DNA Structure Pogil 2020 PDF

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This is a document about the needs of attending and passing something you are two dumb to do on your own and i cannot do it...

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DNA Structure and Replication How is genetic information stored? Deoxyribonucleic acid or DNA is the molecule of heredity. It contains the genetic blueprint for life. For organisms to grow and repair damaged cells, each cell must be capable of accurately copying itself prior to cell division.

Model 1 – The Structure of DNA

1. Refer to the diagrams in Model 1 a. What are the three parts of a nucleotide?

b. What kind of sugar is found in a nucleotide?

c. Which nucleotide component contains nitrogen?

d. What are the four nitrogen bases?

2. DNA is often drawn in a “ladder model.” Locate this drawing in Model 1. a. Circle a single nucleotide on each side of the ladder model of DNA. b. What part(s) of the nucleotides make up the rungs (steps) of the ladder?

c. What part(s) of the nucleotides make up the sides (or backbone) of the ladder?

3. On the ladder, label each of the bases with an A, T, C, or G. 4. The two strands of DNA are held together with hydrogen bonds between the nitrogen bases. These are weak bonds between polar molecules. How many hydrogen bonds connect adenine and thymine? Hint: Count the lines

5. How many hydrogen bonds connect Cytosine and Guanine?

READ THIS! Erwin Chargaff (1905–2002), an Austrian-American biochemist, investigated the ratio of nucleotide bases found in the DNA from a variety of organisms. From his research, as well as research by Rosalind Franklin and Maurice Wilkins, Watson and Crick developed the complementary base-pair rule during their race to discover the structure of DNA. The complementary base-pair rule states that adenine and thymine form pairs across two strands, and guanine and cytosine form pairs across two strands. Adenine and Guanine both have two nitrogen rings and are called purines. Thymine and Cytosine have one nitrogen ring and are called pyrimidines.

6. Which nitrogen bases are purines (write out the full name)? 7. Which bases are pyrimidines (write out the full name)? 8. The nucleotides pair following the complementary base-pairing rules. a. Use the diagram above to determine which nucleotide pairs with adenine? b. Which nucleotide pairs with cytosine? Fill in the complementary bases. A

T

C

G

A

G

T

T

9. The proportions of the bases are consistent within a species; however, they vary between species. Complete the table to show the percentages of each type of base in the five different organisms. Remember the complementary base pair rules. Percentage of Each Base Organism Adenine Human

31

Cow

28

Salmon

Thymine

Cytosine

31 22 19

Wheat Yeast

Guanine

23 31...