What do I know about the Human Body... not too much actually.

Honestly, the only time I can remember studying a system in the human body was back in 5th and 6th grade. In 5th grade we learned about our heart and how it works. Then in 6th we learned about the digestive system and how many calories a whale eats in one day. I can remember doing a project where we used the total number of calories a whale eats each day (which I believe is north of a million) and then figured out how many cheeseburgers and French fries that would amount to. Considering we eat about 2,000 calories each day, think about how much food 1,000,000 calories would be. I'll give you a hint, its a lot.

So what can I tell you about the digestive system?Well, I can tell you it begins with the consumption of food. It is then broken up into smaller molecules by stomach juices that are made in the liver and I believe also in the pancreas. The broken down molecules eventually make there way to the small intestine. From there it is broken down further and turned into waste. I think from there we all know what happens. Also throughout this process all the nutrients and other good things that are broken apart are put to good use and absorbed into cells. This process is what gives us energy to do things, this is why we need food.

I can briefly talk about the heart and how it functions. In 5th grade we did a lab, and we found out exercise made our heart beat faster. Then we took it even further and had to draw a diagram of the heart and where it pumps blood. I found out that human blood is blue until it comes in contact with oxygen, which as a 5th grader I found mind-blowing. I always wanted to see blue blood, and every time I got a cut I thought there was a chance it would be blue for a second before would come in contact with oxygen. Sadly, I have since realized this is impossible because the second it leaves my body it is exposed to air. Anyways from what I can remember there are things called ventricles, a right one and a left one. I think those pump blood one has un-oxygenated blood and the other has oxygenated blood. Then there is the renal artery, which I think we talked about this year, and I think that carries impure blood to the kidneys. Anyway that's all I can tell you about the human body and how it works.

Mendelian Genetics... why can I flip my eyelids?

During this week in science, we started researching Mendelian genetics. In our research, we have studied certain genetic traits in our families. Those traits include, being able to roll ones tongue, having a widow’s peak, hitchhiker’s thumb, and attached or unattached earlobes. After researching what traits my parents have in comparison to my own, I can determine some of my own genotypes for these traits. First, I tested their ability to roll their tongues. My dad could, whereas my mom could not. Because this is a dominant trait, I know that my mom is homozygous recessive, and both my dad and I are either homozygous dominant or heterozygous. Next I found if either of them had a widows peak.  Like myself, my mom does not, however, my dad does. Because this is a dominant trait, my dad is either homozygous dominant or heterozygous, and my mom and I are homozygous recessive or heterozygous. After that I determined if they had attached or unattached earlobes. My mom’s earlobes are unattached like mine, but my dad’s are attached. Having an attached earlobe is a dominant trait; therefore I have to be homozygous recessive or heterozygous. Finally, I determined if they had hitchhikers thumb or a straight thumb like myself. Both of them have straight thumbs, and due to the fact that having a hitchhikers thumb is a recessive trait, I must be homozygous recessive. Although this was an interesting study, I wasn’t really surprised to find that I am a mix of both my parents. However, the one thing I did find interesting was the fact that I can flip my eyelids back over themselves, but no one else in my family can, not even any of my cousins, aunts or uncles. I’m guessing this is a recessive trait and I wonder if some past relative of mine was able to do it as well, and if it comes about in our family ever so often???

Influenza Vaccine- Don't let the flu bug get you!

As we all know, an Influenza vaccine, or what is more commonly referred to as a “flu shot,” is preventative measure to protect oneself from getting the flu. However, most of us are unaware of the science behind this truly remarkable and safe substance. Each year scientists go to work on creating a vaccine different from that of the year before. Through extensive research they determine what genus of influenza is most likely infect people in the upcoming year, and use those virus strains in the vaccine. 

Because Influenza is a RNA virus, it is constantly changing and evolving. Therefore, scientists need to begin preparations for the next flu season well before the current season is over. The vaccine is made up inactivated viruses, which is just a scientific way of saying the viruses are dead. The vaccine usually contains type A as well as type B viruses that are grown in chicken eggs. For those viruses to go from eggs into the common, injectable flu shot that is in almost every drug store during the winter, they must first be inactivated (killed) by formaldehyde, purified and packaged into a vial or syringe. This process takes approximately six months, so you can see why it is important for scientists to predict what type if influenza will be present six-months or a year down the road.

