Monday, May 9, 2011

What I know About The Human Body

After a year of studying nothing but the Systems of the body in 5th grade I am sad to say I don't remember too much. If look broadly at the year I can remember most of the major systems of the body: Circulatory System, Digestive System, Immune System, , Muscular System, Nervous System, Reproductive System, Respiratory System, Skeletal System and Urinary System. I can't remember what I am missing, but I know there are eleven and I have only listed nine. I also remember how a few of these systems work or at least what they do.
The Circulatory System is the the circuit of Blood through out the body. The blood is pumped by the heart. When blood enters the heart through right side it has no oxygen present. But after it has been pumped through the lungs, regaining oxygen, it exits the heart through the aorta to be pumped through the rest of the body.
The Digestive System is the way in which food passes through our body and the nutrients extracted for use. Food enters through the mouth and travels down the esophagus to the stomach. The stomach breaks down the food, but it is the small and large intestines that pull out the nutrients from the food. What is left of the food is then excreted through the anus
I dont remember too much about the Immune System. I all I know is that it protects the body from harmful diseases and other unknown objects. I also know the white blood cells play a big factor.
The Muscular System is pretty basic in the way that it is simply the use of the muscles that hold us upright and allow us to move.
The Nervous System is what allows us to feel. Nerves cover every inch of our skin and travel to our brain allowing us to feel the things that touch us.
The Reproductive System is probably one that most fifth graders remember because it was uncomfortable and scared us all. The reproductive system is simply the way babies are made, the birds and the bee's, sex, etc.
The Respiratory System deals with the lungs and the intake of oxygen into the body and the Skeletal System is the 206 bones in our body that keep us from flopping over.
Finally,  The Urinary System, with out getting too complicated, is the way in which water enters our bodies. This system uses the kidneys and keeps us hydrated.

Sadly this is mostly what a remember from fifth grade. If I really though hard I could probably think of funny things my teacher said or memories from class, but the basic information I know about the human body is all above.

Thursday, April 21, 2011

Genetics Reflection

In our Biology class this week we have learned about genetics. We learned about many dominant and recessive traits, figured out which traits we have, and then discovered which traits out parents and siblings have. Being the youngest of five, theres is no way for me to contacts all of my siblings but I was able to obtain my parents and my oldest sister. Here was some of the data I obtained.

Trait                              Mom                  Dad                Katie            Me 
Tongue  Roller               +                        +                      +                  -

Attached Ear Lobe         +                        -                       +                  -

Hitch Hikers Thumb      +                        +                      +                  +

Widows Peak                 -                         -                        -                   -


By knowing this simple information I was able to figure out my parents genotype for certain traits. Due to the face that both my parents and my sister can roll their tongue and I cannot, it is safe to assume that both of my parents is heterozygous for tongue rolling.  If either on was homozygous dominant then I would have to be able to curl my tongue because I would have to be either homozygous dominant or heterozygous not homozygous recessive. As for hitch hikers thumb, I know for a fact that everyone in my family has one, meaning that most like both my parents are homozygous recessive. 

Being a lefty I took the time to research the topic of handedness. For the past three generations on my mothers side, the youngest in the family has been a lefty, including myself. This made me think that left handedness is a recessive trait and I obtained it because my mom and dad are heterozygous; however, this is not true. I researched handedness and found that much is still a mystery. One thing that they are sure of is that Handedness is not entirely a recessive or dominant gene. When both parents are left handed, meaning they would both be homozygous recessive their children have a 30-40% chance of being lefty. If being left was recessive gene then this would mean that all of their kids would be lefty. Scientists are now beginning to take into account environmental factors and although they are not 100% certain why it is caused, it is something that I am interested to learn more about. 

