Replication, History of DNA, Transcription control, Recombinant DNA Flashcards
(replication) topoisomerase … DNA to release … –> acts before …
cuts; helical stress; helicase
(NJCTL) it is the building block of the … that control how bodies are shaped and how organisms react to environmental factors. DNA is …
genes; evolution
(NJCTL) DNA is called the … gene. Genes are the … and we are the … –> genes are like …
selfish gene; replicators; survival machines; viruses
(NJCTL) a physical trait is called a …, and is controlled by …
phenotype; genes
(NJCTL) blue eyes are controlled by … gene(s). A … in one individual’s OCA2 gene (gives … to eyes), about 8,000 years ago, gave rise to blue eyes.
one; mutation; pigment
(NJCTL) The mutation for blue eyes has been passed on. Each individual with blue eyes carries … copies of the original mutation
2
(NJCTL) Nucleic acids were first isolated by Friedrich Miescher, who in 1869, discovered a microscopic substance in the … of discarded … At the time it was an unknown … substance and was not considered important until many years later.
pus; surgical bandages; cellular
(NJCTL) In 1928, Griffith conducted an experiment using 2 strains of Streptococcus pneumoniae. He found that the live S strain … mice, the live R strain … mice, the killed S strain … mice, and the killed S mixed with living R … mice.
killed; did not kill; did not kill; killed
(NJCTL) Smooth strain has a … which allows it to adhere to cells and tissues within the mice. The rough strain does no have this which is why it appears rough.
capsule
(NJCTL) As part of Griffith’s experiment, the living R … into living S. Bacteria undergo transformation, by which they take in … from the environment and incorporate it into their own
transformed; DNA
(NJCTL) After Griffith’s experiment most scientists believed that the chemical transforming bacteria was a …, not a …
protein; nucleic acid
(NJCTL) Avery used a … to perform his experiment. This is when a scientist compares differences in … after treating each differently. The benefit is that you can discover more … reactions. This approach led to more information than dead/living mice provided.
test tube assay; test tubes; specific
(NJCTL) First, Avery heat-killed the S strain bacteria and mixed it with …, causing the cells to break apart. Their … lysed and spilled out the cell’s contents.
detergent; membranes
(NJCTL) The upper portion of the test tube, the …, contains less dense materials like …, …, and …
lysate; proteins; enzymes; nucleic acids.
(NJCTL) the precipitate in Avery’s experiment contained the large … and … of the cell. Avery isolated the … to use because it contained … molecules that were more likely to be the …
proteins; lysate; smaller; genetic material
(NJCTL) Avery took the lysate and mixed it with … to see if it would transform the bacteria and it worked (he was ensuring the lysate had the genetic info)
R strain
(NJCTL) Avery then put in an … that digests proteins into the lysate and the bacteria still …. He also devised a technique that used … to isolate and purify … from solution. He and is team then mixed this from the S strain with that from the R strain to observe what would happen.
enzyme; transform; alcohol; nucleic acids
(NJCTL) The Hershey-Chase experiments were a series of experiments conducted in 1952 by Alfred Hershey and Martha Chase that confirmed
DNA was the genetic material.
(NJCTL) Hershey and Chase concentrated on … These were known to only be composed of … and …
bacteriophages; DNA; proteins
(NJCTL) Hershey and Chase used a novel approach that took advantage of a new technique called … which allowed them to track different parts of the virus by looking for …
radioactive labeling; radiation
(NJCTL) a .. can find and measure radioactive particles
Geiger counter
(NJCTL) Hershey and Chase began by creating 2 kinds of radioactive viruses using a labeling technique. To make virus A, they used …, marking the .
radioactive sulfur; proteins
(NJCTL) Since …, not …, need sulfur to be constructed only the … in the virus A phages are radioactive
proteins; DNA; proteins
(NJCTL) To make virus B, they used …, marking …
radioactive phosphorus; DNA
(NJCTL) Since …, not …, need phosphorus to be constructed only the … in the virus B phages are radioactive
DNA; proteins; DNA
(NJCTL) Viruses A and B are mixed with … and left for .. hours. For virus A, there was … in the cells after centrifugation. For virus B, there was … in the cells after centrifugation.
