Biology 1 Exam 2

glycogen

A polysaccharide that is used for storing energy in human muscle and liver cells is __________.

DNA

A shortage of phosphorus in the soil would make it especially difficult for a plant to manufacture __________.

bacteriophage; DNA; protein

A virus that infects bacteria is called a __________, which is made up of the macromolecules __________ and __________.

that not all genes code for enzymes; some genes code for structural proteins such as keratin

An exception to the one gene-one enzyme hypothesis is __________.

chitin

At a conference, the speaker's grand finale was sautéing mealworms (insect larvae) in butter and serving them to the audience. They were crunchy (like popcorn hulls) because their exoskeletons contain the polysaccharide __________.

the genetic code is nearly universal

Bacteria can transcribe and translate human genes to produce functional human proteins because __________.

coupled transcription and translation

Because the bacterial cell's DNA is not surrounded by a nuclear envelope, __________ occur(s).

nutritional mutants; biochemical pathway

By bombarding the fungus Neurospora crassa with X-rays, Beadle and Tatum were able to study __________ and characterize enzymes in a __________.

energy storage and release

Carbohydrates are used in our bodies mainly for __________.

3' end; 3' end

DNA polymerase adds nucleotides to the __________ of the leading strands, and to the __________ of the lagging strands (Okazaki fragments).

replication fork; helicases

DNA replication begins at a site called the origin of replication, forming a bubble, which is followed by a __________, where parental strands are unwound by __________.

Helicases separate the two strands of the double helix, and DNA polymerases then construct two new strands using each of the original strands as templates.

Describe DNA replication

the addition of a 5ꞌ cap, a 3ꞌ poly-A tail, and the splicing out of introns

Eukaryotic processing of the primary transcript includes __________.

Microorganisms in their digestive tracts hydrolyze the cellulose to individual glucose units.

Generally, animals cannot digest (hydrolyze) the glycosidic linkages between the glucose molecules in cellulose. How then do cows get enough nutrients from eating grass?

RNA

Genetic information of eukaryotic cells is transferred from the nucleus to the cytoplasm in the form of __________.

at least 1,350

How many nucleotides are needed to code for a protein with 450 amino acids?

2

How many rings are in a structure of purines?

1

How many rings are in a structure of pyramidines?

3ꞌ (hydroxyl) end; DNA polymerase

In DNA replication, the next nucleotide is incorporated into the growing polymer at the __________ of the molecule by an enzyme called __________.

water

In a dehydration synthesis reaction, __________ is always formed as a by-product of the reaction.

DNA polymerase III; DNA polymerase I

In bacterial DNA replication of the lagging strand, __________ is required for the synthesis of a new DNA strand whereas __________ is required for removing the RNA primer and replacing it with DNA nucleotides.

signal peptide; signal-recognition particle

In eukaryotic cells, a __________ by a __________ targets a growing peptide to the endoplasmic reticulum.

double helix; running antiparallel

In living organisms, DNA exists as a __________ with the strand(s) __________.

promoter

In order for transcription to occur in that strand, there would have to be a specific recognition sequence, called a(n) __________, to the left of the DNA sequence indicated.

frameshift

Insertions and deletions are called __________ mutations.

trace elements

Macromolecules, the molecules of life, include all of the following except __________.

adenine and guanine

Nitrogenous bases are classified as either purines or pyrimidines. Examples of purines are __________.

they are all disaccharides

One characteristic shared by sucrose, lactose, and maltose is that __________.

groups of ribosomes

Polysomes may be defined as __________.

amino acid molecules

Protein molecules are polymers (chains) of __________.

nucleosomes; histones

Proteins that are involved in packaging the eukaryotic chromosome into "beads" called __________ are __________.

ribozymes

RNA molecules that function as enzymes are called __________.

short RNA primers; Okazaki fragments

Replication of the lagging strand of DNA is accomplished by repeatedly making __________ followed by 1,000-2,000 nucleotide segments called __________.

a single amino acid change; primary structure

Sickle-cell anemia is a disease that is caused by __________ in the __________ of the protein.

do not code for amino acids that allow a releasing factor to bind to the A site of the ribosome

Stop codons are unique because they __________.

a 1:2:1 ratio of; carbohydrates

Sugars are molecules that have __________ C:H:O and are called __________.

carbonyl (-C=O); hydroxyl (-OH)

Sugars have a(n) __________ group that interacts with a _________ group that forms ring structures when the dry molecule is placed in water.

three nucleotides code for a single amino acid

The "triplet code" refers to the fact that _________.

phosphate; hydroxyl

The 5ꞌ end of a DNA strand always has a free __________ group while the 3ꞌ end always has a free __________ group.