Wednesday, March 9, 2011

Stem Cell Research

Stem cells are biological cells found in all multicellular organisms that can divide through mitosis and differentiate into diverse specialized cell types or can self renew to produce more stem cells. In mammals, there are two broad types of stem cells: embryonic stem cells that are isolated from the inner cell mass of blastocysts, and adult stem cells that are found in various tissues. In adult organisms stem cells and progenitor cells act as a repair system for the body; however, in a developing embryo, they can differentiate into all the specialized cells but also maintain the normal turnover of regenerative organs.

Embryonic stem cell lines are cultures of cells derived from the epiblast tissue of the inner cell mass of a blastocyst or an early stage embryo ( usually 3-5 days old). Embryonic stem cells are pluripotent and give rise during development to all derivatives of the three primary germ layers: ectoderm, endoderm, and mesoderm. In other words, they can develop into each of the the more than 200 cell types in the adult body. In July 2008 an update on the subject of stem cell research has a potentially revolutionary development. Japanese researcher Shinua Yamanaka discovered how to take ordinary skin cells from and adult mouse, turn back the genetic clock, and transform them into an equivalent of embryonic stem cells. All research to date has taken place using mouse embryonic stem cells or human embryonic stem cells (both have essential stem cell characteristics but need different environments in order to maintain and undifferentiated state); but, after nearly ten years of research there are no approved treatments using embryonic stem cells.

Adult stem cells, also known as somatic stem cells, are different. They are rare but can be found in a number of tissues including umbilical cord blood. A great deal of adult stem cell research had focused on clarifying their capacity to divide or self renew indefinitely. Adult stem cell treatments have been successful for many years to treat leukemia and related blood/bone cancers through bone marrow transplants. Also the use of Adult stem cells in research and therapy is not as controversial as Embryonic stem cells because their production does not require the destruction of an embryo.

In 1981, scientists discovered ways to derive embryonic stem cells from early mouse embryos. The study of the biology of the mouse's stem cells led to the discovery of a method to derive stem cells form human embryos and grow them cells in a laboratory. Embryos used in these studies were created for reproductive purposes through vitro fertilization procedures. Then in 2006 researchers made a breakthrough by identifying conditions that would allow some specialized adult cells to be reprogrammed genetically to assume a stem cell like state. This new type of stem cells are called induced pluripotent stem cells. Because of their generative abilities, they offer a new potential for treating diseases like diabetes and heart disease. Cells can also now be artificially grown and transformed into specialized cell types using cells that can be taken from a variety of sources like an umbilical cord or blood and bone marrow.

As for treatments, medical researches believe that stem cells have the potential to dramatically change the treatment of human disease. New stem cells therapies exist like bone marrow transplants for leukemia and in the future researches anticipate being able to use technologies from stem cell research to treat a wider variety of diseases like other cancers, Parkinson's disease, spinal chord injuries etc; however, there is a great deal of of social and scientific uncertainty surrounding stem cell research. Once concern of treatment is the possible risk that the transplanted cells could form tumors and have the possibility of becoming cancerous if cell if cell division continues uncontrollably.

Wednesday, February 23, 2011

Larons Disease and Cancer

Recently on MSNBC.com, Jennifer Welsh posted a article talking about the link between Laron Syndrome and Cancer. The rare disease causes stunt in growth due to a mutation in the gene that codes for growth hormone receptor (GHR), which causes cells to grow and divide. It has now come to scientists attention that those diagnosed with the disease are immune to diabetes and cancer.  Scientists are now trying to harness what causes there immunity and use it to save others from these deadly diseases.

I had my doubts about this article. First of all, with only 250 people infected, the disease seems very rare so I don't think people will be able to get the disease naturally, especially because it is genetically transmitted. This makes the process seem really risky because they would then have to mutate GHR. I don't think many people want to risk their growth hormones to prevent cancer; however, if they are able to obtain the idea of this disease without putting peoples height at risk, then they are definitely taking a step in the right direction.

Despite my doubts about this article, overall it gave me hope.   Even if the research is unsuccessful, they will still end up with more knowledge of cancer then they had before.