bacteria; 36; no sulfur; phosphorus
(NJCTL) the three steps of the experiment that took place within bacteria (hershey-chase):
1. …, 2. …, 3. …
infection; blending; centrifugation
(NJCTL) Rosalind Franklin and Maurice Wilkins produced … images of DNA to try to discover its shape and understand its mechanisms
x-ray diffraction
(NJCTL) X-ray diffraction shoots … into a substance. The collision of these particles with those of the molecules in the substance cause them to …, or .., at …. this gives insight to the structure of the substance
subatomic particles; diffract; ricochet; specific angles;
(NJCTL) Watson and Crick analyzed “photo …” and determined that DNA was a … They began to build models of the structure to determine how DNA can … and … for all the … of living things
51; double helix; self-replicate; code; traits
(NJCTL) … is a nitrogenous base in RNA but not in DNA. … is a nitrogenous base in DNA but not in RNA. RNA is … and can .. into many different …, whereas DNA is .. and can only be a …
uracil; thymine; single stranded; fold; shapes; double stranded; double helix
(NJCTL) DNA is an informational molecule encoding the .. used in the development and functioning of all known living organisms. Guanine and cytosine form .. hydrogen bonds, while adenine and thymine form .. hydrogen bonds
genetic instructions; 3; 2
(NJCTL) The two strands of DNA run in … directions to each other and are therefore …, one backbone being … and the other … This refers to the direction the .. and … on the sugar molecule is facing
opposite; anti-parallel; 3’; 5’; 3rd; 5th carbon
(NJCTL) RNA makes the … necessary for the function of DNA. It plays a major role in the replication of DNA and the reading of the information stored in DNA.
molecular machinery
(NJCTL) typically, eukaryotic cells have .. chromosomes and prokaryotic cells have … chromosomes
large linear; smaller circular
(NJCTL) in eukaryotes, nuclear chromosomes are packaged by proteins into a condensed structure called … This allows the very long DNA molecules to fit into the … Chromosomes are the essential unit for … and must be replicated, divided, and passed successfully to their daughter cells to ensure the genetic diversity and survival of offspring
chromatin; cell nucleus; cellular division
(NJCTL) Since eukaryotes are larger and more complex, eukaryotic chromosomes are much larger and require more complex methods for storage of their numerous genes. Special proteins called … and … pack the DNA strand into tight coils.
histones; scaffolds
(NJCTL) chromatid: one of the two … of the chromosome
centromere: the point where the two chromatids …, and where the microtubules … during cell division
Eukaryotic chromosomes also have … and … arms
identical copies; touch; attach; short; long
(NJCTL) Chromosomes are often represented as … that show the .. of …
genetic maps; loci; genes
(NJCTL) humans have … pairs of chromosomes in each of their cells that contain multiple copies of about … genes
23; 40,000
(NJCTL) chromosomes can be …- … versions of each chromosome, or …- … versions of each chromosome
diploid; 2; haploid; 1
(NJCTL) When cells reproduce, they must … their DNA.
In complex organisms, … of copies of cells are made from one original cell
replicate; trillions
(NJCTL) Watson and Crick found that the fact that there are two DNA strands that are … of one another suggested how copies could be made of each sequence
mirror images
(NJCTL) Each molecule of DNA is made of a … and a … strand. The … is used to make the … strand and is also known as the … strand since it came from the original DNA molecule. The new strand is also known as the …
template; new; template; new; parent; daughter strand
(NJCTL) the template strands of the DNA molecule .. and the new strands are made on the …
separate; inside
(NJCTL) Nucleotides can only be added to the … end, so all new strands are made in the …-… direction
-OH; 5’; 3’
(NJCTL) DNA nucleotide monomers are made ahead of time and stored in the cell. … is the enzyme responsible for adding each new nucleotide to the growing strand
DNA polymerase
(NJCTL) The result of this process is 2 new DNA molecules each having an old template strand and a new strand. This is called .. because it “….” some of the old DNA in each copy.
semi-conservative; conserves
(NJCTL) Topoisomerase is an enzyme that controls … of DNA during replication. This type of problem arises due to the intertwined nature of its double helical structure. During DNA replication, DNA becomes … ahead of a replication fork. This tension would eventually …
winding; overwound; stop replication
(NJCTL) Helicase breaks the weak … that hold nucleotides together, opening up both strands to become templates for new strands. Helicase is the molecule that creates the …
hydrogen bonds; replication fork
(NJCTL) single stranded binding proteins ensure that the nucleotide pairs do not .. after helicase passes
re-bind
(NJCTL) Since the strands are anti-parallel they are arranged in opposite directions. In order to replicate both strands in the same direction, there are 2 different strategies, one for each template (.. and …)
leading; lagging
(NJCTL) The leading strand is simple since it runs … to … DNA polymerase can follow behind … and simply copy the template as it is being exposed.
