This chapter describes the various processes in cells that make up the human body.
The regulation of these processes is discussed before concluding with a discussion about viruses,bacteria, and genetic engineering.
There is a double helix of adenine-thymine.
Adenine-uracil, cytosine-guanine are single stranded.
During the S-phase, DNA replication occurs in a 5' to 3' direction.
There is a DNA template.
A ribosome is lined up with a specified sequence of amino acids.
Operons allow for the production of genes only when needed.
Genetics affects all of biology.
We begin our study of this subject with a description of the various processes in cells that are involved in the regulation of all these processes.
The chapter ends with a discussion of genetic engineering.
Two scientists spent a lot of time trying to prevent information.
They noted that adenine always pairs with amine held together by two hydrogen bonds and that guanine always pairs with cytosine held together by three hydrogen bonds.
The nucleotides are connected with the strand through a sugar-phosphate backbone.
There is sugar.
The last structural note about DNA is that it has two ends, a 5' end and a 3' end.
The 5' end of one strand of DNA runs parallel to the other strand, and vice versa.
The world is known to have ribonucleic acid.
There are similarities between the two.
Both of them have a sugar-phosphate backbone.
The structure of the molecule is made up of four different nucleotides.
Don't worry if you don't see that last similarity, they both have three letters in their nickname.
There are differences between these two molecules.
uracil beat out thymine for the job and probably had a better interview during the hiring process.
There is a difference between the sugars for the two substances.
While DNA is a double strand, RNA is a single strand and tends to roam the cells as a single strand.
There are three main types ofRNA that you should know about, all of which are formed from DNA templates in the nucleus of cells.
Human cells don't have machines to do the dirty work.
This process takes place during the S-phase of the cell cycle to make sure that all cells receive the correct amount of DNA.
In the late 19th century, the mechanism for DNA replication was the subject of much debate.
In this model, the double helix of DNA is the same as it was when it was first created.
Only one of the daughter cells has the parent's DNA in it.
One strand of the parent's DNA goes to the daughter cell, and the other strand goes to the second daughter cell.
They would not be happy to see that we did not draw the double helix.
The debate about replication mechanisms was helped by an experiment performed in the 1950s.
The experimenters used a heavier-than-normal form of nitrogen to growbacteria that were denser than normal.
The 15N was picked up by the bacteria and incorporated into their DNA.
The medium for the transfer of thebacteria was 14N nitrogen.
It was possible to reproduce and produce half 15N and half 14N.
When the first generation of offspring were duplicated to form the second generation, there were two different types of DNA, one with half 15N and half 14N and the other completely 14N.
The semi-conservative theory of DNA replication was defeated.
There is a mechanism for semi-conservative DNA replication.
During the S-phase of the cell cycle, the double-stranded DNA prepares to replicate.
The original parent's genes are not contained in the original DNA.
The original parent's genes are contained in the DNA.
Only the 3' end of a parent strand can be added to the DNA polymerase.
Only one strand can be produced in a continuous fashion.
The model of DNA replication is semi-conservative.
Mistakes are made in the process of DNA replication.
Each time, the DNA is properly replicated with the help of a series of proofreading enzymes.
One out of every 10,000 base pairs is estimated to have a nucleotide mismatch during the first run-through.
The newly added base is checked by DNA polymerase to make sure it is the right one.
The correct one is added to the incorrect one by the polymerase.
The identities of the other proteins that assist in the repair process are unimportant.
DNA repair is a very efficient process and you should be aware of it.
Unless it occurs late in production, this kind ofmutation usually produces a nonfunctional protein.
It could cause no problem at all, or it could cause a big problem like in sickle cell anemia, in which a single mistake in one of the genes leads to a disease that wreaks havoc on the body as a whole.
The stop codons are UAA, UAG, and UGA.
A nonfunctional protein is usually the result of this type of mutation.
When this exposure occurs, the thymine nucleotides located adjacent to one another bind together.
This can affect the replication of DNA.
