Chapter 8 Essential Cell Biology Exam Questions and Answers Latest Update

Chapter 8 - ANSWER-Control of Gene Expression gene expression - ANSWER-A complex process by which cells selectively direct the synthesis of the many thousands of proteins and RNAs encoded in their genome Differentiation - ANSWER-process in which cells become specialized in structure and function. It is caused by different gene expression What percent of a cell usually expresses its genes? - ANSWER-About 50% out of all of its total repertoire. For a human, out of 21,000 protein coding genes we have, we use How is the protein content analyzed nowadays? - ANSWER-Proteins are analyzed by mass spectrometry. This technique is much ore sensitive than electrophoresis and it enables the detection of even proteins that are produced in minor quantities housekeeping proteins - ANSWER-Proteins common to many cell types, concerned with basic metabolic and structural functions. True or False: different cell types often respond in different ways to the same extracellular signal contributes to the specialization that gives each cell type its distinctive character. - ANSWER-True as heck What are the six ways a cell can control proteins? - ANSWER-1. Controlling when and how often a given gene is transcribed 2. Controlling how an RNA transcript is spliced or otherwise processed 3. Selecting which mRNAs are exported form the nucleus to the cytosol 4. Regulating how quickly certain mRNA molecules are degraded 5. Selecting which mRNAs are translated into protein by ribosomes 6. Regulating how rapidly specific proteins are destroyed after they are made What is the main way a cell controls gene expression? - ANSWER-They control transcription of new mRNA molecules Promoter - ANSWER-specific region of a gene where RNA polymerase can bind and begin transcription. It also correctly orients the enzyme. regulatory DNA sequences - ANSWER-DNA sequence to which a transcription regulator binds to determine when, where, and in what quantities a gene is to be transcribed into RNA. They can be 10 nucleotides long and be simple switches or be as