DIVE INTO THE What do you think this image shows? Hint: It's NOT an underwater - Scholastic
←
→
Page content transcription
If your browser does not render page correctly, please read the page content below
SCHOLASTIC and associated logos are trademarks and/or registered trademarks of Scholastic Inc. All rights reserved. © 2021. 715984
Images courtesy of NIGMS.
Sponsored Educational Materials
DIVE INTO THE
ocean scene! (Answer inside)
Hint: It’s NOT an underwater
What do you think this image shows?
The Imaging Issue
Feature
Discover how scientists unlock
How do you digest food?
the big (or very small!) mysteries
of our cells and molecules. Cool image fact The protein ribonuclease A is found in all living cells.
It is an enzyme that breaks down the RNA found in foods like meat and
magine you’re trying to take a photo of legumes, helping with digestion.
something small—say, a bug with a cool
pattern on its back. You zoom in, but the
image gets grainy and blurry.
Bugs can get pretty tiny, but they’re huge
compared to your cells, let alone your atoms.
About 5 million hydrogen atoms can fit on Crystallizing this
enzyme (main image;
the head of a pin. How can something so about the size of a
astonishingly small be photographed? grain of salt) allowed
Over the past century, scientists have scientists to map its
atomic structure (inset).
developed a variety of ingenious technologies
to answer this question. Using increasingly
advanced imaging tools, scientists have How scientists created these images Using chemistry, scientists
peered at protein molecules folded like prompted the protein sample to grow into a highly organized form
origami, cells pushing out harmful particles, called a crystal (over months). Then they fired X-rays through it. The
and much more. (Check out some examples X-rays bent in different directions upon hitting the individual atoms in
featured on these pages!) Studying the body’s the protein crystal, forming a dot pattern. Scientists used a formula to
normal and abnormal processes can lead to infer what 3D structure would cause that pattern. This process, X-ray
developing more effective, targeted treatments. crystallography, only works with specimens that can be crystallized.
How does your brain send messages?
Cool image fact This nerve ending has been broken open to reveal
vesicles containing chemicals called neurotransmitters that pass
messages in the nervous system. Researchers colorized the vesicles in
orange and blue to help viewers see the different parts of the image.
How scientists created this image A scanning electron microscope
works by moving (scanning) a narrow beam of electrons across a sample
(which is often coated in gold to make it conductive). By detecting how ON THE COVER
electrons are reflected or absorbed, scientists can create an image. But Magnify a throat 10,000x
why not just shine a light? Light is made up of photon particles that and you’d find a “sea” of
This vesicle is mop-like cells that sweep
reflect off objects and into our eyes. But some specimens are too tiny for
part of a nerve out unwanted particles
a photon’s wavelength! Electrons have a smaller wavelength that can with a continuous motion,
cell, or neuron.
interact with tiny specimens, such as the one pictured here. as shown in this colorized
mouse throat.
2 PATHWAYS
How do you sense pain? How do cells take out the trash?
Cool image fact Did you notice those stringy things on the
cover? Called cilia, they wiggle in a wavelike motion to sweep
Images: 3D Cilia Rendering, from Jianfeng Lin and Daniela Nicastro, "Asymmetric distribution and spatial switching of dynein activity generates ciliary motility." Science 360 (2018). Reprinted with permission from AAAS;
out debris or propel cells forward. Defects in cilia can cause
several diseases, so uncovering how healthy cilia move is an
This structure important foundation for developing treatments.
could help
scientists
develop drugs
to block pain!
Cool image fact This is a molecular model of the TRPA1
protein, which is involved in sensing pain. It is responsible for Inside a 3D
the burn you feel on your tongue when you eat hot mustard or model of a cilium
(singular of cilia)
wasabi. It’s informally known as the “wasabi receptor”!
How scientists created this image Scientists flash-froze How scientists created this image Cryo–electron
the protein by plunging it into liquid ethane to preserve it. tomography (cryo-ET) is similar to cryo-EM but used for cell
A cryo-electron microscope (cryo-EM) recorded how structures that are too big for standard cryo-EM. Scientists
the protein deflected electron beams to map the protein’s capture high-resolution images of the sample tilted at many
structure. (Cryo- means extreme cold.) angles, then combine the images into a 3D model.
Explore technological advancements
Scanning Electron Microscope photo, Prof. Dr. h. c. mult. Manfred von Ardenne; all other images courtesy of NIGMS.
in scientific imaging through the decades.
Hair follicle stem
With this technique, cells (in red and
future scientists were orange) activating
able to map this inner to regrow hair
ear protein (a mutation
here causes deafness).
