Taking care of business Go to this page and enter room SJ123: http://tinyurl.com/PhysClicker

Take 2 minutes to complete this survey: http://tinyurl.com/PhysDis

Online quiz this weekend: Released Thursday night or early Friday morning and will be due Monday morning at 9am.

Lab next week: We will meet in the first floor lobby of the Tech building (right next to Science Complex) for lab next week. We’re going to try to apply some of the stuff we’ve learned so far in a simulated clinical environment. It’ll be cool.

Online discussions: Reminder-please post ANY questions you might have about anything related to the class to the weekly discussion. Happy to help! Homeostasis Recap

Membrane Dynamics Chapter 5 Super duper Super duper hyper osmotic hyper osmotic

What will happen to cell? A. Swell up B. Shrivel C. Stay the same D. I don’t know Our patient for the day

https://www.youtube.com/watch?v=w3uWg4KjX4Y Name: Matilda Age: 78

In hospital for severe dehydration

Staff puts her on IV of pure water Soon after IV:

Severe fatigue

Dizzy

Yellow eyes Iced tea analogy

On board Describing how concentrated a solution is: Molarity= moles solute / Liters solution

Osmolarity= osmoles solute / Liters solution 1) NaCl dissociates into Na+ and Cl- 1 mole of NaCl = 2 osmoles of NaCl

2) Glucose does not dissociate in water Diffusion, osmosis, concentration....

WHO CARES?!?!? Hippotonic (hypotonic) solution makes cell swell like a hippo Table 5.3 Tonicity of Solutions Tonicity describes the volume change of a cell Differences between osmolarity and tonicity Differences between osmolarity and tonicity

•Osmolarity = concentration of particles in a solution.

•Tonicity has no units. It just describes whether cell gained/lost water.

•Osmolarity is used to compare any two solutions, tonicity only can compare a solution to a cell

•Osmolarity alone does not tell you what happens to a cell placed in a solution (as we’ll see). Table 5.2 Comparing Osmolarities

Osmolarity comparisons

hypo=lower Salt becomes two ions/ particles in water. Glucose iso=same doesn’t hyper=higher Tonicity comparisons

Hippotonic (hypotonic) solution makes cell swell like a hippo Name: Matilda Age: 78

In hospital for severe dehydration

Staff puts her on IV of pure water What do you think caused this?

1.) Think for 1 minute

2.) Pair up

3.) Share your ideas What do you think caused this? Hyptonic Low osmolarity 1.) Think for 1 minute

2.) Pair up

Low3.) ShareNa+ osmolarityyour ideas Figure 5.1a ESSENTIALS – Body Fluid Compartments

Sidenote: other cells in body need proper salt, water balance

The body fluids are in two compartments: the extracellular fluid (ECF) and intracellular fluid (ICF). The ECF and ICF are in osmotic equilibrium but have very different chemical composition.

Intracellular fluid is 2/3 of the KEY total body water volume. Material moving into and out of the ICF Intracellular fluid must cross the cell membrane. Interstitial fluid

Plasma Extracellular fluid includes all fluid outside the cells. The ECF is 1/3 of the body fluid volume. The ECF consists of: • Interstitial fluid (IF), which lies between the circulatory system and the cells, is 75% of the ECF volume. • Plasma, the liquid matrix of blood, is 25% of the ECF volume. Substances moving between the plasma and interstitial fluid must cross the leaky exchange epithelium of the capillary wall. Following slides have material that will be addressed with discussion topics questions in class worksheet. Super duper Super duper hyper osmotic hyper osmotic

What will happen to cell? A. Swell up B. Shrivel C. Stay the same D. I don’t know Part 2: Tonicity depends on what KINDS of solutes are in solution, not just osmolarity Can solutes in the solution pass through membrane or not? Super duper hyper osmotic

WillDoes water the soluteflow into penetrate or out of the the cell? cell membrane?

Super duper hyper osmotic Figure 5.3 The relationship between osmolarity and tonicity If you’re given the osmolarity, what could tonicity possibly be? *

OSMOLARITY

TONICITY Hyposmotic Isosmotic Hyperosmotic

Hypotonic

Isotonic

Hypertonic *Assume all intracellular solutes can’t penetrate cell membrane Figure 5.3 The relationship between osmolarity and tonicity If you’re given the osmolarity, what could tonicity possibly be?*

OSMOLARITY

TONICITY Hyposmotic Isosmotic Hyperosmotic

Hypotonic

Isotonic

Hypertonic *Assume all intracellular solutes can’t penetrate cell membrane Figure 5.3 The relationship between osmolarity and tonicity If you’re given the osmolarity, what could tonicity possibly be? *

OSMOLARITY

TONICITY Hyposmotic Isosmotic Hyperosmotic

Hypotonic

Isotonic

Hypertonic *Assume all intracellular solutes can’t penetrate cell membrane Figure 5.3 The relationship between osmolarity and tonicity If you’re given the osmolarity, what could tonicity possibly be? *

OSMOLARITY

TONICITY Hyposmotic Isosmotic Hyperosmotic

Hypotonic

Isotonic

Hypertonic *Assume all intracellular solutes can’t penetrate cell membrane Steps to determine tonicity of a solution compared to a cell 1.) Assume all particles inside the cell cannot cross cell membrane. They’re stuck.

