AP BIOLOGY

Detailed explanation-1: -The type of RNA that contains the information for making a protein is called messenger RNA (mRNA) because it carries the information, or message, from the DNA out of the nucleus into the cytoplasm.

Detailed explanation-2: -Within the ribosome, the rRNA molecules direct the catalytic steps of protein synthesis-the stitching together of amino acids to make a protein molecule. In fact, rRNA is sometimes called a ribozyme or catalytic RNA to reflect this function.

Detailed explanation-3: -A gene is the section of DNA required to produce one protein. Genes are typically hundreds or thousands of base pairs in length because they code for proteins made of hundreds or thousands of amino acids.

Detailed explanation-4: -All of the RNA in a cell is made by DNA transcription, a process that has certain similarities to the process of DNA replication discussed in Chapter 5. Transcription begins with the opening and unwinding of a small portion of the DNA double helix to expose the bases on each DNA strand.

Detailed explanation-5: -The main job of DNA is to make the proteins that living things need to grow. So lets look a little closer at proteins. Proteins are large molecules made of smaller molecules called amino acids. Proteins have special shapes that help them to bind tightly to specific other molecules in the cell.