Brave New World?

Explain the key ideas that make PCR possible.

DNA must first be denatured through the use of heating and annealing, this is followed up by the extension of the separates strands of DNA, thereby replicating the DNA. This is repeated again and again. Since the DNA generated will be used as a template for replication, this is why PCR becomes exponentially amplified, as the number of DNA produced and uses as a template is growing exponentially.

Genetic Engineering Techniques

Briefly discuss the following genetic engineering techniques - include a model of each and explain how each can be used to manipulate DNA

Gel Electrophoresis

This is an indirect method to quickly analyze and compare genome. The use of a gel that acts as a molecular sieve. Separates nucleic acids or proteins by size. A current is applied through the gel, which causes the molecules to move accordingly depending on attraction. The end result has molecules sorted into bands by size, and this allows for the mapping and comparison of genetic material.   

http://sciencefair.math.iit.edu/techniques/gelelectrophoresis/

Plasmid-based Transformation

Plasmids [found in bacteria] are small circular DNA molecules that replicate separately from bacterial chromosomes. So, these units are very useful in carrying foreign DNA into cells, with the intent to insert a particular gene into the aforementioned cells. The end result of this, leads to the cells producing whatever protein is coded for in the plasmid DNA.

https://en.wikipedia.org/wiki/Transformation_(genetics)

Polymerase Chain Reaction (PCR)

This is a method to reproduce many copies of a specific segment of DNA. This three-step cycle involves heating, cooling, and replication. It serves to produce an exponentially growing population of identical DNA molecules.

https://www.quora.com/profile/Amina-Zaid

Restriction Enzyme Analysis of DNA

Enzymes are used to cut DNA to produce fragmented DNA that can be used for gel electrophoresis. This is very useful when comparing two different DNA molecules.

Lytic and Lysogenic Cycles

Compare and contrast the differences between lytic and lysogenic life cycles of a virus.

The lytic cycle is a reproductive cycle of a phage, that results in destroying the host cell. This cycle produces new phages by using the host cell to replicate itself. Once the phages have assembled within the host cell, they will digest and break through the host’s cell wall. The lysogenic cycle replicates the phage’s DNA and incorporates it into the DNA of the host cell. Every time the host cell divides, it will replicate this phage DNA along with its own DNA. These two cycles are connected, because a cell in the lysogenic cycle can be triggered to move into the lytic cycle and will start reproducing the actual phages. Phages that can do this are known as temperate phages, phages that can only utilize the lytic cycle are known as virulent phages.

https://sites.google.com/site/namoshomeworksite/ap-biology/virus

Viruses

Develop a model and explain the components of a virus.

There are various forms of viruses, these are small infectious particles consisting nucleic acid which is enclosed in a protein coat known as a capsid, and sometimes also an envelope membrane. Depending on the nucleic acid contained in the virus, it will either be a DNA or an RNA virus. Capsids can have various structures, as a result, can form different looking viruses.

Take a look at some different types of viruses below.

Mastering Biology | Pearson; Campbell Biology

Cancer Hands

Compare and contrast the role of oncogenes, proto-oncogenes, and tumor suppressor genes in cancer.

Oncogenes are cancer causing genes, and proto-oncogenes are normal cellular genes that are responsible for normal cell growth and division. So proto is good, once the proto is gone, we’ve got cancer on our hands. Not actually, I mean you can get cancer nearly anywhere.. ANYWAYS,

tumor suppressor genes are responsible for repairing damaged DNA, controlling cell adhesion, and inhibiting the cell cycle when necessary. They also prevent uncontrolled cell growth/division.

DNA Methylation and Histone Acetylation

Describe the impact of DNA methylation and histone acetylation on gene expression.
DNA methylation adds methyl groups to specific bases in DNA, which leads to turning off the transcription of some genes. This typically causes long-term inactivation of a gene. For example, the gene for humans to grow tails has been methylated, we only have a tailbone and cannot grow tails. Histone acetylation adds acetyl groups to the lysines in histone tails that are positively charged. [See “Wiggly Purple Guys” under Ch 16 & 17] This functions to loosen up the chromatin structure, so that transcription can be initiated. Also, methylation in chromatin can cause it to condense more. Phosphate groups added to methylated amino acids also can loosen up wound up chromatin.

Why Repressing Stuff can be Good

Explain the role of repressor genes in operons and why they are important.

Repressors genes are important for these segments of DNA code for repressor proteins. Repressor proteins are necessary for the proper functioning of operons, repressors make sure operons are only active when they need to be, and not otherwise.

Inducible vs Repressible

Compare and contrast an inducible operon and a repressible operon. Include an example of each.

Inducible: The lac operon is an example of an inducible operon. It is usually off, but can be induced to turn on when needed. In these operons, there is an active operon always attached to the operator of the operon, until an inducer attaches to it and causes it to change shape and detach. This allows for RNA polymerase to go through reading the operon, to create the protein it codes for. The lac operon codes for enzymes that are used to hydrolyze and metabolize lactose. So, this operon will only be active when there is lactose present. When lactose is present, allolactose is the inducer which will inactivate the repressor attached to the operator.  

http://biology-forums.com/index.php?action=gallery;sa=view;id=11503

Repressible: The trp operon is an example of a repressible operon. It is usually turned off, but can be repressed when it is not needed. These operons are turned off by the binding of a repressor protein, that may need a corepressor in order to be activated, to the operator of the operon. In the trp operon, tryptophan is coded for. When there is tryptophan present in the cell and does not need to be synthesized, this acts as a corepressor and causes the operon to be blocked and turned off.

http://www.slideshare.net/kindarspirit/18-regulation-of-gene-expression

Oper-on or Oper-off?

Describe the structure of an operon. Include a model with your discussion.

An operon is a segment of DNA that includes an operator, a promoter, and a stretch of functionally related genes. Operons are regulatory switches for the production of specific proteins that are only needed during certain times.

https://diaryofanalevelstudent.wordpress.com/2013/02/23/the-lac-operon/