Modeling Milestone: Modeling Milestone:
Rosalind Franklin uses Using cryo-EM and improved
X-ray crystallography to The first practical cameras, researchers
produce images from DNA confocal laser scanning break resolution barriers
fibers, which leads to the microscope creates to produce the first
X-ray crystallography discovery of DNA’s double- detailed images with a image of the individual
is invented. helix structure. focused laser beam. atoms in a protein.
1912 1937 1950s 1960s 1970s 1980s 2020
The scanning electron Osamu Shimomura discovers Cryo-EM is invented, allowing
microscope is invented. glowing green fluorescent protein specimens to be examined in
(GFP) in jellyfish. It’s used to label high-resolution in their natural
biological parts and track state—without the need for
processes under a microscope. crystallization.
A cell (green) leaves a trail of
fluorescent material. Scientists
can trace its path and how
long its journey took.
NEWS
Caption Challenge
Complete the captions for these microscopic images using concepts you’ve picked up in class.
Model of a A time-lapse sequence These thin, fibrous Scientific illustration The dendrites of this
bacterial __________ of mitosis in a flower tubulin proteins help shows an enzyme __________ located in
created using cell. Also known as to make up a cell’s wrapping around the brain’s hippocampus
cryo-electron __________, this skeleton, also known as a a broken strand of transfer electrochemical
tomography. process was captured _____________. __________ to signals to the body’s
with a light microscope. repair it. central nervous system.
Word Bank Cytoskeleton ◆ Cell Division ◆ Neuron ◆ DNA ◆ Cell
Scientists in the Spotlight
Meet four scientists who use cool imaging tools and tech in their work.
Sudha Chakrapani, Ph.D. Christopher Barnes, Ph.D.
Professor, Case Western Reserve University Postdoctoral Fellow, California Institute of Technology
Caption Challenge images courtesy of NIGMS; Scientists in the Spotlight photos courtesy of interviewees.
Type of Scientist: Structural biologist, researching how Type of Scientist: Structural biologist, researching
the brain communicates with the body how viral proteins infect human cells
How could your work lead to new medicines? We recently What’s the coolest part of your day as a scientist? No
solved the first cryo-EM structures for a type of serotonin question—it’s the chance to use high-powered tech to
receptor [serotonin is a kind of neurotransmitter that collect datasets! A few years ago, I worked with an X-ray
sends messages in the brain]. We went on to show how free electron laser. At the time, there were only two of them
blocking this serotonin channel could help treat nausea in existence. Sitting at the controls, knowing I was one of
and vomiting in cancer patients. only two scientists in the world doing this work—it’s so cool!
Shraddha Nayak, Ph.D. Melody Campbell, Ph.D.
Postdoctoral Fellow, University of Utah Assistant Professor, The Fred Hutchinson Cancer
Type of Scientist: Molecular animator, using graphic Research Center
design software, coding, and images of protein structures Type of Scientist: Biophysicist, using cryo-EM,
physics, chemistry, and math to research how cells communicate
Tell us about the tools you use in your work: The 3D
animation software I use has mind-blowing capabilities! Why do you study proteins? Protein structures not only
It lets me create a setting within a cell, simulate a tell us about shape, but also if the protein is more likely to
process that is taking place, and show movements and interact with things like water or things like soap or oil. We
changes over time. The tools I work with allow scientists can then make small changes to a drug so it binds more
to see their hypotheses and communicate their findings. tightly in a patient and becomes more effective.
4 PATHWAYS
Sponsored Educational Materials
G R A D E S 6 –1 2
SCHOLASTIC and associated logos are trademarks and/or registered trademarks of Scholastic Inc. All rights reserved. © 2021.
MAGAZINES
Unlocking the
& ACTIVITY
SHEETS Mysteries of
Cells & Proteins
TEACHING GUIDE
Photo: SDI Productions/Getty Images.
About Microscope Technologies,
Biological Discoveries, and Research Careers
Visit scholastic.com/pathways for
additional lessons, videos, and more.
BROUGHT TO YOU BY:
Teacher Instructions
A Closer Look at Scientific Imaging
Discover the stunning images created with advancing microscope
technologies. Then have your class create a gallery of colorful
scientific illustrations of their own.
Objective PART A
Inside an Imaging Lab
1
Students will model cell Hold up a pin. Ask students how
parts and functions, plus many cells they think could fit on its
learn about technologies Meet STEM pros who work with
head. Reveal that about 10,000 cells
used to capture cellular can fit on the head of a pin. exciting imaging technology:
and molecular structures. scholastic.com/pathways/techlab
NGSS Standards 2 Ask: What kinds of challenges might
researchers and structural biologists
encounter when studying cells, compare with static 2D images in
Grades 6–8 helping students better visualize
MS-LS1-2. Model a cell’s proteins, molecular structures, or
their atoms? Prompt for ideas like: energy production in mitochondria
parts and its function. or the process of mitosis?
size (too small to be seen without
6
Grades 9–12 the help of imaging technology), Discuss the career profiles on
HS-LS1-4. Model the appearance (can be translucent or the bottom half of the last page.
process of mitosis. require staining to visualize), and Have students imagine they are a
movement (a biological process structural biologist or molecular
HS-PS4-5. Communicate
could be moving too fast to capture, animator with access to high-
how technological devices
or the requirements of the imaging powered microscopes. Ask: What
use waves to transmit and
technology could kill the specimen, would you want to study?
capture information.
stopping the biological process).
