SUMMER Review Exam 1 CONCEPTS TO FOCUS ON FOR EXAM 1

SUMMER Review Exam 1 CONCEPTS TO FOCUS ON FOR EXAM 1 NOTE: I included MOST of these concepts in the live chat, but may not touch on some if fairly straight forward. However, review ALL of these concepts. – Week 1 & 2 Cellular Biology & Genetics 1. Main components of the cell: The nucleus contains the nucleolus, a small, dense structure composed largely of RNA; most of the cellular DNA; and the DNA- binding proteins, the histones, that regulate its activity. The DNA chain in eukaryotic cells is so extensive that the risk of breakage is high. Therefore, the histones binding to DNA cause DNA to fold into chromosomes (see Fig. 1.2, C). The wrapping of DNA into tight packages of chromosomes is essential for cell division in eukaryotes. Ribosomes are RNA-protein complexes (nucleoproteins) that are synthesized in the nucleolus and secreted into the cytoplasm through pores in the nuclear envelope called nuclear pore complexes (NPCs). These tiny ribosomes may float free in the cytoplasm or attach themselves to the outer membranes of the endoplasmic reticulum (see Fig. 1.1, A). Their chief function is to provide sites for cellular protein synthesis. The Golgi complex (or Golgi apparatus) is a network of flattened, smooth membranes and vesicles frequently located near the nucleus of the cell (Fig. 1.4). Proteins from the endoplasmic reticulum are processed and packaged into small membrane- bound sacs or vesicles called secretory vesicles, The Golgi complex is a refining plant and directs traffic (e.g., protein, polynucleotide, polysaccharide molecules) in the cell. ............................................continued.................................................