(d)+Making+proteins

**__Making proteins __** Complete Biology: pages 192-3 ( Section 11.3 ).
 * __Proteins __**
 * __What is a triplet? __**

A triples is a part of the DNA which stands for an amino acid. It is a series of three nucleotide bases and it forms a Genetic code used by the cell. Since proteins are made up of amino acids, multiple triplets essentially stand for proteins.

__**What is each triplet code for? **__ The sequence of bases ('letters') in DNA is a series of coded instructions for the building up of proteins by chaining amino acids. Each of the triplets stands for a single amino acids, but since there are less amino acids than possible triplets, some amino acids have more than one triplet.

DNA (coiled up into chromosomes) __**can't**__ leave the nucleus, because it is too dangerous for genetic information to travel outside of the nucleus. However, genetic information must still be __**carried outside**__ of the nucleus in order for the cells to build proteins. This is because the organelles that produces proteins, called ribosomes, are stationed outside of the nucleus, as illustrated in the diagram below:

//The red line is the distance in which the DNA must travel//

So for genetic information to travel from the nucleus to the ribosomes safely, a clone of the DNA must be created and then the clone will travel to the ribosomes. This means that the original copy of the genetic information is still safe, and ribosomes can still receive instructions to build **specific** proteins. This clone is then transported to the ribosomes by a type of **nucleic acid** called messenger RNA, or **mRNA**. The process of replicating and transporting the DNA to the ribosomes is called Transcription (literally means "cross writing". A copy of the sequence of bases in the DNA is created, very similar to the process of __replicating DNA__ (refer to page __c__). However, **mRNA doesn't use exactly the same bases as DNA**. Instead of the base T, it uses the replacement base U. So, the DNA information was **transcribed** into a base sequence that mRNA can understand. //*Note: Not the whole chromosomes with all the DNA is replicated. Only a specific section of the DNA containing the specific information for building// **//one//** //specific protein is transcribed onto the mRNA.//

The message on the DNA is copied onto __messenger RNA__ (__mRNA__). __mRNA__ leaves the nucleus and goes to a __ribosome.__ Inside the __ribosome__, the message on the mRNA is read and a __protein__ is built.



(19) How fast can this process occur?

**Processes of DNA codes for characteristics in cells:**

Below is the process of making protein from DNA and how information in DNA codes for characteristics in cells. Here is the summary of all the process: DNA mRNA protein Characteristic __Transcription:__



Transpiration is the process of producing mRNA from a DNA sequence by using the similar base pairing rules in DNA replication. The most important difference between these two processes is instead of pairing with Thymine (T) like in DNA replication, Adenine (A) pairs with Uracil (U) in transcription. There are 3 main steps in transcription: 1. Initiation: 2. Elongation: Termination: At the maximum speed, the transcription process can produce from 40 - 80 mRNA base pairs per second. //This video will show clearer how transcription occurs.//
 * RNA polymerase bonds with DNA double helix at a part of the DNA double helix called promoter
 * The RNA polymerase break down the nucleotides hydrogen bonds
 * The DNA double helix is unwound, ready for the next step
 * One of the DNA strand is used as the template for the RNA synthesis
 * Now each un-paired base pairs with nucleotides which have the appropriate complementary base: A - U and C - G
 * <span style="direction: ltr; font-family: Calibri; font-size: 14pt; margin-bottom: 0px; margin-top: 0in; unicode-bidi: embed; vertical-align: middle;">The hydrogen bonds between the newly formed mRNA strand and DNA template strand break
 * <span style="direction: ltr; font-family: Calibri; font-size: 14pt; margin-bottom: 0px; margin-top: 0in; unicode-bidi: embed; vertical-align: middle;">The new mRNA is released
 * <span style="direction: ltr; font-family: Calibri; font-size: 14pt; margin-bottom: 0px; margin-top: 0in; unicode-bidi: embed; vertical-align: middle;">The DNA double helix rewind
 * <span style="direction: ltr; font-family: Calibri; font-size: 14pt; margin-bottom: 0px; margin-top: 0in; unicode-bidi: embed; vertical-align: middle;">The mRNA exit the nucleus through the small holes in the nucleus surface

media type="file" key="TRANSCRITION.flv" width="360" height="270" align="center"

