Case StudySubzero temperatures span across the prairie. Animals hibernate, grow winter coats, or fly south to warmer climate zones. Goldenrod gall moth larvae survive harsh winters in the stem galls of goldenrod plants.

How do the moth larvae survive?

GLYCEROL AND

ANTI-FREEZE PROTEINSCheryl Hosie

Cryoprotectant• Macromolecules, like Glycerol, are

used to protect tissues from freezing

• As ice forms outside the cell, water leaves the cell to dilute the higher concentrations of solutes

• Cryoprotectants prevent all the water from leaving by increasing the concentration of solutes inside the cell

Glycogen to Glycerol•Larvae prepare for winter by consuming large quantities of plants

•Low temperatures initiate accumulation of glycogen

•Glycerol is easily synthesized from glycogen storages

•Metabolism Pathway of glucose to glycerol is shown in the diagram

https://openi.nlm.nih.gov/detailedresult.php?img=PMC2712079_pone.0006394.g004&req=4

Glycerol•Glycerol has three hydroxyl groups That hydrogen bond to water

•This binding of glycerol to water reduces the amount ice crystals that form inside the cells

https://www.quora.com/Why-does-glycerol-retain-water

Anti Freeze Proteins•Lower freezing point•Protect cell from ice damage

•Used in food industry

https://pdb101.rcsb.org/motm/120

Anti-Freeze Proteins•The lighter blue areas on these proteins represent the water binding sites

•Anti-Freeze Proteins bind to the water in the extracellular matrix

•This prevents large ice crystals to form in freeze avoiding fish and insects

https://pdb101.rcsb.org/motm/120

Freeze-Avoiding Gall Moth•Freeze-Avoiding Insects, like the Goldenrod Gall Moth, can not survive with large amounts of ice crystals intracellularly and/or extracellularly

•Glycerol binds to the water inside the cell to prevent ice crystals

•In addition, anti-freeze proteins, such as Protein Kinase prevent cell death

REFERENCES"PDB-101: Antifreeze Proteins". Pdb101.rcsb.org. N.p., 2016. Web. 16 Dec. 2016.

Pfister, T.D and K.B Storey. "Protein Kinase A: Purification And Characterization Of The Enzyme From Two Cold-Hardy Goldenrod Gall Insects". Insect Biochemistry and Molecular Biology 32.5 (2002): 505-515. Web.

TOLLAROVA, Michaela. "Seasonal Activity-Profiles Of Enzymes Involved In Cryoprotectant Biosynthesis In Pyrrhocoris Apterus (Heteroptera: Pyrrhocoridae)". European Journal of Entomology 105.1 (2008): 149-152. Web.