Survival of the sickest I --- Fava Beans

Chapter 4 of Survival of the sickest is about fava beans. Despite fava beans are type of food, they can be lethal to some people. The beans contain two sugar-related compounds called vicine and convicine. These produce free radicals (un-paired electrons) and some people that eat fava beans experience where the hydrogen peroxide formed from the vicine and convicine attack the red blood cells and break them down. Therefore, fava beans are deadly to people with favism.

Favism is a hereditary disease. This means it is passed on through the genes from a parent to the child. It leads to a form of anaemia. As it is linked to the X chromosome, most people who suffer from it are males. Females are less common than males because of XX chromosome. Favism is also known as G6PD, glucose-6-phosphate dehydrogenase deficiency. People with G6PD have a different circulation of sugar in their body. More red blood cells in their bodies will be destroyed because of G6PD.

Besides fava beans, this chapter also explains about plants in terms of their defense systems and birth control. For defense, plants are good at being toxic. For example, every spicy pepper has something in it called capsaicin. This is what makes it spicy; however, it is also considered poison. To avoid poison, people develop their ability to taste bitterness in order to avoid these poisons in plants. Keep in mind, not everything we eat is good for us. It might be dangerous to our healths, such as fava beans and celery.

Here is a mind map for Chapter 4: 

Summary of Ch. 4 

The Devil---Fava Beans

glucose-6-phosphate dehydrogenase

Red cell burst 

Evolution --- Quiz

Evidence of Evolution Quiz 

1. The following picture presents one of the evidences for evolution, which is the fossil record. The comparison between these fossils shows us that present-day species have morphological features of species in the past. These features further prove that present-day species have been modified from ancestral form. Fossil record is an important evidence for evolution. Even though fossil record is incomplete, fossils can show many evolutionary changes. Some of these changes are gradual, such as the following picture. The picture shows revolutionary changes of species from terrestrial to aquatic.Besides fossil record, homology is also an important evidence for evolution. In this case, limb is the homologous structure between Mesonychid, Ambulocetus, Rodhocetus, and Basilosaurus. Despite Mesonychid lives on land and Basilosaurus lives in water, this picture clearly presents the gradually evolutionary change from the limbs of Mesonychid to the fins of Basilosaurus. 

2. Marsupials begun from North America.  

3. Dragonflies, birds and bats all have the ability to fly. Between birds and bats, limbs under their wings are homologous. This homologous structure proves that they are descendants from a common ancestor. Although dragonflies have legs, they do not have limbs under their wings.This difference of dragonflies' underlying structure indicates that dragonflies are evolved from different ancestral structure. However, dragonflies do contain many similarities of birds and bats. They are all able to fly, and they all have light, broad surfaces. These organisms present convergent evolution. 

4.  During the Common Descent Lab, we are able to link species together by examing the amino acid sequence in the protein, Cytochrome C. Gens are made of DNA and are inherited from parent to offsprings. Some DNA sequences code for the amino acid sequence of proteins. Therefore, by comparing the amino acid sequences, we are able to make a cladogram to show the relationships between species. With the help of cladogram, we are able to see the evolutionary changes between species. For example, the difference between amino acid sequences of cow's and horse's is only, which indicates that cows and horses might be evolved from a common ancestor. This is the reason why the Common Descent Lab shows DNA as evidence of evolution. 

5. As mentioned in Inner Fish, Dr, Shubin found a perfect transitional organism between fish and amphibians, Tiktaalik. In order to prove that Tiktaaklik is the missing link between fish and amphibians, Dr. Shubin proved himself by applying homology. Homology is the study of similar body structures. These similarities imply that single ancestral species branch into many closely related cpecies. For Tiktaalik, the most amazing thing is that instead of having fins on the sides, it has short forearms that enable it to do push-ups. These forearms are similar to the limbs of amphibians. By comparing these homologous structures, we could define Tiktaalik as the perfect transitional organism between fish and amphibians.    

