Monday, 2 August 2010
♥
7:16 pm
Here's the Dove video that Ms. Liang was talking about... I'm a little confused at the moment, as the commercial is basically saying that Dove soap has the mildest formula compared to the other soaps... But, isn't there a reason the other soaps are alkaline? I always thought it had something to do with their cleaning ability, like, if its more alkaline, then its more effective. I can understand that milder soaps can be used for people with sensitive skin... But if the pH level of the soap is close to the pH level of distilled water... THAN WHAT'S THE POINT?!?!?
I hope someone can explain this?
Saturday, 10 July 2010
Atoms, Molecules, and Isotopes ♥
2:39 pm
We talked about atoms and molecules in Chemistry lesson the other day, and in particular, about Isotopes. Here's a video about Carbon and its isotopes:
Wednesday, 5 May 2010
Digestion ♥
8:36 pm
Okay, so here's another video (don't you just love videos?), this time about digestion.
And another more wordy video, which is actually a video version of a powerpoint slide:
Xylem and Phloem ♥
8:25 pm
Here's a super cool video about the xylem and phloem. Its a bit random, and is based on the song 'Sugar We're Going Down' by Fall Out Boys, with some lyrics changed:
In case you couldn't really hear, the lyrics are:
Did you get what you bargained for yet?
Ive been dyin because I have
no food, to survive,
Cause I cant photosynthesize.
Water you got, sent to you through transpiration,
It went up through the xylem,
Cohesion helped it along.
(It went up through the xylem, cohesion helped it along)
Tracheids, vessel elements,
Water goes up them, and I need you man, to reward me.....
Leaves, Leaves, sugar source of the trees,
Your sugar is going down Phloem.
Cause a sugar sink would enjoy it,
If you send it to him to use it or store it.
Leaves, Leaves, sugar source of the trees,
Your sugar is going down Phloem.
Cause a sugar sink would enjoy it,
If you send it to him to use it or store it.
Did you get what you bargained for yet?
Ive been waitin for
tasty sugar to supply me
Wishin those sieve-tubes leave sap at my door
Youve really messed up, please send some sugar to me,
Or Ill stop sending water, youll realize that you have done wrong,
Your guard cells, would lose firmness.
Your stomata would close, no way to undergo, photosynthesis.
Leaves, Leaves, sugar source of the trees,
Your sugar is going down Phloem.
Cause a sugar sink would enjoy it,
If you send it to him to use it or store it.
Leaves, Leaves, sugar source of the trees,
Your sugar is going down Phloem.
Cause a sugar sink would enjoy it,
If you send it to him to use it or store it.
BLOOD ♥
8:15 pm
So I was revising my Bio, and found this video on youtube explaining the various components in blood... Check it out!
And another interesting science project relating to blood:
ENJOY!♥
Thursday, 25 March 2010
Raw food vs. Cooked food ♥
9:48 pm
So, today, during Biology, we were talking about food. In particular, there was a discussion about whether raw food is better, or cooked food is better. So, Mrs Phua pointed us to two questions, that I'm going to answer here. :)
1. Is raw food or cooked food digested faster?
You can see coagulation of protein take place on a macroscopic level when you fry an egg. The clear protein gel surrounding the yolk whitens, thickens, and coagulates into a glue-like consistency. Digestive enzymes (peptones and proteases) cannot readily break down coagulated protein molecules once they fuse together. Not only are heated proteins unavailable to your body, worse yet: the indigestible, coagulated protein molecules tend to putrefy as bacteria in the body feed upon this dead organic matter. Bacterial enzymatic by-products are carcinogenic. Coagulation occurs on a microscopic level in all cooked protein molecules whether witnessed or not.
(http://www.living-foods.com/articles/rawfreshproduce.html)
That was taken from a website talking about raw vs cooked food. It seems that, in protein especially, cooking food would cause its protein to be harder and harder to digest. Therefore, I think we can assume that raw food would be easier and faster to digest.