Monday, February 14, 2011

Throat Cancer

Throat cancer is a horrible disease with deathly consequences. It traumatizes all of its inhabitants no matter how severe the case, and leave scars that do not fade with time.

Throat cancer is a general term that applies to cancer that develops in the throat (pharyngeal cancer) or in the voice box (laryngeal cancer). The two cancers are often linked together due to fact that the voice box is located directly below the throat. Within the voice box and throat there are more specific types of cancer. Nasopharyngeal cancer is cancer that begins in the nasopharynx or the part of the throat located just behind the nose. Oropharyngeal cancer begins in a part of the throat right behind your mouth, that includes the tonils. Hypopharyngeal cancer begins in the lower part of your throat just above your esophagus and windpipe. Glottic cancer is cancer of the vocal chords. Lastly supraglottic cancer and subgottic cancer begin in the upper (spraglottic) and lower portion (subglottic) of your voice box. Each of the separate types has a link to its own symptoms, some of which include a cough, change in voice, difficulty swallowing, ear pain, sore throat, unintentional weightless, or a lump or sore that doesn’t heal.

Throat cancer occurs when cells in your throat develop genetic mutations, causing cells to grown uncontrollably and continue living after healthier cells would normally die. What causes the mutations is generally unknown but risk factors show a link to carcinogens like alcohol and tobacco.

Carcinogenesis is literally the creation of cancer. Proto-oncongenes are genes that promote cell growth and mitosis. Tumor suppressor genes discourage cell growth or temporarily halt cell decision to carry out DNA repair. What a mutation is to occur in a proto-oncogene (becomes oncogene) damage would be suppressed by normal mitosis control and tumor suppressor genes. One mutation tumor suppresses would not cause caner either because of many backup genes that duplicate it’s functions. Only when enough proto-oncogenes have been mutated into oncogenese and enough tumor suppressor genes are deactivated or damaged signals for cell growth overwhelm the signals to regulate it and cell growth quickly spirals out of control.

One’s risk of throat cancer increases if they smoke or drink alcohol. People who use tobacco and alcohol together are at more of risk then those who use them separately. Some research also suggests that leukoplakia (white patches in mouth) or erythorkplakia (red raised patches in the mouth) may also be throat cancer risk factors. Most throat cancers develop in adults older then 50 and men are ten times more likely the women. Ethnicity may also be a factor with African American men in the U.S. being found to be at a 50% higher risk of throat cancer than Caucasian men.

When it comes to diagnosing throat cancer doctors have several different options. Doctors may use a special lighted scope (endoscope) to get a closer look at throat during a procedure called an endoscopy. And Laryngoscope is another type of scope that can be inserted in your voice box. If abnormalities are found you can pass a surgical instrument through the scope to collect a tissue sample (biopsy). Imaging tests, including X-ray, computerized tomography scans, magnetic resonance imaging, and positron emission tomography may help doctors determine the extent of your cancer beyond the surface of your throat or voice box. Once diagnosed, the next step is to determine the extent or stage of the cancer. Stages help to determine treatment options per patient. Stages are characterized by roman numerals I- IV and each subtype ahs its own criteria for each stage.

Treatment options are then based on many factors: location and stage of throat cancer, type of cells involved, overall heath, and personal preference. Radiation therapy uses high-energy particles like X-rays to deliver radiation to the cancer cells causing them to die. Another option is surgery. Depending on the stage or type of cancer the procedures vary. For cancer that is confined to the surface of the throat or the vocal chords may be treated surgically using endoscopes. For serious cases of throat cancer there are procedure to remove all or part of ones throat or voice box. Other options include: chemotherapy, uses chemicals to kill cancer cells, and targeted drug therapy, which treats throat cancer by altering specific aspects of cancer cells that fuel their growth.

Rehabilitation after treatment for throat cancer is tough. Treatment often causes compilations that may require working with specialists to regain the ability swallow, eat solid foods, and talk. This terrible disease is one that I would wish on nobody, and hopefully one day we will find the cure.


