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assignment comments 2

Submitted by cdkelly on Tue, 10/30/2018 - 22:39

Because p53 and RB are so crucial to tumor suppression, their failure can be fatal. If either protein sustains a loss of function mutation, then errors in the DNA can make it past checkpoints. These errors can then lead to malfunctioning cells that cannot regulate their processes and become cancerous. Thus, both proteins are tumor suppressors.

For this scenario, a cell would need to receive a signal to divide. Since it is cloning itself for the replacement of a damaged cell, there must be a mechanism that releases division signals into the body. Perhaps this could be a signal released by the damaged cell itself or maybe another companion cell. What's important is that the replacement cell gets a signal to divide.

How does the cell accumulate extra cellular material to prepare for duplication? If it is increasing the rate of protein synthesis and doubling the cellular genome, where does it acquire all of the extra amino acids, nucleic acid, and other various cellular material?

It's interesting that the mechanisms of proteolysis can occur during the process of the cell cycle. This means that the proteins that add ubiquitin to other proteins functions during this period. These ubiquitinated proteins are then directed to the proteasome, meaning that the proteasome also functions during this time. They are lysed in the proteasome and degraded.

Cancerous cells take advantage of the failure of checkpoints and as a result accumulate more and more mutations. This is why cancerous cells are so hard to eradicate. Drugs can target specific players in specific pathways and disable them to prevent propagation of signals for growth, avoidance of cell death, and motility. But due to the mutability, cancer is able to adapt and utilize a different pathway or player to accommodate its needs for growth and spread. This is known as oncogene addiction.

Retinoblastoma (Rb) is an extremely commonly mutated protein in cancerous cells. Since it acts as a controller of a transcription factor for proteins (E2F)involved in the S phase of the cell cycle, when it has loss of function mutation it is not able to inhibit this TF. That is why Rb is considered a tumor suppressor.

 

Addiction to narcotics draft

Submitted by yurigarcia on Tue, 10/30/2018 - 22:14

Addiction to narcotics, how did this lethal epidemic start in the U.S?

The deaths for overdose in the next decade will be more than the victims of HVI. There is an actual crisis of addiction of medicines that derivate from opioids in the U.S. This will cause a half a million deaths in the next decade. There should be something we can do to stop it and try to prevent it.

rough draft of proposal part 2

Submitted by msalvucci on Tue, 10/30/2018 - 21:12

Each plant’s nastic movement will be tested and timed 10(?) times by the same person to keep the data uniform. Each time will be recorded and organized into a data table. The average nastic movement time for each environment, including the control group, will be compared. This will be represented in a graph showing all 5 of the environment data averages. This will allow us to compare the data points to eachother in a conclusive graph.

(more on this)

SIGNIFICANCE:

The goal of this study is to understand how environmental factors affect thigmonasty of the Mimosa Pudica species. There is little know about the nastic movements in Mimosa Pudica in undesirable environments, so this project will give new insight to this topic of plant movement. Thignomasty in plants may be used as a defense mechanism so it is important to understand when plants can use this movement against certain stimuli to defend themselves.

 

neurons notes rough draft

Submitted by msalvucci on Tue, 10/30/2018 - 21:09

The neurons in the human body are constantly moving and firing signals at all times. When a neuron is stimulated, it fires an impulse to its neighboring neurons. The nerve impulse is called the action potential. Within the body, ions both positive and negative are floating around constantly. Certain areas are more negatively charged, while others are more positively charged. These charges can indicate an action potential. The action potential works when the ions inside and outside of the cell fluctuate. The membrane potential, or difference between the positive and negative areas, can cause the event that triggers the flow of ions across a membrane. A resting neuron is typically negative on the inside of the cell and this resting membrane potential lays at -70 millivolts. The positive sodium ions outside of the membrane and positive potassium ions inside the cell work together in the sodium potassium pump. For every 2 potassium ions that float into the cell, 3 sodium ions are pumped out of the cell. Ion channels are then opened when the membrane potential reaches -55 millivolts. When these channels open, the ions move in and out of the cell depending on the chemical gradient. When a stimulus occurs, the increase in positive ions make the membrane potential exceed -55 millivolts. The resting neuron becomes depolarized, and lets a lot of sodium rush into the cell which creates an action potential. This action potential then flows down the axon of the neuron, and the stimulus occurs. However, when the potassium channels open, the voltage tries to equal out in the cell, and the action potential degrades. This is called the hyperpolarization; the voltage drops to -75 millivolts.

 

 

assignment comments

Submitted by cdkelly on Tue, 10/30/2018 - 19:59

 

There needs to be an extremely diverse collection of immune system components on T cells and B cells because they have to be prepared to deal with the huge variety of foreign molecules that can get into the body. They recognize anything that is not "self" and mark them for destruction. The different immune system cells need to be trained to not target normally functioning cells within the body.

A new cutting-edge method for targeting cancer is to create an antibody based of the composure of the tumor and create a corresponding T cell receptor that targets it. This allows the immune system to continually target the tumor rather than using a drug to disable a specific part of a pathway. This method allows for oncogene addiction to be dealt with and furthers the likelihood of remission.

Recombinase has to take into account the DNA sequence of the invader and make a copy of it for the purpose of identification. These signal sequences must be extremely specific because if they are not, then the wrong molecules could be targeted by the immune system and lead to an autoimmune disorder. The immune system could target our own cells and cause a number of bad symptoms.

