1. Energy in Living Systems
Pre-AP Biology

2. Bellwork List as many different forms of energy as you can
Give at least 2 examples of energy being converted from one form to another

3. Learning Objectives Define thermodynamics
Explain the first and second laws of thermodynamics
Distinguish between a catabolic and anabolic biochemical pathway
Explain the structure and function of ATP

4. Key Terminology Thermodynamics Autotroph Heterotroph Metabolism
Anabolic
Catabolic
Photosynthesis
Cellular Respiration
ATP

5. Energy Definition: ability to do work Sources of energy for organisms
Food we eat (chemical energy)
Energy from sun – ultimate energy source
Energy from sun used to create
organic compounds (chemical energy)
that other living organisms can use

6. Food Chain

7. Thermodynamics
Definition: Study of energy transformations in the universe
Two laws of Thermodynamics
First law:
Energy is neither created or destroyed
merely converted from one form to another
(example-blender)
Second law:
Energy cannot be converted without loss of useable energy
Energy lost in the form of heat
thermal energy; considered unusable energy

8. Think-Pair-Share
Explain how the second law of thermodynamics applies to the blender when making a fruit smoothie.
3. Think-pair-share
teacher presents a question
teacher gives wait time for student to form answer
teacher instructs students to share their answer with a partner
teacher calls on non-volunteers to share with the class 3

9. Organisms Need Energy to Live
Organisms get their energy in two different ways:
Autotrophs
Organisms that make their own food
(Ex. Plants)
Heterotrophs
Organisms that get food from external environment
(Example-humans)

10. Autotrophs or Heterotrophs?

11. Metabolism Definition: all the biochemical reactions in a cell
Biochemical pathway
chemical reactions that are aligned in sequence
A  B  C  D

12. Two types of Biochemical Pathways
Anabolic Pathway
Build large molecules from small molecules
requires energy
Catabolic Pathway
Break large molecules into small molecules
releases energy

13. In an Ecosystem: Photosynthesis Cellular Respiration
performed by autotrophs
Anabolic pathway - makes organic compounds
Chemical reaction:
Light Energy + CO2 + H20 C6H12O6 + O2
Cellular Respiration
Catabolic pathway - organic compounds are broken down
Chemical Reaction:
C6H12O6 + O2  CO2 + H20 + Energy (ATP)

14. Think-Pair-Share
Compare the reaction for photosynthesis and cellular respiration. What do you notice about the two reactions?
3. Think-pair-share
teacher presents a question
teacher gives wait time for student to form answer
teacher instructs students to share their answer with a partner
teacher calls on non-volunteers to share with the class 3

15. Chemical Energy In Cells
ATP (adenosine triphosphate)
Most important biological molecule that provides chemical energy to the cell

16. Structure and Function of ATP
Structure: made of adenine base, ribose sugar, and three phosphate groups
Function: Releases energy when the bond between second and third phosphate group is broken

17. Minute Paper
Explain how the energy in a ham and cheese sandwich ultimately came from the sun. In thinking about this problem, consider the energy transformations that occur in the food chain.
Be prepared to share
29. Minute paper or Quick Write
teacher provides a prompt from the lesson
students have one minute to write down a summary of the key points
students compare with a partner
teacher uses a strategy to check all 17

18. IYOW answer the following questions