The Molecules for Life (the small ones) part 1

The main essential molecules are phosphates, organic, fatty, and amino acids, sugars and purines and pyrimidines!
We'll start with the phosphate ion: PO4^3-

How it normally exists in the cell: Phosphoric acid, H3PO4

Phosphoric acid

Why it is important:
 Unlike other inorganic ions it combines very readily with other organic compounds because it has strong electronegativity, and so forms salts, e.g. potassium phosphate K3PO4, and esters, (mono-, di-, or triphosphate esters).

Triphosphate ester (where R is any organic alcohol)

 The phosphate ester is especially useful as it can convert a previously pretty much inert organic compound into a much more reactive one, with di- and triphosphate esters making them even more reactive than monophosphate ones. This is vital in particular for adenine triphosphate, or ATP, which I will go into later.

Source: The Chemistry of Life by Steven Rose

PTEN gene

Melanomas are a type of skin cancer. Although not quite as common as some, they can be very dangerous, due to their greater likelihood become malignant and spread than other cancers (thought to be because pigment cells are migratory cells already). They are also able to colonise most other areas of the body. All of which means they are extremely deadly.

Melanoma

Now scientists have discovered a set of genes, including the PTEN gene, which control how the melanoma cells shift rapidly between two shapes - one of the reasons why they can spread so easily. They can have rounded shapes, which they normally use to travel in the blood, or elongated shapes, which they use to travel through harder tissue, e.g. bone.
From studying fruit flies (whose cells have 5 different shapes as they grow during the flies' lifetime) it has been discovered experimentally, from switching off certain genes, which genes correspond to which shapes.
It has been found to be the same with melanoma cells - and specifically switching off the PTEN gene means that there are more elongated cells than rounded cells, and so can then more easily escape from the skin and advance to other areas. PTEN being deactivated is common in most cancers, for one in eight melanomas the gene isn't active.
Although this discovery at the moment is simply observational, hopefully it will lead to future options in helping treat and prevent melanomas.

Source: Genes help spread of shape-shifting skin cancer cells from the Conversation.

Homeostasis vs Homeodynamic

Recently in a book (The Chemistry of Life by Steven Rose) I was reading I came across an interesting point about the word 'homeostasis'. Homeostasis is defined as the tendency toward a relatively stable equilibrium between interdependent elements, especially as maintained by physiological processes, and is often used when studying life.
 Put simply, it means how an organism maintains itself as it is altered and changed by environmental factors.
For example, water levels in the body have to be carefully controlled, to ensure that no cells are damaged from osmosis. If too much water enters the cell it can cause lysis, or if too much water exits the cell it can lead to crenation, for red blood cells.

However the problem of using the word homeostasis in regards to living organisms is that organisms, both as a species and individuals, do not remain the same. As an individual they are born, they grow, the reproduce, they age and, eventually, they die. As a species they adapt, and evolve, over millions and millions of years.
 The book suggests that a more accurate word would instead be 'homeodynamic'. This would then describe the need for constancy as the organism changes, both in response to its own internal growth and also any environmental influences.

I do not expect that the word will actually change anytime soon, but I will probably start using the term instead for this blog.

(Sorry for the long delay in posts!!! I have been away for awhile - but I hope to get back to this blog now!)

Source: The Chemistry of Life by Steven Rose (I may use this source a lot too!)