The first thing that must be transcribed is DNA.
They speak the same language.
The blueprints for producing theProtein of interest are conveyed to the ribosomes by differen, which is a template for mRNA.
The three steps of transcription are initiation, elongation, and termination.
The polymerase of transcription needs helpers to find and attach to the promoter region.
Once bound, the RNA polymerase works its magic by adding aRNA to the 3' end of the strand.
The added nucleotides are 5' to 3'.
As the strand grows longer, it separates from the DNA.
The mRNA is set free after reaching this site.
After it is released from the DNA, mRNA is ready to rock.
This is not the case in eukaryotes.
The nucleus of the cell must be modified before the nucleus can leave the cell.
The ends of the molecule are touched up.
The guanine cap on the 5' end protects the RNA and helps in attachment to the ribosome later on.
It does seem strange and inefficient that the DNA contains so many regions that are not used in the production of the gene, but perhaps there is a way to madness.
It is thought that introns give flexibility to the genome.
The only difference is which introns get spliced out from one to the other.
Now that the nucleus has been removed, the mRNA is ready to be used in the construction of proteins.
The ribosome is where this process occurs.
In Chapter 5, it's mentioned that proteins are made of amino acids.
There is a distinct and particular order to each of the genes.
There must be a system that the cell can use to convert the sequence of nucleotides that make up an mRNA molecule into the sequence of amino acids.
A series of codons make up the code.
There are 64 different combinations of codons.
This means that there are more than one codon.
The reading frame is established in August.
The production of a protein stops when the machinery hits the codons.
A lot of a ribosome is built out of rRNA.
The ribosomes are where the amino acids are carried.
There are a number of codons in the mRNA molecule that is involved in the formation of aProtein.
The tRNA leaves the site if it is needed again at the ribosome, just in case.
There are less than 50 different types of tRNA.
There are more codons than that.
Some tRNA can match with more than one codon.
The third position of the anticodon is where some tRNA molecules have an altered form of adenine.
There are different types of codons in mRNA.
The translation process begins when a small ribosomal subunit is attached to an mRNA.
August is the first codon for this process.
The AUG codon has a tRNA molecule attached to it.
When this happens, the ribosome's large subunit binding to the complexample is ready to begin.
The A site is where the next amino acid sits, while the P site is where the growingProtein is carried.
AUG is the first codon bound, and the P site is carrying the methionine.
The tRNA is bound to the site.
The tRNA arrives at the A site.
The A site becomes the new P site when the next acid from the P site hops onto the A site.
The process continues until the stop codon is reached.
The A site of the ribosome is where the tRNA molecule sits.
There is a bond between the A site tRNA and the P site tRNA.
After this happens, the A site becomes the location for the tRNA to leave the ribosome.
There is a step called translocation.
The ribosome moves along the mRNA in a way that the A site becomes the P site and the next tRNA comes into the new A site.
The process continues until the stop codon is reached.
The "regulator" is located thousands of bases away from the promoter and influences transcription by interacting with specific transcription factors.
Big Idea 4.C.2 organisms need the proper and efficient functioning of their genes.
Operons are used to control the expression of genes.
Three genes are involved in the process of Lactose metabolism.
The genes that help the bacteria digest lactose are contained in this tors.
It makes sense that probacteria can influence genes only if there is Lactose.
It's pointless to waste the energy on expression.
This is where operons come into play--in the absence of lactose, a repressor binding to the promoter region and preventing transcription from occurring.
When lactose is present, there is a binding site on the repressor that causes the repressor to let go of the promoter region.
TheRNA polymerase is free to bind to that site.
The process is halted when the promoter is free to bind to the repressor.
There are more places where gene control can occur.
If the ribosomes are prevented from attaching, or if the initiation factors vital to the synthesis of the proteins are inactivated, this can happen.
There are many examples of gene expression control that occur in the eukaryotes.
Don't get lost in the details.
Viruses do not have ribosomes for the synthesis of proteins.
They are dependent on their host.
