Chapter 7

what is the central dogma of molecular biology?

DNA -> RNA -> Protein

Antibacterial medications called fluoroquinolone target which of the bacterial enzymes?

DNA gyrase

Which two proteins bind to the origin of replication leading to initiation?

DNA gyrase, helicases

In RNA, Adenine pairs with

Uracil

What are the roles of ribosomes in translation? Multiple select question. a. aligning amino acids and catalyzing the formation of peptide bonds between them b. bringing amino acids to the site of protein synthesis c. Ribosomes detect sequences that indicate where translation should start and finish. d. carrying information for the synthesis of a protein

a. aligning amino acids and catalyzing the formation of peptide bonds between them c. Ribosomes detect sequences that indicate where translation should start and finish.

A tRNA has a(n)_______, a group of three nucleotides that is complementary to the codon of the mRNA.

anticodon

During what process is the information in mRNA used to make a protein? a. replication b. transcription c. translation d. transduction

c. translation

inducible enzymes usually function in

catabolic pathways; their synthesis is induced by a chemical signal

genome is interchangeable with

chromosome

Enzymes of glycolysis are _____

constitutive

sigma factor

controls the binding of RNA polymerase to the promoter

Some microorganisms can alter characteristics of certain surface proteins, allowing them to avoid detection by the host's immune system. This phenomenon is called ______. Multiple choice question. a. natural selection b. phase variation c. quorum sensing d. antigenic variation

d. antigenic variation

All of the following are examples of means by which microorganisms can respond to changing environmental conditions EXCEPT ______. Multiple choice question. a. quorum sensing b. signal transduction c. two-component regulatory system d. production of different ribosomes

d. production of different ribosomes

RNA polymerase

enzyme that synthesis RNA using one strand of DNA as a template

DNA Polyermerase

enzyme that synthesizes DNA, using an existing stand as a template to make a new complementary strand

What is the difference between a DNA sugar and RNA sugar?

in RNA, it has an oxygen atom that deoxyribose lacks.

The single-stranded DNA from which a new DNA strand is synthesized is referred to as the ______.

template

which antibiotics interfere with the function of the bacterial 70S ribosome?

tetracycline and azithromycin

what is a cells fundamental aspect of gene expression regulation?

the cell's ability to quickly destroy the mRNA

Gene

the functional unit of a genome; it encodes a product, most often a protein

translation

the process by which the information carried by mRNA is used to synthesize the encoded protein

transcription

the process by which the information encoded in DNA is copied into RNA

signal transduction

the process that transmits information from outside a cell to the inside. It allows cells to monitor and react to environmental conditions.

phase variation

the routine switching on and off of certain genes

transfer RNA (tRNA)

type of RNA molecule involved in interpreting the genetic code; each tRNA molecule carries a specific amino acid

A and T are held together by how many hydrogen bonds?

2

How many replication forks are formed from opening a section of a circular DNA molecule as part of DNA replication?

2

The genetic code includes _______ stop codon(s).

3

The two ends that are in every DNA strand are:

3' end and 5' end

G and C are held together by how many hydrogen bonds

3, have a slightly stronger attraction than that of A-T pair

a set of ____ nucleotides ecode for a ____

3, specific amino acid

Why is regulation of gene expression important? Multiple choice question. A. A cell does not need all of its encoded proteins at the same time. B. The cell needs a "rest period" when making protein. A cell can only express certain genes C. at any one time.

A. A cell does not need all of its encoded proteins at the same time.

In general, the chromosome of a bacterial cell is a _______ DNA molecule that is replicated _______. A. circular; bidirectionally from one origin of replication B. linear; bidirectionally from multiple origins of replication C. linear; bidirectionally from one origin of replication D. circular; bidirectionally from multiple origins of replication E. circular; unidirectionally from one origin of replication

A. circular, bidirectionally from one origin of replication

Which of the following is found in all DNA nucleotides? Multiple choice question. A. the same sugar, but different phosphates and nucleobases B. the same nucleobase and phosphate, but different sugars C. the same sugar and phosphate, but different nucleobases D. the same nucleobase, but different phosphates and sugars

C. the same sugar and phosphate, but different nucleobases

In DNA....guanine is paired with_________

Cytosine

An essential macromolecule that encodes all of the information needed by a cell to synthesize its components is

DNA

what step must be done before cell division?

DNA replication

which would result in more long-term consequences to a cell or its progeny: a mistake made during DNA synthesis or RNA synthesis

DNA synthesis

True or false: An RNA transcript is a strand of RNA copied from an RNA template.

False, an RNA transcript Is a strand of RNA copied firm DNA template

What is the outcome if translation begins at the wrong reading frame?

Generally, a non-functional protein is made.

antigenic variation

Pathogens alter their surface antigens (and antibodies are rendered ineffective)

Transcription is carried out by an enzyme called _______ _________

RNA polymerase

What enzyme binds to a DNA promoter region to initiate transcription?

RNA polymerase

How is transcription initiated?

RNA polymerase binds to the promoter sequence

quorum sensing

The ability of bacteria to sense the presence of other bacteria via secreted chemical signals.

in DNA adenine pairs with

Thymine

True or false: Regulating gene expression involves controlling mRNA synthesis and rapidly destroying mRNA transcripts.

True

Messenger RNA (mRNA)

Type of RNA molecule translated during protein synthesis

In DNA, what does each nucleotide consist of?

a 5-carbon sugar(deoxyribose), a phosphate group, and 1/4 nucleobases

a string of amino acids make...

a protein

codon

a series of three nucleotides that code for a specific amino acid

Which of the following describes the termination of translation? Multiple choice question. a. A stop codon is reached and the polypeptide is released from the ribosome. b. tRNA leaves the E-site on the ribosome. c. A terminator sequence is reached and mRNA is released from the DNA template.

a. A stop codon is reached and the polypeptide is released from the ribosome

Which of the following initiates translation? Multiple choice question. a. Ribosomes assemble on the mRNA. b. Amino acids are joined by peptide bonds. c. RNA polymerase binds the DNA promoter.

a. Ribosomes assemble on the mRNA.

