1. Plants and Cold Temperatures

2. 2 lettuce leaves Make observations about them.
What might have happened to them?

3. What happens to plant cells when they freeze?

4. What happens to water when it freezes?

5. What happens to water when it freezes?

6. What happens to plant cells when they freeze?

7. What happens to plant cells when they freeze?

8. What happens to plant cells when they freeze?
Much of the damage is done as the plant thaws

9. What signals plants to get ready for winter?
Temperatures drop
Growth & photosynthesis slow or stop

10. How do plants get ready for cold?
Some cells are tougher than others

11. How do plants get ready for cold?
Cells contain molecules that act like antifreeze
Mainly sucrose that lowers the freezing temperature
Antifreeze proteins (AFPs) have the ability to bind to ice crystals and restrict their growth, enabling certain organisms to survive under freezing conditions that would otherwise prove fatal.

12. How do plants get ready for cold?
Cells contain molecules that act like antifreeze
Mainly sucrose that lowers the freezing temperature
Proteins that help prevent ice crystals from forming outside the cell
Antifreeze proteins (AFPs) have the ability to bind to ice crystals and restrict their growth, enabling certain organisms to survive under freezing conditions that would otherwise prove fatal.

13. How do plants get ready for cold?
Cells may make proteins called “dehydrins”
Inside cell
Bind to water molecules and alter the structure of water
Antifreeze proteins (AFPs) have the ability to bind to ice crystals and restrict their growth, enabling certain organisms to survive under freezing conditions that would otherwise prove fatal.

14. How do plants get ready for cold?
Cells can alter lipid composition of cellular membranes to adjust fluidity
Antifreeze proteins (AFPs) have the ability to bind to ice crystals and restrict their growth, enabling certain organisms to survive under freezing conditions that would otherwise prove fatal.

15. How do plants get ready for cold?
Plants move the water in their cells into intracellular spaces

16. Why does this apple look red?

18. LAB: Freezing Beet Cells

19. Results:

20. Frozen:
Peak Absorbance: 1.1
Refrigerated:
Peak Absorbance: 0.05
Room Temp:
Peak
Absorbance: 0.05

21. The End.

22. Quiz Monday 11/20 Winter in our Gardens/Reproduction
What are the structures and functions of flowering plants?
How does pollination and fertilization work?
What are the benefits of Mulch and Cover Crops?
What happens to Cells When They Freeze?

23. How will the plants in our garden tolerate cold?

24. How will the plants in our garden tolerate cold?
Plants have different adaptations for different climates

25. How will the plants in our garden tolerate cold?
We will decide which plants will…
Survive the winter
Survive the winter with some help
Won’t survive… harvest now