Month: September 2016

Proteins

Proteins

Proteins

09/03/16

“Have you ever wondered about what protein exactly is?”

Do you know what  are the “worker” units of a cell are? Well, believe it or not, they are actually something that you hear of everyday, proteins. Now, you might find it a bit funny that such an important part of biology is named after a simple nutrient, but you will soon find out why they are so necessary.Proteins simply are polymers of smaller units called amino acids, of which there are twenty different types that can be combined to make a protein. These different combinations can specialize a protein to do different tasks. For example, one combination called an antibody is used to neutralize foreign particles (such as viruses and bacteria). Another combination is called an enzyme, which can carry out all of the chemical reactions within a cell and help out with the formation of new molecules by reading the genetic information within a cell. Messenger proteins can transmit different signals to correspond different processes between biological frameworks such as organs, tissues, and cells. A structural component protein gives a cell a framework for it to move, and a transport/storage protein can bind and carry small molecules within a body. So by consuming proteins, you can obtain many necessary units for your body’s function!

Significant figures

Significant figures

Significant figures

09/02/16

“How can we scientifically analyze a number for it’s accuracy?”

 

Believe it or not, scientific numbers are very different from mathematical numbers. This may sound absurd at first, but if you read on then it will start to make sense. In mathematics, there is no real difference between the number 1 and 1.0 and even 1.00000 for that matter. But when working in science, these numbers are anything but interchangeable! But why is that so?

Well, it’s all because scientists and engineers have to deal with something called accuracy. When working with empirically derived numbers such as the mass on a scale, it’s impossible to know the true value of a measurement. So each number one works with has a certain level of accuracy to  it. So to quantify this accuracy, we use a tool called significant figures, and they follow a certain set of rules.

Each number that we care about is termed a significant figure, or sig fig for short. All non zero numbers are significant (as they represent a quantity), all zeroes between two significant figures are significant (as the number will not be able to be simplified), and the numbers trailing after a sig fig and decimal point will be accurate (as they measure the level of accuracy of our measurements).

Let’s do a few examples. 400 has only 1 significant figure, (the four is a non zero integer, and none of the zeroes are “sandwiched” in between other significant figures and are before a decimal point).404 has 3 significant figures (The zero is sandwiched between two o non-zero numbers) 4 has only 1 significant figure (The only number is four, a non zero integer). 4.00 actually has 3 significant figures (Both of the zeroes are behind the decimal). .040 only has 2 significant figures (The first zero is  behind the zero but not behind any non-zero integers).

Scientific notation

Scientific notation

Scientific notation

09/01/16

“How do scientists and engineers represent complex numbers?”

When working in a technical subject, you will probably have to deal with numbers that are either extremely large or extremely small, or have to work with empirically obtained values. For example, the number 602000000000000000000000 is really to read, as well as 0.000027. So how can we make them simpler and more accurate?

Well, let’s try to tackle this problem ourselves. What if we took our understanding of significant figures, and applied it to this problem? Since the only numbers that  we actually need to care about is significant figures, how about we just remove all of the unnecessary zeroes? And how can we accomplish this? Well since we know that if we multiply or divide anything by 10 we will just shift the zeroes behind the numbers, how about we simplify all of the extra zeroes into a power of ten? the For example, when we have the number 602000000000000000000000, we can turn this in to 6.02*10^23. And for the number 0.000027, we can shift it into 2.7*10^-5. This way of working so much simpler! Scientists and Engineers have termed this framework scientific notation.

Now how can we apply this system for calculations? Well, first let’s divided it into two cases, multiplication/division, and addition/subtraction.  In the first case, we will multiply both numbers and round our final answer to the number of significant figures of the variable with the lowest amount of sig-figs. For example, 5.2*10.81 will be 56 instead of 56.212 since the former only has two significant figures. For addition and subtraction, We will simply put all of the numbers in terms of the highest amount of digits after the decimal place, and then round to the lowest amount of significant figures. Let’s do an example. Suppose we have the numbers 3.14 and 2.1, and 1. When we ad the numbers together, we will notice that 3.14 has the highest amount of digits (2), and then rewrite everything else accordingly to become 3.14 + 2.10 +1.00 = 6.24, and then we will round down to one significant figure to finally arrive at 6.

Scientific notation is an amazing tool for scientific accuracy, because when working with complicated systems such as mechanical engineering precision or particle physics, a single bit of inaccuracy could destroy all of our hard work!