Cells remind me of yorkshire puddings.

So, I thought I'd start off with the most important aspect considered in Biology.

CELLS.

The cell is the fundamental organizational unit of life. Every living thing is composed of cells. Anything that is not made of cells, are just mere chemicals.

We as human beings, are made up of groups of cells which as a result, make up the different systems that are built within our body.



Cells, you are just so beautiful.

In fact, let me tell you a few interesting facts about cells before delving in to all the whole cell malarchy!

So... :)

1. The longest cell in your body is the motor neuron cell, which is located in the spinal cord.
2. It is believed that there are more nerve cells in your brain than stars in the milky way. WOW!
3. There are more bacterial cells in the body than human cells. (Crazy right?)
4. Cells commit suicide. Yep, they kill themselves.
5. There are anywhere from 75 to 100 trillion cells in our body.

I shall try to break it down and relate some funny examples with each one if possible. I'm going to do this all from memory, so do excuse any mistakes within what is written. 

Some reoccurring cell structures & and their functions:

The organelles (a term used for specialised structures within a cell) can be split into two categories:

Membrane bound

• Plasma membrane: Acts as the boundary between both the inside & the outside of the cell, and therefore controls the entry and exit of the cell. It also maintains the cells integrity. It does this as the membrane is well built, by being made up of two layers. These two layers contain phospholipids with embedded proteins. It's much like the top layer of ferrero rocher. You know the nutty layer on the top, protecting that delicious ball of chocolate underneath. Just imagine the nuts, as the phospholipids - constructing that divine membrane that it is. Yeah, like that. Mhmmmm... chocolate *Drools*.

• Endoplasmic reticulum: There are two types of endoplasmic reticulum. The first is rough endoplasmic reticulum (RER) and ribosomes that are attached to rough RER synthesise proteins - which then exit the cell via another organelle, called the Golgi apparatus. The smooth endoplasmic reticulum synthesises lipids. These lipids make up cell membranes, steroid hormones and certain carbohydrates (in order to form certain glycoproteins).

Rough endoplasmic reticulum



Smooth endoplasmic reticulum

• Golgi apparatus: Synthesises carbohydrates and binds them with the proteins that have been passed on previously from the endoplasmic reticulum. The Golgi apparatus packages the product and turns the final product in to a glycoprotein, which then eventually leaves the cell. It's much like an assembly line found in a factory, where items such as yummy Doritos, are in there final stage and are packaged before they are sent out of the factory, for their deliveries to Sainsbury's or Tescos or Walmart (as you fellow Americans would call it).

• Lysosomes: Is much considered like Dettol in my eyes, it reminds me much like an anti-septic. Lysosomes are specialised vesicles and contains enzymes that digests things, such as food, organelles or when cells die. They break down and digest structures within a cell, by releasing there enzymes on them. They are just so gangster yo!

• Peroxisomes: Are much like lysosomes. They also contain enzymes that eliminate any harmful substances. The main difference found between lysosomes and peroxisomes, is that lysosomes contain a different type of enzyme, to those found in Peroxisomes. Peroxisomes also work best in oxygen rich areas, whereas lysosomes, can work in oxygen poor areas.

Perioxisomes

• Mitochondria: They are considered the "power houses" of the cell. Much like a battery. But a trillion times better than them Duracell batteries. Oh yeah. Majority of the chemical reactions that take place during cellular respiration occur within the mitochondria and therefore contribute in ATP synthesis. The amount of mitochondria varies from cell to cell. Some cells that require high amounts of energy will need more mitochondria (such as muscle cells) and others in comparison, will need less mitochondria (such as nerve cells - to carry out nerve impulses). Mitochondria are made up of two membranes. The outer membrane covers the outside of the organelle, whilst the inner layer folds over repeatedly and these folds are called the cristae. The folding of the cristae provides a larger surface area, and therefore allows more chemical reactions to take place more easily and more readily. Inside the inner membrane, there is a fluid filled sac called the matrix.

So just try and think of it like this. The outer wrapper of the batteries is much like the outer membrane. And the silver, metal part in the middle that you see, could be considered the matrix (within the inner membrane).

Mitochondrian

• Nucleus: It's functions remind me of my mum. No really they do. Haha. They command the cell to do everything. They know everything that goes on within the cell, nothing slips past the nucleas. Oh no it doesn't. They are basically, like the godfathers of the cell. Okay, so before we start not all cells contain a nucleus. The ones that do, are called eukaryotic cells, and those that don't are called prokaryotic cells (much like those mother rebels) haha.

The nucleus, also has a membrane like the cell membrane. Although it's not a membrane really. It's called a nuclear envelope, and it surrounds the nucleus and all it's contents. Inside the nuclear envelope contains the chromatins (which is made of DNA, RNA and nuclear proteins) and also, contains the nucleolus inside. So in other words, it houses the genetic code, which in turn controls protein synthesis. This is incredibly important as it plays a role in lots of other activities that take place in cells - such as metabolism and growth.

Non-membrane bound organelles:

• Ribosomes: They remind me of builders. Them really good polish dudes that are amazing at what they do. Ribosomes are needed to make proteins. They are the main site for protein synthesis. They can be found in various places within a cell, either randomly lying within a cell a cells cytoplasm - where the proteins made, would essentially be used for the inside of the cell only, or it can also be found attached on to the RER (rough endoplasmic reticulum) and the constructed proteins can be used either inside or exported out of the cell.

The ribosome is made up of two subunits, the 60s subunit and the 40s subunit. When the ribosome wants to make a protein, mRNA (made from the nucleus) is sent to the ribosome and attaches on to the subunits. Which in turn, starts protein synthesis.

Ribosomes. Yeah they look weird, I know. 

• Cytoskeleton: Reminds me much like the wires that hold a bridge together (the ones found on the side of the bridge). If you think about it, the clue is within the name, when you think of cyto- you know it's something regarding cells, and a skeleton acts much like the human body's support or framework. This is the same concept found within cells. The cytoskeleton acts like a mesh work to support the cell and all of it's organelles. It also plays a role within the cells movement.

Cytoskeleton

• Nucleolus: Plays an essential role in the formation of ribosomes & is found within the nucleus. It's much like Lindor chocolate, that round ball found in the middle, (the one that tickles your taste buds) is the nucleolus and the outside layer is just that hard layer of chocolate (the nucleus).