Inner Fish

The book, Your Inner Fish, is an introduction to Biology! Your Inner Fish is mainly about how Dr. Shubin found an organism, Tiktaalik that, for all intents and purposes, is the perfect transitional organism between fish and amphibians.

Dr. Shubin propsed a hypothesis in the book: If all vertebrate land animals descended from a common ancestor that had that limb structure, then we should be able to find that common ancestor in rock of an appropriate age. Based on this general thought, Dr. Shubin then started searching for this partiular transitional oraganism's fossil. Hard work eventually paid off. After years of hardworking, Dr. Shubin finally found this special fish that lived in 375 millions years ago, Tiktaalik.

Why is Tiktaalik so special? It's just a fish, isn't it? NO! Tiktaalik has features both of fish and amphibians. Though Tiktaalik has fins and scales, it has a flat head that is different from other fish. Also, Tiktaalik's eyes are on the top of his flat head, not on the side. The special location of its eyes provides a better view for him on land.  The most fascinating part is that Tiktaalik has short forearms. Forearms enable Tiktaalik to do push - ups so that it can survive and hunt better on land. Furthermore, Tiktaalik is a great example for studying homology. Based on the structure of Tiktaalik, paleontologists could figure out the similarities between organisms and find out more information about evolution.

*Evidence for evolution: Fossil / homology / geology

Dr. Shubin and Tiktaalik

The amazing missing link! --- Tikataalik

Macromolecule part II

Part II. Lab for determining unknown substances / Applying the knowledge of macromolecule 
We have 4 known substances, which are lipid, starch, gluctose and protein. Moreover, we have four testing solutions, which are benedict, iodine, biuret and sudan III. First of all, we test out the reactions for the 4 known substances with the testing solutions. Then, use the results to figure out the unknown A- J solutions.

* Only use test tubes and hot plates when doing benedict's test.  

Macromolecule part I

Part I.  Intro to macromolecule

A macromolecule is a very large molecule, whic is commonly created by polymerization of smaller subunits. Macromolecues have three conventional biopolymers (nucleic acids, proteins, and carbohydrates) as well as non-polymeric molecules with large molecular mass such as lipids and macrocycles.  

The individual constituent molecules of macromolecules are called monomers. 

In - class notes
Cell membrane serves as a security wall.
The sturcture of cell membrane:
1) bilayer, which is phospholipid (phosphate and fat)
2) Imbedde protein
3) cholestera (fluid shape) 
4) carbohydrate ( C, H, O) 
5) Glycoprotein (combination of imbedden protein and carbohydrate)

* #1 is hydrophobic, afraid of water
   # 2, 3, 4, 5 are hydrophilic, like to engage with water
Function of glycoprotein is that it chemically communicates with cells.
Function of imbedded protein: 1) transport 2) enzymatic activity 3) signal transduction / passing signal 4) cell - cell regonition 5) intercellular joining 6) attachment to the cell and protein

HOUSE

HOUSE CASE #1 

During today's class, we had our first House case.

For my very first time, I became a professional doctor. Throughout the class, I learnt that a doctor does not only need to be confident, but also needs to be careful. Since many diagnosis have simliar symptoms, in order to identify the real problem of patients, a professional doctor needs to have certain tests to estimate patients' problems. Moreover, a doctor needs to be careful enough to examine these sympotoms and test results so that the doctor could determine the real problem of the patient.

The patient for House case #1:

He is an 18-year-old senior at high school. He is a cross-country runner. However, after today’s practice, he started to vomit and had a sever headache. Also, he felt extremely tired. He was confused about why he was sent to the emergency room. 

My first three diagnoses: Heat stroke/ aneurysm / Migraines 

 

See the test results and find new diagnoses for next time

Pictures for the lab

cell size and diffusion 

Cell size with diffusion

Potato!! 

Cool colors! Part 1---Diffusion 

LAB---Diffusion and Osmosis

During today's class, we did a combination of labs. This huge lab is divded into five parts:

Part 1: Diffusion/ Part 2: Osmosis/ Part 3: solute % of potato/ Part 4: Solute % of Rehydration Drinks/ Part 5: cell size and diffusion.
After the lab, we organized our data and pluged them in a google doc. This combination of labs helped me to understand more about diffusion and osmosis.

