Bioe 20B W2D1 Oct 8 ANNOTATED SLIDES (1) PDF

REMINDERS ANNOUNCEMENTS 1. Today: Digestion/Osmoregulation Tuesday, 10/8/24 2. Due Sunday: HW 2, Quiz 2, Plain Language Summary Week 2, Day 1 Nutrition & Digestion Osmoregulation TODAY’S AGENDA (8-9:35AM) Finish Nutrition...

REMINDERS ANNOUNCEMENTS 1. Today: Digestion/Osmoregulation Tuesday, 10/8/24 2. Due Sunday: HW 2, Quiz 2, Plain Language Summary Week 2, Day 1 Nutrition & Digestion Osmoregulation TODAY’S AGENDA (8-9:35AM) Finish Nutrition and Digestion Kahoot: Metabolism & Digestion 5 min break Osmoregulation Review of osmosis and diffusion What is osmoregulation? Osmotic challenges across habitats Kidney structure and function Regulation of kidney function REVIEW: DIGESTION & ABSORPTION Digestion of Fats 1. Fats are insoluble in water Micelles increase SA of fat 2. Bile salts have hydrophilic & hydrophobic end Lipase can then -hydrophobic end binds fat & creates digest it (break smaller fat droplets down into monomers) 3. Micelles form (biles salts on outside, triglycerides on inside) 4. Lipase can then digest fat Fig. 50.14 REVIEW: DIGESTION & ABSORPTION Absorption of Fats 5. FAs & monoglycerides enter Lumen of epithelial cells of small intestine Small intestine 6. Endoplasmic reticulum reforms FA + monoglycerides into triglycerides and packages Cell them into Chylomicrons membrane Epithelial 7. Chylomicrons leave epithelial cell of cells by exocytosis and enter small intestine lymphatic system Fig. 50.14 REVIEW: DIGESTION & ABSORPTION 1) WHERE are fats being absorbed? Fats are absorbed in the small intestine (duodenum; first ¼ of small intestine) 2) What is the purpose of bile salts? Increase surface area of lipid droplet so lipase (enzyme) can break triglyceride into fatty acid and monoglyceride 3) Why is a transmembrane transporter NOT needed to get fatty acids across the epithelial membrane? Fats can passively move across cell membrane because both are hydrophobic (like dissolves like)  Wondering what to study to change the world? Our microbiome can influence our health and even our mood! Our gut is the biggest source of serotonin in the body!  KeyKey Concepts forToday Concepts for Today 1. What do you need from your diet? 2. Regulation of Caloric Intake 3. Digestion & Absorption 4. Hormonal Control of Digestion and Blood Sugar REVIEW: BLOOD SUGAR Pancreas releases insulin Glucose Regulation Blood sugar rises Pancreas Muscles Eat a meal 1. glucose level rises pancreas secretes 1. Glucose insulin into the blood 2. stored as glycogen 2. insulin enhances the Liver Blood sugar transport of glucose into lowers cells & stimulates the liver and muscle to store glucose as glycogen Hungry Blood sugar rises Blood 3. as blood glucose drops sugar pancreas releases glucagon (a hormone) which opposes 4. Liver lowers Glycogen insulin converted 3. Pancreas 4. glucagon promotes into glucose breakdown of glycogen in the liver to release glucose into the blood Pancreas releases glucagon See fig 51.17 REVIEW: BLOOD SUGAR 1. Draw graph with the following relative concentrations before and after a meal: EAT (What is the Blood Glucose setpoint?) (mg/100mL of Insulin or blood) Glucagon relative concentration Time (hours) REVIEW: BLOOD SUGAR 1. Draw graph with the following relative concentrations before and after a meal: EAT Urination helps bring blood sugar back down 1) Normal blood sugar 2) Insulin Blood Glucose 3) Glucagon (90mg/100mL of 4) Diabetic blood sugar blood) relative concentration Time (hours) REVIEW: BLOOD SUGAR 2) What is the job of insulin in the body? Insulin helps transport glucose from the blood into cells 3) How are the two types of diabetes different? Type 1 (Juvenile/Late onset): Auto-immune disease that targets beta cells so insulin cannot be produced Type 2: Glucose gates less/unresponsive to insulin; insulin resistance 4) Why would injecting too much insulin be dangerous? Blood glucose level would get too low; can cause health problems (ex: hypoglycemia)  Key Concepts for: Digestive System What did we learn? Describe the major organs involved including what type of fuels are digested and absorbed and where Understand the difference between digestion and absorption Understand that digestion is extracellular Describe mechanisms of transport of lipids across epithelial cells Understand that mechanism of absorption is based on molecular characteristics. Be able to describe hormonal regulation of digestion Draw a graph of blood sugar, insulin, and glucagon over time and before and after a meal. Describe the difference between Type I and Type II diabetes 13  Let’s review Metabolism and Digestion! Top 3 winners get extra credit!  