Energy in Living Systems Pre-AP Biology

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

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

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

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

Food Chain

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

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

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)

Autotrophs or Heterotrophs?

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

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

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)

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

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

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

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

IYOW answer the following questions