20 Scientific Questions About the World Around Us

From the article, The 20 Big Questions in Science, the one "big" question that I found very interesting was: Why do we Dream? I thought that it was fascinating that we spend over a third of our lives sleeping and I've always wondered where the sometimes random dreams that I have come from, and what sparks them. There are two possible hypothesis for this question: that dreams are "expressions of unfulfilled wishes," or "random firings of a sleepy brain."

Here are 20 "big questions" of my own:

1. When we look at many animals from the same species, they seem identical to us. Do other species think the same thing of us humans?

2. Roughly when and how did the first human being evolve?

3.  How did scientists come to know so clearly about the structure of the whole universe when space probes nor people have explored that far?

4. Were humans initially intended to consume dairy?

5. Is there scientifically such a thing as a genius? If so, what in their DNA gives them these special qualities?

6. If a child has a physical or mental disability, when in their childhood will signs of this start to show in their behavior?

7. What makes some cancers more life-threatening than others?

8. If a cancer is diagnosed sooner, does that mean that the patient has a greater chance of being cured?

9. If it is said that babies don't have long-term memory, how long will they remember each event that happens to them? How long will it stay in their memory?

10. As time progresses, will people begin to live longer and longer each generation?

11. Why do some genetic disorders develop later in life?

12. Why don't any children remember their infancy?

13. Which continent on the Earth became inhabited first?

14. What is the most common species on the Earth?

15. How are viruses fought by the body, and why do they not require antibiotics?

16. Why are people more likely to be woken up in certain times of their sleep than other times?

17.  Are you more likely to have dreams if you go to bed preoccupied?

18. Does growth happen in spurts?

19. What are some major technological advancements that might happen in our lifetime?

20. Why can't we get vaccinated for common colds?

Identifying Questions and Hypotheses

Is GMO safe?

On the Center for Food Safety, it is explained how scientists have conducted an experiment to test whether or not GMO foods are safe for us to eat. Even though some people (such as GMO seed developers), are saying that these GMO foods are safe to eat, there is no scientific evidence for that. The study proves that there is still valid concern about the safety of genetically engineered foods. The question that the scientists asked in this study was "Is GMO safe?" There has been quite a bit of speculation by scientists that GMO foods are not safe to eat. There has been international recognition that acknowledges the risk posed by GMO's. The scientists conducting this study hypothesize that GMO foods do pose some risk, as engineering foods is very different from conventional breeding. There were also previous aspects that led the scientists to form this hypothesis such as concerns regarding the spread of herbicide weeds, negative health impacts, and increasing the use of herbicide.


Center for Food Safety (Source) 

Unit 2 Reflection

This unit, titled "Chemistry for Biologists" gave us a basic understanding of chemistry as it relates to biology, the study of life. We learnt about the basic structure of all matter, the atom. Exploring deeper into the structure of the atom, we learnt about protons, neutrons, and electrons, where protons and neutrons are roughly equal in mass, but an electron is 1/1840 of the mass! Atoms can bond with each other either in an ionic bond (transfer of electron(s)) or a covalent bond (sharing of electron(s)). I feel strong in this area, and I understand atoms, elements, and how atoms bond with other atoms. We studied "the big 4" macromolecules (giant molecules formed during polymerization): carbohydrates, lipids, proteins, and amino acids. We needed to understand both their structure and function. Carbohydrates look like rings of carbon, hydrogen, and oxygen, and can be either monosaccharides, disaccharides, or polysaccharides, depending on how many of these "rings" are chained together. Proteins are made of amino acids and have four levels of structure: primary, secondary, tertiary, and quaternary. Nucleic acids are formed from nucleotides, which are made up of a nitrogenous base, a 5-carbon sugar, and a phosphate group. I think that the structure of carbohydrates, proteins, and nucleic acids is an area of strength for me, but the structure of lipids is a weak point. I understand lipids are long chains of carbon, hydrogen, and oxygen, but I can't really visualize the general structure. In class, we also discussed and performed experiments about enzymes and how they work best in their optimal pH and temperature.

Learning about the basic chemistry to understand life science was a great experience for me because it helped me understand the science behind many routines we have in our everyday lives. For example, we are told often to eat certain foods because they have protein in them and are good for us. However, before this unit, I did not know how amino acids were broken down and then rearranged to create new proteins.

During this unit, I found enzymes very interesting. I want to learn more about what reactions they speed up in our bodies and why we cannot live without them.

