NU545 Patho Practice Questions & Answers

NU545 Patho Practice Questions & Answers What is metabolic absorption? (p.2) - ANS-• 1 of 8 cellular functions of eukaryote cell • Chief function is to take in & use nutrients or other substances from surroundings • Ex: kidney (fluid absorption and synthesize proteins) and Intestinal epithelial cells (fluid absorption/protein enzyme synthesis) What uses oxygen to remove hydrogen atoms in an oxidative reaction? (p.8) - ANS-• Peroxisomes contain enzymes that use O2 to remove H+ in oxidative reactions that produces hydrogen peroxide which is then used by catalase to further oxidize other substances like: phenols, formic acid, formaldehyde, and alcohol During cell injury what is released that is capable of cellular autodigestion? (p. 8) - ANS-• Lysosomal enzymes (hydrolases), or the digestive enzymes within the lysosome • Autolysosomes, or autophagosomes Where is the genetic info contained in the cell? (p. 2) - ANS-Nucleus, specifically the nucleolus Cell membranes contain which major chemical components? (p. 12) - ANS-Lipids & Proteins in a complex lipid bilayer What allows potassium to diffuse in and out of cells? (p. 31-32) - ANS-• The Na+-K+-ATP pump. Uses direct energy of ATP; found in excitable tissues (muscles/nerves) & also in kidneys & salivary glands. Involves the movement of Na+ & K+ against a concentration gradient. • Protein enzyme ATPase allows potassium to move in and out of the cell. • Mediated transport = channel protein through which ions can diffuse (K+ leak channel). How is a cell protected from injury? (p.12) - ANS-• Plasma membrane - Acts as a barrier to toxic molecules, macromolecules, & foreign organisms/cells. • Exists in a state of change & modulation. Alternates receptor numbers & patterns. • Gating protects cells from release of Ca from injured cells by sealing off or decreasing permeability at junctional complexes. In cirrhosis, what does cholesterol have to do with the erythrocytes? (p.68) - ANS-• Associated with chemical changes that result in structural & metabolic abnormalities of the erythrocyte membrane leading to cell shape changes & hemolytic anemia. • Increase in unesterified serum cholesterol owing to lecithin cholesterol acyl transferase (LCAT) deficiency in cirrhosis leads to expansion of the lipid bilayer & macrocytosis without megaloblastic changes in precursors. Substitutions of phosphatidyl choline (PC) moieties in the erythrocyte lipid bilayer lead to echinocytes (desaturated PC) or to stomatocytes (diunsaturated PC). In some patients, high density lipoprotein (HDL) abnormalities lead to erythrocyte surface changes causing rapid formation of echinocytes. (Ann Clin Lab Sci. 1990 May-Jun;20(3):169-74. Mechanisms of hemolysis in liver disease. Morse EE1. Department of Laboratory Medicine, University of Connecticut School of Medicine, Farmington 06032) • Alters fluidity & function of cell membrane as well as intercellular transport What is platelet-derived growth factor? (p.39) - ANS-Stimulates production of connective tissue cells & neuroglial cells What is cell communication? How does it occur? (p.20) - ANS-• Required for homeostasis, regulate cellular growth/division & development/organization into tissues, & coordinate cellular function. • Occurs in 3 ways: -via protein channels & gap junctions that directly coordinate activities of adjacent cells (must be touching) -via plasma membrane-based signaling molecules (receptors) that affect the cell itself & cells that come in direct contact -via chemical signals that must enter the distant cells to affect the receptors inside of the distant cell (the most common means of communication). • Primary modes of intercellular signaling are hormonal, neurohormonal, paracrine, contact-dependent, & neurotransmitters. There is also Autocrine signaling where the cell signals itself. What is chemical signaling? (p.20) - ANS-Involves the secretion of chemicals, such as hormones, neurohormones, paracrine, autocrine, and neurotransmitters. Chemical signaling may occur through the bloodstream or in small discrete spaces How is glucose transported from the blood to the cell? (p. 33) - ANS-Passive protein channels. Passive mediated transport or facilitated diffusion moves the glucose via a uniport mechanism into the cell. When all glucose-specific receptors are occupied, the transport system is saturated and operating at maximal capacity. Direction of movement is the same as passive simple diffusion-down the concentration gradient, from an area of high concentration to low concentration until equilibrium is achieved. Understand the transportation of potassium and sodium across plasma membranes. (p. 29-32) - ANS-• The Na+ K+ antiport (opposite directions) system uses direct energy of ATP to move cations. • ATPase is transporter protein. • Concentration of ATPase in plasma membranes is directly related to Na+ K+ transport activity. • Process: - 3 Na+ ions bind to Na-binding sites on carrier's inner face. - ATP molecule produced by cell's mitochondria binds to carrier. - Carrier changes shape, releases 3 Na+ ions to outside of cell, & attracts 2 K+ ions to K-binding sites. - Carrier returns to original shape, releasing 2 K+ ions & the leftover ATP molecule to inside of cell. - Carrier can now repeat cycle. What is active transport? (p. 31-33) ch.1 - ANS-• The movement of a substance across a membrane by a carrier protein. Requires metabolic energy (ATP) to move the molecules against the concentration gradient. • Active transport also occurs by endocytosis (vesicle formation), where substances are engulfed by a segment of the plasma membrane, forming a vesicle that moves into the cell. What are cytokines? (p.38-39) Or cytokinesis? (p.37) - ANS-• Cytokines are peptides that transmit signals within/between cells to stimulate tissue growth & development continues...