ch 11
B DNA is a right-handed helix and the backbone is helical, whereas Z DNA is a left-handed helix and the backbone appears to zigzag slightly. Z DNA has the bases tilted relative to the central axis, where they are perpendicular to that axis in the B DNA. The two forms also differ in the number of Base Pairs per turn.
what are the structural differences between B DNA and Z DNA
hydrogen bonding between base pairs and base stacking hold the DNA strands together
what holds the DNA strands together
covalent bonds hold nucleotides together in an RNA strand
what types of bonds hold nucleotides together in an RNA strand
deoxyribose and phosphate form the backbone of a DNA strand
which components of nucleotides form the backbone of a DNA strand
c. deoxyribose, phosphate, and thymine
which of the following could be the components of a single nucleotide found in DNA a. deoxyribose, adenine, and thymine b. ribose, phosphate, and cytosine c. deoxyribose, phosphate, and thymine d. ribose, phosphate, and uracil
d. does all of the above.
A double-stranded region of RNA a. forms a helical structure b. obeyes the AU/GC rule c. may promote the formation of a structure such as a bulge loop or a stem-loop d. does all of the above.
a. the indentations where the bases are in contact with the surrounding water.
A groove in a DNA double helix refers to a. the indentations where the bases are in contact with the surrounding water. b. The interactions between bases in the DNA c. the sprial structure of the DNA d. all of the above
3.4
A single turn of the DNA double-helix has a length of _____nm.
nucleoside
A sugar, such as ribose or deoxyribose, attached to a base but not to a phosphate group is called a __________.
1. a fragment of DNA binds to the cell surface 2. it penetrates the cell membrane 3. it enters the cytoplasm 4. it recombines with the chromosome 5. the genes within the DNA are expressed (transcription and translation) 6. the gene products create a capsule. That is they are enzymes that synthesize a capsule using cellular molecules as building blocks.
After the DNA from type S bacteria is exposed to type R bacteria, list all of the steps that you think must occur for the bacteria to start making a capsule
hundred thousand
Although there is significant variation in the length of RNA molecules, they are generally much shorter than chromosomal sequences of DNA. In fact, they range from only a few _______ nucleotides long to several ______ nucleotides long.
water molecules.
Base stacking stabilizes the DNA double helix by excluding phosphodiester bonds. bases. water molecules. proteins.
backbone
Phosphate groups and sugar molecules make up the ___________ of a DNA strand.
A few hundred to several thousand nucleotides long
RNA molecules are, on average, much shorter than chromosomal DNA. Approximately, what is the size range of most RNA molecules? A few hundred to several thousand nucleotides long Tens of thousands to hundreds of thousands of nucleotides A few thousand to several tens of thousand nucleotides long Less than 200 nucleotides long
Hydrogen bonding between base pairs Hydrogen bonding between bases and backbone regions Base stacking
Select the factors that contribute to RNA stability. Hydrogen bonding between base pairs Hydrogen bonding between bases and backbone regions Bonding between DNA and RNA Base stacking
complementary single
Some parts of RNA molecules become double-stranded because the base sequences are___________. Other regions remain ______________-stranded.
Contain information Be transmissible Be able to be replicated Potential for variation
What are the criteria DNA must meet to fulfill its role? Contain information Be transmissible Be able to be replicated Store carbon and energy Potential for variation Be unchanging over time
Helical Double-stranded
What are the features of the structure that forms when short regions of RNA form base-pairs? Single-stranded Helical Planar (flat) Double-stranded
There are 12 base-pairs per turn The bases are tilted relative to the central axis of the molecule The helix is left-handed The sugar-phosphate backbone zig-zags slightly
What are the main structural features of DNA found in the Z conformation? There are 12 base-pairs per turn The bases are tilted relative to the central axis of the molecule The helix is left-handed There are 10 base-pairs per turn Hydrogen bonds between bases are perpendicular to the central axis of the molecule The sugar-phosphate backbone zig-zags slightly The helix is right-handed
The building blocks of a nucleotide are a sugar (ribose or deoxyribose), a nitrogenous base, and a phosphate group. In a nucleotide, the phosphate is already linked to the 5' position on the sugar. When two nucleotides are linked together a phosphate on one nucleotide forms a covalent bond with the 3' hydroxyl group on another nucleotide.
What are the three components of a nucleotide? With regard to the 5' and 3' positions on a sugar molecule, how are nucleotides linked together to form a strand of DNA?
