5 labs

CellMembraneTransport

Hands-OnLabs,Inc.Version42-0034-00-01

Lab Report Assistant Thisdocumentisnotmeanttobeasubstitute foraformallaboratoryreport.TheLabReport Assistantissimplyasummaryoftheexperiment’squestions,diagramsifneeded,anddatatables thatshouldbeaddressedinaformallabreport.Theintentistofacilitatestudents’writingoflab reports by providing this informationin an editable filewhich can be sent to an instructor.

Exercise1:DiffusionthroughanArtificialMembrane

Observations

Questions

A. What is the purpose of this exercise? What is being tested?

B. What color change did you observe in the dialysis tubing? What does that change indicate? C. Was there a color change in the water surrounding the tubing? If so, explain.

( Ex p e ri m e n t ) ( C el l Membran e T r a nsp o r t )

( ww w . H O L s c i e n c e . c o m ) ( 112 ) ( © H a nds-On L a bs, I n c . )

D. WhatcolorchangedidyouobserveinthewatercontainingtheIKIafterheating?Whatdoes that change indicate?

E. What does the Benedict’s reagent detect? F. What does the IKI solutiondetect?

G. In what way is a cell membrane similar to the model cell made of dialysis tubing? H. Is the transport mechanism in the model cell passive or active?Why?

Exercise 2: Diffusionat differenttemperatures

Observations

Questions

I. How does temperature affectthe rate of diffusion?

J. State a general hypothesis to cover how temperature affectsrate of diffusion

Exercise 3: Tonicity and Diffusion

Observations

Questions

A. Whatistheconditionofeachpotatostripaftersoakinginthetesttubesforanhour?Which one is limp and which one is crisp?

B. Howwouldyou explainthedifferenceintheconditionsofthepotatostripsusingtheconcept of tonicity?

C. What was the tonicity of the fresh water solutionwith respect to the potato cells? D. What was the tonicity of the salt water solutionwith respect to the potato cells?

E. How do the changes in the conditionsof the potato strips relate to the wiltingof plants?

F. How does keeping vegetables cool slow them from wilting?