Download tagging macromolecules

SBI4U
TAGGING MACROMOLECULES
Name:
Date:
The 4 macromolecules
are:
Constituent Monomer
Function of
Macromolecule
Part of working out the function of a macromolecule is placing it in the right part of the cell.
This is called tagging molecules. We will learn about different forms of molecular tagging
this year. Our first method involves radioisotopes.
18
O
16
and
O
are isotopes.
How are they different?
How are they the same?
Radioisotopes can be detected using X-ray film. Why is this important?
Cell Localization Images
Here’s a picture from a light microscope:
What advantages does cell localization with
molecular tags give Biologists?
So where do we expect to find macromolecules?
Draw a line between each macromolecule and its organelle. Try to match the function of the
macromolecule with the function of the organelles.
Carbohydrates
Cell Wall
Cell Membrane
Proteins
Nucleus
Mitochondria
Nucleic Acids
Chloroplasts
Ribosomes
Lipids
Lysosomes
Cytoplasm
Endoplasmic Reticulum
What patterns do you see? Are any macromolecules more important/ubiquitous than others?
What organelles are being tagged here? Which radiolabelled macromolecule do you think is being
used to make this image?
Follow-up Questions:
If all molecules can undergo diffusion, how can you account for the localization of
macromolecules to concentrated areas in the cell?
Compare and contrast polar vs. non-polar molecules
Polar
Non-polar
Is the interior of a cell (cytoplasm) polar or non-polar?
Is the exterior of a cell polar or non-polar?
What is the structure of the cell membrane (phospholipids bilayer)? How does the polarity
of the cell membrane help to maintain an uneven distribution of macromolecules between a
cell and its environment?