Enzymes involved in essential metabolic pathways, such as glycolysis, are usually ______. Multiple choice question. a. constitutive b. repressible c. inducible

a. constitutive

Information encoded in genetic material is translated into proteins based on rules known as the ______. Multiple choice question. a. genetic code b. central dogma c. RNA world hypothesis

a. genetic code

An mRNA sequence has ______. a. three potential reading frames, but only one is typically used for translation b. only a single reading frame, which must be used for translation c. three potential reading frames, and any one can be used for translation

a. three potential reading frames, but only one is typically used for translation

what are the nitrogenous bases?

adenine, thymine, guanine, cytosine, uracil

Repressible enzymes usually function in ____________ pathways.

anabolic pathways, routinely produced and can be turned off

How many codons are used to specify the 20 possible amino acids? Multiple choice question. a. 20 b. 61 c. 64 d. 3 e. 30

b. 61

DNA replication is described as being ______, because each new DNA molecule formed by the process has one original strand and one newly synthesized strand. Multiple choice question. a. antiparallel b. semiconservative c. conservative d. complementary

b. semiconservative

The function of mRNA is to ______. Multiple choice question. a. compose ribosomal subunits b. serve as a template for protein synthesis c. bring amino acids to the ribosome for transcription

b. serve as a template for protein synthesis

Which type of RNA carries amino acids during protein synthesis? a. rRNA b. tRNA c. mRNA

b. tRNA

What is the proper order of the following events in the expression of a eukaryotic gene?1. translation2. RNA processing3. transcription Multiple choice question. a. 2, 3, 1 b. 1, 3, 2 c. 3, 1, 2 d. 3, 2, 1 e. 1, 2, 3

d. 3, 2, 1

The lac operon only functions when ______ is present in the medium but ______ is absent from the medium. Multiple choice question. a. lactose; maltose b. glucose; allolactose c. glucose; lactose d. lactose; glucose

d. lactose; glucose

A ______ is a sequence of nucleotides that usually codes for one functional protein.

gene

The functional unit of a genome that codes for a product is a(n)

gene

What process occurs after DNA replication?

gene expression

What type of bond holds nucleobases together in DNA?

hydrogen bonds

What type of bond hols the tRNA three dimensional shape?

hydrogen bonds

replication fork

in DNA synthesis, the site at which the double helix is being unwound to expose the single strands that can function as templates fro DNA synthesis

Eukaryotic cells can regulate the levels of mRNA by destroying specific RNA transcripts through a process known as RNA ________, abbreviated RNAi.

interference

_______ is transcribed from a DNA template and translated during protein synthesis

mRNA

Separating two strands of DNA is called:

melting or denaturing

What is the most common product of an encoded gene?

most commonly a protein

Eukaryotic cells have ____ origins of replication and bacteria have _____

multiple, 1

All DNA nucleotides contain the same deoxyribose and phosphate group, but different

nucleobases, nitrogenous bases

terminator

nucleotide sequence t which RNA synthesis stopes; the RNA polymers falls off the DNA template and releases the newly synthesized RNA

promoter

nucleotide sequence to which RNA polymerase binds to start transcription

To initiate replication of a DNA molecule, specific proteins must bind to a specific DNA sequence called the ______.

origin of replication

The ability of Escherichia coli to randomly turn on or off the the production of attachment pili is an example of ______. Multiple choice question. a. quorum sensing b. two-component regulatory system c. antigenic variation d. phase variation

phase variation

polypeptide vs protein

polypeptide is a string of amino acids, and a protein is a functional molecule made up of one or more polypeptides

Eukaryotic mRNA is first synthesized as an immature transcript called _____ _____. It has to be processed significantly before it forms mature mRNA.

pre-mRNA

What enzyme synthesizes the short segments of RNA required to initiate DNA replication?

primase

alternative sigma factors

recognize different sets of promoters to control expression of specific groups of genes

Cells duplicate their DNA before cell division using a process called DNA _______

replication

A _____ _______is a Y-shaped point on a replicating DNA molecule where the DNA polymerases are synthesizing new strands of DNA.

replication fork

The pentose sugar in RNA is______, while in DNA the pentose sugar is_______

ribose, deoxyribose

RNA contains the sugar _____, which differs from its DNA counterpart by possessing _____ oxygen atom.

ribose, one more

In bacteria, the ribosome starts to assemble at a sequence in mRNA called the ___- ____site. Translation begins at the first AUG codon after that.

ribosome- binding

Protein synthesis involves ________, which align amino acids and catalyze peptide bond formation between them.

ribosomes

Ribosomal RNA (rRNA)

structure that facilitates the joining of amino acids during translation; composed of ribosomal RNA (rRNA) and protein

genomics

study of whole genomes, including genes and their functions

The process of translation requires the three major structures. What are they?

tRNA, mRNA, & ribosomes

DNA replication

the duplication of a DNA molecule

A codon contains how many nucleotides?

three

Information is passed from the environment into the cell by a process known as signal ______

transduction

_______ is the process of decoding the information carried by mRNA to synthesize a protein.

translation

which two events are involved in gene expression?

translation and transcription

True or false: DNA replication must occur prior to cell division to ensure that each new cell has a complete genome.

true

True or false: Several codons code for the same amino acid, which is called the redundancy of the code. Because of redundancy, the genetic code is said to be degenerate.

true