At least one phosphate group A pentose sugar A nitrogenous base
What are the three parts of a nucleotide? Two fatty acid chains A molecule of glycerol An amino terminus A carboxylic acid group At least one phosphate group A pentose sugar A nitrogenous base
Two sugars on adjacent nucleotides in DNA or RNA
What does a phosphodiester bond link together? Opposing bases of the DNA double-helix The glycerol and the fatty acids of a trigylceride Amino acids in a polypeptide Two sugars on adjacent nucleotides in DNA or RNA
The bases of one strand can base-pair with the bases of the other strand
What does it mean for two strands of DNA to be complementary? The bases of one strand can base-pair with the bases of the other strand That there are no hydrogen bonds between the two strands The two strands have equal amounts of each of the four bases
A base attached to either a ribose or deoxyribose sugar
What is a nucleoside? A nucleotide that contains a pyrimidine as a base A ribose or deoxyribose attached to only a phosphate group A nucleotide that contains a purine as a base A base attached to either a ribose or deoxyribose sugar A base attached to a phosphate group only
A nucleoside with an attached phosphate group
What is a nucleotide? A nucleoside where the base is a purine A nucleoside with a deoxyribose sugar A nucleoside where the base is a pyrimidine A nucleoside with an attached phosphate group
Right-handed
What is the conventional "handedness" of the spiral in the DNA double helix? Right-handed Left-handed
The nucleotide
What is the fundamental repeating structural unit of DNA and RNA? Glycerol A glucose subunit The phospholipid The amino acid The nucleotide
Phosphodiester linkage
What is the name for the type of bond connecting two sugar molecules via a phosphate group in the backbone of DNA and RNA? Phosphoglycosidic linkage Glycosidic bond Peptide bond Phosphodiester linkage
Ribose
What is the sugar found in nucleotides used to make RNA? Deoxyribose Any hexose sugar Fructose Ribose Glucose
The bases occupy the major and minor grooves. Phosphates and sugars are found in the backbone. If a DNA-binding protein does not recognize a nucleotide sequence, it probably is not binding in the grooves, but instead is binding to the DNA backbone (i.e., sugar-phosphate sequence). DNA-binding proteins that recognize a base sequence must bind into the major or minor groove of the DNA, which is where the bases are accessible to a DNA-binding protein. Most DNA-binding proteins that recognize a base sequence fit into the major groove. By comparison, other DNA-binding proteins such as histones, which do not recognize a base sequence, bind to the DNA backbone.
What part(s) of a nucleotide (namely, phosphate, sugar, and/or base) is/are found in the DNA backbone? If a DNA binding protein does not recognize a specific nucleotide sequence, do you expect that it binds to the major groove, the minor groove, or the DNA backbone? Explain.
its base sequence
What structural feature allows DNA to store information?
A helical double-stranded structure
What structure forms when regions of RNA form base-pairs with themselves? A helical double-stranded structure A planar single-stranded structure A helical single-stranded structure RNA bases cannot base-pair with one another A planar double-stranded structure
Genetic material
What substance needs to meet the following criteria: ability to contain the information necessary to construct an entire organism; ability to be passed from parents to offspring; ability to be replicated; contains variation? Cellular organelles Genetic material Lipids Proteins
To determine the nature of the transforming principle and thus the nature of the genetic material
What was the purpose of the experiments of Avery, MacLeod, and McCarty? To show that DNA was a double-helix To refute the work of Griffith that they did not believe To determine the structure of DNA To determine the nature of the transforming principle and thus the nature of the genetic material
He found that a mixture of living rough-type and dead smooth-type bacteria killed mice. He found that living rough-type bacteria did not kill mice. He found that living smooth-type bacteria killed mice.
What were the main outcomes of the experiments performed by Griffith (1928)? He found that a mixture of living rough-type and dead smooth-type bacteria killed mice. He found that living rough-type bacteria did not kill mice. He found that dead smooth-type bacteria killed mice. He found that living smooth-type bacteria killed mice. He found that heat-treated viruses killed mice. He found that dead rough-type bacteria killed mice.
2 3
When adenine base pairs with thymine, _____, hydrogen bonds form, and when cytosine base pairs with guanine, ______, hydrogen bonds form.
DNA
When bacteriophage T2 infects an E. coli cell, which phage component enters the host cell? phage coat phage proteins RNA DNA
c. nucleotide, DNA strand, double helix, chromosome
When going from simple to complex, which of the following is the proper order for DNA? a. nucleotide, double helix, DNA strand, chromosome b. nucleotide, chromosome, double helix, DNA strand c. nucleotide, DNA strand, double helix, chromosome d. chromosome, nucleotide, DNA strand, double helix
antiparallel
When one strand of DNA in a double helix has the chemical polarity 5' to 3', and the other, running in the opposite direction, has the chemical polarity 3' to 5', then it would be said that the two strands are .
complementary.