Time
60 minutes 3 Distribute and have students explore
the themes in Pathways student
7 Distribute and have students
complete the Create a Scientific
Illustration activity sheet, referring
Allow extra work periods magazine. to the Imaging Resource sheet if
4
to complete scientific Have students read the main text needed. (You may wish to assign
illustrations and imaging on pages 2–3. After they read, Challenge A for middle schoolers
research projects. ask them to quickly sketch one of and Challenge B for high schoolers.)
8
the imaging processes they read Hang or compile completed student
Materials
about. In small groups or as a class, diagrams for a physical or digital
Pin (or image of a pin) have them discuss their sketches gallery walk. Have students take in
Pathways student and collaborate to deepen their and respond to one another’s work.
magazine understanding of the processes.
Create a Scientific
Illustration activity sheet 5 Direct students to complete the
caption activity on the last page of
9 Extend the learning for high school
students. Distribute the Research
Imaging Tech activity sheet. Once
Research Imaging Tech the magazine. Have them consider research projects are complete,
activity sheet advancements like 3D imaging have students present or share their
and time-lapse imaging and make work in small groups.
Imaging Resource sheet
connections to ongoing lessons. For
(bit.ly/imagingresource)
example, how might these techniques
NSWER KEY Caption Challenge
A
in the student magazine: cell; cell
division; cytoskeleton; DNA; neuron
Protein Alphabet
Researchers have found a protein in the shape of every letter of the alphabet!
Have high schoolers play with the protein alphabet at: bit.ly/proteinABC or, for
middle schoolers, project and play with the alphabet together as a class!
Activity
Name
Create a Scientific Illustration
Staining is a technique biologists can use to better visualize cells, their
components, and their functions under a microscope. Researchers can
“label” parts of biological specimens with different dyes to add color (in
microscopes that use light) or contrast (in microscopes that use electrons).
A few examples of staining:
› Crystal violet can be used to tint cell walls purple.
› Nile blue can stain a cell’s nucleus blue.
› Green fluorescent protein (GFP) can be used to label organelles and proteins a glowing green.
In addition, when scientists combine photos to create a 3D model of a specimen, they may add color to the
illustration (known as colorizing) to help viewers differentiate the parts.
Colorizing Cells
Give the colorizing concept a try for yourself. On a separate piece of paper, complete challenge A or B.
Optional: Access the Imaging Resource at bit.ly/imagingresource to check out brightly colored examples
of staining and colorizing.
CHALLENGE A CHALLENGE B
Create an eye-catching visual aid that helps its Create an eye-catching visual aid that helps
viewers understand the function of a cell and the its viewers better understand the process of
ways parts of cells contribute to its function. mitosis (cell division).
➜ Draw a diagram of a bacterium or a plant or ➜ Diagram the stages of mitosis.
animal cell. ➜ “Stain” centrioles, chromosomes,
➜ “Stain” each component of the cell structure centromeres, the nuclear membrane, and the
a different color. cell membrane different colors.
➜ Create a key to link your chosen stain color ➜ Create a key to link your chosen stain color
with each cell component. with each cell component.
➜ Provide a brief explanation of the function of ➜ Provide a brief, written explanation for each
each cell component. stage of the process.
Think About It
1. What are the advantages of adding color to an image of a microscopic specimen?
2. What are the limitations of looking at single, static photographs of cells to understanding biological processes?
Activity
Research Imaging Tech Drawing
of the first
commercialized
Learn more about the imaging technologies researchers use confocal
microscope:
to make basic science and structural biology breakthroughs. the tandem
Plus, explore some of the educational and career pathways scanning
microscope,
that have led researchers to their areas of study. developed by
Mojmír Petráň
1 SELECT the imaging technology of your choice or one from the list below.
❒ Confocal Laser Scanning Microscope ❒ X-Ray Crystallography
❒ Scanning Electron Microscope ❒ Raman Spectroscopy
❒ Scanning Tunneling Microscope ❒ Nuclear Magnetic Resonance (NMR)
❒ Cryo-Electron Microscope Spectroscopy
❒ Lattice Sheet Microscope ❒ Cryo-Electron Tomography
❒ Fluorescence Microscope ❒ Digital Scientific Illustration or
Animation (3D or 4D Modeling)
2 CONDUCT research to find out:
➜ How the technology works
➜ Which fields of study it’s used in
➜ The imaging result it produces (example: 3D model, molecular-level resolution, etc.)