2.) Compare solute concentrations for each particle inside the cell vs. outside

3.) Allow any particles that are outside the cell to diffuse into the cell to equalize their own concentration inside vs. outside the cell.

4.) Compare solute concentrations again inside vs. outside the cell.

5.) Determine where water would go based on osmosis (it goes towards higher solute concentration) Name: Matilda Age: 78

In hospital for severe dehydration

Staff puts her on IV of water

Why might this IV solution cause Matilda serious problems? Severe fatigue

Dizzy

Yellow eyes

Rapidly increasing heartrate Table 5.5 Intravenous Solutions

Common IV solution properties as compared to a normal human cell End material that was covered by discussion questions in class Simple Diffusion is what we’ve been talking about so far.

Simple Diffusion is when particles, gases, whatever passes directly through the cell membrane on its own, without any assistance Figure 5.7 Fick s law of diffusion ’ 5 factors affect the rate of diffusion

4 1 Extracellular fluid Membrane Lipid Molecular Concentration surface area solubility size outside cell 2 Factors affecting rate of diffusion through a cell membrane:

• Lipid solubility 5 Concentration • Molecular size 3 gradient • Concentration gradient • Membrane surface area Composition • Composition of lipid layer of lipid layer

Intracellular fluid Concentration inside cell

Fick’s Law of Diffusion Membrane Permeability

lipid solubility Rate of diffusion ∝ surface area × concentration gradient × membrane permeability Membrane permeability ∝ molecular size

Changing the composition of the lipid layer can increase or decrease membrane permeability. For next time:

Think about how YOU would have treated Matilda differently than the nurses did. Name: Megan Age: 3

Chronic Resp. Infections

Thick mucus in airways

Severe difficulty breathing Part II: Transport Processes Across the Membrane via Proteins The cell membrane is packed with proteins that serve many functions

Transport The cell membrane is packed with proteins that serve many functions

Transport Signaling The cell membrane is packed with proteins that serve many functions

Transport Signaling Catalysis The cell membrane is packed with proteins that serve many functions

Transport Signaling Catalysis Structural The cell membrane is packed with proteins that serve many functions

Transport Channel protein transporters are like doors

Channel Proteins Open

Free Passage

E.g. Aquaporin Transports Water Channel protein transporters are like doors

Channel Proteins Open Closed X Free Key Passage Needed

Transport “Gated” Channels Chemically Gated Channels Require Molecule Binding Voltage-Gated Channels Respond to Change in Charge Across Cell Membrane

So, channel proteins, either the open or gated kind, are like doors

Carrier Proteins Change Confirmation to Pass Solute Carrier Proteins Have a Variety of Unique Properties

•Used to carry large and/or ionic substances •Never make continuous passage to ECF •Require conformational change Figure 5.12 Facilitated diffusion by means of a carrier protein Carrier Proteins Change Confirmation to Pass Solutes Intro to Physio Closed gate Extracellular fluid Intracellular fluid

Pacific Atlantic Passage Gate closed MotivationOcean and Molecule Ocean open to Relevance one side to be Carrier transported Membrane How I learn science

Transition Pacific Atlantic state with Ocean Some Course Deets Ocean both gates closed Real Intro to Physio: Homeostasis

Passage NegativePacific Feedback Atlantic open to Gate closed Ocean Ocean other side

Positive Feedback

Homeostasis v. Equilibrium Figure 5.13 Facilitated diffusion of glucose into cells CarrierLarge andProteins Polar Change Molecules Confirmation Use Carriers to Pass Solutes Intro to Physio To Passively Diffuse Across Membrane

High glucose [Glucose] = high[Glucose]out Motivation and concentration out Relevance

[Glucose]in [Glucose]in GLUT stays low ATP How I learn science ADP G-6-P Glycogen Some Course DeetsLow glucose concentration Glycolysis Real Intro to Physio: Homeostasis Facilitated diffusion brings glucose Diffusion reaches equilibrium when the Conversion of imported glucose into into the cell down its concentration glucose concentrations inside and glucose 6-phosphate (G-6-P) keeps Negativegradient. Feedback outside the cell are equal. intracellular glucose concentrations low so that diffusion never reaches equilibrium.

Positive Feedback Passive, facilitated diffusion uses no energy Homeostasis v. Equilibrium TRANSPORT AGAINST CONCENTRATION GRADIENT REQUIRES ENERGY “Active Transport” Uses Energy to Move Solutes Against Gradient “Active Transport” Uses Energy to Move Solutes Against Gradient “Active Transport” Uses Energy to Move Solutes Against Gradient “Active Transport” Uses Energy to Move Solutes Against Gradient

Fun Fact! ~30% of our energy goes to powering the Na+/K+ pump!