Showing posts with label Transcription. Show all posts
Showing posts with label Transcription. Show all posts

Monday, April 15, 2013

Thursday Translation continued

On Thursday you had a 5 minute quiz on the differences and similarities between transcription and translation. (make sure you can explain these)

Remember DNA (a gene)--->mRNA--->Protein--->Trait. Where does environment come into play?


You then drew the process of translation up on the board. Here are the steps of translation: Make sure you can explain the whole process!

1. mRNA exits the nucleus
2. mRNA goes to the ribosome (in the cytoplasm) and ribosome attaches to the mRNA
3. mRNA moves through the ribosome 1 codon at a time
4. tRNA comes in and reads codon, if the anticodon is the correct one (with the complementary bases) the amino acid gets added to the peptide chain (remember the first codon read will always be the start codon... what amino acid does this code for?)
5. The amino acids are covalently bound to each other (this is called a peptide bond)
6. Once the ribosome gets to the stop codon of the mRNA, this is the signal to stop translation.
7. The protein (peptide chain) is released from the ribosomes and tRNA
8. The protein is then folded in a 3 dimensional structure.

Think about the following questions:
Describe the process of translation
How does translation relate to making proteins?
Where does translation take place?
What is the result of translation?
What do proteins do?
How does this relate to "Is Biology Destiny?"

Also here is the correct video for the HHMI video of translation


Can you transcribe then translate the following sequence?
TAC CCG GTA TTA CAG TGG GAA TGA ATT

Monday, April 8, 2013


Today we reviewed "What is a gene"

Made of DNA
Codes for a protein
Has a promoter (start sign for RNA Polymerase)
Has a Terminator (stop sign for RNA Polymerase)
Has Exons (coding region)
Has Introns ('junk' DNA)

Link for "what is a gene"



Remember! Not All genes are expressed (made into proteins!) at the same time/same cell) - we will discuss this more in translation.

We began to talk about the transition from Transcription to Translation with the process of RNA editing (processing).
After transcription, the splicesome removes the unneeded introns and then ligates (glues) the remaining exons back together. After this a guanine 5' cap is placed on the 5' end of the new mRNA along with a poly A tail at the 3' end of the complete mRNA. The mRNA then leaves the nucleus and is ready to be translated into amino acids which are the building blocks of proteins!

We then discussed the sports gene article. Don't forget to review the 4 principles of natural selection!
Heredity
Variability
Selective Pressure
Differential survival and reproduction

This article plays into our question of the term! Is biology only destiny? Only environmental? or Both?

Friday, April 5, 2013

DNA Transcription

Today we reviewed replication and began discussing the central dogma and DNA Transcription.
Thought Questions:

1. What are the main differences between DNA replication and DNA transcription?
2. Why do cells do replication, why do they do transcription and how are the reasons different?
3. Why is the Central Dogma important?

Central Dogma: Gene--->mRNA---->Protein---->Trait  (Where does the environment come into play?)


The 2 main jobs of DNA are: 1. code for proteins (which result in traits). 2. Inheritance (pass along genetic information to offspring)

TRANSCRIPTION: (Basic Transcription video)
Jeopardy Game (Basics and Transcription are the only categories you need look at! the basic section still covers some things we've not discussed yet)

What is it?
Transcription is making a 'copy' of a gene to make a protein. (Many genes may be transcribed at one time, but not all of them).
What are the steps?
1. RNA polymerase unzips the DNA double helix at the beginning of a gene (where does it bind? -the promoter!).
2. Complementary Nucleotides (which have a sugar (ribose in RNA!), the phosphate group, and the nitrogenous bases) are brought in.
3. RNA polymerase connects the sugar-phosphate backbones of the nucleotides by covalent bonds.
4. Hydrogen bonds have formed between the nitrogenous base portions of the mRNA and DNA so these are broken
5. mRNA leaves the nucleus via pores to go to the ribosomes (where translation occurs!)

Here is the ppt on central dogma and transcription!



Central dogma transcription only from lvilleDrFox

Here is another document to help you review Transcription (don't worry about Translation yet!!). Don't forget Cells, Scope lab, and DNA replication!



Tuesday, April 2, 2013

Finishing DNA replication and Homework For Thursday April 4th

Today we finished reviewing replication. You should be able to explain how and why it occurs. For thursday, please finish watching the video below and take notes. You should also read pgs 238-243 in your textbook and take notes.

Don't forget the Central Dogma
Gene---->Protein---->Trait


We will begin reviewing transcription and translation. Here is the Crashcourse video on both processes.








Here is a great video on the central dogma. It is a bit more detailed than we need but still a good one.