➜ Examples of specific images it has produced
➜ Major milestones or discoveries associated with the technology or its advancement
➜ How it can be used to learn more about life or human health
Confocal microscope drawing: United States Patent and Trademark Office.
➜ Types of careers that use this imaging technology
3 PACKAGE and PRESENT your research findings using the method of your choice:
Create a handy Write a blog post or Storyboard or create Write a journal entry
user manual or guide, design an informative a short video for or letter to yourself
with images. webpage. presentation to or a friend.
your class.
THE IMAGING ISSUE
V O C A B U L A RY L I ST
BIOLOGY IMAGING
DNA (noun): the molecule found in cells crystallize (verb): to cause a material to organize into
that carries instructions for cell structure a crystal form in which its atoms or molecules are
and processes in the body. DNA contains arranged in a highly ordered structure.
genes that are passed on from parents to
offspring and give living things their inherited diffraction (noun): the slight bending of light, or other
characteristics. The letters DNA stand for waves (like X-rays), when passing around something in
deoxyribonucleic acid. its path.
enzyme (noun): electron (noun): a particle that orbits the nucleus of an
a type of protein atom and carries a negative electrical charge.
found in animals
and plants that fluorescence (noun): light that a substance (like a
speeds up chemical protein) first absorbs and then emits (gives off).
reactions by imaging (noun):
reducing the amount techniques used by
of energy needed for scientists that make
the reactions to proceed. cellular, molecular, and
gene (noun): a small section of DNA that atomic structures and
contains instructions, usually for making a processes visible.
specific protein.
laser (noun): a very
mitochondrion (noun; plural is narrow beam of light,
mitochondria): an organelle (part of a cell) or a device that uses
that converts food and oxygen into energy to the vibrations of
fuel the cell. atoms or molecules to
generate light.
neuron (noun): a cell within the nervous
system that transmits information to other light microscope (noun): a type of microscope that
nerves, muscles, or gland cells. uses light rays and curved glass lenses to magnify a
specimen; also known as an optical microscope.
proteins (noun): large, complex
molecules that are essential for all life specimen (noun): a sample or example
processes, playing a key role in the of something that is used for scientific
HER
structure, function, and regulation TAKE IT FURT study.
cabulary
of the body’s cells, tissues, and Choose five vo
think will structural biologist (noun): a
organs. words that you
member, scientist who studies how biological
be hardest to re
agraph
RNA (noun): the molecule then write a par molecules are built. Using a variety
nfiction
that delivers a copy of the with them (no of imaging techniques, structural
instructions in DNA so that cells can or fiction). biologists view molecules in three
produce proteins according to the dimensions to see how they are
instructions. The letters RNA stand for assembled, how they function, and how
ribonucleic acid. they interact.
Imaging Resource
The Colorful World of
I m a g i n g Te c h n o l o g y
Check out some of the ways color and contrast can help scientists better
visualize tiny specimens, and how this research can help human health!
Staining and Colorizing Specimens
Cryo-ET image before and after colorizing
Specimen: Caulobacter bacterium
Color key: In the second image, cell membranes are
highlighted in red and blue, protein shell in green,
ribosomes in yellow, and storage granules in orange.
Why study this? By studying this bacterium, scientists
learn more about asymmetric cell division—an important
factor in our understanding of human disease and the
growth of tumors.
Light sheet fluorescence Confocal microscope + Scanning electron X-ray fluorescence
microscope fluorescence microscope technology
Specimen: Jellyfish Specimen: Fruit fly brain Specimen: Leg muscle Specimen: Leaf
Color key: Nervous system Color key: To create this Color key: Blood vessels Color key: The levels of zinc
is stained green. Musculature digital, 3D color-coded map, are colorized pink (with red in the leaf from lowest to
is stained red. Cell nuclei are scientists labeled the brain’s blood cells at the bottom). highest are marked in blue,
stained blue. parts with fluorescence, The light brown marks the green, red, and white.
Why study this? By then captured and combined extracellular matrix (ECM), Why study this? Zinc is
studying jellyfish tissues, thousands of photos. made up of molecules like required for the function of
scientists learn more about Why study this? By studying proteins that physically more than 300 enzymes in
the evolution of animals, the brain of fruit flies, support the muscle. the human body. With a goal
including humans! researchers aim to learn Why study this? Disruption of improving human health,
more about the functions of the ECM is associated researchers are investigating
and structures of the with many muscle disorders. how plants distribute zinc to
images courtesy of NIGMS.
human brain. Scientists hope to learn find ways of increasing the
more about how the ECM zinc content of crops.
functions and how muscle
disorders can be treated.You can also read
