Cellular Compartmentalization

Unit

Context of Unit in Course

• Unit is for a second year, intro cell biology or intro microbiology course, scalable to first year intro biology

• This unit comes in the middle of the course• Students are expected to know what cells are

and basic cell structures as prior course knowledge

• Enduring concepts are compartmentalization in cells, and differences between prokaryotes and eukaryotes

Unit Learning Goals and Objectives

1) Understand what cellular compartmentalization isa. LO – define cellular compartmentalizationb. LO – explain the advantages of compartmentalization

2) Understand structural differences between pro and eua. LO – distinguish structural differences between pro and eu cellsb. LO – explain organization without membrane-bound structures

3) Understand functional differences between pro and eua. LO - distinguish functional differences between pro and eu cellsb. LO – be able to match processes with organelles

Students will…

Tidbit Learning Goals and Objectives

1) Understand what cellular compartmentalization isa. LO – define cellular compartmentalizationb. LO – explain the advantages of compartmentalization

2) Understand structural differences between pro and eua. LO – distinguish structural differences between pro

and eu cellsb. LO – explain compartmentalization without membrane-

bound structures

3) Understand functional differences between pro and eua. LO - distinguish functional differences between pro and eu

cellsb. LO – be able to match processes with organelles

Students will…

ALIEN MYSTERYA probe has returned from Venus with life! You, the ridiculously overpaid NASA staff biologist, are responsible to classify these cells as prokaryotic or eukaryotic. Let’s look at the first data from the lab. You can assume these are similar to known life forms (not silicon-based etc.)

Experiment 1Collect cells Cell lysis

Analyze components

Experiment 1

1) Prokaryotic

2) Eukaryotic

3) Can not determine

The cells contain DNA, RNA, proteins, and phospholipids, and is therefore exclusively classified as:

TPS

• Explain to your neighbor why your answer is correct.

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Countdown ClockBy Dr. Jeff Ertzberger

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Countdown ClockBy Dr. Jeff Ertzberger

TPS

• Correct answer is 3, cannot determine at this point.

• Central concept: prokaryotic and eukaryotic cells are similar at the basic molecular level . “What is true of E. coli is true of the elephant.” -- Jacques Monod Nobel Laureate 1965

Experiment 2

1) Prokaryotic

2) Eukaryotic

3) Can not determine

We now have some more analysis. Using light microscopy, we can see that the cells have two chromosomes. Based on that, they can exclusively be classified as:

Experiment 2 – accessory dataAll of these cells are bacterial

Fluorescent microscope images

E. coli Vibrio cholerae Paracoccus denitrificans

TPS

• In light of the accessory observations, explain to your neighbor the correct answer.

01 595857565554535251504948474645444342414039383736353433323130292827262524232221201918171615141312111009080706050403020100

Countdown ClockBy Dr. Jeff Ertzberger

00 595857565554535251504948474645444342414039383736353433323130292827262524232221201918171615141312111009080706050403020100

Countdown ClockBy Dr. Jeff Ertzberger

Experiment 2

1) Prokaryotic

2) Eukaryotic

3) Can not determine

After our discussion, let’s vote again. Since the cells have two chromosomes, they should be classified as:

TPS

• In light of the accessory observations, explain to your neighbor the correct answer.

• Central concept: a common misconception is that all prokaryotes have one circular chromosome

Experiment 3

The investigator is designing the next step. What evidence should she look for that would differentiate between prokaryotic and eukaryotic cells?

Experiment 4

1) Prokaryotic

2) Eukaryotic

3) Can not determine

We now have further analysis. Using electron microscopy, we generated this image of the cells. Based on that, they can exclusively be classified as:

Wrapup

• House analogy for cellular compartmentalization

Eukaryotic compartmentalization

Prokaryotic organization

Which represents prokaryotic and which represent eukaryotic?

Eukaryotic compartmentalization

Prokaryotic organization

Wrapup

• House analogy• Both organized functionally• While eukaryotes have extensive

compartmentalization due to internal membrane-bound organelles, prokaryotes are also organized intracellularly

Homework

LO – distinguish structural differences between prokaryotic and eukaryotic cells

Complete this interactive animation from Wiley Publisher.http://www.wiley.com/legacy/college/boyer/0470003790/animations/cell_structure/cell_structure.htm Complete the popup questions for prokaryotic cell, animal cell, and plant cell. Then complete the construct a cell exercise.