movement across cell membranes moretti and dickson

MOVEMENT ACROSS CELL MEMBRANES

Moretti and Dickson

Homework:Read pages 182-189 (Section 7-3): Take notes based on the questions on the back of Assignment Sheet and write your answers in your notebook.

Silent Do Now: (in your notebook w/ title & date)Which molecule is bigger, starch or glucose?

Explain with a diagram in your notebook.When you’re done, take out your Digestion

Project and make sure it is ready to hand in!

Bio 9A: Wednesday, 12.1.10Title: Movement Across Cell Membranes – Day 1

Today’s Agenda & Objectives Objectives:

Design an experiment by drawing on your knowledge of starch, glucose, cell membranes, and experimental indicators that test for the presence of starch and glucose.

Agenda: Quick sharing of Digestion Projects (10

min max) Review Do Now (5 min max) Experiment Design (30 min)

Planning the Experiment: Individual:

Read Overview Small Groups:

Planning the Experiment How do we test for Starch and

Glucose?

Whole Class Discussion Small Group:

Experimental Set-Up Whole Class Review:

Experimental Set-Up

Designing a Lab:Diffusion Across Cell Membranes

Objectives for Class: Design an experiment by drawing from your knowledge of starch,

glucose, cell membranes, and experimental indicators that test for the presence of starch and glucose.

Water

Model Cell w/ Dialysis Tubing Membrane

Starch & Glucose Solution

Yamile Erick

Amrita

Lila

Kenny Cassandra

Hajar Martely

Imani

Olivia

Martin

BryanNathy

Javier

Devin

Lorena

Alerte

Lennin

Victor

Joshua

Daysia

Emiliano

Jesse

Joelle

Naidaliz

Beverly

Homework:Rough draft of Background Info and Purpose & Hypothesis sections for a lab report on the membrane experiment (refer to the handout from yesterday)

Type and print or bring a handwritten copy to class tomorrow!

Silent Do Now (in NB w/ title & date) What is happening to the dye in the water? What vocabulary word from last night’s reading

applies to this situation? Why? What do you think will happen to the dye by the

end of class?

Bio 9A: Thursday, 12.2.10Title: Movement Across Cell Membranes – Day 2

Today’s Objectives

Describe and explain the following terms: Lipid Bilayer Selective Permeability Diffusion Osmosis

Use this vocabulary to explain how a cell membrane controls what enters and leaves a cell

Agenda: Notes/Discussion/Quick Animation Ticket To Go Plan lab procedure w/ partner

Lipid Bilayer Two layers of lipids that form

the outer membrane of a cell. Flexible Strong Do not Dissolve in water

Cell Membrane Vocabulary

Objectives for Class: Use scientific vocabulary to explain how a cell membrane controls what

enters and leaves a cell

Image to the right shows the lipid bilayer of a cell. Notice how it has other components like protein channels & “pumps” built into it.

zoom out

Selective Permeability When a membrane only

allows certain substances to pass across the membrane (and not others)

Substances usually pass across based on the size, shape, and charge (+/-/neutral) of the molecules

New Vocabulary



Concentration How much “stuff” is in a given amount of liquid Mass of a solute (stuff in the liquid) per a given

volume of the total solution i.e.: 12g of salt in 3L of water = 12g/3L = 4g/L

Diffusion Movement of molecules from a

high concentration (more stuff) to low concentration (less stuff)

Osmosis Movement of water through a selectively

permeable membrane from a high concentration to low concentrationNote: For osmosis to occur, the membrane only allows water to pass across and not the solute

New Vocabulary



Diffusion

Osmosis

Diffusion, Osmosis and Selective Permeability In Action:

http://zoology.okstate.edu/zoo_lrc/biol1114/tutorials/Flash/Osmosis_Animation.htm

New Vocabulary





Ticket to Go

On your small piece of paper: Draw one picture that illustrates at least 3 of the

words we’ve talked about today Lipid Bilayer Selective Permeability Concentration Diffusion Osmosis

Write the words on the picture so I know which ones you’re drawing

If you’re done early: Take out the lab handout for tomorrow and work w/ your partner to start planning your procedure

Homework:None!

Do Now:Take out the Diffusion Lab Handout.With your partner from Wednesday, talk QUIETLY

to discuss and fill in the Procedure Overview (Parts 1-4) on the back of this handout.

You have 10 minutes to complete this.

Today’s Objective: Design, conduct, and analyze data from an experiment to determine which substances (glucose and/or starch) can pass through a cell membrane.

Bio 9A: Friday, 12.3.10Title: Movement Across Cell Membranes – Day 3

Yamile Erick

Amrita

Lila

Kenny Cassandra

Hajar Martely

Imani

Olivia

Martin

BryanNathy

Javier

Devin

Lorena

Alerte

Lennin

Victor

Joshua

Daysia

Emiliano

Jesse

Joelle

Naidaliz

Beverly

Do Now #2 – In your notebookTitle for Today: Diffusion Lab1. Summarize the purpose of this

experiment:

2. Write a specific prediction for this experiment:

Set-up Dialysis Bag Moisten tube and tie one end Add the starch & glucose solution to the tube Tie the top of the tube

Rinse w/ tap water to wash excess solution from outside of bag

Set-up Beaker Fill a 250 ml beaker ¾ of the way with water Add Iodine to water – mixture should be

orange Put dialysis bag into beaker with water

and iodine

Diffusion Lab:Procedure Review – Part 1

Water and Iodine




Starch How do we test for it?

Use Iodine How do we know starch has passed through membrane?

