PHYT 7103 Human Physiology Module 1 Learning Guide.docx

**PHYT 7103 Human Physiology Module 1 Learning Guide** \*\*\*Use this weekly content guide to help organize key concepts within this week's module.   This learning guide is not fully exhaustive. However, you can use it to help learn the content for this week and how it will build in the following...

**PHYT 7103 Human Physiology Module 1 Learning Guide** \*\*\*Use this weekly content guide to help organize key concepts within this week's module.   This learning guide is not fully exhaustive. However, you can use it to help learn the content for this week and how it will build in the following weeks. Composition of a Cell Membrane - What is a cell membrane? What is it made of? -- **cell membrane is a layer of phospholipid molecules and it regulates what comes in and out of the cell ; it is made up of a glycerol hydrophilic head, fatty acid tails that are hydrophobic** - How does the structure of the cell membrane impact transport of items into and out of a cell? -- **it is made up of a glycerol hydrophilic head, fatty acid tails that are hydrophobic** - How does cholesterol impact the structure of the cell membrane? **Without cholesterol,** at low temps the phospholipids pack tightly together and less fluid, making the membrane **brittle,** **without cholesterol** at high temps, phospholipids separate making membranes **leaky and weak** - What does it mean that the cell membrane is semipermeable? **it is semipermeable** so it allows some things through like O2 and CO2 but **does not allow glucose or sugars** - What is a phospholipid molecule? What does it mean that phospholipid molecules are amphiphilic? How does that impact the cell membrane? **a group of polar lipids and made up of a glycerol hydrophilic head, fatty acid tails that are hydrophobic and a phosphate group** - **Amphiphilic means** they have hydrophilic (water-loving) and hydrophobic (water-fearing) - What are protein channels and why are they necessary to the functioning of a cell? Type of **facilitatd diffusion** that move through a protein without using energy, only allow certain substances through - What is the cytoskeleton and what is it made of? Framework that provides structural stability, made of proteins, microfilaments, microtubules, and intermediate filaments - What are the functions of the cytoskeleton? Allows cell to change shape but contracting and extending filaments (muscle contraction, cell division and movement - What is the intracellular fluid and what is it made of? It is made of **cytosol, and** resides inside the cells and provides the medium for cellular reactions - What do each of the organelles (nucleus, ribosomes, endoplasmic reticulum, Golgi apparatus, transport vesicles, and mitochondria) do? Cell Structure Function ----------------------- ------------------------------------------------------------------------------------------------------------------------------------------------------ Cell Membrane **Regulates what comes in and out of cell** Nucleus **Home to genetic material (genes and DNA)** Ribosomes **Use mRNA copies to produce proteins (protein synthesis** Endoplasmic Reticulum **Translates mRNA into protein (Rough ER actually produces proteins and smooth ER produces lipids and steroid hormones)** Golgi Apparatus **takes proteins, lipids, and hormones from rough and smooth ER and packages them into vesicle then transports them around cell using cytoskeleton** Transport Vesicles **Help move materials like proteins from one part of cell to another** Mitochondria **Power generator, provides energy** Homeostasis - What is homeostasis and why is it an important concept in physiology? Maintence of a stable environment, constant - **Bloode glucose 90 mg/ml and body temp 98.4 F** **Steady State:** constant and unchanging but NOT homeostatis (ex. cycling, have a constant HR - Negative feedback control: look over the components of a negative feedback control system as found in your reading for this module (Kibble, Figure 1-1) and be able to define the function of each of the elements (controlled variable, set point, sensors, comparator, effectors). Figure 1-1 **Controlled variable:** maintained within narrow normal limits **Set point:** center of normal range, target value of control system **Sensors:** monitor controlled variable **Comparator:** interprets input from sensors to determine when deviations have occurred initates counter response **Effectors:** mechanisms that restore a set point - Describe intracellular fluid (ICF) and extracellular fluid (ECF) (Kibble, Figure 1-2) Figure 1-2  **Intracelluar fluid- fluids in cell** **Extracelluar fluid- fluid outside cell divides into interstital fluid and blood plasma** Cell Membrane Transport Mechanisms - What is selective permeability? -- regulates what comes **in and out of cell** - How does the size, polarity, and charge of molecules and ions impact the ability of the molecule or ion to move through the cell membrane? Molecule Size, Polarity, and Charge Examples ------------------------------------- -------------------------------------------------------------- Small and Nonpolar Oxygen; Carbon Dioxide diffue rapidly Small and Polar **Water diffuse slowly** Large and Nonpolar **Vitamin a diffuse slowly** Large and Polar **Glucose highly unlikely to diffuse** Highly Polar and Charged **Sodium, potassium, chloride, amino acids highly unlikely** - What are the different types of transport proteins in the cell membrane? **Channel proteins which form a tunnel through membrane, h2o and ions flow through (aquaporin channels and chloride channels) ; carrier proteins which only allow specific molecules to bind to it and go through, ex. glut4 ; enzymes use ATP to pump ions in or out of cell against concentration gradient (ATPase) low to high concentration** - What is the difference between passive and active transport? What are the different types of passive and active transport mechanisms? **Passive transport-** movement across cell membrane requires NO ENERGY / **Active transport-** requires ATP, molecules move AGAINST concentration gradient - What are some examples of each type of membrane transport mechanism? Transport Mechanism Type of Transport Mechanism Types of Molecules and Ions Transported Across the Cell Membrane ---------------------------- ----------------------------- ------------------------------------------------------------------------------------------------------------------------------------------- Diffusion Passive Transport **Small, nonpolar (o2, Co2) from high concentration to low concentration** Facilitated Diffusion Passive Transport **Large, polar (vitamin A) use transport proteins (channels and carriers)** Osmosis Passive Transport **Movement of water across semipermeable membrane (from hypotonic side of low concentration to hypertonic side of high concentration** Primary Active Transport Active Transport **Sodium/potassium pump (3 sodium come out and 2 potassium go in), uses ATP as fuel** Secondary Active Transport Active Transport **DOES NOT DIRECTLY USE ATP, uses electrochemical gradient ex. Na+ glucose transporter (glucose pulled out with 2 Na+ against gradient)** Bulk Transport **Uses endocytosis (pulling in cell) or exocytosis (pushing out of cell)** - What is endocytosis and exocytosis? What are the different types of endocytosis? **Endocytosis-** tranports things into the cell (engulfs extracellular material) - 3 types: **Phagocytosis** which means to eat (macrophages) to **patrol body for** debris and dead cells ; **Pinocytosis** which means cell drinks, cell membrane **invaginates** extracellular fluid and solutes that are dissolved in it ; **Receptor-mediated endocytosis:** cell absorbs hormones and proteins **Exocytosis-** expelling things out of cell (expelling extracellular fluid) - What is osmosis? What does it mean if a fluid is isotonic, hypotonic, or hypertonic? **Osmosis-** movement of water across semipermeable membrane - **Isotonic-** same solute and water concentration - **Hypotonic-** low solute and high water concentration - **Hypertonic-** high solute and low water concentration - Why is osmosis important for our cells? -**because it doesn't allow shrivaling or swelling of the cell** ***Reflect on the following questions:*** ***How does the net movement of water between hypertonic and hypotonic solutions occur?*** ***What happens to cells if a patient is intravenously infused with a hypotonic saline solution? What if they were intravenously infused with a hypertonic saline solution?*** **When there is net movement, water moves from low to high solute concentrations (hypotonic to hypertonic** - **Infused with hypotonic saline would cause swelling of the cells because water will be moved into intracellular fluid** - **Inflused with hypertonic saline would cause the cells to shrivel because water is being taken out of the intracellular fluid** - What are the steps involved in the development of a diffusion potential (look in Chapter 1 of the Kibble textbook)? - Define depolarization, hyperpolarization, and repolarization. - **Depolarization:** shift of electrical charge so the cell is LESS negatively charged compared to the environment - **Hyperpolarization:** shift of electrical charge so the cell is MORE negatively charged compared to the environment - **Repolarization:** the return of electrical charges to their original state Cellular Respiration - What is adenosine triphosphate (ATP)? How is ATP formed and how does it provide energy to the body? **ATP is energy** and it is formed through glycolysis, krebs cycle, and ETC - What is the ATP-PC system and during what type of activity is this system used to provide energy for the body? System is used for short burst of energy (like a 40 m dash or 1 rep max), breakdown of of ATP and phosphocreatine - What is glycolysis? What are the molecules that glucose breaks down into during glycolysis? Is glycolysis aerobic or anaerobic? **Glycolysis-** a series of enzymatic reactions where glucose is broken down into 2 3 carbon pyruvate molecules then enters mitochondria to form ATP (**anaerobic)** - What is the relationship between glycolysis and ATP? How much ATP is produced through the process of glycolysis? ATp is formed from glycolysis, 2 total ATP produced - Where does glycolysis occur? **Cytoplasm of the cells** - Glycolysis is used to provide energy for what type of activity? Moderate intensity excerise, 800 m run or 200 meter swim - How does glucose get inside the cells? Utilizes glucose transporters, and by insulin - What is the role of insulin in glycolysis? What is the role of glucagon in glycolysis? What causes increased insulin or increased glucagon? **Insulin** simulates glucose update (helps glucose get into cells, muscle cells, liver cells), insulin increases right after you eat, glucagon increases if you haven't eaten or are fasting - What is the Citric Acid Cycle (Kreb's Cycle)? How much energy is produced from the Citric Acid Cycle? Generates energy in the form of GTP, NADH, FADH2 (generates 1 GTP, 3 NADH, 1 FADH2) It also produces 30-32 ATP - What is the electron transport chain? electrons are passed on from complex to complex, then to O2 creating a proton gradient used to make ATP - What is oxidative phosphorylation? How is ATP produced from oxidative phosphorylation, and how much energy is produced through this process? Generates energy as ATP (in the ETC system) process of making ATP by donating electrons (NADH and FADH2) to complexes, 30-32 ATP - What type of activity utilizes aerobic production of ATP to supply most of the energy needed to complete the activity? Long distance running, cycling - Compare and contrast how the body uses carbohydrate, fat, and protein to provide energy to maintain cellular activities during rest and exercise/activity. What are the primary nutrients used for energy during exercise/increased activity? Sources Provide energy during rest Provide energy during exercise Primary nutrients ---------- ---------------------------- --------------------------------------------------------------- -------------------------------------------------------------------------------------------------- Carbs Primary source (rapid energy) Monosaccharides (glucose) ; disaccharides( sucrose) ; polysaccharide ; monosaccharide (glycogen) Fats Primary source Primary source( prolonged exercise) Stored body fat (fatty acids primary source for energy) steroids, triglycerdies Proteins Requires cellular proteins to be broken down into amino acids Amino acids A chart of energy efficiency Description automatically generated **ATP-PC system -- activity would be a 100 meter sprint, (lower functioning patients) sit to stand, step up** **Fast glycolysis- 200 m sprint** **Krebs cycle and ETC- marathon** **They grow**