A virus takes over a cell's machinery and uses it to produce whatever it needs to survive and reproduce.
Depending on what type of virus it is, a virus can act after entering a cell.
The viruses have a genome and acapsid.
Some elements from the host cell and the virus are contained in the viral envelope.
The HIV virus can cause T cells in our body to die, and the bacteriophages can only causebacteria.
A retroviruses is a type of virus that deserves discussion.
Once in the nucleus of the cell, the RNA virus uses this enzyme to "reverse transcribe" its genetic information fromRNA into DNA, which then enters the nucleus of the cell.
When the host cell undergoes normal transcription, the newly transcribed DNA is incorporated into the host DNA.
The new retroviruses offspring can leave the cell in a lytic pathway after being produced from this process.
The HIV virus of AIDS is an example of a retroviruses.
A lytic or a lysogenic pathway can be taken by a DNA virus once inside the cell.
The virus can stay alive from generation to generation without being killed by the host cell if the cell reproduces itself quietly.
The lysogenic cycle can sometimes cause a Viruses to separate from the host and enter the lytic cycle.
There are many types of Viruses.
An incorrectly folded form of a brain cell protein works its magic by converting other normal host proteins into different shapes.
"mad cow" disease is an example of a prion disease that has been getting a lot of press coverage.
Prion diseases can cause brain problems such as dementia, muscular control problems, and loss of balance.
The Genetics ofbacteria are prokaryotic cells with a single double-stranded circular DNA molecule.
The main chromosome is not replicated by plamids.
A daughter cell that is identical to the parent cell is created when the cell replicates its DNA and pinches in half.
It seems unlikely that there could be variation among bacter Big Idea 3.C.1 ial cells.
This is not the case, thanks to genetics.
Somebacteria can have a pronounced effect on their variability by replicating so quickly that there are ways to increase their genetic make up.
Foreign DNA is taken from the environment.
The process of transformation occurs when the surface of the cells is stained with pieces of the same species of DNA.
A strain that can cause an illness is called a virulence strain.
The experimenters exposed the mice to different types ofbacteria.
The mice were given live Sbacteria.
The mice were given live Rbacteria.
The heatkilled Sbacteria survived.
The heat-killed S and live Rbacteria killed the mice.
This was the kicker.
The live Rbacteria underwent transformation when exposed to heat-killed S. The instructions on how to make the vital Big Idea 3.C.3 component were found by some of the Rbacteria.
The Rbacteria became aggressive.
The mechanism by which a cell is attacked by a phage reminds me of a needle in a haystack.
A phage is trying to deliver a strand of DNA.
A phage fires its DNA through the cell's membrane and onto the surface of the cell.
The two main forms of transduction are generalized and specialized.
Imagine that a viruses takes over a cell that has a resistance to penicillin.
Sometimes pieces of host DNA are accidentally put into a phage.
When the cell lyses, expelling the newly formed viral particles, the phage containing the host DNA may latch onto another cell, injecting the host DNA from one cell into another bacterial cell.
The effects of the transduction process can be observed if the cell contains a nonfunctional gene for resistance to penicillin.
After injecting the host DNA containing the functional penicillin resistance gene, there could be a switch between the nonfunctional and functional genes.
The new cell would be resistant to penicillin.
This type of transduction involves a virus that is in the lysogenic cycle, resting quietly along with the other DNA of the cell.
When a lysogenic virus becomes lytic, it may bring with it a piece of the host's genetic material.
Imagine if it had a functional gene for resistance to penicillin.
The host cell's resistance genes will be passed on to new viral offspring that contain them.
If the new phage offspring attach to a cell that is penicillin resistant, specialized transduction will occur.
The raciest of the genetic recombinations will be covered.
If you want to take the AP Biology exam, you need a basic understanding of the most common laboratory techniques.
When added to a solution containing a specific sequence of DNA, the enzymes cut it.
The same ends of other DNA fragments can be found with the help of DNA ligase.
The plasmid can be used to create a vector that can be used to transport DNA.
