NU 545 Unit 1 Study Guide Latest With Correct Answers.

NU 545 Unit 1 Study Guide Latest With Correct Answers. What is metabolic absorption? - ANSWER The uptake and use of nutrients and other substances from the cells surrounds What uses oxygen to remove hydrogen atoms in an oxidative reaction? - ANSWER Peroxisomes contain enzymes to use o2 to remove H atoms. This produces hydrogen peroixide. During cell injury what is released that is capable of cellular autodigestion? - ANSWER Lysosomes aid in cellular digestion, seen as "trash cans and recycling agents" "as cells complete their life span and die, lysosomes digest...the debris... Lysosomes involved in this process of autodigestion are called autolysosomes or autophagomes Where is the genetic info contained in the cell? - ANSWER The nucleus contains the Nucleolus, a small dense structure composed of RNA, DNA, DNA protein. Cell membranes contain which major chemical components? - ANSWER "The main components of cell membranes are lipids and proteins. The basic structure of cell membranes is the lipid bilayer..." What allows potassium to diffuse in and out of cells? - ANSWER Diffusion is the movement of a solute molecule from and area of greater solute concentration to an area of lesser solute concentration. . Active transport of K+ and Na+ requires a Sodium-Potassium Pump NU 545 Unit 1 Study Guide Latest With Correct Answers How is the cell protected from injury? - ANSWER Plasma membrane In cirrhosis, what does cholesterol have to do with the erythrocytes? - ANSWER causes a decrease in membrane fluidity and affects the cells' ability to transport oxygen What is platelet-derived growth factor? - ANSWER PDGF stimulates proliferation of connective tissue cells and neuroglial cells. Can help with creating blood clots. Pg 38. What is cell communication? How does it occur? - ANSWER Cells need to communicate w/ each other to maintain a stable internal environment, or homeostasis; to regulate growth and division... it is done by 3 main ways. 1) they display plasma membrane-bound signaling molecules (receptors) that affect the cell itself and other cells in direct physical contact. 2) they affect receptor proteins inside the target cell and the signal molecule has to enter the cell to bind w/ them. 3) they form protein channels that directly coordinate the activities of the adjacent cells. What is chemical signaling? - ANSWER Primary means of cell-to-cell communication. 5 forms of signaling mediated by secreted molecules: (1) Contact-dependent signaling requires cells to be in close membrane-membrane contact; (2) Paracrine signaling- cells secrete local chemical mediators that are quickly absorbed, destroyed, or immobilized; (3) Autocrine signaling- cells produce signals that they, themselves, respond to (cancer cells); (4) Hormonal signaling involves specialized endocrine cells that secrete chemicals called hormones (TSH). Hormones are released by one set of cells and travel through the tissue and through the bloodstream to produce a response in other sets of cells; (5) Neurohormonal signalinghormones are released into the blood by neurosecretory neurons. How is glucose transported from the blood to the cell? - ANSWER Pancreatic cells secrete and release insulin to signal muscle cells to absorb sugar from the blood for energy. Understand the transportation of potassium and sodium across plasma membranes - ANSWER The Na+ -K+ antiport system (Na+ moving out of the cell and K+ moving into the cell) uses the direct energy of ATP to move these cations. The transporter protein is the enzyme adenosine triphosphatase (ATPase). Approximately 60% to 70% of the ATP synthesized by cells is used to maintain the Na+-K+ transport system. 1, three Na+ ions bind to sodiumbinding sites on the carrier's interface. 2, at the same time, an energycontaining adenosine triphosphate molecule produced by the cell's mitochondria bind to the carrier. The ATP disassociates, transferring its stored energy to the carrier. 3 and 4, the carrier then changes shape, releases the three Na+ ions to the outside of the cell, and attracts two potassium ions to its potassium- binding site. 5, the carrier then returns to its original shape, releasing the two K+ ions and the remnant of the ATP molecule to the inside of the cell. The carrier is now ready for another pumping cycle What is active transport? - ANSWER requires life, biologic activity, and the cell's expenditure of metabolic energy. Unlike passive transport, active transport occurs across only living membranes that have to drive the flow "uphill" by coupling it to an energy source.