Transcription video

__Translation:__ Translation is the process of making protein from mRNA. Below are all the steps occurred in translation: At the maximum speed, the translation process can produce up to 20 amino acids per second.
 * <span style="direction: ltr; font-family: Calibri; font-size: 14pt; margin-bottom: 0px; margin-top: 0in; unicode-bidi: embed; vertical-align: middle;">The mRNA joined a small ribosomal subunit
 * <span style="direction: ltr; font-family: Calibri; font-size: 14pt; margin-bottom: 0px; margin-top: 0in; unicode-bidi: embed; vertical-align: middle;">tRNA carries amino acid binds to a suitable codon sequence on the mRNA strand
 * <span style="direction: ltr; font-family: Calibri; font-size: 14pt; margin-bottom: 0px; margin-top: 0in; unicode-bidi: embed; vertical-align: middle;">A large ribosomal subunit join the group to form a functional ribosome
 * <span style="direction: ltr; font-family: Calibri; font-size: 14pt; margin-bottom: 0px; margin-top: 0in; unicode-bidi: embed; vertical-align: middle;">A new tRNA comes to bind to the next 3 nucleotides on the mRNA strand
 * <span style="direction: ltr; font-family: Calibri; font-size: 14pt; margin-bottom: 0px; margin-top: 0in; unicode-bidi: embed; vertical-align: middle;">With the support of the ribosome, the 2 amino acids on the tRNA which are next to each other bind together
 * <span style="direction: ltr; font-family: Calibri; font-size: 14pt; margin-bottom: 0px; margin-top: 0in; unicode-bidi: embed; vertical-align: middle;">When the first tRNA separates from its amino acid, it moves out of the ribosome on one side, leaving space for another tRNA to enter on the other side of the ribosome
 * <span style="direction: ltr; font-family: Calibri; font-size: 14pt; margin-bottom: 0px; margin-top: 0in; unicode-bidi: embed; vertical-align: middle;">After leaving the first ribosome, tRNA quickly moves and attaches to another ribosome
 * <span style="direction: ltr; font-family: Calibri; font-size: 14pt; margin-bottom: 0px; margin-top: 0in; unicode-bidi: embed; vertical-align: middle;">With each tRNA comes in, the amino acid strand increases its length and form the 3D structure of protein
 * <span style="direction: ltr; font-family: Calibri; font-size: 14pt; margin-bottom: 0px; margin-top: 0in; unicode-bidi: embed; vertical-align: middle;">This process continued until the ribosome reaches the termination codon of the mRNA
 * <span style="direction: ltr; font-family: Calibri; font-size: 14pt; margin-bottom: 0px; margin-top: 0in; unicode-bidi: embed; vertical-align: middle;">When the process ends, the 2 ribosomal subunit separate, ready to join again later

Here are some diagrams demonstrating the translation process:



// The video below will also help demonstrating the translation process. // media type="file" key="From RNA to Protein Synthesis2.flv" width="360" height="270" align="center"

After translation and the formation of protein, protein is transported to cells where it is needed. Protein have many different functions, depending on the cell where it is transported to. For example, in hemoglobin cells, protein are used as transport molecules to help hemoglobin to transport oxygen. Protein can also be used as storage molecules for iron.



__Transcription__ is when base pairing rules G-C and A-U are used to create a messenger RNA (mRNA) molecule against one strand of the DNA double helix. mRNA leaves the nucleus through small holes found in the nuclear membrane.
 * Summary:**

__Translation__ is when genetic coding rules are used to create a protein, which is a string of amino acids, against the strand of mRNA. Ribosome is an organelle found in the cytoplasm that bonds amino acids into proteins.

** Work Cited **


 * RockABrain. "Cross Section of an Animal Cell and a Plant Cell." //RockABrain.com//. None. Web. 26 Apr. 2011. [].


 * "Ch 17 Collaboration 2010." //BioAP.com//. Web. 2 May 2011. http://bioap.wikispaces.com/Ch+17+Collaboration+2010.


 * "Genetic Transcription- Suite101.com Images." //Suite101.com: Online Magazine and Writers' Network//. Web. 04 May 2011. <http://www.suite101.com/view_image_articles.cfm/230867>.