eukaryotic promoter; transcription factors; RNA polymerase II

The TATA box is a __________ that allows for the binding of __________ and __________.

hydrogen bonds

The bonds that hold tRNA molecules in the correct three-dimensional shape are __________.

gene expression

The process by which DNA directs the synthesis of proteins

molecules called chaperonins

The proper three-dimensional shape and folding of a protein is assisted by _________.

attach free nucleotides to the new DNA strand

The role of DNA polymerases in DNA replication is to __________.

hydrogen bonds; α helix; β pleated sheet

The secondary structure of a peptide backbone is stabilized by __________ forming either a(n) __________ or a(n) __________.

protein

The sequence of amino acids in a protein is called the __________ structure of the protein.

lipids

The sex hormones estrogen, progesterone, and testosterone belong to which class of molecules?

missense mutation

The sickle-cell β-globin mutation is an example of a __________.

part of a spliceosome

The structures called snRNPs are __________.

glycosidic linkages

The subunits (monomers) in cellulose are linked together by __________.

peptide

The tertiary structure of a protein includes all of the following interactions except _________ bonds.

hydrogen bonds between nucleotide bases

The two sugar-phosphate strands that form the rungs of a DNA double helix are joined to each other through __________.

liquid at room temp and have double bonds

Which of the following statements concerning unsaturated fats is true?

chaperonins

Which type of protein shields a newly forming protein from cytoplasmic influences while it is folding into its functional form?

Chargaff

Who discovered complementary base pairing?

Messelson and Stahl

Who discovered that DNA is a semi conservative replication?

Hershey and Chase

Who discovered that DNA was the genetic material?

Griffith

Who discovered that the transformation of bacteria results in a change of genotype and phenotype?

Watson and Crick

Who discovered the structure/model of DNA?

Beadle and Tatum

Who formulated the one gene-one enzyme hypothesis?

Franklin

Who was able to produced x-ray diffraction images of DNA, revealing that it was a double helix

x-ray crystallography

Wilkins and Franklin studied the structure of DNA using ___________________, a technique to examine molecules

water

__________ is always involved in hydrolysis reactions.

transcription

__________ is the synthesis of RNA using information in the DNA.

translation

__________ is the synthesis of a polypeptide using information in the mRNA.

Cellulose, a plant cell wall component

Give an example of a polymer

pathogenic; transform; nonpathogenic; pathogenic

Griffith showed that dead __________ cells __________ living __________ cells into living __________ cells.

a nitrogenous base, a pentose sugar, and a phosphate

The components of nucleic acids are __________.

deliver amino acids to their proper site during protein synthesis

The function of tRNA during protein synthesis is to __________.

the sequence of nucleotides along the length of the two strands of the DNA molecule

The information in DNA is contained in __________.

phospholipids

The lipids that form the main structural component of cell membranes are __________.

cholesterol

The molecule with four fused rings that is found in animal membranes and is the precursor of vertebrate sex hormones is __________.

1 error per 10,000,000,000 nucleotides

The overall error rate in the completed DNA molecule is approximately __________.

a covalent bond joining amino acids together to form a polypeptide

The peptide bond is __________.

covalent

The type of bond that forms to join monomers (such as sugars and amino acids) into polymers (such as starch and proteins) is a(n) __________ bond.

nonsense

The type of point mutation that results in a premature stop codon is called a _________ mutation.

topoisomerase

The unwinding of DNA at the replication fork causes twisting and strain in the DNA ahead of the fork, which is relieved by an enzyme called __________.

telomeres

What are repeating noncoding sequences at the ends of linear eukaryotic chromosomes

cytosine, uracil, thymine

What are the pyramidines?

In prokaryotic cells, the mRNA transcript is immediately available as mRNA without processing.

What is a key difference in gene expression between eukaryotic and prokaryotic cells?

Cleavage of a polypeptide into two or more chains

What is a post-translational modification of a polypeptide?

Bacteria have a single circular chromosome whereas eukaryotes have several linear chromosomes.

What is the major difference between bacterial chromosomes and eukaryotic chromosomes?

thymidine dimers; nucleotide excision repair enzyme

When __________ form after an exposure to ultraviolet (UV) light, a __________ can remove the damaged nucleotides and replace them with normal nucleotides.

hydrophobic

Which is the term for compounds that do not mix with water?

The three-nucleotide words of a gene are arranged in a nonoverlapping series on the DNA template strand.

Which of the following best describes the arrangement of genetic information in a DNA molecule?

RNA polymerase

Which of the following catalyzes the linkage between ribonucleotides to form RNA during gene expression?

RNA primer

Which of the following components is required for DNA replication?