Chapter 7 Connect SB

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What is the central dogma of molecular biology? -The flow of information is from DNA to RNA to protein. -RNA is used to make DNA, which is used to make protein. -Protein is used to make RNA, which is used to make DNA.

The flow of information is from DNA to RNA to protein.

The molecule that encodes all the instructions needed to produce a cell's component is _____ - Protein - RNA - DNA

DNA

The signal to end protein synthesis is indicated by sequences called ______ _____

stop codon

Which of the following are true statements about events that take place during the elongation phase of translation? CHOOSE ALL THAT APPLY -A peptide bond is formed between amino acids on adjacent tRNAs. -tRNAs carrying amino acids occupy the A-site and the P-site of the ribosome. -Amino acids are joined together by the enzymes RNA polymerase. -Elongation starts at the promoter sequence of the DNA. -Empty tRNAs leave the ribosome via the E-site.

-A peptide bond is formed between amino acids on adjacent tRNAs. -tRNAs carrying amino acids occupy the A-site and the P-site of the ribosome. -Empty tRNAs leave the ribosome via the E-site.

RNA polymerase can only add nucleotides to the ______ end of a growing strand. 3' 1' 5'

3'

The subunits of the 70S ribosome are ______. CHOOSE ALL THAT APPLY 30S 40S 60S 50S

30S & 50S

DNA is a simple structure made up of only____ - 3 different nucleotides - 4 different codons - 4 different nucleoli - 4 different nucleotides - 3 different codons

4 different nucleotides (A, T, C, G)

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

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

Which start codon is associated with the amino acid methionine? UAG AUG UAC UGA

AUG

Which of the following are nucleobases found in DNA? -adenine -cysteine -cytosine -alanine -uracil -guanine -thymine

Adenine, Cytosine, Guanine, Thymine

After the initiation of replication of a bacterial chromosome, the enzyme _______ adds nucleotides to a growing strand. DNA polymerase DNA ligase Primase RNA polymerase

DNA polymerase

True or false: A codon and an anticodon base pair with each other because they have identical nucleotide sequences.

FALSE (it's complementary)

A ______ is a sequence of nucleotides that usually codes for one functional protein. -codon -gene -chromosome -protein -triplet -genome

Gene

The amino acid that is placed first during translation in bacteria is _______. N-formylmethionine glycine methionine N-formylglycine

N-formylmethionine

The ______ sequence of DNA encodes the ______ sequence of protein. -protein; amino acid -amino acids; protein -nucleotide, amino acid -codon; nucleobase

Nucelotide; amino acid

The building blocks of DNA are called_____

Nucleotides

To start translation, the initiating tRNA occupies the _______ site; in subsequent steps the tRNAs enter through the _______ site. A; P E; A P; E A; E P; A

P; A

During DNA replication, why are primers necessary? -Primers stabilize the open helix during replication. -Primers provide DNA polymerase with the 3' end needed for synthesis. -Primase needs a primer to add DNA nucleotides to a growing strand. -Helicase won't function in the absence of a primer sequence.

Primers provide DNA polymerase with the 3' end needed for synthesis.

RNA polymerase binds to a ______ to begin transcription. initiator promoter terminator primer

Promoter

Transcription is carried out by an enzyme called

RNA polymerase

A replication fork is ______. -a site where one DNA strand serves as a template for the synthesis of an RNA transcript -a structure formed only during replication of a circular chromosome -a Y-shaped structure where both DNA strands are being replicated

a Y-shaped structure where both DNA strands are being replicated

During replication, DNA polymerases ______. -generate short stretches of RNA called primers to initiate replication -add nucleotides to the 3' end of the new DNA strand -unwind the DNA double helix at the replication fork -add nucleotides to the 5' end of the new DNA strand

add nucleotides to the 3' end of the new DNA strand

What are the roles of ribosomes in translation? CHOOSE ALL THAT APPLY -carrying information for the synthesis of a protein -aligning amino acids and catalyzing the formation of peptide bonds between them -bringing amino acids to the site of protein synthesis -Ribosomes detect sequences that indicate where translation should start and finish.

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

The function of a tRNA is to ______. -bring a ribosome to the amino acid -compose ribosomal subunits -carry the amino acids used in translation

carry the amino acids used in translation

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

circular; bidirectionally from one origin of replication

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

gene

The complete set of genetic information in an organism is referred to as the____

genome or dna

Which proteins are involved in the initiation of DNA replication? helicase DNA gyrase Sigma factor Rho factor DNA ligase

helicase and DNA gyrase

In DNA replication, ______ unwind the double helix at the replication fork, ______ synthesizes the short RNA primer, and DNA ______ adds nucleotides to the new chain.

helicases, primase, polymerase

The A-T and G-C base pairs in DNA are formed via ______ bonds. -hydrogen -ionic -covalent

hydrogen

The E-site of the ribosome ______. -is the site through which tRNAs gain entry -is responsible for the release of the tRNA -is where the growing polypeptide chain resides

is responsible for the release of the tRNA

The enzyme DNA ligase ______. -synthesizes Okazaki fragments -creates a primer to initiate DNA replication -separates the two DNA strands -joins adjacent DNA fragments

joins adjacent DNA fragments

Which strand is replicated continuously during DNA replication? the lagging strand only the leading strand only neither the leading nor lagging strands both the leading and lagging strands

leading strand only

The term polycistronic refers to ______. -DNA that has multiple origins of replication -mRNA that carries more than one gene -protein that has multiple polypeptides -tRNA that can bind more than one amino acid

mRNA that carries more than one gene

Cells synthesize proteins by translating the molecule called ______ RNA. -messenger -transfer -ribosomal

messenger

The ______ DNA strand is used as the template for RNA synthesis. plus (+) minus (-)

minus (-)