Diffusion & Osmosis

I. Diffusion

Diffusion refers to the process by which molecules intermingle as a result of their kinetic energy of random motion. A distinguishing feature of diffusion is that it results in mixing or mass transport, without requiring bulk motion. According to Fick's laws, the diffusion flux is proportional to the negative gradient of concentrations. It goes from regions of higher concentration to regions of lower concentration. 

II. Osmosis 

Osmosis is the spontaneous net movement of solvent molecules through a partially permeable membrane into a region of higher solute concentration, in the direction that tends to equalize the solute concentrations on the two sides. (Low concentration to high concetration) 

What's your favourite drink?

To be honest, my favourite drink is everything except water. I don't really like water. Yet, water is essential to all living matters.

AGUA! 

 #Waterisimportant
1. Water is the only common substance that exists in the natural world in all three physical states of matter: solid ice, liquid water, and water vapor.
Water is polar because of the difference in electronegativity between hydrogen and oxygen. The highly electronegative oxygen atom attracts electrons or negative charge to it, making the region around the oxygen more negative than the areas around the two hydrogen atoms. Therefore, the charge is unevenly distributed.  

2. Hydrogen bonds

Due to the polarity of water molecules, the small negative charge on each oxygen atoms is attracted to the hydrogen atoms of other water molecules. These attractions are called hydrogen bonds. 

3. Properties of water

1）Organisms depend on the cohesion of water molecules. The hydrogen bonds joining water molecules are weak, about 1/20 as strong as covalent bonds. They form, break, and reform with great frequency. Each hydrogen bond lasts only a few trillionths of a second. At any instant, a substantial percentage of all water molecules are bonded to their neighbors, creating a high level of structure. Collectively, hydrogen bonds hold water together, a phenomenon called cohesion.

2)  Adhesion, clinging of one substance to another, as water adheres to the wall of the vessels.

3) Surface tension, a measure of the force necessary to stretch or break the surface of a liquid, is related to cohesion. Water has a greater surface tension than most other liquids because hydrogen bonds among surface water molecules resist stretching or breaking the surface.

4) Water moderates temperatures on earth. Water stabilizes air temperatures by absorbing heat from warmer air and releasing heat to cooler air. Water can absorb or release relatively large amounts of heat with only a slight change in its own temperature. This is due to the molecular motions between water molecules. 

      The faster a molecule moves, the more kinetic energy it has. As we known heat is a measure of the total quantity of kinetic energy due to molecular motion in a body of matter.

      Temperature measures the intensity of heat in a body of matter due to the average kinetic energy of molecules. As the average speed of molecules increases, a thermometer will record an increase in temperature.

Extra questions: 

What does cabbage have in it that enables it to be a pH indicator. 

Cabbage contains a pigment molecule called flavin (an anthocyanin).Very acidic solutions will turn anthocyanin a red color. Neutral solutions result in a purplish color. Basic solutions appear in greenish-yellow. This is the reason why cabbage can be used as a pH indicator. 

1. Explain how the chemistry of acid and bases affects the indicator.
2. Explain how acid rain would affect red cabbage growth and development.

#1: 
An acid-base indicator is a weak acid or a weak base. The undissociated form of the indicator is a different color than the iogenic form of the indicator. An Indicator does not change color from pure acid to pure base at specific hydrogen ion concentration, but rather, color change occurs over a range of hydrogen ion concentrations. This range is termed the color change interval. It is expressed as a pH range.

Weak acids are titrated in the presence of indicators which change under slightly alkaline conditions. Weak bases should be titrated in the presence of indicators which change under slightly acidic conditions. 

#2:

Since cabbages are pH indicators, and acidic solutions will turn the color of cabbages into red. Therefore, acid rain will increase the growth of red cabbages. Yet, too much acidic solutions will destroy cabbages. Red cabbages would not survive long enough through acid rain.