This technique can be used to separate and examine DNA fragments.
The restriction enzymes are cut with the DNA and then separated.
The pieces of DNA are separated using an electric charge.
Know this is cold.
Smaller pieces travel farther along the gel.
The bigger you are, the harder it is to move.
It is possible to match a crime scene's DNA with that of a suspect.
Different combinations of RFLPs will be obtained from person to person when it is mixed with restriction enzymes.
The sample from the suspect is separated from the sample from the scene of the crime.
If the RFLPs match, there is a high degree of certainty that the sample came from the suspect.
It's desirable to get large quantities of a gene for the treatment of diabetes.
The process of cloning involves many steps.
One of the genes used for cloning provides resistance to an antibiotic, and the other gives thebacteria the ability to metabolize some sugar.
The galactose hydrolyzing and ampicillin resistance genes will be used.
Both the plasmid and DNA are cut with the same restriction enzyme.
There is a restriction site in the middle of the galactose gene.
When the sticky ends are created, the plasmids are mixed and joined together.
The scientist is not looking for every combination made here.
The plasmids are turned into cells.
The two specific genes for the plasmid are here.
The transformed cells are placed on a medium that has ampicillin.
The cells that have taken in the 11_Anestis_ch11_p117-135.qxd will survive.
There is a special sugar in the medium that is broken down by a galactoseidase to make a colored product.
The cells containing the galactose gene will remain white since they have been rendered nonfunctional.
The experimenter can isolated cells that contain the desired product.
It is time for us to use another genetic engineering technique.
It can be used to produce large quantities of a particular sequence of DNA in a short period of time.
The Concorde is the clone reaction if it is copying DNA.
The process begins with double-stranded DNA.
A lot of nucleotides and primers specific for the sequence of interest are added to the mixture to help initiate the synthesis of DNA.
The cooling of the strands will allow the primer to bind to the sequence of interest.
The rest of the molecule is created by adding the nucleotides to the growing strand of DNA.
At the beginning of the cycle, the amount of DNA doubled.
Every few minutes, the cycle is repeated over and over, until a huge amount of DNA has been created.
It's possible to detect the presence of HIV in cells, diagnose genetic disorders, and amplify trace amounts of DNA found at crime scenes with the help of the help of the help of the help of the help of the help of the help of the help of the help of the help of
The nucleus of a cell must be processed before A. Messenger can leave.
The host cell was destroyed by C. AUG.
E. UAG can add nucleotides only in a 5' to 3' direction.
The C. Uracil-adenine hundred nucleotides are long.
The small ribosomal A. episomes have small ribosomal RNAs.
This is a signal to the C. operons.
The small riboso mal subunit has a first codon in the cor A.
This is a signal to the large B.
The synthesis of a string of adenine nucleotides should bind to the pro to the 3' end of the tein machinery.
The attachment of acids to the ribosomes is the job of transferRNA.
This is a signal to B.
TransferRNA is only used once during translation when attaching to the large ribosomal.
There is a sig amino acid.
The first codon bound something.
The AUG codon is found in the P site and the adenine pairs are held together with the methionine.
The next codon in the by two hydrogen bonds and guanine pairs with sequence determines which tRNA bind next, and the appropriate tRNA molecule sits in the A site bonds.
The ribosome is one of the differences between the two.
uracil is in the bond that forms between it and the peptide.
The P site tRNA and the A site tRNA have the same amount of guanine and ade acid.
The A site allows the tRNA to leave the ribosome in the P site.
The ribo they discovered was true, and a purine must always move along the mRNA with a pyrimidine.
The A site is now the P site and the next nine are the purines and the pyrimidines.
Answer choices A, B, C, and E are all correct.
Prions are the cause of mad cow disease.
They are self-replicating and are vital to the poly-A tail and the introns process of genetic engineering.
When the lysogenic cycle process is completed, theRNA is free to leave the nucleus and the incorpo leads the production of proteins.
The end of retroviruses is signaled by stop codons.