The base compositions of two DNA molecules is shown here.Molecule 1: 25% C, 25% G, 20 % A, and 30% TMolecule 2: 15% C, 15% G, 35 % A, and 35% T. Which of these two molecules is double-stranded? -molecule 1 only -neither molecules 1 nor 2 -both molecules 1 and 2 -molecule 2 only

molecule 2 only

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

nucleobases

To initiate replication of a DNA molecule, specific proteins must bind to a specific DNA sequence called the ______. -origin of replication -start sequence -beginning point

origin of replication

In a nucleotide, the 5' carbon has a _______ attached, while the 3' carbon has a bound _______. -carboxyl; amino -hydroxyl; phosphate -amino; carboxyl -phosphate; hydroxyl

phosphate; hydroxyl

The nucleotide sequence of RNA is the same as the _______ except that it contains ________ -plus strand; thymine instead of uracil -minus strand; uracil instead of thymine -plus strand; uracil instead of thymine -minus strand; thymine instead of uracil

plus strand; uracil instead of thymine

What enzyme synthesizes the short segments of RNA required to initiate DNA replication? primase helicase DNA polymerase DNA gyrase ligase

primase

To initiate DNA replication, short sequences of RNA are needed. These are called

primers

Transcription is initiated when RNA polymerase binds to a ______ region of the DNA. sigma polymerase promoter starter

promoter

Each subunit of the ribosome is made up of _____ and a type of RNA called _____

proteins; rRNA

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

rRNA or Ribosomes

The complex of enzymes and other proteins involved in DNA synthesis is known as the

replisome

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. -ribulose; one fewer -ribulose; one more -ribose; one fewer -ribose; one more

ribose; one more

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

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

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

translation

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: During protein synthesis, many copies of a specific protein can be synthesized from a single mRNA transcript.

true

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

true

What are the subunits of proteins and nucleic acids? -Proteins and amino acids -Carbohydrates and nucleotides -Amino acids and carbohydrates -Amino acids and nucleotides -Nucleic acids and nucleotides

Amino acids and nucleotides

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

DNA

Which of the following are involved in breaking and unwinding the DNA helix at the origin of replication? DNA gyrase, helicase and primase DNA gyrase and primase Primase and helicase Helicase and DNA gyrase

Helicase and DNA gyrase

Which of the following breaks the hydrogen bonds between two strands of DNA, causing them to denature (separate)? -Neutral pH -Cold temperature -Ultraviolet light -High temperature

High temperature

The two strands of the DNA helix are _____ , meaning they are oriented in opposite directions

anti-parallel

In general, RNA is a _______ molecule that is much _______ than DNA. -single-stranded circular; longer -double-stranded linear; shorter -single-stranded linear; shorter -single-stranded circular; shorter -single-stranded linear; longer

single-stranded linear; shorter

The genes for rRNA and tRNA are ______. -transcribed but not translated -translated but not transcribed -neither transcribed nor translated -transcribed and translated

transcribed but not translated

During DNA replication, the enzyme that seals the gaps between Okazaki fragments by forming a covalent bond between adjacent nucleotides is ______. DNA polymerase DNA strands. DNA gyrase DNA ligase Helicase

DNA ligase

Which of the following are removed by the process of splicing carried out in eukaryotic cells? introns transposons exons degenerate codons

Introns

A prokaryote transcript that carries one gene is called ______ RNA while a transcript that carries multiple genes is called ______ RNA.

monocistronic; polycistronic

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

The process of translation requires the three major structures. What are they? ribosomes sRNA DNA polymerase tRNA mRNA RNA polymerase

ribosomes, tRNA , mRNA

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

serve as a template for protein synthesis

Bacterial cells can control which genes are transcribed by producing different types of ______factors, each binding to a specific promoter.

sigma

mRNA is synthesized using DNA as a template. The mRNA fragment that results is referred to as the

transcript

RNA polymerases of archaea use proteins called ______ factors to recognize promoters.

transcription

A ______ is a sequence of nucleotides that usually codes for one functional protein. Multiple choice question. triplet -protein -chromosome -codon -genome -gene

Gene

Which unit of heredity includes the others? -Chromosome -Genome -Gene

Genome

Which of the following initiates translation? -RNA polymerase binds the DNA promoter. -Ribosomes assemble on the mRNA. -Amino acids are joined by peptide bonds.

Ribosomes assemble on the mRNA

Gene expression involves these two events: _____ (the information in DNA is copied into RNA) and _____ (the information in RNA is used to synthesize protein).

Transcription; translation

Exposing double-stranded DNA to high temperatures can lead to the separation of the two strands from each other. This process is called melting or

denaturing

True or false: An RNA transcript is synthesized in the 3' to 5' direction.

false

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

false ( its from DNA template)

The single-stranded DNA from which a new DNA strand is synthesized is referred to as the ______. -nucleotide -origin of replication -template -transcript -complement

template

When RNA polymerase reaches a sequence called a(n) _____ it falls of the DNA template and releases the newly-synthesized RNA.

termination

What purpose do Okazaki fragments serve during DNA replication? -to enable replication of the lagging strand -to help the helicase unwind the DNA helix -to enable replication of the leading strand -to form the template for the RNA primers

to enable replication of the lagging strand


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