Nucleic acids and A.t.p .

1. Nucleic acids and A.t.p.

2. Tap. 31e One last group of Organic (carbon and hydrogen-containing) molecules that is extremely important to the body are Nucleic Acids You have probably heard of the nucleic acid called DNA – Deoxyribonucleic Acid, and maybe even its close partner molecule called RNA – Ribonucleic Acid.

3. Both DNA and RNA are extremely long macromolecules that perform very complex crucial processes in each of our trillions of cells. But despite being so long and so important, their structure is quite simple. They are built by joining several NUCLEOTIDE monomers together via Dehydration Synthesis. General Structure Detailed Structure • Each nucleotide, whether it be a DNA nucleotide or a RNA nucleotide will consist of three key components: • A Phosphate group –consisting of phosphorous and oxygen • A 5-carbon sugar –classified as being a PENTOSE (penta = 5) sugar. • A Nitrogen-containing base (alkali-basic in pH) –which may have a single ring structure or may be a double ringed structure.

4. Tap. 40 In this DNA nucleotide the single-ringed base is called CYTOSINE

5. Just like the other organic macromolecules (polymers) we studied in this chapter; an “H” is taken off of one of the monomers and an “OH” off the other to link the two monomers together. The “H” and “OH” then join together to form a “H2O” water. As illustrated in the “Dehydration Synthesis” A.K.A. “Condensation Synthesis” reaction shown below.

6. We will be looking at DNA structure in more detail when we hit Unit D –Chapter 25. But for now, we should at least know that there are four different DNA nucleotides found in a DNA molecule. Each of the four DNA nucleotides have the same phosphate group, and the same 5-carbon sugar (Deoxyribose). The thing that distinguishes the four DNA nucleotides is what type of base is found coming off of the Deoxyribose sugar.

7. The four different bases are Adenine, Guanine, Cytosine and Thymine. A helpful Mnemonic for DNA is “Any Geek Can Teach”. As you are witnessing!

8. Fig. 2.28 DNA is also unique in that it is a double stranded molecule. Two strands form then link together with weak Hydrogen bonding between the bases

9. Fig. 2.28ab

10. Fig. 2.28c

11. Table 2.3 We will be comparing DNA and RNA structurally and functionally in greater depth in the next unit. But when it comes to bases, recall that “Any Geek Can Teach”, yah, “Any Geek Can U?”

12. Nucleotide monomers are used to build nucleic acids like DNA and RNA (we will study RNA later on). But the cells of your body will also take a RNA nucleotide and modify to make it into an energy rich molecule that is used universally by life forms to release energy. This modified Nucleotide is called – A.T.P. = Adenosine Triphosphate. Note that this molecule posseses the base called Adenine, a 5-carbon pentose sugar called “Ribose” (found in RNA nucleotides). But instead of a single phosphate group like a typical nucleotide, it possesses three phosphate groups. There are very high energy bonds between each phosphate group.

13. Fig. 2.29 Cells in life forms, build this ATP molecule then they quickly perform a hydrolysis reaction on the bond between the second and third phosphate groups. When this happens, energy is released to perform processes in the body and within the cell. Then the life form will burn carbs and fats to acquire caloric energy to run a dehydration synthesis reaction to rebuild the ATP molecule from the ADP (adenosine diphosphate) and the free phosphate group.

14. The A.T.p. Cycle

15. Tap. 43 The diagram below illustrates the process of building various polymers from their respective monomers. For Example – “a” could be GLUCOSE, then “c” could be STARCH. “b” represents dehydration synthesis, while “d” represents hydrolysis of the polymer back down to its monomers.