Inquiry hour 1.2

The most interesting science question is: Is time travel possible? There have been several photographs of people in the past using technology from our time or ahead and having a sense of fashion that seems a bit too modern. Not only is time travel a fascinating science-fiction idea that has been around for decades, but making time travel possible might just help us solve many other scientific questions. For example, time travel can be used to see: how life began, how the universe came into being, will robots take over in the future, will we ever solve global warming?  A current hypothesis for this could be-  if physicists have already planned how to travel back in time and astronauts in the international space station experience time ticking slower, then time travel is possible.

Some questions I have:
How did the universe come into being?
Will the universe ever end? If so, when and how?
Can anything live forever?
Will time ever end?
Will humans ever live on another planet/moon?
For how much longer will the earth be habitable?
How did DNA evolve?
Why are hammer head sharks shaped the way they are?
How did the dionsaurs become extinct?
What will humans evolve into in another 2000 years?
Why can't we remember our dreams?
Why can't we manufacture water?
Why are some people superstitiuos?
Why don't we use up our entire brain?
How did humans become the dominant species?
What would have been the dominant species if humans didnt evolve well?
Will robots ever take over the world?
Can diabetes be cured?
Can stress be a good thing?
How do dogs learn human languages?

Unit 2 Reflection

In this unit, we learned about the chemistry of life. The first thing we learned about was atoms. The three subatomic parts are neutrons,protons, and electrons. Neutrons and protons make up the nucleus at the center of the atom, and the electrons revolve around it. Material made out of one type of atom is called an element. Two or more elements come together to form a compound. Atoms also form bonds. Ionic bonds are formed when electrons are transferred from one atom to another. Double ionic bonds are formed when two electrons are shared. Covalent bonds are formed when atoms are shared between two atoms.

Water works well due to it polarity or unequal distribution of electrons. Its oxygen has a negative charge, but the two hydrogen have a positive charge. Water also is very cohesive, meaning it has a strong attraction with molecules of the same substance. It is also very adhesive, meaning it also has a strong attraction with molecules of different substances. Because of these properties, water makes a great solvent. A solution is a mixture of equal components. A solute is what is being dissolved and a solvent is what the solute is dissolved in. Suspensions have an unequal distribution of the substances. Different substances can also have different levels of acid or bases. The pH scale is used to measure that. The more H+ ions, the more acidic something is. The less H+ ions, the more basic something is. 7 on the pH scale is neutral. Anything lower than 7, from 0 to 6 is acidic. Anything higher than seven, 8-14 is basic.

Four main macro molecules make organic compounds- carbohydrates, lipids, proteins, and nucleic acids. Carbohydrates are sugars. They are made up of rings of carbon, hydrogen, and oxygen. Producers use it to store energy and consumers use it as a source. Monosaccharides are one ring of sugar, disaccharides are two, and polysaccharides are three rings or more. Lipids are long chains of carbon and hydrogen and most are nonpolar. They are used for energy storage, make up cell membranes,and make hormones. There are two types- saturated fats and unsaturated fats. Proteins are used for structure. Nucleic acids are used mainly for carrying out and passing out genetic information. Enzymes are catalysts that help reaction go faster by lowering activation energy. They work best in certain pH and temperature or else they become denatures/deformed.

The themes were mainly the four macro molecules, their structure and function. Enzymes were pretty important as well. I think this unit went pretty well, the only confusing part was the different structures and functions of the macromolecules because there were so many. I think I would like to learn more about nucleic acids. We focused A LOT on carbohydrates, proteins, lipids, and enzymes which mostly have to do with energy and structure of organisms. However, we talked very little about nucleic acids. How exactly do they write the genetic code? How do they carry it out? How can the information for a whole organism be written by a few nucleic acids? What is the structure of DNA?

Cheese Lab

In this lab, we asked the question: what are the optimal conditions and curdling agents for making cheese? We found that warm and acidic conditions are optimal and chymosin is the best curdling agent. Chymosin, rennin, and buttermilk all curdled the milk in five minutes or less in a more acidic environment. Chymosin and rennin showed some signs of curdling in five minutes or less in the heat. Nothing curdled in a colder environment within the time we had. Chymosin was the only enzyme that curdled the milk within the time we had with a time of 20 minutes in a more basic environment. The warm and acidic conditions had the fastest times for all the different enzymes. Since chymosin curdled the milk in almost every condition except the cold, it was the optimal curdling agent. While rennin still curdled milk a little quicker in the pH control, we decided chymosin was better because it curdled the milk in more conditions.