Sources:






Wednesday, December 15, 2010

Better Then Revenge- Cellular Respiration Song

This week we had to create a project on cellular respiration. My partner and I, decided to take a song and change the lyrics to create an awesome song about cellular respiration. After trying out a few songs we decided that we would use Better Then Revenge by Taylor Swift from her Speak Now album. We sat for an hour and a half, through our double bio class, and created this new song. Actually completing the task was much harder to do then we thought. We hope you enjoy our song, we had a ton of fun writing it.

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Tuesday, November 23, 2010

Tuataras: The Living Fossil

U.N. reports Decrease In New HIV Infections.

Fewer people are being infected with HIV, the virus that causes AIDS, then at the epidemics peak, but progress is still halting and fragile. 2.6 million people were infected in 2009, 20 percent fewer then in the late 1990's. Although about 25 countries are doing better at prevention, including a few in south africa, (high in aids rates) the progress is still spotty.

South Africa, home of the worlds worst AIDS epidemic, benefited from the change in president from Thabo Mbeki, hostile in distribution of AIDS drugs, to Jacob Zuma, who publicly took an AIDS test, urging citizens to do the same. Although south africa still faces 350,000 to 500,000 infections per year, there has been much improved progress to give mother drugs to prevent infection of babies trough breaks milk. Acording to Michael Saibe, executive director of UNaids, there has been a 50% reduction of young deaths in south africa. Some reasons for this are: parents and children are discussing sexuality more, and people are sleeping around less. When 57 countries were surveyed, only 25% said that they had had more then one partner in the last year.

Despite progress being made, some countries, mostly in Western Europe and Central Asia, are becoming worse, where the epidemic on concentrated in heroin- injectors and their sexual partners. The more the heroin spreads the more addictions there are and therefore, resulting in more HIV infections.

There is good and bad news on the treatment front. 5.2 million people are getting antiretroviral drugs, more then there has ever been before; however 10 million people still need immediate treatment. It has been 3o years since the start of the AIDS epidemic and about 33.4 million people are living with HIV. A comparison shows how much progress needs to be done before we can say the world is winning the war on aids: for every 100 people put on treatment, 250 become newly infected. Now it is about 200 become newly infected. It is a small improvement, but an improvement none the less.

Link to Original Article: http://www.nytimes.com/2010/11/24/world/africa/24infect.html?partner=rss&emc=rss

Sunday, November 7, 2010

Osmoregulation in Marine Reptiles

Marine Reptiles consist of animals like crocodiles, sea turtles, marine iguanas, marine snakes. Marine Reptiles have inherited or retained the osmotic concentration of bodily fluids of about 300-350 mOsm (milliosmole), therefore they are hyporegulators.

Marine Reptiles differ from fish or amphibians because they only use their lungs. Lungs don't come in contact with water so they have developed a respiratory epithelium. The epithelium is thin and highly permeable to gasses. The skin is thick and reduces permeability to water. Nonetheless, no epithelial is entirely impermeable to water and marine reptiles still lose some water through their integument to the seawater. Thinner epithelia covering the mouth, nasal passages, and eyes are sites of osmotic water loss.

Despite the relative impermeability of skin, reptiles still face a substantial osmotic load. If they feed on fish, they have food source with an osmotic concentration isosmotic to their own blood. It is likely that they will ingest at least small quantities of seawater with he fish as the capture and eat them.  Other food sources in the sea are osmoconformers and eating them is equivalent to drinking salt water. This poses problems for crocodiles, feeding on crabs, turtles, feeding on jellyfish, and marine iguanas, feeding on algae.

