Catalyst part 1Write a response to yesterday’s discussion onthe achievement gap. How did you feel listen-ing to it? What implications will it have on your life? Have you ever had someone tell youthat you couldn’t do something? What happened? What will happen now?
Binders by tomorrow
Test grades and quiz retakes tomorrowQuiz reaveraged
Catalyst part 2
1) What does it mean to be in balance?
2) Why is it important to maintain balance?
3) Give an example of something in your body that must remain balanced?
Answer in your composition or spiral note-book. You have 2 minutes.
Homeostasis{or maintaining the balance}http://www.youtube.com/watch?v=LTCDGzF7s54
Homeostasis literally means SAME STATE
• Homeostasis refers to the body’s constant struggle to keep all of the internal functions balanced• The endocrine (hormone) and nervous systems are
continually working to keep the body’s environment steady
DETERMINE THE BREATHING RATE OF YOUR PARTNER
Count for 15 seconds: _____* 4 = breaths per minute
Would you expect the rate to increase or decrease after exercise? Why or why not?
Breathing Lab
HAVE YOUR PARTNER DO JUMPING JACKS FOR 1 MINUTE
Re-measure their breathing rate.Count for 15 seconds: _____* 4 = breaths per minute
Would you expect the rate to increase or decrease after sitting for 3 minutes? Why or why not?
Breathing Lab
RE-MEASURE THEIR BREATHING RATE AFTER SITTING FOR 3 MINUTES
Count for 15 seconds: _____* 4 = breaths per minute
Breathing Lab
The Cell Membrane and Homeostasis
MUST maintain concentrations of:- Water - Wastes- Glucose - Salts-Nutrients
MUST maintain constant:- Temperature- pH- Glucose levels- Water balance
Homeostasis: refers to the body’s constant struggle to keep all of the internal functions balanced
Cell membrane: regulates what enters and leaves the cell and maintains homeostasis
Phospholipid bilayer: two layers of lipids that make a flexible barrier- Like “Red Rover”
selective-permeability: only some things can cross the membrane
Can Cross Can’t Cross
Small particles and water
Large particles...they need help!
Fluid Mosaic StructureAllows molecules to move around easily in the lipid bilayer.Carbohydrates and proteins are embedded in the bilayer
Particles move in response to a concentration gradient:
Movement across membranes can be
Which results in
Can be
which requires which requires
and a
In order to move particles from a region of
to a region of
The three types are…
They move particles from a region of
to a region of
Two categories of transport: Passive and Active
Passive Transport: a substance can move across the membrane with the concentration gradient without using energy/ATP
Active transport: Particles move from an area of low concentration to high concentration usingEnergy/ATP
Passive Transport
Passive Transport = Diffusion
https://www.youtube.com/watch?v=STLAJH7_zkY
= the movement of particles from a higher concentration to a lower concentration
Osmosis: The diffusion of water from high to low concentration
Passive transport results in equilibrium when the gradient is balanced. Movement still continues but there is no net change in concentration.
Facilitated diffusion (Facilitated= help/assist): Diffusion of particles with the help of a carrier protein or protein channel. Moves from high to low concentration. Still no energy usage.
Can be a protein channel (the particles just move through) or a carrier protein (changes shape to allow particles to fit through)
http://www.youtube.com/watch?v=YYdFixaYX3g&feature=endscreen
Practice!
1. Which direction will the water move? __________________ What type of transport? _______________
2. Which way will the glucose molecules move across the membrane? Draw an arrow to show the movement. What type of transport is this? ___________________
3. Which of the following represents dynamic equilibrium?A. Water was 80% inside the cell and 80% outside the cellB. Protein was 30% inside the cell and 35% outside the cellC. Water was 85% inside the cell and 80% outside the cell
4. Fill out the chart to compare and contrast the types of PASSIVE TRANSPORT. Put an X in the box if the statement is true.
Diffusion Osmosis Facilitated Diffusion
Moves from HIGH to LOWNeeds a proteinNeeds energyMoves particlesMoves water
Active Transport: a substance can move across the membrane, AGAINST the concentration gradient with the help of ATP• LOW to HIGH concentration• Needs a PROTEIN CARRIER“pump”• Needs ATP (energy)
Practice!1. What type of transport will move the H+ ions
from low to high?
2. Freshwater protozoans, such as Paramecia, must constantly pump water out to keep from bursting. What does this tell you about the concentration of particles inside a Paramecium compared to the concentration of particles of its environment?
3. Fill in the table below to compare and contrast PASSIVE and ACTIVE transport. Place an X in the boxes that apply.
Diffusion Osmosis Facilitated Diffusion
Active Transport
Moves from HIGH to LOWMoves from LOW to HIGHNeeds a proteinNeeds energyMoves particlesMoves water
Check Yourself:1. If a particle is moving from high to low concentration, what type of transport will it use?
2. If a particle is moving from low to high concentration, what type of transport will it use?
3. If water is moving from high to low, what type of transport will it use?
Hypertonic vs. Hypotonic Solutions
How does this affect cells?In animal cells…
In plant cells…