Pre-Ch 7 Pt 1 Reading

During translation initiation, the first codon to specify a particular amino acid is usually ______, which encodes the amino acid ______.

AUG; methionine

The mRNA sequence ______ codes for the amino acid sequence Met-Trp-Arg.

AUGUGGAGG

During transcription, the template strand of ______ contains the nucleotide sequence that is transcribed into RNA.

DNA

The instructions in ______ encode the information that a cell needs to produce proteins, which are vital to living things.

DNA

includes many genes

DNA molecule

_____ are portions of mRNA that get spliced together to form mature mRNA before translation occurs in eukaryotes.

Exons

True or false: Complementary base pairing rules state that in DNA, A pairs with G and T pairs with C.

False

During transcription, what reads the template strand within a gene and adds complementary bases?

RNA polymerase

The modern definition of gene is any sequence of DNA that is transcribed into

RNA.

What structure is the site of protein synthesis (translation)?

Ribosome

What contains about 6.4 billion base pairs and about 20,000 genes?

The human genome

Select all of the following that are true about the termination stage of translation.

The large and small ribosomal subunits separate. The polypeptide is released. A release factor protein prompts the release of the last tRNA from the ribosome.

Select all of the bases that can be present in DNA nucleotides.

adenine guanine cytosine thymine

Two strands of DNA within the double helix are said to be complementary to each other because ____ on one strand always pairs with thymine on the opposite strand, and cytosine on one strand always pairs with ____ on the opposite strand.

adenine; guanine

Gene expression is the production of

an RNA molecule or protein.

After transcription in eukaryotes, a modified nucleotide called the ______ is added to one end of the mRNA molecule, and a string of 100 to 200 adenines called the ______ is added to the opposite end of the mRNA molecule.

cap; poly A tail

discrete package of DNA coiled around proteins

chromosome

DNA is coiled around proteins to form discrete packages called

chromosomes.

In an RNA molecule, a(n) ______ is a genetic "code word" that corresponds to one amino acid.

codon

Messenger RNA contains ____ , which are triplets of bases that act as "code-words" corresponding to the ____ acid monomers that make up a polypeptide.

codons; amino

During transcription, a gene's DNA sequence is transcribed into a

complementary RNA molecule.

Select all of the following that are true about chromosomes.

contain DNA and proteins can be tightly coiled contain DNA with no known function

Within the DNA double helix, the so-called backbone is composed of ______ sugars alternating with phosphate groups.

deoxyribose

A DNA molecule consists of two intertwining strands of nucleotides that form a

double helix.

What are coding regions of eukaryotic mRNA that are translated?

exons

A(n) ______ is a sequence of DNA nucleotides that codes for a specific protein or RNA molecule.

gene

a sequence of nucleotides that codes for a specific protein or RNA molecule

gene

The human genome contains about 20,000-25,000 ____ scattered on its 23 pairs of ____ .

genes; chromosomes

all of the genetic material in a cell

genome

Put the following stages of translation into the correct order, beginning with the first stage at the top.

initiation elongation termination

A(n) _____ is a portion of mRNA that is about 1,000 nucleotides long and that is removed before translation.

intron

What process describes the removal of portions of mRNA after transcription to produce mRNA consisting of regions to be translated?

intron removal and splicing together of exons

In archaea and eukaryotes, a part of an mRNA molecule that is removed before translation is called a(n)

intron.

In eukaryotic cells, the mRNA is altered before it leaves the nucleus. After transcription, the ______ are removed from mRNA, and ______ are spliced together to form the mature mRNA.

introns; exons

Select all the types of protein modification that can occur after translation to produce a functional protein.

joining with other polypeptides cutting of the protein by enzymes

carries the information that specifies a protein

mRNA

A codon consists of three ______ that correspond to one ______.

mRNA bases; amino acid

In transcription, the genetic information in DNA is copied into a(n) ______ molecule, and in translation, the "message" in an mRNA molecule is translated into a(n) ______ sequence.

mRNA; amino acid

The start codon AUG of translation corresponds to ______.

methionine

The DNA double helix is made up of two strands of ______ monomers oriented in opposite directions.

nucleotide

Subunits called ______ are the building blocks of DNA.

nucleotides

The DNA double helix resembles a twisted ladder, where the rails of the "ladder" (also called the "backbones") are composed of alternating deoxyribose sugars and _____ groups joined by covalent bonds, while the rungs of the ladder are composed of A-T and G-C base pairs joined by ____ bonds.

phosphate; hydrogen

RNA ______ is the enzyme that builds the RNA chain during transcription.

polymerase

Some proteins are composed of multiple ______ that join together after translation.

polypeptides

What is produced during translation?

protein

Messenger RNA carries information that specifies the amino acid sequence of a

protein.

In the "central dogma," information flows from DNA to RNA to ______.

proteins

What type of RNA combines with proteins to form a ribosome?

rRNA

structural component of the ribosome

rRNA

A(n) _____ is composed of rRNA and proteins and is the site of protein synthesis.

ribosome

In eukaryotes, the cap and poly A tail on the mature mRNA protect the mRNA and ensure that ______.

ribosomes attach to the correct end of the mRNA for translation

When the ribosome reaches a UGA, UAG, or UAA codon on the mRNA, it halts because none of these codons has a corresponding tRNA. These three sequences are called _____ codons.

stop

What role does DNA play in the cell?

store instructions for making proteins

connector molecule that binds to an mRNA codon and to an amino acid

tRNA

Select all of the following that are used during translation.

tRNA mRNA ribosome

The DNA strand that is "read" during transcription is called the _________ strand.

template

Select all of the following that describe RNA.

the nitrogenous base uracil is used instead of thymine nucleotides contain the sugar ribose can catalyze chemical reactions can be single-stranded

In a process called ______, an RNA copy of a gene sequence on the DNA molecule is made.

transcription

During ____ , the information that is encoded in the DNA base sequence is copied into the complementary language of mRNA. Then, once the mRNA is produced and modified, a process called _____ uses that information to assemble a sequence of amino acids.

transcription; translation

In the "central dogma" describing the flow of genetic information from DNA to protein, DNA is copied to RNA in a process called ____ , and the information in RNA is used to direct the synthesis of a protein in a process called ____.

transcription; translation

In a process called ______, an RNA molecule is used to produce a protein.

translation

Select all of the following that can be components of RNA nucleotides.

uracil ribose guanine adenine