Cheese Lab Conclusion

In the lab in which we researched which conditions and which curdling agents would be optimal for making cheese. We tested four curdling agents: chymosin, rennin, buttermilk, and milk as a control. To see which pH conditions were best, each curdling agent was tested in acidic conditions, basic conditions, and a neutral pH control. In order to find out which temperature conditions were optimal for the enzymes to work best, each curdling agent was also tested in a hot temperature, a cold temperature, and temperature control. We found that chymosin and rennin are the most effective curdling agents, and their optimal conditions are in warm and acidic environments. The lowest curdling time in the experiment was found under acidic and warm conditions, the lowest time being 5 minutes. Under many of the conditions we tested, such as basic and the controls, the only curdling agents which produced curds were chymosin and rennin. Milk did not produce any curds in 35 minutes, our given amount of time, while buttermilk only produced curds in acidic conditions. Rennin is an enzyme which in found in the lining of a baby calf’s stomach, in which the conditions are warm and acidic. This explains why warm and acidic conditions were optimal. This data support our claim because the numbers show that chymosin and rennin produced curds in the least amount of time (5 minutes) in a warm and acidic environment.

While our hypothesis was supported by the data, there could have been errors due to the fact that we checked for curds every 5 minutes. The data shows that under acidic conditions, chymosin, rennin, and buttermilk all curdled in exactly 5 minutes. This is a false conclusion to make because it is highly possible that one or more of the curdling agents curdled before 5 minutes. However, we did not account for this because we only measured time every 5 minutes. This was probably an accuracy error. To avoid this error we could have checked for curds every 2 or 3 minutes instead of 5. Also, there was some error in lack of accuracy in timing. We added the acid, base, and water control to each test tube at slightly different times, and more time had passed still by the time we recorded our initial time and officially started the five minutes. This may have affected the experiment in that the first time we checked for curds, it had probably been more than five minutes. In our data, it shows that buttermilk, rennin, and chymosin all curdled in 5 minutes in the acidic conditions. This may not have actually been true. In the future, it will be better to be more prompt with added the acids and bases and recording the initial time.

This lab was done to demonstrate an understanding of how enzymes work and how they speed up chemical reactions. From this lab I learned that there are clear differences in the results when enzymes are in their optimal conditions, which helps me understand the concept of how enzymes work best in their optimal pH and optimal temperature. Based on my experience in this lab, I now understand that to produce best results, it works well to use as many substrates and enzymes as possible, in their optimal conditions.

	Time to Curdle (minutes)
Curdling Agent:	Chymosin	Rennin	Buttermilk	Milk (control)
Acid	5	5	5
Base	20
pH control	15	10
Cold
Hot	5	5
temp control	10	10

        In the lab, we wanted to find out which carbohydrates tasted the sweetest: monosaccharides, disaccharides, or polysaccharides? Carbohydrates which are monosaccharides and disaccharides have a significantly sweeter taste than carbohydrates which are polysaccharides. Fructose, which definitely stood out as the sweetest carbohydrate, had 180 as its degree of sweetness on a sweetness scale of 0 to 200. We set the sweetness level of sucrose as 100 initially, and then worked around it as we tasted all of the other carbohydrates. We chose fructose to be 180, significantly sweeter than sucrose. Sucrose and fructose, both monosaccharides, tasted sweeter than all the other carbohydrates that were sampled. The lowest numbers on the sweetness scale were both given by polysaccharides: starch and cellulose. Starch and cellulose both had fine, powdery textures, and tasted very bland, without the faintest hint of sweetness. While collecting initial information, we found that sucrose and fructose, the sweetest tasting carbohydrates, are both found in fruit, table sugar, sugar cane; foods which have a sweet taste. Polysaccharides such as starch and cellulose are found in foods such as potatoes and vegetables, which have a bland, non-sweet taste.
   
     Polysaccharides are made up of many monosaccharide rings that are all bonded together. Since a chemical bond is stored energy, if there are more bonds, then there is more energy in that carbohydrate. Therefore, if an organism were to eat a carbohydrate that was a polysaccharide such as starch or cellulose, that organism would benefit from the energy. As humans, we try to eat foods that contain carbohydrates such as starch before a long run because of the amount of energy stored in it. Polysaccharides such as starch would probably be more desirable due to this energy.

   Although every person tasted the same carbohydrates, they gave different ratings on the sweetness scale. Everyone would have tasted the carbohydrates in a unique way because their taste buds taste different substances differently. Also, taste is something that is extremely subjective, and prone to observer bias, so the numbers would have certainly varied. There might have also been error of the taster due to whether they accurately remembered the sweetness of each carbohydrate. Even though the ratings varied, the overall trend was the same. Most people found that polysaccharides tasted less sweet than the monosaccharides and disaccharides.

    According to NCBI, for any food that we eat or drink, there are taste receptors in the taste buds on the mucous membrane that test the taste of food. Chemical substances from the food are recognized by the sensory cells. According to Popular science, people who have a lot of papillae on their tongue taste certain flavors stronger than others who have less papillae. The chemicals on our tongue that trigger recognition of the five senses vary between people, causing them to taste foods slightly differently. This may have caused some of the varying ratings in our sweetness lab.

Biology Collage