The DNA Connection

1. The DNA Connection

2. Chromosomes are made of DNA

3. The DNA Code

4. Each chromosome contains thousands of genes.

5. The sequence of bases in a gene forms a code

6. Every 3 Letters is called a CODON • Code = protein

7. DNA carries the codes

8. DNA • Deoxyribonucleic Acid (DNA) • Double Stranded

9. DNA Bases • Purines: • 1. Adenine (A) • 2. Guanine (G)

10. Pyridimines • 1. Cytosine (C) • 2. Thymine (T)

11. DNA Base Pairing • A=T • G C

12. RNA Base Pairing • A=U *Uracil • There is NO “T” in RNA • G C

13. Transcription

14. The process by which RNA is made from DNA • Occurs in the Nucleus

15. Since DNA is too big to fit through the nuclear pores, messenger RNA is used to “read” DNA

16. RNA • Single Stranded • Same bases as DNA EXCEPT instead of T RNA contains U

17. After transcription mRNA leaves the nucleus and attaches onto a ribosome

18. Translation

19. The message is translated into an amino acid sequence • Occurs on ribosomes

20. Every 3 Letters is called a CODON • Code = protein

21. Requires tRNA to translate the code

22. tRNA can only read 3 mRNA codes at one time (codon)

23. The Genetic Code • The Codon codes for which amino acid is to be made

24. Amino Acids – the building blocks of proteins

25. mRNA codon • UAC • Translated Code • Tyr

28. DNA Sequence: • A T G C A A T G C • U A C G U U A C G

29. RNA Sequence: • UAC GUU ACG • Amino Acids Produced: Tyr – Val – Thr

32. DNA Mutations

33. Substitution

34. Deletion

35. Addition