The basic but complex pieces of biology: DNA, RNA, & Proteins (aka Central Dogma)

Important concepts:

All of biology functions around the core of DNA, RNA and Proteins or the so called Central Dogma of Molecular Biology. The key here is that you always go in the order of DNARNA→protein. You can’t jump from DNA to protein or visa versa; it just doesn’t happen. However, you don’t have to go all the way. Just because you made RNA doesn’t automatically mean it will be a protein. This is also not necessarily a one-to-one relationship. One RNA can be used to make several copies of the exact same protein.

Why do I care?

Because a gene can be looked at in each step of the DNARNA→protein progression. We look at all the different steps because how a gene is functioning can be regulated or changed at any point. However, in all cases, we are still interested in the gene.

Note that detailed technique explanations, will include a discussion of what (DNA vs. RNA vs. Protein) is being measured. This is especially true for techniques involving gene expression as this can be measured on either the RNA or protein level.

Biological Levels

Biome :: anthology
Person :: book
Organ :: chapter
Tissue :: page
Cell :: paragraph
Protein :: sentence
Gene :: word

While words are necessary to communicate a story to the reader, without context and structure, you won’t be able to follow along. But put words together into a sentence and suddenly you have a functional unit that can be used to say something. Put sentences together and now you can actually communicate an idea to a reader. This is very similar to a cell, which can actually do something useful - change shape, carry oxygen, or sense something like light from the environment. Cells are built of proteins which are described by genes.

Many cells together form tissues. Tissues are capable of doing more complex tasks just as a page can communicate a concept. In some cases, these tasks are sufficient to do the whole job - just as a short poem is capable of conveying a concept.

Skin is a good example as it is both a tissue and an organ. It functions as a barrier which allows it to complete the job of protecting our internal organs.

In other cases, tissues like muscles only carries out a small portion of the job. However, when several muscles work together at their tasks, they can do the job of beating a heart. Thus an organ does a job just as a chapter in a book advances the story.

When stories come together an anthology is created. In some cases, like the Lord of the Rings or Star Wars, it is all tied together to create a complete arc. Other times, like Aesop’s fables, the stories each function individually, but are tied together in that they all carry similar messages or settings.

Biomes are created when many organisms come together and interact in an area together. They influence each other and the environment. Birds, who live in trees eat worms. Worms who soften the dirt so allowing trees to grow. When a bird dies it provides nutrients to the soil which then help feed the worms. Thus birds and worms need each other.

In some cases, its not clear to us how the organisms depend on each other, just as a chapter in Gulliver’s Travels may not relate to another.

So where is DNA and RNA in this?

Well, honestly, the main item of interest is the gene. A gene’s information is kept in DNA and communicated via RNA.

It stretches the analogy, but the gene is written by the DNA (letters) and RNA is used to convey the gene (ink lets the reader see what is written). However, especially starting out, its more important to pay attention to the gene rather than DNA or RNA.

Other Biology Terms

Operons :: clause