1. DNA Review

2. Sugar
Purine ( A/G)
Nucleotide

3. 1. Guanine, cytosine, __adenine and thymine are four bases in DNA.
_2. In DNA, cytosine is complementary to guanine.
3. Sugars and phosphates form the sides or backbones while the bases are the rungs of a twisted ladder.
4. The double ring nucleotides, A and G, are classified as purines
5. Two purines would never be paired because the rung of the ladder would be too long
6. A DNA nucleotide would contain a deoxyribose sugar, nitrogen base and a phosphate group.

4. 7. There are 2 types of nucleic acids. 
8. After replication, each new molecule has one parental strand and one new strand. This pattern of replication is semi-conservative
 9. Adenine and uracil are complimentary in RNA
10. Replication begins at the origin
 11. Since the sugars in DNA are orientated in opposite directions, the two strands of DNA are called antiparallel
12. The phosphate group of a nucleotide is always attached to carobon #5.
 13. In RNA editing the introns are cut out, and a cap and tail are added
 14. The process by which DNA makes a copy of itself is replication
15. The process of converting the RNA code into amino acids is translation
 16. The process of copying the genetic information mRNA is called transcription

5. 17. The DNA coded message is copied on onto mRNA
18. Each set of 3 nitrogen bases on mRNA is called a codon.
19. Transcription begins at a region called the promotor
20. DNADeoxyribose, double stranded, stays in nucleus, thymine, one less oxygen
RNAribose, single stranded, uracil, one more oxygen
21 F
22 E
23 C
24 D
25 B

6. 26. The geneic code is said to be universal because a codon represents the same amino acids in all organisms
27. The tRNA brings amino acids to the ribosome.
28. The ribosome is made up of protein and rRNA
29. The four bases of DNA can make 64 combinations in three letter codes.
30. Proteins are made in the ribosome
31. It would take 150 bases to code for 50 amino acids.
32. A change in the sequence of bases is a mutation
33. These changes (#32) can be caused by mutagens such as X-rays, UV light, chemicals, pollutants and radioactive substances.

7. 34. The genetic code is determined by the order/ sequence of nucleotides.
35. The last codon on mRNA, UAA, is a stop codon.
 36. When a single base is removed, the resulting chain of amino acids are all off. This results in a frameshift

8. 37. untwists/unzips DNA E. helicase
38. pairs up new DNA nucleotides
A. DNA polymerase
39. bonds DNA nucleotides to other nucleotides
c. ligase
40. makes peptide bonds d. peptidyl transferase
41. pairs RNA nucleotides B. RNA polymerase
42. Lays down the primer f. primase

9. The coding DNA strand Is: ATG CGT AGG ATT
43. What is the complementary noncoding strand? TAC GCA TCC TAA
44. What would be the sequence of bases on mRNA? AUG CGU AGG AUU
45. Which DNA strand is mRNA complementary to? NONCODING the same as? CODING
46. What would be the amino acid sequence that mRNA would code for? START ARG ARG ILE
47. If the amino acid sequence is: cys arg leu met, what would be the mRNA sequence?(There are sequences that are OK…just use one)
UGC AGG CUU AUG

10. 48. REPLICATION
a. DNA unzips when the weak hydrogen bonds are broken by helicase
b. DNA polymerase pairs up free DNA nucleotides
c. the nucleotides are bonded together by the enzyme, ligase
d. the 2new DNA strands retwist

11. 49. Transcription
a. DNA unzipswhen weak hydrogen bonds are broken by helicase
b. RNA polymerase attaches at the promoter region and starts pairing up free RNA nucleotides to the noncoding strand of DNA
c. the nucleotides are bonded by ligase
d. the new RNA strand peels away
e. DNA rezips when the hydrogen bonds reform

12. 50. Translation a. mRNA attaches to the ribosome
b. the first tRNA pairs up with the start (AUG)codon
c. the anticodon of the second tRNA pairs with the codon on mRNA
d. the amino acids are joined with a peptide bond using the enzyme peptidyl transferase
e. the first tRNA leavesand another tRNA enters the ribosome
f. the process continues until the stop codon is reached
g. all parts break apart and release a protein