Iodine outside the dialysis bag turns from yellow-orange to purplish- brown

Glucose How do we test for it?

Boil it in Benedicts solution or use a glucose test strip How do we know glucose has passed through the

membrane? Glucose test strip will change color

Diffusion Lab:Procedure Review – Part 3



Do Now #3

In your notebook, create a data table for this experiment!

Your table must include a place to record beginning and ending colors of: The water/iodine in the beaker The dialysis bag (“cell”) The glucose test strip

Kenny

Yamile Lennin

Martin

Amrita

Javier

Lorena

Lila

Emiliano

Nathy

Jesse

Hajar

Bryan

Victor

MartelyDaysia

Devin Naidaliz

Joshua

Joelle

Cassie

Beverly

Erick

Olivia

9A – Same seats as last week!

Imani Alerte

Homework:Revise Background Info if necessary; continue with other sections of lab report (whole thing due Thursday)

Silent Do Now (in notebook w/ title & date) Find your Diffusion Lab data table Summarize your results in your notebook and try to

explain what each result means. Was there a color change in the beaker? What does this tell

us about a substance that did or did not diffuse? Was there a color change in the bag? What does this tell us? Was there a color change in the glucose test strip? What

does this tell us?

Bio 9A: Monday, 12.6.10Title: Diffusion Lab – Day 2

Today’s Objectives & Agenda

Discuss and analyze the results of the diffusion experiment

Use the lab report rubric to identify mediocre versus excellent examples of Background Info sections

Identify the strengths and areas for improvement in your own background info section

Agenda: Quick Class Discussion of Results Evaluate examples of Background Info Class discussion & brainstorm

Color Change?

Diffusion Across Cell Membranes:Presenting the Data/ Results



Water and Iodine


Bag Turned Purple/ Black

No Color Change to the Water

Glucose Test Strip changed color


Discuss and analyze the results of the diffusion experiment


Identify the strengths and areas for improvement in your own background info section

Agenda: Quick Class Discussion of Results Evaluate examples of Background Info Class discussion & brainstorm Peer editing

Lab: Diffusion Across Cell MembranesWriting Better Background Information Sections

Objectives for Class:


Task 1 – Do this silently on your own:• Read the two example Background Information sections from the Denatured Enzyme Lab

• Grade them according to the rubric.• Identify strengths and areas for improvement

Sample Background Info sections

Strengths: gives exact definitions, defines all the words, necessary for understanding the lab

Things to improve: do not give examples, not detailed, needs a paragraph, flow, no creativity, seems robotic, definitions were not explained well

Overall grade: ¾ or 15/20 or C

Strengths: it’s flows like a riverIt gave examples, they avoided

phrases like “a word you need to know is blahblblah” they included every definition. They included the concept/idea.

Things to improve: don’t use technical words. It doesn’t give a one sentence overview of the lab

Overall grade: 4/4

A or A+

Example 1 Example 2

Objectives for Class: Use the lab report rubric to identify mediocre versus excellent examples of Background Info sections

Lab: Diffusion Across Cell MembranesWriting Better Background Information Sections

Objectives for Class: Identify the strengths and areas for improvement in your own background info section

Task 2 – Do this silently on your own:• Trade Lab Reports with your partner• (5 min) Read their Background Info and identify…

• Does it start with a logical and meaningful topic sentence?

• Does it make strong connections between sentences? Between words?

• Does it explain many important terms and concepts necessary for understanding the lab?

• Does it avoid phrases like “what you need to know is…”

• Write down the strengths and areas for improvement on your partner’s background info section.• Take 2 minutes per partner to explain and give feedback

Homework: Finish Cell Membrane worksheet if not finished in

class Completed, typed, printed lab report due Thursday

Silent Do Now (in notebook w/ title & date) Look back at your vocab notes from last week1. Compare and contrast diffusion and osmosis

How are they similar? How are they different?

2. What do you understand about facilitated diffusion? How is it different from regular diffusion?

3. What do you know about active transport?

Bio 9A: Tuesday, 12.7.10Title: Cell Membranes Wrap-Up


SWBAT… Define and illustrate diffusion, osmosis, facilitated

diffusion, and active transport Explain when each process would be used for

materials entering a cell

Agenda: Notes/Discussion: Facilitated Diffusion & Active

Transport Review QuestionsNote: Thanks for your feedback at the end of class

yesterday. We will discuss this further in class on Thursday.

Diffusion Movement of molecules from a

high concentration (more stuff) to low concentration (less stuff)

Osmosis Movement of water through a

selectively permeable membrane from a high concentration to low concentration

Vocabulary Review



Diffusion

Osmosis

Facilitated Diffusion When a substance diffuses

through a membrane by going through a protein channel

Regular diffusion goes through the lipid bilayer

New Vocabulary



Prot

ein

Cha

nnel

Active Transport When a substance is pumped across a

membrane from where there’s a low concentration (less stuff) to where there’s a high concentration (more stuff)

Requires a pump (made of protein) and ATP energy!

New Vocabulary




SWBAT… Define and illustrate diffusion, osmosis, facilitated

diffusion, and active transport Explain when each process would be used for

materials entering a cell

Agenda: Notes/Discussion: Facilitated Diffusion & Active

Transport Review Questions

Work on your own Finish in class, otherwise for HW along w/ lab

report

movement across cell membranes moretti and dickson

Documents

cell slide

cell agenda

cell membranes objectives

cell membrane controls

cell image

cell membranes day

cell membranes moretti

membrane experiment