Marine Reptiles maintain osmotic homeostasis by excreting a hyperosmotic, sodium chloride-rich fluid from their bodies in the surrounding waters. This is carried out by a epithelia in the head region. Crocodiles have glands in the tongue that can secrete hyperosmotic fluid. In sea turtles, it is carried out by the lacrimal (tear) glands surrounding the eye. In marine iguanas, nasal glands are the site of active salt transport. The situation with marine snakes is a bit more uncertain.

Wednesday, October 13, 2010

Clostridium Tetani

Clostridium Tetani is a rod shaped bacteria that is found as spores in soil or as parasites in animals. C. Tetani produces biological a biological toxin called tetanospasmin, which causes tetanus. Tetanus is a disease characterized by muscle spasms tetanospasmin, which can lead to respiratory failure and, 40% of the time, death.

Characteristics:
C. Tetani bacteria are rod shaped and look like mini tennis rackets. During their growth process, they cannot survive in the presence of oxygen and are heat-sensitive. As they mature, the bacteria develops ad terminal spore which gives them their characteristic appearance. Their spores are extremely hardy and resistant to heat and most anesthetics. The spores can be found in manure treated soils, human skin, and contaminated heroin.

Toxicity: 
C. Tetani enters through a wound in the skin and then multiplies. Once infected it produces two exotoxins: tetanolysin and tetanospasmin. The tetospasmin is distributed in the blood and lymphatic system. It acts at several sites with in the nervous system: the peripheral nerve terminals, spinal cord, brain, sympathetic nervous system. Then it attaches to gangliosides at the presyneptic junctions of inibitoty more nerve endings. The clinical manifestations are caused when tetanus blocks the inabitory implies, which interferes with the neurotransmitters. This leads to muscle contraction and spasm. Characteristic features are risus sardonicus (rigid smile), trismus (lock-jaw), opisthotonus ( rigid arched back). Seizures may also occur. Because of this, the autonomic nervous system may also be effected.

Types of Tetanus: 
Generalized Tetanus is the most common type of tetanus (80%). The first signs of generalized tetanus are risus sardonics and trismus. Then comes the stiffness of neck, difficulty in swallowing and regidity of pectoral and calf muscles.
Neonatal Tetanus if a form of Generalized Tetanus that occurs in newborns. It accounts for 14% of all neonatal deaths. Infants with out acquired passive immunity because their mothers have never been immunized are at risk. The infants are usually infected though the umbilical stump.
Local Tetanus is very uncommon and is more mild then Generalized Tetanus and only 1% who are infected die. It occurs in contractions of muscles around the area of the injury.
Cephalic Tetanus is a rare form of the disease that occasionally occurs with ear infections. C. Tetani becomes present in the flora, middle of the ear, following injuries to the head.

Image sources:/
www.google.com/imgres?imgurl=http://farm1.static.flickr.com/205/519944432_858d235bef_m_d.jpg&imgrefurl=http://www.microbiologybytes.com/blog/2007/07/20/the-surface-layer-protein-of-clostridium-tetani/&usg=__ispMGGzzsAPI9uBmD75-


www.google.com/imgres?imgurl=http://phil.cdc.gov/PHIL_Images/20041014/19f02a819c8f4352804bc5abbdd820c0/6374_lores.jpg&imgrefurl=http://prep4md.blogspot.com/2008/08/medically-important-bacteria-images.html&usg


Sources: 
http://bioweb.uwlax.edu/bio203/s2008/unrein_bren/


http://student.ccbcmd.edu/courses/bio141/lecguide/unit1/prostruct/diseases/ctetani/ctetani.html


http://www.cdc.gov/ncidod/diseases/submenus/sub_tetanus.htm 

Thursday, October 7, 2010

Macromolecules Lab

This week, we conducted a lab testing for four different macromolecules like starch, protein, lipids, and glucose. Each pair was given a food (apple, onion, lemon, egg white, egg yolk, potato, strawberry) and they were to test which of the macromolecules was in each of them. We tested for most of the compounds by mixing them with things like biuret solution and Lugol's iodine solution and see if they changed the right color; however, to test for lipids and glucose was a bit more complicated. To test for lipids you had to take your food and rub it on a piece of brown rapping paper and let dry. To test for proteins you had to mix Benedict's solution with the food and then place it in a hot water bath. If it changed a bright orange color then it contained glucose.


