Bio111 online CH. 11 – Flashcards

Unlock all answers in this set

Unlock answers
question
List the four key criteria that the genetic material must fulfill
answer
Information, Replication, Transmission, and variation
question
Information
answer
The genetic material must contain the information necessary to construct an entire program
question
Replication
answer
The genetic material must be accurately copied
question
Transmission
answer
The genetic material can ve passed from parent of sprain. It must be passed form cell to cell. During the process of cell division
question
Variation
answer
differences in the genetic material must account for the known variation within each species and among different species.
question
Analyze the results of the experiments that identified the DNA as the genetic material.
answer
When Type R bactei awith heat- killed type S vacteria and then injected them into a moucse- the mouse died. The blood from the dead mouse contained living types S bacteria Transfomration was responsible fro this phenomeon. The transformed bacteria had acquired the informations to make a capsule from the heat-killed cells. For the transformed bacteria to proliferate and therby kill the moust, the substace conferreing the abliluty to make a capsuled must be replicasted and then trasnmiteed from mother to daughter cells during cell division.
question
outiline the structrusal featurs of DNA at five levels of complexity.
answer
At five levels of complexity DNA has nucleotides and a strnd and double heloix and a genome.
question
Nucleotides
answer
the building blocks of DNA
question
The second complexity OF DNA: strand
answer
A strand of DNA is formed by the covalent linkaged nucleotides in a linear manner.
question
The third complexity of DNA: Double helix
answer
Two strands of DNA hydrogen-bond with each other form a Double helix. In a DNA double helix, two DNA strands are twisted together to form a structure that resembles a spiral staircase.
question
The fourth complexity of DNA
answer
In living cells, DNA is associated with an array of different proteins to form chromosomes. The association of proteins with DNA organizes the long strands into a compact structure.
question
The Fifth complexity of DNA
answer
A genome is the complete complement of an organism's genetic material. For example, the genome of most bacteria is a single circular chromosome, whereas eukaryotic cells have DNA in their nucleus, mitochondria, and chloroplast
question
purines
answer
Adenine and guanine have a double-ring structure, due to differences in their structures
question
pyrimidines
answer
Thymine, cytosine, and uracil have single-ring structure. Adenine guanine, and cytosine are found in both DNA and RNA.
question
adenine (A)
answer
A nucleotide base in both DNA and RNA. A double ring structure.
question
Guanine ( G)
answer
In both DNA and RNA, this has a double-ring structure. A part of the purines.
question
Thymine ( T)
answer
Only found in DNA. A single ring structure apart of the pyrimidine.
question
Cytosine (C)
answer
A single ring structure in both DNA and RNA
question
Uracil ( U)
answer
a single ring structure found in RNA.
question
Discuss and interpret the work of Franklin; Chargaff; and Watson and Crick
answer
Franklin-> made a mark advance in X-ray diffraction techniques involving DNA, The diffraction pattern of DNA fibers produced by him who suggested a helical structure with a diameter that is relatively univorm an too wied e to be a single-stranded helix. Chargaff-> Analyzed the base composition fo DNA tha t was isolated form many different species. His experiments consistently showed that the amount of adenine in each sample was similar to the amount of thy mind, and the amount of cytosine was similar to the amount of guanine. Watson and Crick-> They realized that the hydrogen bonding of adenine to thymine was structurally similar to that of guanine to cytosine. In both cases, a purine base ( A or G) bonds with a pyrimidine base ( T or C). With an interaction between A and T and between G and C , the ball- and-stick model showed that the two strands would form a double helix structure in which all atoms would fit together properly.
question
Discuss and interpret the experiments of Meeselon and Stahl
answer
Meelson and Stahl devised a way to determine between the three mechanisms. They came up with Isotope labeling. Nitrogen, which is found in DNA, occurs in a common light from and a rare heavy form.
question
daughter strands
answer
The two newly made strands
question
parental strands
answer
the original strands
question
semiconservative mechanism
answer
the double stranded DNA is half conserved following the rplications precscess so the new double stranded DNA contains one parental strand and one daughet strand.
question
conservative mechanism
answer
Both parental strnads of DNA remain together folowin gDNA replications. THe oringianl arrangement fo parental strands is completely conserved, nad the tweo newly made daught er starnds are aslo tgoheer folowin replication
question
dispersive mechanism
answer
proposed that segments of parental DNA and newly made DNA are interspersed in both strands following the replication process.
question
Describe the double stranded structure of DNA an explain how the AT/GC rule underlies the ability of DNA to replicate semi conservatively .
answer
Individual molecules have access to the template strands in a region called the replication fork. Individual nucleotides hydrogen bond to the template strands according the AT/ GC rule: an adenine base in one strand bonds with a thymine base in the opposite strand or a guanine base bonds with a cytosine. Next, a covalent bond is formed between the phosphate of one nucleotides and the sugar to the previous nucleotide.
question
template strands
answer
the two complementary strands of DNA separate and serve. Also called parental strands, for the synthesis of daughter strands of DNA.
question
Describe how the synthesis of new DNA strands at an origin of replication
answer
.The DNA strands unwind. DNA replication proceeds outward form two relpleication forks. vai bidirectional replication. The number fof origins of replication varie amoung different organismis. Bidirectional replication starts arthe origin of replication sand preceeds until the new starnds meet on the opposite side of the chromosome.
question
origin of replication
answer
a site withian a chromsosomethat servas a s astarting point of DNA replication.
question
bidirectional replicatoin
answer
a process that forms two replication fork
question
replication fork
answer
DNA proceeds outward from the two of these.
question
List the functions of helicase, topisomerase, asingel strand binding protein, priamse, an DNA polymerase at he replication fork.
answer
tHE strands of a deoul ehelix must separate, and the resulting formk must move. An origin of replication serves as a site where theis sepration initially occurs. The strand separtaaiton at ehac fork the moves outward from the origin via the action of an enzyme
question
DNA helicase
answer
The enzyme that separates DNA the fork. It binds to one of the DNA strand s and travels in the 5' to 3' direction toward the fork.
question
topoisomerase
answer
helps untwist the strands. The actions of DNA helicase generates additional coiling just ahead of the replication fork that is alleviate by another enzyme.
question
Outline the key difference between the synthesis of the leading and lagging strands
answer
The synthesis of strand always the beings with a n RNA primer and the new DNA is made in the 5' to 3' direction. the manner in which the two daughter stands are synthesized is strikingly different.Te leading strand I ssytnthesizes as one long continuous molecule. The
question
leading strand
answer
made is the same direction that the fork is moving. The leading strand is synthesized as one long
question
lagging strand
answer
made as a series of small fragments that are subsequently connected to each other to form a continuous strand.
question
Okazaki fragments
answer
who initially discovered term in the late 1960s. The synthesis of Okazaki fragments occurs in the opposite direction of the replication fork. For example, the lower fragment is synthesized from left to right.
question
Processivity
answer
DNA polymerase III has a subunit called the clamp protein that allows the enzyme to slide the along the template strand without falling off.
question
DNA ligase
answer
catalyzes the formation of a covalent bon between these two DNA fragments to complete the replication fprocess tin the lagging strand.
question
List three reasons why DNA replication is very accurate
answer
1. Hydrogen bondng between A and T or between G cand C is more stalbe than btween msimtached pairs.2. the active site of DNA polymerase is unlikely to catalyze bond from in between adjacent nulcotides, if a mismatched bsae pair is formed. Thrid , DNA plymerasc canidentify a mismatched nuloetide and remove it from the daughter strand
Get an explanation on any task
Get unstuck with the help of our AI assistant in seconds
New