material must be

able to store information, stable, and undergo mutations

The two strands of DNA are held together by

hydrogen bonds

Type of RNA that transfers a particular amino acid to a ribosome during protein synthesis

tRNA

The original parent strand for which a complementary strand is made is called the

template strand

During this phase of translation, a completed polypeptide is released

termination

End of translation that occurs when a ribosome reaches a stop codon on the mRNA that is translating, causing release of the completed protein

termination