4.10 Lesson 10: Nucleic Acids and Nucleotides
- Nucleic acids are huge organic molecules that contain carbon, hydrogen, oxygen, nitrogen, and phosphorus that carry information.
- The basic units of nucleic acids are nucleotides, composed of a nitrogenous base, a pentose sugar, and a phosphate group joined by dehydration synthesis.
- Deoxyribonucleic acid (DNA), a double stranded nucleic acid, forms the genetic code inside each cell and thereby regulates most of the activities that take place throughouta person’s lifetime. Each gene of our genetic material is a piece of DNA that controls the synthesis of a specific protein.
- The nitrogenous bases found in DNA are Thymine (T), Adenine (A), Cytosine (C), and Guanine (G). The pentose sugar in DNA is deoxyribose.
- In forming the DNA strand, the Guanine and Cytosine from the nitrogenous bases only bond with each other, as do the Thymine and Adenine.
- Ribonucleic acid (RNA) relays instructions from the genes in the cell’s nucleus to guide each cell’s assembly of amino acids into proteins by the ribosomes.
- RNA structure, differs from DNA in that it is: single stranded, contains ribose sugar, and uracil (U) nitrogenous base replaces thymine
- There are three types of RNA within the cell, each with a specific function: -messenger RNA (mRNA): contains a blueprint for the protein being produced -ribosomal RNA (rRNA): the ribosome where the protein is produced -transfer RNA (tRNA): brings the correct amino acids to the ribosome to produce the protein.
- Adenosine Triphosphate (ATP), a nucleotide (but not a nucleic acid), is the temporary molecular storage of energy as it is being transferred to cellular activities.
- ATP is needed for muscle contraction, transport of substances across cell membranes, movement of structures within cells, movement of organelles, and hair growth.
- ATP consists of 3 phosphate groups attached to adenine and the sugar, ribose.
- Formation and usage of ATP:
- Hydrolysis of ATP (using the enzyme, ATP-ase):releases energy leaving ADP (adenosine diphosphate)
- Synthesis of ATP (using the enzyme ATP-synthase): 1 glucose molecule is used to create 36 to 38 molecules of ATP.