This makes sense because the sheer quantity of pathogens and foreign invader molecules that a given person can encounter is massive. Therefore, because the V(D)J recombination allows for so much variability in the antigen-binding region, all of these different possibilities can be taken care of by the immune system. Even the pathogens that mutate rapidly because it can respond to these changes.

 

Cell cycle checkpoint p53

Submitted by bthoole on Tue, 10/30/2018 - 18:19

The cell cycle is a has many components that allow it to function properly and ensure that the cell ready to replicate and does so in a safe manner. This means that the cell needs a way to check that everything is accounted for, there has been no errors in DNA replication and the spindles during mitosis are aligned properly. For these reasons, the cell cycle has checkpoints that make sure the important processes of the various stages of the cell cycle have finished and been completed correctly before moving on to the next stage of the cycle. These checkpoints have the ability to put a hold on the cell cycle if more time is needed for the cell to catch up and is done so through the control of CDK. The stages of the cell cycle have various proteins that are capable of deactivating CDK directly or activate CDK inhibitor proteins. One of the most important checkpoint proteins in the cell cycle is p53. Described as the “guardian of the genome”, p53 is activated in cells in response to DNA damage. The transcription factor p53 activates upon the detection of DNA damage and activates the transcription of p21, which serves as a CDK inhibitor. The transcription factor is carefully controlled through posttranslational modification. In the absence of DNA damage, p53 is degraded by proteasomes, but in the presence of damage it is phosphorylated to a stable and activated state. The inhibition of G1/S CDK and S CDK by p21 is necessary to stop the cell cycle before DNA replication occurs in the S-phase of the cell cycle so that the DNA damage is not replicated in the new strand and passed along to the new cell.

Orgo Lab - Benzoin Experiment Discussion Draft Part 2

Submitted by sbrownstein on Tue, 10/30/2018 - 11:43

The crude product was then recrystallized to purify the compound. The recrystallized product of 1,2-diphenylethane-1,2-diol weighed 0.07 g and obtained a melting point of 138-139 ℃. The melting point for the recrystallized product is higher than the melting point of the crude product. This makes sense because the recrystallized product is pure compared to the crude product. Yet, the melting point of the recrystallized product is lower than the melting point of 1,2-diphenylethane-1,2-diol because it still obtains a minimal amount of impurities. The impurities may be due to not allowing the reaction to complete before ice bathing, filtrating, and recrystallizing the product.

A very rough research design

Submitted by mtracy on Tue, 10/30/2018 - 10:55

Mimosa pudica seeds are to be purchased and grown in 5 different environments including a control. Once adequately grown the plants in each environment are to be brushed against the lateral edge of their flower with a q-tip. The time it takes for a plant to complete its closure will be timed. In the event of partial closing, the timer will be stopped when the nastic movement has completely halted.

    There will be a total of 5 different environments that each group of M. pudica will be grown in. All environments are to be on an # hour day night cycle. The control environment will be designated as Environment 1. Plants under these conditions will be allotted a normal amount of water and will be kept at a temperature of 21C. Environment 2 will have high heat and a normal water supply. Plants under these conditions will be kept at a temperature of 24C. Environment 3 will have a low heat and will be kept at a temperature of 16C. The water supply under this condition is to remain normal. Environment 4 will have a high amount of water supplied to them but be maintained at a normal temperature of 21C. Environment 5 is to have a low supply of water, and be maintained at a normal temperature of 21C.

Neoteleostei

Submitted by mtracy on Tue, 10/30/2018 - 09:48

The Neoteleostei is a clade of Actinopterygii fish and includes the Aulopiformes, Myctophiformes, and Stomiformes. All these fish largely dwell at low depths. It is important to note that as we get deeper into the ocean, the diversity of life decreases. These orders are united by several synapimophies, though the most prominent is the presence of a retractor dorsalis muscle, which aids in the manipulation of prey in the fishes phryengeal cavity. Unfortunately little is known about most of these fishes. The Aulopifromes is a bottom dwelling fish (800-15000 ft), which uses its fins to primitively walk along the substrate. This fish has no swim bladder and has a fatty adipose fin. The mouth of this fish is at an odd upward angle. Mychtophifromes, otherwise known as the lantern fish also has an adipose fin on their caudal end. These fish have photophores, which emit light. The light is ethier directly emited by the fish or by bacteria in pockets on the fish. Stomiformies, otherwise known as the dragon fish has similar photophores to Mychtopiformes. These fishes have long barbles located on their "chins" as well.

genetics draft

Submitted by curbano on Mon, 10/29/2018 - 20:46

While gene editing can be used for the wrong reasons, I do like the fact that CRISPR-Cas9 could be used to cure viruses such as Hepatitis B and HIV. This would be life-changing and completely change the world of medicine and treatment for these incurable viruses and other untreatable diseases. Like mentioned in the article, however, genome editing is not quite there to actually do this. While there has been promise of fixing these viruses, there has also been several cases of gene modification that can lead to the virus becoming more violent and aggressive. Although still a work in progress, I can only imagine how expensive it would be to cure things such as HIV, Hep B, leukemia, etc. I do think it would be beneficial to cure these viruses/illnesses, but at the same time who knows how effective gene therapy would be for these types of diseases. I wonder how patients would be after undergoing this treatment and how likely it would be for these diseases to resurface.

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