We’re all made up of billions of tiny cells. They keep us alive and help us function, letting us grow and change. They are the basis of all life on earth, but how much do you really know about them?
At the smallest level
Let’s start at the smallest level, with DNA. Deoxyribonucleic acid (DNA) is like an instruction manual for everything that is you. All of your genetic code that makes you develop and lets you be able to perform activities is condensed into tiny, twisting strands that look like helixes. These strands actually pair up to form “double helixes”, which is the shape that we all recognize as DNA. They don’t pair in any random order though.
Rogue genome editing twists DNA ethics - Data Driven Investor
Genome editing is on the cutting edge of science. It's also morally questionable and possibly illegal in many…
There are four chemical units, called nucleotide bases, within DNA that they are always paired by. These bases are (A) adenine, (T) thymine, (G) guanine, and (C) cytosine. A + T always pair up together meaning that C + G always pair up. The order of these bases is what determines the meaning of the information in them.
Along with DNA, we also have ribonucleic acid (RNA). The main difference from DNA is that does not pair up with another strand because they have extra oxygen in the backbone, making pairing impossible. This difference actually turns out to be quite useful though, because it makes them perfect messengers. Messenger RNA (mRNA) is an intermediate messenger for communicating the information contained in our genes to the rest of the cell. They are a copy of our DNA so once they travel out of the nucleus, they are translated into proteins which help the cell.
Getting a little bit bigger
Now that we’ve learned what DNA is, let’s find out how it fits into the cell. Since DNA is so small it wraps tightly around a protein called histone. Histones are positive so they attract the negative DNA which fulfills their main purpose of compacting the DNA strands. Without histones, the DNA would be around 1.8 meters long, but with them, it’s only around 90 millimeters of chromatin. The histones then group together to form nucleosomes, which look like beads on a string. Each nucleosome has eight histones, creating the name ‘histone octamer’. The nucleosomes then group together to form a pack of chromatin. Two chromatin form a chromosome.
Each cell contains 23 pairs of chromosomes, meaning that one cell actually contains 46 chromosomes. 22 pairs of chromosomes look relatively the same in males and females and are called autosomes. The 23rd pairs look different and are called the sex chromosomes because they decide whether you look like a male or female. Females have two copies of the ‘X’ chromosome while males have one ‘X’ and one ‘Y’ chromosome. There is always one copy of the ‘X’ chromosome because the mother passes them on.
As a whole
Scientists believe that the human body contains around 30 - 40 trillion cells, meaning that you have around 700 trillion chromosomes. All of these chromosomes contain DNA and RNA which form your organs and tissues. This is your genome; an organism’s complete set of DNA. The study of these genomes is called genomics.
The main way to study genomes is through genome sequencing. In simple terms, genome sequencing is determining the order of nucleotide bases in a DNA strand. There are many ways to sequence a genome, but the most common type used today is sequencing by synthesis. This is done by using DNA polymerase to generate a new strand of DNA, based off a particular strand. The polymerase enzyme incorporates chemically-tagged nucleotides into the strand, which causes the bases to emit a bright color when shone with a light, showing their differences.
Genome sequencing has many uses, one of which is disease detection. When sequencing, there are occasional anomalies in the DNA (variations, mutations, etc.) that may help the development of diseases. By finding those anomalies, we can use gene therapy to fix/eliminate them.
Another use of genome sequencing is personalized medicine. By knowing the layout of the DNA and about any anomalies, we can figure out the best medicines to help or create new ones that would help more.
- DNA contains all the genetic code that makes you, you
- Of the four DNA bases, A + T always pair and C + G always pair
- RNA does not pair up, meaning it is a good inter-cellular messenger
- The DNA is stored in 23 pairs of chromosomes in each cell
- A genome is an organism’s complete set of DNA
- Genomics is the study of genomes
- Genome sequencing can uncover many secrets about our bodies, including diseases
Thank you for reading my article about genomics, I hope you enjoyed! Please leave a comment down below telling me what you liked / what I can improve upon. Also, if you’d like to read more of my articles, check out this one on the basics of artificial intelligence!