While our hypothesis was supported by our data, there could have been errors due to timing and the control/heat. There could be errors due to timing because our instructions told us to check for curds every five minutes. However, the curds could have appeared after four or even three minutes. So while the data says that milk with chymosin, rennin, or buttermilk under acidic conditions curdled in exactly five minutes, the times could actually be quicker. Another was with the control because the temperature of everyone’s armpit could be different. Some people had jackets on and some did not. This could have an effect on the curdling time as well, because as we can see, warm conditions are better for the reactions to happen. Everyone has a slightly different body temperature, so the cooler people would have slower reactions, and the warmer people would have faster reactions. Due to these errors, in future experiments I would recommend two changes. One, check the curds every minute instead of every five minutes. This will reduce the margin of error. Two, put the mixtures in an environment with a similar temperature to the human body, but make all of them exactly the same temperature.

This lab was done to demonstrate how enzymes work at their best when they are in favorable pH and temperature conditions. From this lab I learned that enzymes work best in certain conditions and not very well in others, which helps me understand the concept of denaturation and activation energy. Based on my experience from this lab, I will be able to change the conditions if I want a reaction with an enzyme to occur faster.

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

Sweetness Lab

In this lab, we asked the question: how does the structure of a carbohydrate affect its sweetness. We found that the monosaccharides are very sweet, and polysaccharides are quite bland; therefore, the fewer the rings, the sweeter the carbohydrate. The monosaccharides fructose and glucose and the disaccharide sucrose were the top three sweetest carbohydrates. Sucrose was used as the standard sweetness at 100. Fructose had a sweetness degree of 115 and glucose had a sweetness degree of 90. The polysaccharides starch and cellulose were extremely bland. Starch had a sweetness degree of 10, and cellulose had no sweetness degree. Since the sweetest carbohydrates were monosaccharides and the blandest were polysaccharides, a carbohydrate is sweeter when it has less rings of carbon, hydrogen, and oxygen.  

Monosaccharides and disaccharides are mainly used as sources of energy for the cell. This is because they are easier to break up since not many rings are bonded together. The polysaccharides are mostly used for forming the cell wall since there are more rings bonded together it is more resistant and cannot be broken apart so easily.  

Not all of the tasters gave the exact same rating. One reason could be that different testers are used to eating different sweetness levels, so someone who eats a lot of sugar will need more sugar for the carbohydrate to be sweet and someone who is accustomed to less sugar needs less for the carbohydrate to taste sweet. Another reason could be that some people are genetically inclined to have more taste buds on their tongue. Therefore, the more tastebuds they have the more flavor they can detect. A third reason is ability smell. It is possible that one person had a cold and a blocked nose, so he or she could not smell very well. Smell helps in identifying flavor.

According to Dr. Robert Magolskee on NPR, the taste bud contains about 50 or 100 taste cells, and maybe a quarter of them are responding to sweetness, and a different percentage of them will respond to salty and sour and bitter. Sweet receptor protein and the sugar encounter each other, they excite the sweet taste cell, and that sends a signal to the brain, to particular centers of the central nervous system that respond to sweetness. In particular for common types of sweet compounds such as sucrose and glucose and fructose, the monosaccharide and disaccharide sweeteners, there are extra pathways, extra mechanisms that allow us to taste something as being sweet. These are sugar transporters and special ion channels, potassium ion channels. The number of tastebuds could play a role in tasters ranking the same samples differently because the more taste buds, the more sweet receptor proteins. Some people will have more proteins to taste all the sweetness.

Sources:

"Getting a Sense of How We Taste Sweetness." NPR. NPR,  Mar. 11  2011. Web.Sept. 16 2015. <http://www.npr.org/2011/03/11/134459338/Getting-a-Sense-of-How-We-Taste-Sweetness>

Carbohydrate	Type of Carbohydrate	Degree of Sweetness	Color	Texture	Other Observations
Sucrose	Disaccharide	100	white	granular	sugar
Glucose	Monosaccharide	90	transparent white	granular	granulated sugar
Fructose	Monosaccharide	115	white	granular	granulated sugar
Galactose	Monosaccharide	50	brownish yellow	powder	powdered sugar
Maltose	Disaccharide	110	white	soft	brown sugar
Lactose	Disaccharide	20	white	soft powder	powdered milk
Starch	Polysaccharide	10	white	sticky powder	potato/corn
Cellulose	Polysaccharide	0	white	soft and sticky	paper

What is Biology?