1. Biochemistry Part IV Nucleic Acids

2. Largest organic molecule made by organisms Largest organic molecule made by organisms Include 2 main types: Include 2 main types: DNA – Deoxyribonucleic Acid DNA – Deoxyribonucleic Acid RNA – Ribonucleic Acid RNA – Ribonucleic Acid

3. DNA Contains an organisms’ genetic information Contains an organisms’ genetic information Nucleic acid arranged in nucleotides: Nucleic acid arranged in nucleotides: A nitrogen base (next page) A nitrogen base (next page) A 5-carbon sugar called deoxyribose A 5-carbon sugar called deoxyribose Deoxyribose has one less oxygen than Deoxyribose has one less oxygen than ribose sugar (discussed later) ribose sugar (discussed later) A phosphate group A phosphate group

4. DNA Nitrogenous Bases: Nitrogenous Bases: Adenine Adenine Guanine Guanine Cytosine Cytosine Thymine Thymine Purines Pyrimidines Purines have a double ring structure Pyrimidines have a single ring structure

5. DNA Structure 5’ 3’

6. The sequence of bases is the code which determines what proteins the organism’s cellular machinery will build

8. RNA Similar to DNA with the following exceptions (differences) Similar to DNA with the following exceptions (differences) The sugar is a ribose sugar not a deoxyribose sugar (has an extra oxygen) The sugar is a ribose sugar not a deoxyribose sugar (has an extra oxygen) There are no T’s (thymine bases) in RNA, they are instead replaced by U’s (uracil bases) There are no T’s (thymine bases) in RNA, they are instead replaced by U’s (uracil bases) RNA is usually single stranded and does NOT form a double helix like DNA RNA is usually single stranded and does NOT form a double helix like DNA

9. DNA RNA DNA interacts with RNA to build proteins DNA interacts with RNA to build proteins DNA is the original recipe for proteins DNA is the original recipe for proteins RNA acts as a messenger of that recipe and to help assemble proteins RNA acts as a messenger of that recipe and to help assemble proteins This interaction is called gene expression This interaction is called gene expression

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