Can You TRANSLATE That Into English Please?

If you were having trouble understanding RNA transcription, please see my posting addressing that issue. If you are good on that topic but stuck on translation, hopefully I can help you out with that.

By the way, Biology is not meant to sound like another language. While the terms and concepts are difficult, Biology does make sense if you just take time with the material.

Translation is the process where messenger RNA (mRNA), made from RNA transcription is used to make proteins. Translation occurs in the cytoplasm of a cell on a ribosome. Remember, ribosomes are the cell organelles used to make proteins. I will explain what happens during translation now, but PLEASE, PLEASE, PLEASE, watch this video in addiction to reading, because this video is VERY helpful in allowing you to actually see translation occur.

During translation, the mRNA molecule moves through the cytoplasm and eventually sits on a ribosome. A transfer RNA molecule (tRNA) goes to meet up with the mRNA molecule. The tRNA molecule looks like this:



The tRNA molecule carries an amino acid on one side and has an anticodon on another side. OK, let's break this down. Think about a pearl necklace. Each pearl on that necklace is like an amino acid, and the entire necklace would be a protein (not literally, of course). So when a bunch of amino acids are bonded together, they form a protein. That means that many tRNA molecules are involved in making one protein. Now an anticodon is just a fancy word for a three-nucleotide sequence that complementary base pairs to an mRNA codon or three-nucleotide sequence. For example: If I had an mRNA codon that was AGC, then a tRNA molecule carrying the anticodon UCG would bind to the mRNA strand.

Once that bond takes place, the tRNA releases the amino acid and the process is complete. Remember, the number of codons on the mRNA molecule determines the number of tRNA molecules needed to bring amino acids. That also determines how long the protein will be. WATCH THE VIDEO! I promise, it will help!


And finally, once our proteins are expressed or "turned on" so many great things can happen. For example, the pigments in your eyes and skin are the results of proteins being expressed. Cool, huh? That is how you get your phenotype.

RNA Transcription

Perhaps the two most important processes that need to occur in order for a person's genes to make them look a certain way(have a phenotype) are transcription and translation. This first entry will focus on RNA transcription and I will discuss translation in another post.

Let's think about what happens during transcription: An organism's double-stranded DNA, found in the nucleus of its cells, is used as a template or blueprint to create a single-stranded mRNA messenger molecule. Put simply, DNA is used to make RNA. But why? What's the point? Well pretend you were an architect and it took you countless hours to construct the most perfect design for a house and you were instructed by your boss to use those plans to make twenty-five houses. Would you risk giving those plans to a builder? Remember, you only have ONE copy. Reason would tell you, NO! Why would you want to trust someone with a product that you made that took you so much time? The builder could lose it, spill coffee on it, rip it, or countless other things could happen to it. It is much safer to make copies and give a copy to the builder of each house so that the integrity of the original plan is intact, right? RIGHT! Well that is how our DNA "thinks". It does not want to travel outside the nucleus to make the proteins that give us our phenotype. Instead it wants to stay safe inside the nucleus, since it is our only copy, and make copies of itself in RNA form which then get sent out to do the dirty work of making proteins. So not only does the DNA stay safe, but the process of transcription (DNA making many RNA molecules) is so much more efficient as well! Aren't our cells smart?!

Transcription occurs inside the nucleus. It is in the nucleus that the double-stranded DNA molecule unzips at a particular point and nucleotides are left unpaired and exposed. RNA polymerase, an enzyme, picks up RNA nucleotides (A,C,U,G) floating around the nucleus and base pairs it to ONE strand of DNA with exposed nucleotides. Remember, RNA is single-stranded. The strand of DNA being used as a template depends on the specific protein that needs to be made. Once the RNA nucleotides match up with the DNA, the RNA strand slides off and makes its way out of the nucleus and into the cytoplasm. The DNA double-helix rebinds and resumes its original shape. In case you are confused, here is a picture showing you the difference between the shape of double-stranded DNA and single-stranded RNA:



If this was not helpful enough, please view this video. You may need to replay it a few times, but it is very helpful!

Cell OrgaWHAT!!!???

Understanding the functions of the major cell organelles is essential in Cellular Biology. You may be asking yourself right now "What the heck is a cell organelle?" Think about it. What word does organelle have in it? That's right, "organ". So just like our organs are major parts of our body that allow it to function, cell organelles are basically mini organs inside of a cell that allow it to work.

Now, I understand it can be quite scary to consider that you will have to know the functions of about 10-15 cell organelles, but sometimes using memory techniques like analogies can help you, and that is my goal! For those of you that do not know, an analogy is a comparison between two things that are not alike.

The link that I am providing you here compares a cell to a bike factory. It is a great website because it takes the different jobs in the factory and compares each job to a specific cell organelle. The first link takes you to a brief reading that will introduce you to what goes on in a bike factory and it will compare those parts to the cell organelles. The second link will take you to a blank document that you can fill out as you read. The third link will take you to an answer key so that you can check how well you comprehended the reading.

If you LOVE food, like I do, and you want a hands-on way to learn the different parts of the cell, visit this website and follow the directions to make your own edible cell. YUM!

As another extension exercise, see if you can come up with your OWN analogy for the different cell organelles. I would LOVE for you to post your own analogies as comments on this BLOG post!

Introduction to the Site

Greetings Biology lovers (or loathers)!

I have created this website with the hope that those of you taking Biology will use this site as a tool to help you understand the most fundamental, yet challenging topics in Biology. From my teaching experience, I have come across a few topics which students constantly have trouble with. My goal is to provide useful tools and resources for you to aid in your understanding of such topics.

I encourage you to ask questions and make comments as your read through my postings. If you are one of my students, extra credit will be given for thoughtful comments, feedback, suggestions, or posting of other helpful resources. Learning does not stop in the classroom or here!

Have fun!