DNA & Introducing Biology REFRESH : Prep Week 6

This is the final week of our series on how to Prepare for College Biology. I hope you’ve enjoyed this biology topic review, but if you haven’t had a chance to catch up don’t worry. You can find all the lectures and notes at my Biology REFRESH course.

If you haven’t been getting the full lessons, don’t wait because it is completely FREE! It’s a great way to get a quick review of biology topics that colleges assume you know.

The previous topics have been homeostasis, general chemistry, organic chemistry, cellular membranes and mitosis. You can get all of the materials including lectures and notes, by signing into my FREE course here.

I decided to put the information there to make it a little more accessible to people. This review course is not a substitute for coursework and doesn’t guarantee success.

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This week our focus is DNA.

Have you ever been told it is your genes? What about that you get your looks from your dad? Your genes are DNA, specifically, they are the sections of DNA that have the instructions for making a specific protein.

Your DNA holds the recipe book for all of the proteins in the body. Proteins provide the structure and function of most organisms.

The relationship between protein and DNA is universal to all organisms and essential to life, it is called The Central Dogma of Biology.

What does that mean? It means that all living things take DNA and use it to form protein. Nothing living bypasses this process. It is the central unifying principle of biology.

DNA seems to be everywhere these days.

Ever wondered what GMO means? It’s referring to changing the DNA of food sources.

Have you read about the breast cancer gene? It is referring to a gene that is linked to a specific and aggressive form of breast cancer.

DNA has even seeped into pop culture. If you have ever watched the show The Big Bang Theory, Sheldon has a huge DNA model behind him on the shelf behind the couch.

We mentioned DNA briefly in organic chemistry.

DNA is made up of nucleotides that have three parts: deoxyribose sugar, a phosphate, and a nitrogen-containing base.

The type of nucleotide is determined by the base, therefore we often refer to the nucleotide using the base name along.

The four bases are guanine; cytosine; adenine; and thymine. You may remember, that these bases pair in making the center portion of the twisted staircase shape.

Hydrogen bonds holding complimentary base pairs together allowing for adenine to pair with thymine and guanine to pair with cytosine based on these bonds.

The sequence of nucleotides holds the information for building a protein. The order of bases in the DNA determines the amino acid sequence.

The amino acid sequence will determine the 3D structure, by influencing how hydrogen bonds and other influencers interact. That sequence of bases is your genetic code and is the biological blueprint of you. Check out this DNA model.

How do we get from DNA to protein?

It is a complex procedure. DNA along with RNA and cellular machinery will play a role in making the protein. Do you remember the steps involved? You can find out more here.