5-min Break! Attendance Time Scan the QR code or go to https://tinyurl.com/W2D1Oct8 to answer the following question: 1) Why are juxtamedullary nephrons a key adaptation for mammals and birds? (This will be used for taking attendance today.) Osmoregulation and Excretion  KeyKey Concepts forToday Concepts for Today 1. Review of osmosis and diffusion 2. What is osmoregulation? 3. Osmotic challenges across habitats 4. Kidney structure and function 5. Regulation of kidney function Osmoregulation Hypoosmotic a solution has a ____________ solute concentration compared to another solution Hyperosmotic a solution has a ____________ solute concentration compared to another solution Osmoregulation Hypoosmotic a solution has a relatively lower solute concentration compared to another solution Hyperosmotic a solution has a relatively higher solute concentration compared to another solution REVIEW: OSMOSIS AND DIFFUSION On your boards, draw what will happen to the cell in each environment Hypoosmotic to cytoplasm Shrink Swell No change ?????? Hyperosmotic to cytoplasm Shrink Swell No change ?????? REVIEW: OSMOSIS AND DIFFUSION On your boards, draw what will happen to the cell in each environment Hypoosmotic to cytoplasm Shrink LESS solutes in environment Swell No change ?????? Hyperosmotic to cytoplasm Shrink MORE solutes in environment Swell No change ?????? REVIEW: OSMOSIS AND DIFFUSION On your boards, draw what will happen to the cell in each environment Hypoosmotic to cytoplasm Shrink LESS solutes in environment Swell No change H2 O H2 O ?????? H2 O Hyperosmotic to cytoplasm Shrink MORE solutes in environment Swell H2 O H2 O No change ?????? H2 O  KeyKey Concepts forToday Concepts for Today 1. Review of osmosis and diffusion 2. What is osmoregulation? 3. Osmotic challenges across habitats 4. Kidney structure and function 5. Regulation of kidney function Osmoregulation Osmoregulation process of regulating the concentration of solutes and water in the body. Just like heat: the loss & uptake of water must balance. Different homeostatic set-points in different animals. Osmolarity the total concentration of osmotically active particles in a solution Human set point = 300 mOsm/L Osmoregulation Discuss: What is this graph showing? Some marine invertebrates are osmoconformers like mussels Other marine invertebrates are osmoregulators like brine shrimp  Osmoregulation Freshwater Fish Saltwater Fish Florida largemouth bass Blue Rockfish Salty Not as salty Hyperosmotic Hypoosmotic O 2O Not salty H2 H Very salty Problem: salt loss through gills Problem: salt gain through gills Solution: use energy to transport salts in; produce dilute urine Solution: use energy to transport salts out; produce little urine Is the fish hyperomotic or hypoosmotic compared to environment? Draw an arrow indicating the direction that water will move in each fish (into or out of) Saltwater fish will actively drink water Which fish is actively drinking water? since water is moving out of the fish  KeyKey Concepts forToday Concepts for Today 1. Review of osmosis and diffusion 2. What is osmoregulation? 3. Osmotic challenges across habitats 4. Kidney structure and function 5. Regulation of kidney function REVIEW: OSMOTIC CHALLENGES ACROSS HABITATS What is the tradeoff between energy and water savings in ammonotelic, urotelic, and uricotelic animals? Uses energy to convert toxic nitrogenous waste to a less toxic form that requires less water to store Toxicity aquatic animals terrestrial animals Energy needed to produce REVIEW: OSMOTIC CHALLENGES ACROSS HABITATS What animals have FORM = FUNCTION! these kidneys? Aquatic animals, especially marine ones ? ? ?  