Category: Year11 Biology

Our body is made up of very complex proteins. In fact, it is not just us that is made up of very complex proteins. It is more accurate to say that all the living things are made up of very complex proteins. There are two kinds to proteins – functional protein and structural protein. What is the difference? Well, the functional protein helps with the chemical reactions in our cells – but the structural protein is like what you can see with your eyes and touch. You can touch your skin, finger nail, hair, skin… and organs inside your body!

Why am I talking about these things?

Because I am about to let you know that your cells contain all the information about these proteins. The information is used to make and control every single things which are inside and outside your cell. It is like an encyclopedia, written in the language that our body understands. Where can we find the information then? The famous DNA – inside the nucleus of a cell.

The DNA is a long double helix molecule. Helix is the shape of a twisted ladder.

May be you have seen this picture before. The DNA is made up of thousands and millions of a single unit called NUCLEOTIDE.

Nucleotides have another name – Nucleic acid. This is because we often have to see things from chemistry perspective to understand their property as a molecule.

DNA and RNA is all made up of nucleic acids. But only difference is that DNA is like a ‘REFERENCE COPY’ book in the library. As you know these REFERENCE COPY books cannot be taken out side the library. So, what do you do when you need an information from the book? You would photocopy the pages you need wouldn’t you? The RNA is like the photocopied pages which can take information from DNA in the nucleus to the cytoplasm to make proteins. This is because making protein needs big chemical reaction and this reaction can only take place in the cytoplasm.

This is how RNA and DNA looks like. As you can see RNA is single stranded and DNA is doubles stranded. The part you cannot see is the difference in length. DNA is way way longer than RNA because it contains whole information, unlikely, RNA is way way shorter than DNA because RNA only contains copy of a section in a DNA strand.

You will actually more things about RNAs and DNAs when you take senior Biology subject. Hope this helps for you to kick start!

Human circulatory system

 

Blood from the lungs is pumped by the heart through arteries to all parts of the body. This is known as circulation. Your heart lies in your chest. It is about the size of your fist. It is divided into four chambers. Blood consist of different types of cells floating in liquid plasma. These cells included white blood cells and red blood cells. It contains iron compounds called haemoglobin, which gives red colour to red blood cells and allow red blood cells to pick up oxygen from lungs.

The right atrium receives blood from all over the body. This side of the heart pumps blood to the lungs where oxygen enters it. The left atrium receives blood from the lungs and pumps around the rest of the body. This side of the heart is bigger because it has to pump harder to get the blood all the way around the body.

A microbe is any living organism that spends its life at a size too tiny to be seen with the naked eye. Microbes include bacteria and archaebacteria, protists, some fungi and even some very tiny animals that are too small to be seen without the aid of a microscope. Viruses and the recently discovered prions are also considered microbes.

The term microbe is short for microorganism, which means small organism. To help people understand the different types of microbes, they are grouped or classified in various ways. Microbes are extremely diverse and represent all the great kingdoms of life, including the animals, plants, fungi, protists and bacteria (see the tree below). In fact, in terms of numbers, most of the diversity of life on Earth is represented by microbes.

If you want to learn more about microbe visit http://microbezoo.commtechlab.msu.edu/zoo/ziwim.html