3’; 5’; helicase
(NJCTL) DNA polymerase can only read in the … to … direction. So on the lagging strand there has to be a way to make the new strand in reverse. It starts with an enzyme called … that adds … as a primer for DNA polymerase
3’; 5’; primase; RNA nucleotides;
(NJCTL) DNA polymerase can latch onto the RNA primers and begin to write a fragment of the new strand. Since it is going away from the replication fork it only does a portion, then it jumps back in front of the portion it just did to start again. The fragments formed by this process are called … When the RNA primers fall away from the strand, gaps are left between the fragments that must be repaired.
Okazaki fragments
(NJCTL) DNA ligase finishes the job by filling in the gaps between the
Okazaki fragments.
(NJCTL) Gene expression is the molecular process of reading the order of nucleotides in a DNA molecule and making the coded product. This product is usually a … but … is also coded for in genes. Gene expression occurs whenever a specific … or … is needed by the cell.
protein; RNA; protein; RNA molecule
(NJCTL) in prokaryotes, genes are often clustered into … within the chromosome.
operons
(NJCTL) Operons consist of 3 parts:
an operator- essentially an …
a promoter- an area that attracts …
the genes- which code for the … needed by the cell
on-off switch; RNA polymerase; protein
(NJCTL) an operon can be switched off by a protein called a …., which can be controlled through … with … and …
repressor; allosteric regulation; co-repressors; inducers
(NJCTL) a co-repressor is a small molecule that cooperates with a repressor to help switch an operon …
An inducer is a small molecule that inhibits a repressor to help switch an operon …
off; on
(NJCTL) an inducible operon is one that is usually …: a molecule called an inducer … the repressor and turns .. transcription
off; inactivates; on
(NJCTL) an example of an inducible operon is the lac operon, which contains genes coding for enzymes that break down lactose into … so the bacteria can use it for … If no lactose is present then no enzyme needs to be made. The bacteria saves energy in this way. In this operon, … is the inducer
glucose; energy; lactose
(NJCTL) A repressible operon is one that is usually … When a repressor binds to an operator, transcription is …
on; shut off
(NJCTL) The trp operon is a repressible operon. The trp operon codes for a number of genes responsible for the production of the amino acid tryptophan. If it is present in the environment, the trp operator is not …. … acts as the co-repressor
used; tryptophan
(NJCTL) eukaryotes have much more complex chromosomes that require multiple levels of regulation including:
… of genes
…
… processing
unpacking; transcription factors; RNA
(NJCTL) when DNA is packed in chromatin it is not accessible to … so … cannot happen. The main factor in the specialization of cells in multi-cellular organisms is what genes are … from the chromatin to be exposed to …
RNA polymerase; transcription; unpacked; RNA polymerase
(NJCTL) The genes that need to be expressed are unwound from histones by … in order to expose their nucleotide sequences. Genes that are unnecessary to a particular cell will remain packed while the necessary ones are unpacked.
chromatin modifying enzymes
(NJCTL) After transcription of eukaryotic DNA, the transcript is known as … Enzymes in the nucleus modify this before the genetic messages are sent to the cytoplasm. This is known as ..