My partner and I were given apples. We predicted that apples would have protein, glucose, and starch. You can see in the picture to the right that when we tested for each compound we found that it did not contain proteins.

I really enjoyed this lab. I can't speak for the other students but I know I don't normally look at the nutritional facts of the side of the box, so it was really interesting to see what was in foods that we eat on a regular basis. For instance, I would have never known an egg white contains sugar. Or that a lemon doesn't contain any of the four groups that we tested it for. For our first lab I think it was very enjoyable and interesting. It wasn't very complicated and we were working with very familiar substances which also made the lab more enjoyable. Over all I really liked that lab and I thought it was very interesting. 


Wednesday, September 22, 2010

Properties of Water

Water is one of the most important substances on the planet. Not only does it cover 2/3 of the earths surface, but we also use it to clean, drink, and make electricity. Most importantly water makes up 65% of our bodies making it absolutely impossible for us to live with out. There are many properties that differentiate water from other substances.



Polarity
Polarity means that the molecule has a slightly negative and positively charged end. Because water is polar it means that it can dissolve other polar molecules like sugar and ionic compounds like salt. Because the water molecules have a slightly negative and positive side the negative end of on molecule will attached to the positive side of another molecule create hydrogen bonds. Hydrogen bonds are a relatively week bond but they are the reason for adhesion and cohesion.


Adhesion/Cohesion
water is both adhesive and cohesive. Adhesion is how water is sticks to other things. A great example of this is called capillary action. When you place a straw in a glass of water the water climbs up the straw. This shows adhesion and how water sticks to other substances. The opposite of adhesion is cohesion. Cohesion is when water sticks to itself. An example of this is when you see beads or droplets of water. The water likes to stick to itself as oppose to spreading out.


Surface Tension
Surface tension is the tightness across the surface of water that is caused by the polar molecules pulling on one another. If an item is light enough and doesn't beak the surface of the water it will float on top of the water. This is how bugs can sometimes walk on top of water.


Specific Heat
Specific heat is a a characteristic property that determines the amount of heat needed to increase the temperature of a substances one degree Celsius. Water has a very high specific heat. This is why when your at the beach on a very hot day the sand feels very hot but the water stays cool. The sand has a lower specific heat which allows it to heat up quicker while the water remains the same temperature.


Amphotermism:
Water is amphoteric, which means that it can act as either an acid or a base in chemical reactions. According to the Bronsted-Lowry definition, an acid is defined as a species which donates a proton in a reaction, and a base as one which receives a proton. When reacting with a stronger acid, water acts as a base; when reacting with a stronger base, it acts as an acid.


Density/Lattice Formation of Ice:
Water is unlike any other substance because its solid form is less dense then its liquid form. When water is a liquid it is always breaking and creating new hydrogen bonds, so the molecules sit very close together and make the liquid very dense. As the liquid cools down and freezes the molecules don't move around as much making the bonds much more stable. When the liquid freezes the water molecules create lattice formations which are farther apart then how the molecules sit as a liquid make ice less dense than liquid water. 


http://www.youtube.com/watch?v=4auXUSY9c54 <- Click here to watch a youtube video on the properties of water. 



Sunday, September 12, 2010

Self Reflection

This year I am excited to learn about the study of life. Science has always been one of my favorite subjects and I'm sure this year will be the same. I hope that by the end of year I will have a better understanding of the organisms around me. I want to learn all about cells and DNA. Biology has always interested me and I am excited to learn more about the subject. New technology will help this year. Our blogs will allow my class mates and I share our work and help us understand the material. Also with new information being found everyday the internet allows us access to new information. I am thrilled to be in Honors Biology and excited for all we will learn this year.