Biology Chapter 5: Nucleic Acids

- programs the amino acid sequence of a polypeptide

- genes consists of DNA, which belong to the class of compounds called nucleic acids- nucleic acids are polymers made of monomers called nucleotides

- desoxyrinonucleic acid (DNA)- ribonucleic acid (RNA)

- enable living organisms to reproduce their complex components from one generation to the next

- provides directions for its own replication- directs RNA synthesis and through RNA, controls protein synthesis

- the genetic material that organisms inherit from their parents- each chromosome contains one long DNA molecule, usually carrying several hundred or more genes - when a cell reproduces itself by dividing, its DNA molecules are copied and passed along from one generation of cells to the next- encoded in the structure of DNA, is the information that programs all the cell's activities- DNA however is not directly involved in running the operations of the cell; proteins are required to implement programs

- each gene along a DNA molecule directs synthesis of a type of RNA called messenger RNA (mRNA)- the mRNA molecule interacts with the cell's protein-synthesizing machinery to direct production of polypeptide

DNA>RNA>protein

- the sites of protein synthesis

- ribosomes are in the cytoplasm- but DNA resides in the nucleus- mRNA conveys genetic instructions for building proteins from the nucleus to the cytoplasm

- cells lack nuclei but still use mRNA to convey a message from the DNA to ribosomes and other cellular equipment that translate the coded information into amino acid sequences

Nucleic acids are macromolecules that exist as polymers called polynucleotides

- each polynucleotide consists of monomers called nucleotides- composed of three parts: 1. a nitrogen containing base 2. a five-carbon sugar 3. one or more phosphate groups

In a polynucleotide, each monomer has only one phosphate group

- the portion of a nucleotide without any phosphate group- nitrogenous base and a sugar