1. LG 4 DNA and Protein Synthesis Ribonucleic Acid RNA – Steps in Protein Synthesis Transcription – Translation – Functions of Proteins Structural – Signals – Enzymes – Carriers –

2. Unit IV - Genetics Learning Goal 4 Describe how DNA is used by cells to produce proteins.

3. RNA RNA (ribonucleic acid) is another type of nucleic acid that plays a role in decoding DNA.

4. RNA is different from DNA in the following ways: It contains uracil instead of thymine It contains ribose instead of deoxyribose It is single stranded instead of double stranded

5. Steps in Protein Synthesis Transcription A section of DNA called a gene contains the code for a certain protein. When the protein is needed by the cell, this section unwinds.

6. RNA nucleotides line up and bond with their complimentary nitrogen bases on the appropriate side of the exposed DNA G-C, C-G, U-A, A-T When transcription is complete, messenger RNA (mRNA) separates from the DNA and moves out of the nucleus into the cytoplasm where it hooks up with ribosomes.

7. Translation Transfer RNA (tRNA) brings amino acids to complimentary regions on the mRNA. These regions are called codons and are 3-letter segments The 3-letter tRNA segments are called anti codons

8. Amino acids are positioned side by side and bond together to form polypeptides, which then become part of protein molecules.

9. Functions of Proteins Structural (muscles, connective tissue) Example: collagen

10. Signals (hormones, neurotransmitters) Example: insulin that signals cells to take in glucose

11. Enzymes that speed up chemical reactions in cells Example: lipase for fat digestion

12. Carriers that move substances around in the body. Example: hemoglobin that carries oxygen to cells.

13. http://www.youtube.com/watch?v=h3b9Ar upXZg&feature=player_detailpagehttp://www.youtube.com/watch?v=h3b9Ar upXZg&feature=player_detailpage http://www.youtube.com/watch?v=gqvYOr 78THo&list=RD02iSt7oh9E1Dg&feature=p layer_detailpagehttp://www.youtube.com/watch?v=gqvYOr 78THo&list=RD02iSt7oh9E1Dg&feature=p layer_detailpage