March 2019

Diffusion In Agar Cubes

Biology 12, Leave a comment
  1. In terms of maximizing diffusion, what was the most effective size cube that you tested?

The most effective size that we tested is the smallest cube, which is the 1 cm3 cube.

  1. Why was that size most effective at maximizing diffusion? What are the important factors that affect how materials diffuse into cells or tissues?

The smallest size was most effective at maximizing diffusion because the surface are to volume ration is the biggest, the NaOH could cover more percentage of the agar cube’s surface area that make the diffusion the most effective.

  1. If a large surface area is helpful to cells, why do cells not grow to be very large?

When there is a large surface area, the volume of the cell always become big. And it would take a longer time to diffusion that means the cell need long time to grow very big.

  1. You have three cubes, A, B, and C. They have surface to volume ratios of 3:1, 5:2, and 4:1 respectively. Which of these cubes is going to be the most effective at maximizing diffusion, how do you know this?

The cube C is the most effective at maximizing diffusion because the surface to volume rations id the biggest.

  1. How does your body adapt surface area-to-volume ratios to help exchange gases?

Our body has a large ratios of surface area to volume, which make the rate of gases exchanging big.

  1. Why can’t certain cells, like bacteria, get to be the size of a small fish?

Cells like bacteria cannot get to be the size of a small fish because they need to divide in order to keep a good surface area to volume ratio.

  1. What are the advantages of large organisms being multicellular?

When the large organisms being multicellular which means the cells become small and the surface area to volume rations become bigger, and it could help the diffusion become better.

agar in NaOH after 10 minutes

cut them in half to see how the diffusion goes

environmental ethic

Geography 12 Leave a comment

In this film, the dogs lived on a garbage island, which makes me think about where the garbages go after I throw them away. They are not disappeared, but move to another place that I don’t know. And I’ve noticed that there are many of them were in the sea and gathered on the island.

when there is a new phone, the commecrials are evrywhere and makes me want to change my phone eventhough my old one is still good. At that time, I am not thinking about the environemnt, how the old phone would go and might produce more electronic waste that would cause bad pollution.

Ethic of care

Geography 12 One Comment

Key Question: What would an ethic of care towards the environment look like?

  1. What would be needed to create it.

We need to see the environment as a person that need care from us.

  1. What would we have to believe about the environment? How should we see it?

People should believe that the environment is very important to human, we need to protect it in order to save our life and we also need to believe that what we did really impact the environment a lot, so we need to be careful about our action.

  1. How would we act? – give scenarios

When there is ethic of care, we would think about the environment every time before we do something to it. For example, when we need to cut down tress to built houses or making papers, we would think about where would the animals go. When we use plastic bags, we might think about how the plastic affects the environment and try to reducing the time use it.

  1. What would be different about the world if everyone adopted this ethic of care towards the environment? Benefits and drawbacks?

There would be many benefits when we adopted this ethic of care towards the environment because we live on the earth and the environment is really important in our life. When the time we really care about the environment, we would make our life better and have a better balance. But there are also drawbacks, as we use the resources from the environment, we need to use it to improve our life. The ethic of care would reduce many chances and convenience in people’s life.

  1. Should we adopt an ethic of care towards the environment?

I think we need to adopt an ethic of care toward the environment because I feel we can’t live without the environment, when we use the resources, we really need to think about it in order to keep the environment as before. But maybe not too much because there would be too many restrictions, and we need to live our life.

Brazilian Jiu Jitsu and Physics

Grade 12 Leave a comment
  1. Introduction (a brief overview of why torque would be used in Brazilian Jiu Jitsu, a framing of the with the question [why we are doing this] and a definition of each of the concepts)

Brazilian Jiu Jitsu is a martial art and combat sport system that focuses on grappling with particular emphasis on ground fighting. By the applying of torque in this sports, weak person can defend themselves against a strong person.

Torque: Torque is a measure of the force that can cause an object to rotate about an axis.

Force: a force is any interaction that, when unopposed, will change the motion of an object

Fulcrum: the point on which a lever rests or is supported and on which it pivots.:

  1. Choose 2 of 4 following techniques: a. Take an image of the technique (Kimura, Americana, Kneebar or Armbar) b. Draw on each of the technique images to showing the application of Force, Torque, Fulcrum, etc…
  2. Answer the question using what you have learned

Why does Jiu-Jitsu follow this progression?

When you get the other person down, you can find a fulcrum which there is an Fn support you, then you can control their action by using the force from your leg or arms or your body.

Why does Brazilian Jiu-Jitsu want to control?

Because when people can control the other person, they are active and the people they fight against are passive, it is easier for people who are active to do what they want.

DNA and protein synthesis

Biology 12 Leave a comment

 

  1. How is mRNA different than DNA?

DNA carries the instructions to build protein, it is big and has two backbones. mRNA is single-sided and short, it copies the information carried by 1 gene on DNA and carried this message to the ribose. The function of DNA and mRNA are different.

  1. Describe the process of transcription

When one DNA translated into mRNA, the process is called transcription. The transcription takes few steps, the first step is that a specific section of DNA unwinds, exposing one gene. Then alone 1 strand, the complimentary RNA bases bond, at this time, inside of T bonded with A, Uracil will bond with DNA’s Adenine. The enzymes – RNA polymerase will make adjacent nucleotides form covalent bonds and build RNA backbone. Now DNA is released, DNA reforms double helix.

  1. How did today’s activity do a good job of modelling the process of RNA transcription? In what ways was our model inaccurate

In today’s activity, I understand how transcription is that make DNA translate into mRNA. The different colour of the back bone makes me have a better understanding of how different DNA and mRNA is. The model is inaccurate because a usual size of DNA which make the mRNA would be much bigger than the only 18 base-pairs that we made in this model.

This photo shows how the mRNA is made

  1. Describe the process of translation: initiation, elongation, and termination

Initiation is mRNA binds to small ribosome subunit, then the two ribosome subunits bind together.

Elongation ribosome holds mRNA and allows complimentary tRNA to attach to binding sites, then tRNA binds to P site, another tRNA binds to A site, “empty” tRNA leaves ribosome.

Termination is that the elongation cycle continues until mRNA reads a stop codon.

  1. How did today’s activity do a good job of modelling the process of translation? In what ways was our model inaccurate?

Today’s activity let us built a protein through the DNA to mRNA, then finally get protein. The transcription part is not that much because we did it last time, it is more focus on how translation works to make protein. The P site and A site is very clear when I did this activity and helps me understand how everything works. It might be inaccurate if we couldn’t translate the mRNA well and also it is easy to make mistakes that the amino acid is match with the codon on the mRNA strand but not the anticodon.

transection — DNA translate into mRNA

elongation — start with P site

after P site, the A site is also start matching

after A site matched, the A site move to P site and match the A site again

the protein after the whole process (translation), it stops when their is a stop codon.