2. RNA and Protein Synthesis

3. From Genes to PRoteins

4. fertilized egg All of the 100 trillion cells in your body came from one original cell: the fertilized egg that grew into YOU! So how come there are so many different kinds of cells in your body? How did they get so specialized? And all of those 100 trillion cells have exactly the same DNA in them.

5. The answer is… Different genes are turned on in different types of cells. Each gene carries the instructions for making a protein, which does the work of the cell. Different cells make different proteins. For example, liver cells make different proteins than nerve cells, or eye cells, or stomach cells. DNA DNA is the “boss” or manager of each cell. It’s the DNA that has the instructions for making the proteins. So what are the “workers” of the cells? The answer: RNA

6. Here’s what happens… DNARNA transcription Protein translation Trait

7.  RNA contains the sugar ribose instead of deoxyribose  RNA has the base uracil (U) instead of thymine (T). RNA is very similar in structure to DNA with 3 main differences. RNA

8.   RNA Is Single-Stranded instead of Double-Stranded like DNA

9. microRNA, Recently, a new class of RNA, microRNA, has been shown to regulate gene expression. There are Different RNAs with Different Functions Messenger RNA (mRNA) Transfer RNA (tRNA) Ribosomal RNA (rRNA)

10. DNA/RNADNARNA name sugar shape nitrogen bases location # types function deoxyribonucleic acid ribonucleic acid deoxyriboseribose double-helix (twisted ladder) one-sided ladder adenine cytosine guanine thymineuracil Nucleus, mitochondria, chloroplast travels between nucleus & cytoplasm 1 type 3 types: mRNA tRNA, rRNA forms genetic code that specifies what proteins are produced by a cell mRNA:carries genetic code from nucleus to the ribosomes; tRNA brings amino acids to ribosomes for protein assembly

11. makes an RNA copy of DNA RNA polymerase The enzyme RNA polymerase opens the DNA strands and makes an RNA copy of one of the DNA strands. RNA polymerase acts hereTranscription

12. The Genetic Language Uses 4 Letters Written Into 3-Letter Words

13. Two examples There are 20 different amino acids Amino acids are the building blocks of proteins. A protein is made up of many amino acids bonded together. It’s the proteins that carry out every function in all your cells. It’s the proteins that give an organism its traits. Amino Acids – What the Genetic Code Specifies

14. groups of three  The 4 nitrogen bases (A, C, G, T) are read in groups of three. codon.  Each group of 3 bases is called a codon.  Each codon stands for 1 of the 20 amino acids. AAAAAG lysine  Since there are 64 possible combinations of 3 and only 20 amino acids, some amino acids have more than one codon. For example, AAA and AAG both code for lysine. “Start”“Stop”.  There are also codes for “Start” and “Stop”.

15. Ribosomes are located in two places:  attached to the ER  floating in the cytoplasm  attached to the ER (Endoplasmic Reticulum), or  floating in the cytoplasm. Ribosomes Ribosomes are Complicated Protein- Synthesizing Machines

16. 1.DNA (mRNA) 1. DNA molecule unzips and makes a single-stranded copy of gene (mRNA) 2.mRNA ribosome 2. mRNA leaves the nucleus and attaches to a ribosome. 3.Ribosome mRNA 3. Ribosome moves along the mRNA and “reads” it. 4.tRNA protein chain 4. tRNA brings amino acids to ribosome and attaches them to the protein chain. 5.ribosome protein. 5. The ribosome releases the protein. 1 2 3 5 4 Protein Synthesis Protein Synthesis

17. Protein Synthesis

18. Protein synthesis(mRNA) (tRNA) Protein Synthesis

20. A U G G G C U U A A A G C A G U G C A C G U U messenger RNA This is a molecule of messenger RNA. It was made in the nucleus by transcription from a DNA molecule. mRNA molecule codon

21. A U G G G C U U A A A G C A G U G C A C G U U A ribosome on the rough E.R. attaches to the mRNA molecule. ribosome

22. A U G G G C U U A A A G C A G U G C A C G U U It brings an amino acid to the first three bases (codon) on the mRNA. Amino acid tRNA molecule anticodon U A C A transfer RNA molecule arrives. anticodon) codonThe three unpaired bases (anticodon) on the tRNA link up with the codon.

23. A U G G G C U U A A A G C A G U G C A C G U U Another tRNA molecule comes into place, bringing a second amino acid. U A C C C G Its anticodon links up with the second codon on the mRNA.

24. A U G G G C U U A A A G C A G U G C A C G U U A peptide bond (chemical bond) forms between the two amino acids. Peptide bond C C G U A C

25. A U G G G C U U A A A G C A G U G C A C G U U The first tRNA molecule releases its amino acid and moves off into the cytoplasm. C C G U A C

26. A U G G G C U U A A A G C A G U G C A C G U U C C G The ribosome moves along the mRNA to the next codon.

27. A U G G G C U U A A A G C A G U G C A C G U U Another tRNA molecule brings the next amino acid into place. C C G A A U

28. A U G G G C U U A A A G C A G U G C A C G U U A peptide bond joins the second and third amino acids to form a polypeptide (protein) chain. C C G

29. A U G G G C U U A A A G C A G U G C A C G U U The polypeptide (protein) chain gets longer. G U C A C G The process continues. This continues until a termination (stop) codon is reached.

30. A U G G G C U U A A A G C A G U G C A C G U U The polypeptide (protein) chain gets longer. G U C A C G The process continues. This continues until a termination (stop) codon is reached.

31. A U G G G C U U A A A G C A G U G C A C G U U The polypeptide (protein) is then complete, and is released from the ribosome.