pre-mRNA; mRNA processing
(NJCTL) During mRNA processing, both ends of the pre-mRNA are … Some interior sequences of pre-mRNA may be …, and other parts … together
altered; cut out; spliced
(NJCTL) The 5’ end of the pre-mRNA receives a molecule known as a … (or …) …. This is a modified …
nucleotide; 5’; cap; guanine molecule
(NJCTL) The 3’ end of the pre-mRNA gets a … This is a series of …
poly-A tail; adenosine nucleotides
(NJCTL) The modifications to the ends of the pre-mRNA have several functions:
they facilitate the … of mRNA from the nucleus to the …
They protect mRNA from … once it is in the cytoplasm
They help ribosomes … to the … so they can be translated into a protein
export; cytoplasm; hydrolytic enzymes; attach; mRNA
(NJCTL) Most eukaryotic genes and their RNA transcripts have long noncoding stretches of nucleotides that lie between coding regions. These are called …, or …
noncoding regions; introns
(NJCTL) The other regions called … (because they are eventually expressed), are usually translated into …
exons; amino acid sequences
(NJCTL) RNA splicing removes … and joins …, creating an mRNA molecule with a continuous coding sequence
introns; exons
(NJCTL) Some genes can code more than one kind of …., depending on which segments are treated as … during RNA splicing. … allows the number of different proteins an organism can produce to be much …than its number of genes
polypeptide; exons; alternative splicing; greater
(NJCTL) Alternate splicing can dramatically change the … and/or the … of the polypeptide chain that will be made
length; sequence
(NJCTL) After the finalized mRNA transcript is complete and correct, the pores in the nuclear envelope allow it to pass to the cytoplasm where it can be … into … by ribosomes. The nuclear pore is a protein structure that controls the … of the nucleus. Each nuclear pore is made up of hundreds of individual .. that insure only … with proper … and … can make it to the cytoplasm
translated; proteins; traffic flow; proteins; mRNAs; caps; tails
(NJCTL) Hydrolytic enzymes in the cytoplasm breakdown … molecules. The length of time an mRNA survives in the cytoplasm relates to how much … is made from it. Longer time in the cytoplasm means more … by ribosomes. The length of the … is one of the many factors that determines the time of survival in the cytoplasm. The longer it is, the … it’s survival
mRNA; protein; translation; poly-A tail; longer
(NJCTL) one of the first procedures to use DNA successfully was …. technology
recombinant DNA
(NJCTL) for recombinant DNA, genes from one organism are spliced into the … of another. SInce all organisms use the same genetic code, the cells that contained the recombined DNA will produce the … encoded by the new gene
genome; protein
(NJCTL) This multistep process uses a combination of technologies that mimic biological processes in the laboratory to ultimately make useful …
proteins
(NJCTL) Diabetes is a disease in which a person has high blood sugar either because the pancrease does not produce enough insulin, or because cells do not respond to the insulin that is produced. Untreated, it may cause many problems including …, resulting from the increase d… of the blood for extended periods
kidney damage; solute
(NJCTL) at first doctors treated diabetes by injecting … harvested from … This had some effect but the protein is not exactly the same as the human insulin protein. The symptoms would eventually overcome the patient.
bovine insulin; cows’ blood
(NJCTL) In the late 1970s, scientists started to look for a way to make human insulin in a laboratory. Their efforts produced the first product ever made using genes from multiple organisms. They recombined fragments of DNA from … with the bacterial chromosome of … The new bacteria was then able to produce …
humans; E. coli; human insulin
(NJCTL) The result was a new product called … –the first human hormone to ever be produced by another organism
Humulin
(NJCTL) DNA pieces can be recombined to make unique, manmade sequences. There are … main steps
7
(NJCTL) Step 1: Find the piece of DNA in the genome– the … of …
Today this step is done by … attached to robotic … that fragment, analyze and find a gene based on user input
gene of interest; computers; DNA sequencers
(NJCTL) Step 2: … the gene of interest from the genome
This is made possible by … In nature, these are used by bacteria as weapons against …
cut; restriction enzymes; invading viruses
(NJCTL) staggered ends are called … because they leave a few unpaired nucleotides that will easily stick to another piece of DNA with the same sticky end
sticky ends
(NJCTL) If the sequence of the gene of interest is known and the sequences in the surrounding DNA are known, then restriction enzymes cut sites that are on … of the gene, and can then be used to cut the gene out
opposite sides
(NJCTL) Step 3: … the gene of interest.
isolate
(NJCTL) … is used to separate DNA fragments based on length.
gel electrophoresis
(NJCTL) Step 4: make more of the .. (…)
Once the gene of interest is isolated in the gel, the band that contains the gene can be … from the gel, but this is a very small sample. More copies can be made using …
gene of interest; amplification; cut; polymerase chain reaction (PCR)
(NJCTL) Step 5: … the gene of interest into the host’s DNA
paste
(NJCTL) Step 6: Put the recombined piece of DNA into the …
host organism
(NJCTL) Now that the gene of interest is in a plasmid, it can be mixed with bacterial cells and be taken up into the bacterial chromosome. Remember, all living things use the universal genetic code. The bacterial cells will … the newly acquired gene, … it into mRNA and its ribosomes will … the mRNA into a … The bacterial cells will … and …. the gene. Each time a recombinant bacterial cell divides by binary fission, it will make a new copy of the gene.
read; transcribe; translate; protein; reproduce; express
(NJCTL) Step 7: .. the protein product.
The protein can be extracted from bacterial cultures using various techniques. It can then be delivered ot the patient. Currently there is no cure for diabetes, but with advancements in insulin therapy patients can now avoid many of the life threatening complications
collect