When the bases in one strand of DNA can hydrogen bond exactly with the bases in another strand of DNA, then the two strands of DNA are said to be analogous. complementary. identical. opposite.
1953
When was the structure of the DNA double-helix discovered? 1953 1974 1928 1982 1961
phosphate groups deoxyribose sugars
Which components make up the backbone of a DNA strand? purine bases pyrimidine bases ribose sugars phosphate groups deoxyribose sugars
d. all of the above are features of the DNA double helix
Which of the following is not a feature of the DNA double helix a. it obeys the AT/GC rule b. The DNA strands are antiparallel c. The structure is stabilized by base stacking. d. all of the above are features of the DNA double helix
DNA strands form a helical structure Bases on opposite strands are hydrogen bonded together
Which of the statements below correctly describe the structure of a DNA double helix? DNA strands form a helical structure Bases on opposite strands are hydrogen bonded together The two strands of DNA are held together by phosphodiester bonds between bases on opposite strands The bases in the DNA molecule point outwards, away from the central axis of the molecule It contains one strand of DNA
stacking
Within a DNA double helix, the bases are oriented so that the flattened regions are facing each other. This arrangement is called base ______
d. both b and c are correct
a key difference between the nucleotides in DNA and those in RNA is that a. a DNA has a phosphate but RNA does not b. DNA has deoxyribose, but RNA has ribose. c. DNA has thymine, but RNA has uracil. d. both b and c are correct
a. B DNA is right-handed, whereas Z DNA is left-handed
a keye difference between B DNA and Z DNA is that a. B DNA is right-handed, whereas Z DNA is left-handed b. B DNA obeys the AT/GC rule, whereas Z DNA does not c. Z DNA allows ribose in its structure, whereas B DNA uses deoxyribose d. Z DNA allows uracil in its structure, whereas B DNA uses thymine
c. A and T, and G and C
chagraff's analysis of the base composition of DNA is consistent with base pairing between a. A and G, and T and C b. A and A, G and G, T and T, C and C c. A and T, and G and C d. A and C, and T and G
Yes, a stem-loop could form, as long as there are sequences that are complementary and antiparallel to each other. These would be similar to the complementary double-stranded regions observed in RNA molecules.
could a single-stranded DNA form a stem-loop structure? Why or why not?
the major and minor grooves are the indentations where atoms in the bases are in contact with water in the cellular fluid. The major grove is wider than the minor groove.
describe the major and minor grooves
the structure is a phosphate group connecting two sugars at the 3' and 5' positions, as shown in Figure 11.7
draw the structure of a phosphodiester linkage
d. all of the above
evidence that led to the discovery of the DNA double helix includes a. the determination of structures using ball-and-stick models b. the X-ray diffraction data of Franklin c. the base composition data of Chargaff d. all of the above
information transmission replication variation
genetic material criteria
3'-CCGTAATGTGATCCGGA-5'
if one DNA strand is 5'-GGCATTACACTAGGCCT-3', what is the sequence of the complementary strand?
d. allow the conversion of type R bacteria into type S bacteria.
in the experiment of avery, mcleod, and mccarty, the addition of RNase or protease to a DNA extract a. prevented the conversion of type S bacteria into type R bacteria b. allowed the conversion of type S bacteria into type R bacteria c. prevented the conversion of type R bacteria into type S bacteria d. allow the conversion of type R bacteria into type S bacteria.
A hydrogen bonds with U and G hydrogen bonds with C
what are the base-pairing rules for RNA
phosphate base deoxyribose
DNA nucleotides have three main parts to their structure: at least one _________ group; a nitrogenous ________; and a 5 carbon sugar called ___________.
The structure is shown in Figure 11.5. You begin numbering at the carbon that is to the right of the ring oxygen and continue to number the carbon atoms in a clockwise direction. Antiparallel means that the backbones are running in the opposite direction. In one strand, the sugar carbons are oriented in a 3' to 5' direction, while in the other strand they are oriented in a 5' to 3' direction.