2. Is raw food or cooked food better?
According to the website stated above (under the 1st question), raw food does protect against Cancer. Research has shown that raw vegan diets actually decrease the toxic products in the colon, definitely contributing to our overall health. Also, when we apply heat to cook food, we actually break down protein molecules and make it hard to be digested. Not only that, but when we boil food, or use water in our cooking, the water-soluble vitamins from the food would be lost.
While all this research does prove that raw food is indeed a better and healthier choice for our bodies, one question still stands out in my mind: If raw food is so healthy, why is everyone still cooking their food?!?!
Well, my personal opinion is that raw food can easily be contaminated, and there might still be bacteria in the food. However, this bacteria is easily killed when you cook the food. Therefore, for hygiene reasons, most people cook their food. :)
Saturday, 27 February 2010
Drawing Ray Diagrams ♥
6:09 pm
In the recent CTs, many of us had problems with that one Vain Jane mirror question, because we couldn't draw ray diagrams really well. So, let's take a look at the basics of ray-diagram-drawing.
Here's a sort of "cheat" that allows us to construct a ray diagram quickly, without using a protractor.
The second part of the above video shows a more complicated ray diagram:
Concave mirrors are mirrors that curve inwards. Let's find out more on how to draw ray diagrams for concave mirrors:
On the other hand, convex mirrors are essentially the opposite of concave mirrors, i.e. they curve outwards. Shown below is a video on how to draw ray diagrams for convex mirrors:
I hope that after watching these videos, drawing ray diagrams would be much simplier and clearer for us all! :D
Reflection in a mirror ♥
6:02 pm
Remember that time Mr. Lim showed us that funny prank in the public bathroom? The one with the twins, and the other people who thought they didn't have a reflection? Well, here it is...
Pretty Rainbows in the Sky ♥
4:32 pm
I'm sure all of us have seen rainbows before, right? And most of us also know from Mr. Lim's classes about how rainbows are formed. But how about some fun facts about rainbows?
In Norse mythology, the rainbow is seen as the road between the worlds of gods and men. Similarly, the Holy Bible has also mentioned rainbows in The book of Genesis (Gen 9:8-17) where it is a sign of covenant between God and all life on Eath. The Indians thought that rainbows are bridges between life and death, while the Greeks thought that it was a omen from the gods to foretell war or heavy rain.
But, we all know that a rainbow is an arc of light that has been refracted and reflected through raindrops (or sometimes drops of mist), into several colours. The different colours of the rainbow, red, orange, yellow, green, blue, indigo and violet, are caused because violet refracts the most and red refracts the least.
The rainbow is also always directly opposite the sun. Hence, from different viewpoints of different people, in different places, the rainbow would always be shown in different locations, depending on the position of the sun.
Another interesting fact about rainbows are that there is usually another larger rainbow that can be seen outside the primary rainbow called the secondary rainbow. In such cases of a double rainbow, the secondary rainbow always runs parallel to the primary rainbow. However, the sun's light is reflected twice internally in the secondary rainbow before ermerging from the raindrop, so the sequence of colours would be reversed, with red at the top and violet at the bottom. Also, secondary rainbows are usually harder to spot, as they are not as bright and not as prominent as primary rainbows.
Below are some videos found from youtube showing how rainbows are formed:
And the funniest:
Enjoy! :D
Saturday, 13 February 2010
Water and Electricity don't mix! ♥
4:00 pm
I'm sure that all of us here know some basic safety rules when dealing with electrical appliances, particularly that we shouldn't let them come in contact with water. But have any of us wondered why?
Well, the answer is quite simple. Although pure, distilled water is a bad conductor of electricity, just the slightest impurity and the water becomes a good conductor of electricity. This means that unless your water is 100% pure, which is highly unlikely, then the electricity would be able to travel through water very well. And when this happens, since your in proximity, you have quite a high chance of being electrocuted!
Therefore, next time, listen to your teacher's advice, and never ever let electrical appliances touch water! :D