 Influenza is most commonly contracted through the air from someone sneezing or coughing, but you can also getting it by coming into contact with someone’s spit. The virus then makes its way to the respiratory tract where it attaches to the plasma membrane of nose, mouth, and throat cells. It then enters the cell’s cytoplasm, and from there it goes to the nucleus.  The virus deposits its RNA, which will then be replicated. Those replicated virus particles then go and affect other cells in a process called lyses. The growing amount of infected cells weakens your immune system and increases your chances of a pneumonia related death. Influenza is a difficult disease to deal with, because medications can only be used to treat the symptoms of the disease and not the disease itself.

Laron Syndrome

Laron Syndrome

Austin Holmes

2/23/11

I found the article about short Ecuadorian in relation to cancer to be extremely interesting. The one thing I found that was a little odd was that it said the Ecuadorians with Laron Syndrome were immune to cancer and diabetes. However, the doctor from Ecuador who conducted research on 100 of the patients said that one of the patients had non-fatal cancer. Those two pieces of information contradict each other so I was a little confused about that. 

I also thought this article definitely applied to our study of the cell cycle because it is a result of a mutated gene. It ties in very well with our study of how cancer is caused at a molecular level. In this case what happens is the gene binds with human growth hormone in our body, and produces Insulin-like growth factor 1 or IGF1 this causes the cells to grow and divide. I did find it a little bit surprising how the rates of IGF1 can affect your chances to get cancer. This information definitely gives me hope that cancer is curable. If we can manipulate the rates of IGF1 in our body to reduce cancer many lives can be saved. With each new piece of information I become increasingly more confident that one day we will be able to find a definitive cure for all cancers.  

Non-Melanoma Skin Cancer

Non-melanoma Skin Cancer

Austin Holmes

2/13/11

When you hear the term skin cancer you probably think of Melanoma. However, there are two other main types of skin cancer that, although are less deadly, are still important to be aware of. First, there is basal cell carcinoma. The word carcinoma implies that it rises from the epithelial tissue of the skin.  Basal cell carcinoma accounts for approximately 75% of all skin cancer, and is the least dangerous because it rarely metastasizes, meaning it is unlikely to spread to other parts of the body. Next there is squamous cell carcinoma, which makes up approximately 20% of skin cancer. Although it is still very rare, this type of skin cancer is more likely to spread to other parts of the body through metastasis, because it is slightly more aggressive. Squamous cells are thin, flat cells make up the top layer of your skin, which is called epidermis. Directly below are the basal cells, which are rounder and more thick. Although these two types of skin cancer can appear anywhere on the body, they are more likely to occur in areas that come in contact with the sun frequently. Such as the face, neck, hands, arms, and legs.

Both types of these skin cancers are caused by ultraviolet (UV) radiation from the sun or other sources like tanning beds and sun lamps. However, research has shown that basal cell carcinoma comes as a result of gradual sun exposure, like that received on a vacation. While squamous cell carcinoma is more likely to occur in people who constantly are exposed to sun.

There are many different factors that make you susceptible to getting skin cancer. The highest rates of skin cancer are found in South Africa and Australia, both of which are places that receive high amounts of UV radiation from the sun. You are more likely to develop skin cancer if your skin freckles and burns easily, or does not tan. Things you wouldn’t expect, like the color of your eyes can also play a role in getting skin cancer. People with blue, green or other light-colored eyes are more likely to develop skin cancer. Other factors like having blonde or red hair, having past treatment involving radiation, and being male make you more prone to getting skin cancer as well. Even your ethnicity plays a role. Hispanics and blacks are much less likely to have skin cancer than whites.

Although I was unable to find out exactly how squamous cell and basal cell carcinoma skin cancer are caused at a molecular level, I do know that the UV radiation from the sun damages the DNA in the skin cells. From the knowledge I have gained from bio class I know essentially what happens. It begins with a genetic alteration in your cells. The UV radiation from the sun tampers with the proto-oncogenes, which are involved in promoting cell division, and turns them into oncogenes. The oncogenes increase the rate at which the cell cycle occurs, because they no longer stop at tumor suppressors, which normally would act as stop signs. This then causes a clump of mutated cells or a tumor to form.

Skin cancer is the most common form of cancer, and in the U.S. alone there are 1 to 2 million new cases of non-melanoma skin cancer each year, and half of Americans who live to be 65 will develop some form of skin cancer. Although most cases are found in patients over 50 years of age, it is mainly caused from exposure to UV radiation during the first 20 years of a person’s life. Fortunately, skin cancer is very treatable, especially when caught early. Out of all the 1-2 million cases of non-melanoma skin cancer each year there are only 2,000 deaths. In contrast, melanoma only accounts for approximately 5% of skin cancer, with about 53,600 cases each year. However, it is responsible for more than ¾ of deaths. 7,400 people die each year in the U.S. of melanoma.   