Draw the structure of deoxyribose and number the carbon atoms. Describe the numbering of the carbon atoms in deoxyribose with regard to the directionality of a DNA strand. In a DNA double helix, what does the term antiparallel mean?
coat DNA
During infection by the T2 bacteriophage, the protein-containing phage ___________ remains attached to the outside of the E. coli bacterium, while the _________ enters the cytoplasm of the cell.
c. nucleotide, DNA strand, double helix, chromosome
Going from simple to complex, which of the following is the proper order for the structure of DNA a. nucleotide, double helix, DNA strand, chromosome b. nucleotide, chromosome, double helix, DNA strand c. nucleotide, DNA strand, double helix, chromosome d. chromosome, nucleotide, DNA strand, double helix
phosphorus; sulfur
Hershey and Chase were able to track whether the viral DNA or the viral protein entered the host bacterium because they were able to label the viral DNA with radioactive ______ and the viral protein with radioactive ______. sulfur; phosphorus phosphorus; sulfur
DNA nucleotides contain deoxyribose DNA nucleotides never contain uracil DNA nucleotides may contain thymine
How can nucleotides found in DNA be discriminated from those found in RNA? DNA nucleotides lack a 3' hydroxyl group DNA nucleotides contain deoxyribose DNA nucleotides never contain uracil DNA nucleotides may contain thymine DNA nucleotides are never purines DNA nucleotides are never pyrimidines DNA nucleotides contain ribose
RNA nucleotides don't contain thymine RNA nucleotides contain ribose RNA nucleotides may contain uracil
How can nucleotides found in RNA be discriminated from those found in DNA? RNA nucleotides don't contain thymine RNA nucleotides contain ribose RNA nucleotides may contain uracil RNA nucleotides are never purines RNA nucleotides are never pyrimidines RNA nucleotides lack a 3' hydroxyl group
They labeled the DNA with radioactive phosphorous and the protein with radioactive sulfur.
How did Hershey and Chase discriminate between DNA and protein in their experiments to show that DNA was the genetic material of bacteriophage T2? They labeled the DNA with radioactive sulfur and the protein with radioactive phosphorus. The tracked the movement of the DNA using a microscope. They inferred that the viral protein would take longer to enter the host bacterium than the viral DNA and did timed infections. They labeled the DNA with radioactive phosphorous and the protein with radioactive sulfur.
3.4 nm (involves 10 base pairs)
How long is a single turn of the DNA double-helix? 10 nm 34 nm 3.4 nm 0.34 nm
Two; three
How many hydrogen bonds form between adenine and thymine, and between guanine and cytosine? Four; three Three; four Two; three Two; four Three; two
TAGGATCTAT
If one strand of DNA has the sequence 5' ATCCTAGATA 3', the sequence of the bases on the complementary strand of DNA would be 3'______________5'.
3' TACGATGTAT 5'
If one strand of DNA has the sequence 5'ATGCTACATA3', what would be the sequence of the bases on the complementary strand of DNA? 3' TACGATGTAT 5' 3' UACGAUGUAU 5' 3' ATGCTACATA 5' 5' ATGCTACATA 3' 5' TACGATGTAT 3'
smooth rough died
In 1928, Frederick Griffith did a number of experiments to identify the "transforming principle". Notably, he found that when living ___________-type Streptococcus pneumoniae bacteria were injected into mice, they died. Also, he showed that when living _____________-type Streptococcus pneumoniae were mixed with heat-treated smooth-type Streptococcus pneumoniae and injected into mice, the mice ____________.
a. a 5' carbon in an adjacent nucleotide
In a DNA strand, a phosphate connects a 3' carbon atom in one nucleotide to a. a 5' carbon in an adjacent nucleotide b. a 3' carbon in an adjacent nucleotide c. a base in an adjacent nucleotide d. none of the above
Most of the 32P was found inside the bacteria
In their studies of the transforming principle, Hershey and Chase when they incubated 35S or 32P labeled bacteriophages with E. coli. After infection, they determined which isotope remained outside and which entered the cells. Which outcome indicated that DNA was the transforming principle? Most of the 35S was found inside the bacteria Most of the 32P was found inside the bacteria Most of the 32P was detected outside the bacteria Most of the 35S and most of the 32P were detected inside the bacteria
Most of the 35S was detected outside the bacteria
In their studies of the transforming principle, Hershey and Chase when they incubated 35S or 32P labeled bacteriophages with E. coli. After infection, they determined which isotope remained outside and which entered the cells. Which outcome indicated that protein was not the transforming principle? Most of the 32P was found outside the bacteria Most of the 35S and most of the 32P were detected outside the bacteria Most of the 35S was detected outside the bacteria Most of the 35S was found inside the bacteria
the structure and function of DNA.
Molecular genetics studies the structure and function of DNA. heredity. the structure and function of proteins.