KeyKey Concepts forToday Concepts for Today 1. Review of osmosis and diffusion 2. What is osmoregulation? 3. Osmotic challenges across habitats 4. Kidney structure and function 5. Regulation of kidney function REVIEW: KIDNEY STRUCTURE AND FUNCTION 1. The black arrow is pointing to: a. cortex b. medulla c. renal pelvis REVIEW: KIDNEY STRUCTURE AND FUNCTION 2. In both pictures below, fluid is filtered through or between cells. The fluid that passes through the filter is called the 2) Glomerulus has many tiny fenestrations (holes) similar to a. Nephron fluid coffee filter/cheese cloth that b. Blood filters blood plasma c. Filtrate d. I have no idea 3) Water, ions, glucose filtered through (not cells) 1) Blood pressure REVIEW: KIDNEY STRUCTURE AND FUNCTION 3. The term secretion in reference to excretory organs refers to a. Nitrogen waste being actively pumped into the filtrate and ultimately being excreted as urine. b. The ability of cells in the excretory organ to selectively pump certain ions into the filtrate according to the body’s needs. REVIEW: KIDNEY STRUCTURE AND FUNCTION 4. Only mammals and birds have juxtamedullary nephrons. These nephrons are different from cortical nephrons because a. They have a Loop of Henle that spans the medulla. b. They are longer but are still confined to the cortex. REVIEW: KIDNEY STRUCTURE AND FUNCTION 5. Juxtamedullary nephrons allow birds and mammals to a. Turn ammonia into urea b. Filter waste from their blood through secretion and absorption c. Concentrate their urine ABOVE the osmolarity of the body fluids. REVIEW: MAMMALIAN KIDNEYS What is the big picture with the mammalian and bird kidney? Allows terrestrial animals to produce concentrated urine via the loop of Henle in order to conserve water Ex: Humans can produce urine we cannot actively that is 4 times more concentrated transport than blood plasma water; we use solutes to move water via Ex: Vampire bats can produce osmosis urine that is 15 times more concentrated than blood plasma Countercurrent multiplier in loop of Henle à sets up concentration gradient  KeyKey Concepts forToday Concepts for Today 1. Review of osmosis and diffusion 2. What is osmoregulation? 3. Osmotic challenges across habitats 4. Kidney structure and function 5. Regulation of kidney function  1. Blood is filtered through Cortex glomerulus Blood plasma (300 mosm/l) Glomerulus 2. Selective reuptake of ions and water in proximal tubule Blood in Blood out 3. Ascending limb: permeable Outer to salt but not water, active medulla transport of salt OUT: Osmolarity (mosm/L) of the tissue fluids interstitial fluid of medulla becomes concentrated with Vasa salts recta 4. Descending limb: permeable to water but not salt: filtrate Inner medulla becomes concentrated with salt 5. Urine is concentrated as Diffusion or osmotic flow Active transport filtrate moves through collecting Fluid flow duct REVIEW: REGULATION OF KIDNEY FUNCTION 1. How does the concentration gradient in the interstitial fluid of the medulla get established? Salts are actively pumped out of ascending limb of the loop of Henle 2. Why does it make sense to concentrate the filtrate in the descending limb? (why is the LOH a loop?) Each side of the limb is assisting the other side (loop operates as a counter-current multiplier) 3. Is urine technically concentrated in the loop of Henle or in the collecting duct? Urine is technically concentrated in the collecting duct (filtrate is concentrated in the LOH) 4. How come the water that leaves the descending limb doesn’t dilute the concentration gradient? The vasa recta blood vessel takes the water and excess salt back to rest of the body 5. Where does the urine that leaves the collecting duct go? 6. How come urine can be very dilute or more The bladder and then out of the body concentrated? ADH and aquaporins