Biotechnology Learning Activity Sheets - DNA History, Structure, and Chemistry - PDF

**BIOTECHNOLOGY** **LEARNING ACTIVITY SHEETS** **QUARTER 3** **[DNA HISTORY, STRUCTURE AND CHEMISTRY]** **JOAN C. ZINAMPAN** **TUGUEGARAO CITY SCIENCE HIGH SCHOOL** **BIOTECHNOLOGY** **Name of Learner: \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_Grade Level: \_\_\_\_\_\_...

**BIOTECHNOLOGY** **LEARNING ACTIVITY SHEETS** **QUARTER 3** **[DNA HISTORY, STRUCTURE AND CHEMISTRY]** **JOAN C. ZINAMPAN** **TUGUEGARAO CITY SCIENCE HIGH SCHOOL** **BIOTECHNOLOGY** **Name of Learner: \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_Grade Level: \_\_\_\_\_\_\_\_\_\_\_\_\_** **Section: \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_Date: \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_** **LEARNING ACTIVITY SHEET** **DNA HISTORY, STRUCTURE AND CHEMISTRY** **Background Information for the Learners:** The discovery of the structure of DNA was one of the most important scientific achievements in the last century in human history. Many people have contributed to what we know about it. DNA was first discovered by Friedrich Miescher, but researchers and scientists continue to expound on his work to this day, as we are still learning more about its mysteries. As it turned out, Miescher's discovery was just the beginning. Credit for who first identified DNA is often mistakenly given to James Watson and Francis Crick, who just furthered Miescher's discovery with their own groundbreaking research nearly 100 years later. Watson and Crick contributed largely to our understanding of DNA in terms of genetic inheritance, but much like Miescher, long before their work, others also made great advancements in and contributions to the field. **[HISTORY OF DNA]** - - - - - - 1902 -- Mendel's theories were finally associated with a human disease by Sir Archibald Edward Garrod, who published the first findings from a study on recessive inheritance in human beings in 1902. Garrod opened the door for our understanding of genetic disorders resulting from errors in chemical pathways in the body. - 1939- Phoebus Levene identified the components DNA- bases adenine (A), thymine (T), cytosine (C) and guanine (G) in addition to a sugar molecule (deoxyribose) and a phosphate group. - 1944 -- Oswald Avery first outlined DNA as the transforming principle, which essentially means that it's DNA, not proteins that transform cell properties. - 1944 -- 1950 -- Erwin Chargaff discovered that DNA is responsible for heredity and that it varies between species. His discoveries, known as Chargaff's Rules, proved that guanine and cytosine units, as well as adenine and thymine units, were the same in double-stranded DNA, and he also discovered that DNA varies among species. - Late 1940s -- Barbara McClintock discovered the mobility of genes, ultimately challenging virtually everything that was once thought to be. Her discovery of the "jumping gene," or the idea that genes can move on a chromosome, earned her the Nobel Prize in Physiology. - 1951 -- Roslind Franklin's work in X-ray crystallography began when she started taking X-ray diffraction photographs of DNA. Her images showed the helical form, which was confirmed by Watson and Crick nearly two years later. Her findings were only acknowledged posthumously. - 1953 -- Watson and Crick published on DNA's double helix structure that twists to form the ladder-like structure we think of when we picture DNA.  What we know about DNA today can be largely credited to James Watson and Francis Crick, who discovered *the structure* of DNA in 1953. Despite there being many important and contributing discoveries both before and after their work, this is the year they discovered DNA's double helix, or spiraling, intertwined structure, which is fundamental to our current understanding of DNA as a whole. **[STRUCTURE AND COMPOSITION OF DNA]** The DNA structure can be thought of like a twisted ladder. This structure is described as a double-helix, as illustrated in figure 1. It is a nucleic acid, and all nucleic acids are made up of nucleotides. The DNA molecule is composed of units called nucleotides, and each nucleotide is composed of three different components, such as sugar, phosphate groups and nitrogen bases. The basic building blocks of DNA are nucleotides, which are composed of a sugar group, a phosphate ***Figure 1. DNA Structure*** group, and a nitrogen base. The sugar and phosphate groups link the nucleotides together to form each strand of DNA. Adenine (A), Thymine (T), Guanine (G)  and Cytosine (C) are four types of nitrogen bases. These 4 Nitrogenous bases pair together in the following way: **A** with **T,** and** C** with **G**. These base pairs are essential for the DNA's double helix structure, which resembles a twisted ladder. The order of the nitrogenous bases determines the genetic code or the DNA's instructions***.