NU 545 Unit 1 Exam Questions and Answers 2023/2024 (A+).

NU 545 Unit 1 Exam Questions and Answers 2023/2024 (A+). What is metabolic absorption? “All the cells take in and use nutrients and other substances from their surroundings. Cells of the intestine and the kidney are specialized to carry out absorption. Cells of the kidney tubules reabsorb fluids and synthesize proteins. Intestinal epithelial cells reabsorb fluids and synthesize protein enzymes” (McCance WHAT USES OXYGEN TO REMOVE HYDROGEN ATOMS IN AN OXIDATIVE REACTION? Peroxisomes (microbodies) which are membrane-bound organelles that contain several oxidative enzymes) contain several oxidative enzymes such as catalase and urate oxidase. They detoxify compounds and fatty acids During cell injury what is released that is capable of cellular auto digestion? Lysosomal enzymes - that can react with their specific substrates, causing cellular self-digestion. Where is the genetic information contained in the cell? 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. What are the major chemical components of the cell membranes? Ans: Lipids and Proteins Explanation: The major chemical components of all cell membranes are lipids and proteins, but the percentage of each varies among different membranes. WHAT ALLOWS POTASSIUM TO DIFFUSE IN AND OUT OF CELLS? The sodium – potassium pump with ATP active transport/ ATPase (Adenosine Triphosphatase) How is the cell protected from injury? Plasma membrane functions: Protection, barrier to toxic molecules and macromolecules [proteins, nucleic acid, polysaccharides]” IN CIRRHOSIS, WHAT DOES CHOLESTEROL HAVE TO DO WITH THE ERYTHROCYTES? Affects the cell's ability to transport oxygen . Cholesterol content of red blood cell's plasma membrane increases and interferes with the cell's ability to transport oxygen. Platelet-derived growth factor Secreted by platelets and endothelial cells - Mitotic stimulant for fibroblasts and smooth muscle to multiply and repair damaged vessel What is cell communication and how does it occur? Method that cells use to maintain homeostasis. Regulates their growth and division and their development and organization into tissues and to coordinate their functions. Occurs through gap junctions, receptors, and they secrete chemicals tat signal to cells some distance away What is CHEMICAL SIGNALING? (Transmission between Neurons) information is passed between neurons through chemicals called neurotransmitters. How is glucose transported from the blood to the cell? Passive mediated transport (facilitated diffusion)-does not require energy, down the concentration gradient. Transported by a uniport mechanism Understand the transportation of potassium and sodium across plasma membranes. Active transport and the sodium-potassium pump. Three Na+ ions bund to sodium binding sites on the carrier’s inner face. At the same time an energy containing adenosine triphosphate (ATP) molecule produced by the cell’s mitochondria binds to the carrier. The ATP breaks apart, transferring its stored energy to the carrier. The carrier then changes shape, releases the three Na+ ions to the outside of the cell, and attracts two K+ ions to its potassium binding sites. 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? The movement of materials through a cell membrane against a concentration gradient using cellular energy (ATP). Cytokines Cytokines are a group of proteins that are secreted by a number of cell types, including macrophages and helper T cells, that regulate the function of lymphocytes and other cells of the immune system. Do all cells continue to replicate and divide? All types of cells undergo mitosis during formation of the embryo, but many adult cells, such as nerve cells, lens cells of the eye, and muscle cells, lost their ability to replicate and divide. The cells of other tissues, particularly epithelial cells [e.g., of the intestine, lung, skin), divide When normal columnar ciliated epithelial cells of the bronchial lining are replaced by stratified squamous epithelial cells, the process is called? Metaplasia, is the reversible replacement of one mature cell by another. The best example of metaplasia is replacement of normal columnar ciliated epithelial cells of the bronchial [airway] lining by the stratified squamous epithelial cells The newly formed squamous epithelial cells do not secrete mucus or have cilia, causing loss of vital protective mechanism 18. What is the relationship between ischemia and ATP? The sequence of events leading to cell death is commonly decreasedATP production, failure of active transport mechanisms (the Na+ K+ pump), cellular swelling, detachment of ribosomes from the endoplasmic reticulum, cessation of protein synthesis, mitochondrial swelling as a result of calcium accumulation, vacuolation, leakage of digestive enzymes from lysosomes, auto digestion of intracellular structures, lysis of the plasma membrane and death. when does sodium enter the cell and cause swelling? When there is a reduction in ATP levels this causes the plasma membranes Na/K and Na/C exchange to fail which leads to an intracellular accumulation of Na and calcium resulting in cellular swelling and diffusion of K out of the cell. Happens in hypoxic injuries.