1. Protein Synthesis Transcription & Translation

2. RNA is composed of 3 parts: Ribose: smaller sugar than deoxyribose of DNA Phosphate 4 Bases –Adenine (A) –Guanine (G) –Uracil (U)* instead of T –Cytosine (C) RNA is single stranded and thus smaller & able to leave the nucleus of the cell

3. These 3 parts –ribose, –phosphate and –1 base still form a nucleotide RNA is used by DNA to carry the code and create proteins that control the functioning of the cell There are two main types of RNA used: mRNA (messenger RNA) and tRNA (transfer RNA)

4. DNA is the architect – it tells everyone else what to do, how and when. mRNA is the messenger who carries the message from DNA out of the nucleus to the ribosome. tRNA transfers (transports) amino acids to the ribosome where they can be assembled into proteins.

6. Transcription Writing of DNA Message to mRNA In the nucleus of the cell Information from DNA is transferred to mRNA. DNA uncoils and unzips (with the help of more enzymes) The exposed DNA bases match up with RNA nucleotides to form an mRNA strand. The mRNA strand will be complementary to the original DNA strand.

7. mRNA (Messenger RNA) The DNA strands rejoin. The mRNA will detach, move out of the nucleus into the cell cytoplasm and go to the ribosome.

8. Transcription

9. Translation In the cytoplasm at the ribosomes. The mRNA binds to a ribosome. The strand of mRNA is pulled through the ribosome three bases at a time, in triplets.

11. Each of these triplets on the mRNA strand is called a codon. Each triplet of complementary tRNA is called an anticodon.

12. Translation

13. tRNA (Transfer RNA) Transfer RNA (tRNA), reads the strand of mRNA and translates it into a strand of amino acids. If the 3 base anticodon of the tRNA complements the 3 base codon of the mRNA, they briefly combine. The amino acid is left behind when the tRNA leaves. As each codon is read, the next tRNA brings in a new amino acid and the polypeptide (protein) chain grows. This requires enzymes and ATP.

15. First letter/ second letter UCAGThird Letter U phenylalanineserinetyrosinecysteineU phenylalanineserinetyrosinecysteineC leucineserinestop A leucineserinestoptryptophanG C leucineprolinehistadinearginineU leucineprolinehistadinearginineC leucineprolineglutaminearginineA leucineprolineglutaminearginineG A isoleucinethreonineasparagineserineU isoleucinethreonineasparagineserineC isoleucinethreoninelysinearginineA methionine, start codon threoninelysinearginineG G valinealanineaspartateglycineU valinealanineaspartateglycineC valinealanineglutamateglycineA valinealanineglutamateglycineG mRNA to amino acid

17. Codons code for particular amino acids Each codon will correspond to one amino acid. These amino acids when put together form polypeptides or proteins. The genetic code is redundant. There are 64 possible codons but only 20 amino acids.

18. Translation http://www.nobel.se/medicine/educational/dna/b/translation/translation_ani.html

20. Review