DNA and Proteins Science 10

Investigation  What is DNA?  What is its structure?  What is it made of?  What is its function? How does it work? What are genes and how do we get them from DNA?  What are chromosomes?

Your genome = all your DNA! All your cells have the same genome, but different parts are active in different cells. Your Genome DNA: 6 feet long 3.2 billion bases (A, T, C, G) 25,000 genes (approx.) 46 chromosomes

Recap Your genome = all your DNA! DNA functions as a 4-letter code (A,T,C,G) that forms 3-letter words which code for amino acids. Chains of amino acids make . Proteins are important because they are the building blocks of life and necessary for and cells. Each section of your which codes for a is called a .

Making Proteins The process of making proteins from DNA is called . Synthesis means . are long molecules made up of . There are different amino acids that DNA codes for.

Code for Amino Acids

What is DNA and how does it work? https://www.youtube.com/watch?v=zwibgNGe4aY

RNA DNA is found in the of the cell, but protein synthesis takes place in the of the cell. In order to make or proteins from DNA, the needs to get from the nucleus to the outside where the cytoplasm is. To do this a is needed. This messenger is RNA (Ribonucleic acid). Written as .

RNA versus DNA RNA is to DNA but with . DNA looks like a . RNA looks like only or strand of the ladder. DNA codes RNA codes (U = uracil)

Translating the Genetic Code RNA the genetic code: The DNA strand of a gene between the nitrogen base pairs. The unzipped DNA strands direct the production of a of mRNA. DNA strand = CATGTACAC mRNA strand = GUACAUGUG (see Fig 2-21, pg 50)

mRNA strand = GUACAUGUG Amino Acids DNA strand = CATGTACAC mRNA strand = GUACAUGUG The genetic information in the DNA strand is transferred to the mRNA in the form of a code made of 3-letter code words (ex: GUA). Each code word specifies a particular . Other code words function as “start” and “stop” signals. AUG = “start”. UAA, UAG, and UGA = “stop”.

The Ribosome reads the 3-letter code words on the mRNA strand. 3. The single mRNA strand leaves the nucleus and enters the cytoplasm carrying the coded message from the DNA. The mRNA joins with a . The Ribosome reads the 3-letter code words on the mRNA strand. Transfer RNA (tRNA) carry to the ribosome which puts them into the as it reads the 3-letter code words. A code signals the beginning of the protein chain. A code signals that the protein chain is complete.

Protein synthesis is important to genetics because codes for . The gene is by the protein as it functions in the body. The traits you have are an expression of the DNA gene through the protein it codes for.

From DNA to Protein https://www.youtube.com/watch?v=gG7uCskUOrA

New Vocabulary Protein synthesis: the process of making proteins from DNA Homework Pg 51. #1, 2, 3, 4