2, hydrogen
The structure of DNA that Crick and Watson proposed has __________ (number) strands of DNA that are wrapped around each other to form a double helix. The DNA bases of each strand of DNA point towards the central axis of the molecule and are held together by _________ bonds.
1953
The structure of the DNA double-helix was discovered in the year _____
molecular genetics.
The study of the structure of DNA and how it functions is called cytology. evolutionary genetics. proteomics. molecular genetics.
ribonucleic acid deoxyribonucleic
The two types of nucleic acids are known as ______ and ______. amino acid ribonucleic acid deoxyribonucleic acid linoleic acid fatty acid
uracil guanine
There are several cellular processes that involve the formation of double-stranded RNA. When double-stranded RNA forms, the base A can hydrogen bond with the base _________ and the base C can base pair with the base ________
left 12
There are two conformations of DNA: B DNA and Z DNA. In Z DNA, the helix has a __________-handed twist, the bases are not quite perpendicular to the central axis of the molecule, there are ________ base-pairs per turn of the helix, and rather than being a constantly twisting strand, the sugar-phosphate backbone zigzags slightly.
model
To help them understand the data that Rosalind Franklin obtained by X-ray diffraction studies, Crick and Watson used molecular ________ to develop representations of the DNA double-helix.
Molecular modeling
To work out the structure of the DNA double-helix, Crick and Watson used several strategies. First, they viewed data obtained by Rosalind Franklin who performed X-ray diffraction of crystals of DNA. What was the other main approach they used? Genetic manipulation of mice Molecular modeling Polymerase chain reaction Culturing cells in dishes Western blotting
right
The conventional direction of the spiral in the DNA double helix is ______-handed.
cytosine guanine
DNA sequences with a high proportion of base-pairs between __________ and __________ are most stable.
G:C base pairs
DNA sequences with which kind of base pairs have higher stability? G:T base pairs C:A base pairs A:T base pairs G:C base pairs
phosphate
The difference between a nucleoside and a nucleotide is that the nucleotide has one or more ______ groups attached to the sugar and the nucleoside does not. nitrogen methyl ribose phosphate
transforming substance
The experiments of Avery, MacLeod, McCarty were trying to determine the _____ in the experiments by Frederick Griffith. transforming substance lethal substance mutating substance
The structures are similar in that RNA and DNA double helices are helical and antiparallel and base pairing is due to complementarity. The shapes of the helices are slightly different with regard to the number of base pairs per turn. Another difference is that RNA base pairing involves A with U, whereas DNA base pairing involves A with T.
Compare the structure of deoxyribose and ribose and number the carbon atoms. Describe the numbering of the carbon atoms in deoxyribose with regard to the directionality of a DNA strand. In a DNA double helix, what does the term antiparallel mean?
600
Consider a piece of double-stranded DNA in which each strand of the helix has 1,800 nucleotides. If the piece of double-stranded DNA had a total of exactly 600 deoxycytidine monophosphate nucleotides, how many deoxyguanosine monophosphate nucleotides would be present? [When a nucleoside triphosphate is incorporated into DNA, it loses two phosphates to form a monophosphate.] 800 1400 600 400
1400
Consider a piece of double-stranded DNA that is 2,000 base pairs in length. If this piece of DNA had a total of 600 deoxyadenosine monophosphate nucleotides, how many deoxycytidine monophosphate nucleotides would be present? [When a nucleoside triphosphate is incorporated into DNA, it loses two phosphates to form a monophosphate.] 800 1200 1400 600
Pairing a purine with a pyrimidine ensures a consistent diameter of the helix.
The AT/GC base-pairing rule requires that the purines (A and G) always base-pair with the pyrimidines (T and C). Why is this? Pairing a purine with a pyrimidine prevents mutations. Pairing a purine with a pyrimidine ensures a consistent diameter of the helix. Pairing a purine with a pyrimidine ensures that proteins with accurate sequences will be produced.
B
The DNA double helix can adopt different types of structures. The most predominant form of DNA found in cells is called ______ DNA. A Z B V
B
The DNA double helix can adopt two conformations. The conformation that is most abundant in living cells is called ______ DNA
B DNA Z DNA
The DNA double helix can form two types of structures. What are those two types of structures? B DNA beta sheet Z DNA beta barrel
G=32%, C=32%, A=18%, T=18%
The amount of G plus C in an organism's DNA is 64% of the total base content of that DNA. What are the percentages of A,T,G, and C?
purine pyrimidine
The constant diameter of the double helix is ensured because hydrogen bonding is always between a ____ (A or G base) and a ________ (T or C base).