 The good news is that taking small precautionary action can go a long way in preventing skin caner. Doing things like, limiting your sun exposure between 10 A.M. to 4 P.M. can make a huge difference. Another thing that can help is applying SPF 30, or higher, sunscreen regularly. Covering your skin also helps. Wearing brimmed hats and tightly woven clothing while you’re outside is very helpful, because if your skin is not exposed to the UV radiation from the sun you are protected. Also never remain in tanning beds for extended periods of time; they have UV lights that can be harmful to your skin.

If the appearance of your skin changes, possibly in the form of a growth or sore that will not heal, you should not hesitate to seek medical attention from you doctor so you can receive a diagnosis. The sooner skin cancer is diagnosed, the more treatable it is. Depending on the stage of the cancer, the size, the type, and the patient’s health, different treatment methods can be used. Small cancers in easily treatable areas can simply be scooped out with a curette, which is a spoon like instrument, and then left to heal with out stitches. If the tumor is larger it can be surgically cut out and stitched up. Radiation therapy is used on tumors that are hard to be removed surgically. However, in order to achieve a good result, their needs to be 25-30 sessions, this obviously varies for every case. The final way is called Cryosurgery. This method is not un-similar to having a wart removed. Liquid nitrogen is applied to freeze and kill the mutated cells.   

In conclusion, skin cancer is not something that should be ignored or dismissed, and should be taken very seriously, especially when you have been diagnosed with it. That being said if it is discovered and treated early enough, you will most likely survive with nothing more than scar left behind as a constant reminder.

Sources:

·      http://www.medicinenet.com/skin_cancer/article.htm

·      http://www.cancer.gov/cancertopics/pdq/treatment/skin/Patient

·      http://www.cancer.org/Cancer/CancerCauses/SunandUVExposure/skin-cancer-facts

·      http://www.cancer.org/cancer/skincancer-basalandsquamouscell/detailedguide/skin-cancer-basal-and-squamous-cell-what-is-basal-and-squamous-cell

·      http://www.mayoclinic.org/nonmelanoma-skin-cancer/

·      http://www.cdc.gov/mmwr/preview/mmwrhtml/rr5104a1.htm

Photosynthesis

I made this SketchFu on Photosynthesis to show everything we have learned so far. However, I am also going to write about Photosynthesis to help further explain it. Photosynthesis has two main steps the Light Reaction and the Calvin Cycle. First we have the Light Reaction which takes place in the thylakoid membrane. Its purpose is to convert visible light into chemical energy, which in turn powers the production of sugars in the Calvin Cycle. Chlorophyll and other pigments inside the thylakoid absorb most light but reflect green light, which is why most leaves appear to be green. Those pigments form two clusters, photosystem I and II. As you will see in this presentation the PSII actually comes before PSI. This is because PSI was discovered first. Photons from the suns rays give the electron, located in PSII, extra energy causing it to jolt to other molecules. These molecules are known as electron carriers, and they are embedded along the thylakoid membrane. They are located in such a way that allows the electrons to move easily. Once the electrons reach PSI they are given an energy boost allowing them to reduce NADP+ into NADPH. However, these electrons need to constantly be replaced. To do this, water molecules are broken down into 2H+, 2e-, and O2. This leaves H+ ions, situated in the lumen, which are then pumped across the ATP Synthase to create ATP. 

Next there is the Calvin Cycle. Using the ATP and NADPH created by the Light Reaction as well as three CO2, the Calvin Cycle creates a networth of 1 G3P or PGAL which as you may recall is half of a glucose. However there are steps that need to occur before this happens. First a molecule of CO2 bonds with a 5-carbon sugar, thus creating an unstable 6-carbon molecule that immediately separates into two 3-carbon molecules. Now keep in mind that with three molecules of carbon dioxide there would now be 6, 3-carbon molecules. Each one of those needs one ATP and one NADPH to re-shape and lose a phosphate. Other reactions cause this to rearrange to form the PGAL, which then produces a 5-carbon sugar-phosphate.  Another molecule of ATP is then used to add another phosphate to this, producing RuBP.  So with 3 carbon dioxide molecules six PGALS would be created, five of which would be used to regenerate RuBP. Leaving the plant with one PGAL to use for growth.  

P.S. I think weather and the amount of water will affect the rate of photosynthesis.



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