*** Among the three components of DNA structure, sugar is the one which forms the backbone of the DNA molecule. It is also called deoxyribose. The nitrogenous bases of the opposite strands form hydrogen bonds, forming a ladder-like structure. The DNA molecule consists of 4 nitrogen bases, namely adenine (A), thymine (T), cytosine (C) and Guanine (G) which ultimately forms the structure of a nucleotide. The A and G are ***purines*** and the C and T are **pyrimidines.** The two strands of DNA run in opposite directions. These strands are held together by the hydrogen bond that is present between the two complementary bases. The strands are helically twisted, where each strand forms a right-handed coil and ten nucleotides make up a single turn. **Erwin Chargaff**, a biochemist, discovered that the number of **nitrogenous bases in the DNA** was present in equal quantities. The amount of A is equal to T, whereas the amount of C is equal to G. **A=T; C=G** In other words, the DNA of any cell from any organism should have a 1:1 ratio of purine and pyrimidine bases. **Learning Competency** 1\. Trace the historical development of DNA 2\. Describe the key structural features of DNA, chemical composition and their relationship to DNA's function **Activity 1. Trace and You Will Know** **Directions:** Read through the work of each scientist A-F. Now, use this information to put the scientists in date order of when they made their discovery. The first one has been done for you   ANSWERS: **Activity 2. A DNA Structure** **(A DNA Mastery Unit)** **Directions:** Using a DNA model, answer the questions that follow. A. Label the diagram below with the following choices: ---------- --------- --------------------------- ----------- Adenine Guanine Sugar, Phosphate Backbone Base pair cytosine Thymine Nitrogenous base ---------- --------- --------------------------- -----------  B. 1\. What do the letters DNA stand for? \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_ 2\. What 2 locations is DNA found in a cell? \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_ 3\. What shape does a DNA molecule have? \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_ 4\. What makes up the backbone of this structure? \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_ 5\. What are the four bases that make up a DNA molecule? \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_ 6\. What three structures make up a nucleotide? \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_ 7\. Why is the order of the bases important? \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_ 8\. Explain the base pair rules. \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_ 9\. If one strand of DNA has a sequence of 5' ATG CAG TCT GAT CAT 3', what would its complementary strand be? 10\. If a double stranded molecule of DNA was found to be 30% Adenine, what would be the percent composition of the other 3 bases? (hint: use base pair rules, total is 100%) **Activity 3. Fact Or Bluff** **Directions:** Table 1 contains data that Erwin Chargaff published about the composition of DNA. -------------- ------------- -------------- --------------- --------------- -------------- **Organism** **Tissue** **%Adenine** **% Guanine** **%Cytosine** **%Thymine** Yeast 31.3 18.7 17.1 32.9 Sea Urchin Sperm 32.8 17.7 18.4 32.1 Rat Bone Marrow 28.6 21.4 21.5 28.4 Human Thymus 30.9 19.9 19.8 29.4 Human Sperm 30.3 19.5 19.9 30.3 -------------- ------------- -------------- --------------- --------------- -------------- \_\_\_\_\_\_\_1. In each organism, there is approximately one adenine for every thymine. \_\_\_\_\_\_\_2. In each organism, the proportions of adenine plus thymine equal those of cytosine and guanine. \_\_\_\_\_\_\_3. In each organism, there is approximately one guanine for every thymine. \_\_\_\_\_\_\_4. In each organism, there is approximately one guanine for every cytosine. \_\_\_\_\_\_\_5. The proportions of nitrogenous bases in the DNA of two different human tissues (thymus an sperm) are about the same. **REFLECTION:** 1\. I have learned that \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_ \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_ 2\. I enjoyed most on \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_ \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_ 3\. I want to learn more on\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_ \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_ **REFERENCES:** A. Books Manosa, S. and Talaue, F.T.. 2007*: Breaking Through Biology*. C and E Publishing Inc. B. Websites "The discovery of DNA's Structure ".Accessed February 11, 2021 [[Microsoft Word - Worksheet DNA.docx (smart-learning.co.uk)]](http://www.smart-learning.co.uk/teachers-club/wp-content/uploads/2014/06/Worksheet-DNA.pdf) Prepared by: **[JOAN C. ZINAMPAN]** Tuguegarao City Science High School