Would you be able to complete this lab by Saturday?

Lab5: Follow the instructions and complete the assignment below. Submit your answers through the

Lab 5 Assignment on Blackboard.

Lab 5 1

Lab 5: Solvents and cells

Part 1: Chemistry of Molecules Read/watch the provided resources and take notes, applying
the information to what we learned this week.

CO2 and Soda: https://www.youtube.com/watch?v=HFCeV5BVBh0
Dissolving M&Ms: https://www.youtube.com/watch?v=umJmRaG6v80

When you are finished, answer the following questions:

1. You are having a debate with a friend about the science behind the Diet Coke and Mentos
phenomenon. Your friend thinks that since the volume of matter after the experiment (the big
mess) seems to be more than what was originally present in the individual components
(soda/Mentos) before they were combined, that the “explosion” is the result of carbon dioxide
being produced (made) by the reaction. Is this true? Does the amount of carbon dioxide
increase through this reaction? Use what you’ve learned this week to verify or debunk your
friend’s argument.

2. During the M&Ms experiment, why did the scientist emphasize that each of the treatments
in this experiment needed to be stirred the same say, for the same length of time?

3. For the M&M experiment, name and describe the chemical property that is demonstrated by
both the sugar and the candy coloring in the shell of an M&M that permits dissolution in the
water, but not in the oil.

4. In your own words discuss this quote.
Was Jamf mistaken in his understanding
of the relative strengths of ionic and
covalent bonds? Explain why/why not
(in your own words!).

5. The scientific field of organic chemistry is based entirely on studying the chemical structure
and reactivity (bonds and chemical reactions) of carbon containing molecules. Based on what
you learned in class this week, discuss why carbon is so important that entire fields of study are
dedicated to understanding and applying it.

Lab 5: Follow the instructions and complete the assignment below. Submit your answers through the
Lab 5 Assignment on Blackboard.

Lab 5 2

Part 2: A Picture is Worth a Thousand Words
This unit we learned about cells, their structure, and how they carry out the processes of life.
We know that there are size restrictions that prevent living cells from being too small or too
large. However, the rules that govern cell size may be more complex than scientists originally
thought.

The existence of ultra-small living cells has been debated for two decades. This debate was
settled in February of 2015, when researchers from the U.S. Department of Energy’s National
Laboratory at UC Berkeley obtained the first microscopy images of ultra-small bacteria- about
as small as life can get. Follow this youtube link to view the research images/reconstructed
videos of the cell structure: https://www.youtube.com/watch?v=ofNrtg-FpSc; primary article
may be provided upon request.

This part of the lab will focus on a popular media ScienceDaily article that summarizes the
researchers’ findings. However, before we investigate these ultra-small nanobes, it is important
that we fully comprehend the history and scientific impact behind this debate. For this, you’ll
need to read the following extract:

“In 1996, researchers published a description of a meteorite that fell from Mars, which sparked
a long and complicated debate over the existence of what they called ‘nanobacteria’, later also
described as nanobes. Various teams argued over whether life, theoretically, could live to be
that size, but the debate didn’t really get anywhere because no one really had any evidence for
either side. One side said all the things needed for life – DNA, RNA, proteins and solvents –
couldn’t actually fit inside a cell that small, while others said life could be that small, but just in a
starved, inactive state. Researchers argued over the theoretical limit for how small a cell could
get in diameter and volume, and one team even reported finding some marine nanobes, but
lacked direct microscopic evidence to prove they fit inside the size range to classify them as
such. But now, such bacteria found in some Colorado groundwater have been imaged, and
these things are undeniably tiny – several times tinier than several estimates for the lower size
limit of life on Earth, in fact. And as difficult as it is to see them, the researchers think they could
actually be quite common.”
http://www.sciencealert.com/new-images-reveal-the-tiniest-known-life-forms-on-earth

Next, click the link to read the article describing researchers’ findings and use this information,
along with what you learned this week to answer the provided questions.
https://www.sciencedaily.com/releases/2015/02/150227181339.htm

When you are finished, answer the following questions:

6. The image at the beginning of the ScienceDaily article shows and describes the visible
structure of the cell, and the authors state: “The cell has a very dense interior compartment and
a complex cell wall.” As you remember from your readings, not all cell types contain a cell wall.
What kinds of cells, other than bacteria, would you expect to possess a cell wall? List the

http://www.sciencealert.com/new-images-reveal-the-tiniest-known-life-forms-on-earth

https://www.sciencedaily.com/releases/2015/02/150227181339.htm

Lab 5: Follow the instructions and complete the assignment below. Submit your answers through the
Lab 5 Assignment on Blackboard.

Lab 5 3

functions that this structure provides for these organisms. How do organisms that don’t have a
cell wall execute these same functions?

7. The image at the beginning of the ScienceDaily article shows and describes the visible
structure of the cell, and the authors state: “The darker spots at each end of the cell are most
likely ribosomes.” Of all the different structures that could exist within a cell, why do you think
that the authors think that these are ribosomes? (Hint: think about the types of cellular
structures that are/aren’t found within bacteria, and what ribosomes do, and the importance of
that job, within a cell.)

8. Interestingly, the ScienceDaily article states: “images also revealed dividing cells, indicating
the bacteria were healthy and not starved to an abnormally small size.” This statement implies
that in order for cells to divide they must be “healthy”. Discuss the requirements that a
“healthy” eukaryotic cell must meet before it will under cell division. What are the
consequences if a eukaryotic cell divides even if these requirements are not met?

9. The ScienceDaily authors state: “About 150 of these bacteria could fit inside an Escherichia
coli cell and more than 150,000 cells could fit onto the tip of a human hair”. To provide you
with some context so that you can really understand this statement: the spherical diameter of a

typical Escherichia coli cell is 1.3 m (micrometers), and the spherical diameter of these new

ultra-small bacteria is ~0.23 m. Compare the SVR of these new ultra-small bacteria to that of a
typical E. coli cell (Hint: you need to calculate the SVR for each), which organism has a larger
SVR, does this make sense in the context of the size of the cell?

10. Throughout the ScienceDaily article, the researchers studying these tiny bacteria
acknowledge the challenges that such small cells face when it comes to performing the basic
functions of life, and the additional challenges that limit our ability to study such small
organisms. This makes sense, considering that previously calculated theoretical minimum
diameter of a cell was established (and generally accepted by respected scientists and experts

in the field) to be 0.250-0.30 m. The authors say, “There isn’t a consensus over how small a
free-living organism can be, and what the space optimization strategies may be for a cell at the
lower size limit for life.” Why, before this, did scientists think that living cells couldn’t be much
smaller than this lower limit (why is it that when a cell is too small, that it “can’t” survive)?

11. Choose another statement/quote from this article (or the other summary or the original
research paper) and discuss how it relates to the material that we learned this week. Be sure to
use specific examples (and your own words).