1. Form & Function
at the Atomic Level

2. Which elements are most common in the bodies of living things?
Entry Task:
Which elements are most common in the bodies of living things?

4. Which questions were difficult for you to answer?
Homework Check:
Ch 4 Notes
Concept Check Q’s
Which questions were difficult for you to answer?
Expectation:
Check answers to questions on your own time.
See Ms. Barga or a classmate with questions you still do not understand

5. Form Elements common in living things

6. Number of Bonds formed with other atoms
One
Two
Three
Four
Atoms form connections or BONDS using only electrons in the outer or VALENCE energy level so that the outer level is full and all electrons are paired. Most atoms have 8 electrons in the outer energy level:
Therefore, Hydrogen forms 1 bond, Carbon 4, Nitrogen3, Oxygen 2, P 3 & S 2

7. Form & Function at the Atomic Level
More Next Week!!! Yay Biomolecules! …And you thought Chemistry was over ;)

8. Unique Properties of Water
Why Life Exists

9. Form of Water

10. Function of Water High Cohesion – molecules of water stick together
High Adhesion – water molecules stick to other molecules
Effect on Life:
Allows water to rise through Xylem tissue to the top of very tall plants

11. Celery Experiment

12. Function of Water
High Cohesion: is caused by Hydrogen Bonds between molecules of Water
Water absorbs more heat before increasing temp.
Water releases that heat as it decreases temp.
Effect on Life:
Keeps Earth’s temperature in the small range that is friendly for life

13. Function of Water Solid water molecules spread farther apart
Ice is less dense than liquid
Ice floats on water
Effect on Life
Prevents lake freezing in winter
Protects lake life through winter

14. Function of Water High density of COLD water
Cold water sinks to bottom
Effect on Life:
As ice melts in spring, causes “upwelling” of nutrients
Drives annual cycling of nutrients in water

15. Homework: Ch 4 Review Q’s 1-7 & 20-22 & 25 Read Ch 5 pages 90-102
Reading Notes
Concept Check Questions

16. Explain one way a water molecule’s form affect its function.
Exit Ticket
Explain one way a water molecule’s form affect its function.