Humans haven’t yet figured out how to turn energy from the sun into chemical energy, or how to use that energy to support life—but producers have. From the basic parts of the cell to isolating the variables in photosynthesis inputs, this Digital Teaching Box contains classroom-tested, NGSS-aligned resources for teaching photosynthesis and cellular respiration.
Grade Level & Course
High school biology
Author & Affiliation
Biology teacher, Boulder High School
This unit introduces students to the basic functional units of the cell and gives them the tools to get up close and personal with cells all around them. By pairing the parts and functions of the cell with basic microscope skills, students can make deep connections between what they learn and what they see on the slides they make.
Viewing the Kingdom: Microscope Work
Introduce students to cells from a variety of kingdoms by preparing and looking at them through the microscope.
Katie Ward, Aragon High School
Beginning the unit by addressing the structures of the cell and its organelles allows students to place in context the relative sizes of these structures and their relationships to each other.
The cell is an enclosed unit. Or is it? This unit explores the boundaries between cells and the outside world—how the cell membrane allows some substances in and out, allowing photosynthesis and cellular respiration to take place.
Life at the Edge
This lecture offers students a basic understanding of the structure of the cell membrane and how different types of molecules pass through it.
Use this lecture either before or after the lab included in this unit.
Cell Membrane Lab
Expose students to osmosis in action. By making predictions, observing, and collecting and analyzing data, students see the cell membrane at work.
Teach students the ins and outs of photosynthesis and cellular respiration—literally. This unit includes lectures and hands-on activities emphasizing the inputs, mechanisms, and outputs of these life-supporting processes.
Floating Disk Assay for Photosynthesis
Allow students to see and identify the inputs and outputs of photosynthesis for themselves in this lab.
Julie Thompson (based on an activity from Brad Williamson)
This laboratory activity can be used to test various factors that affect the rate of photosynthesis. For example, if the spinach-disks sample is placed in the dark, no bubbles form, suggesting photosynthesis requires light. Or, if a student performs the protocol but chooses to leave out the bicarbonate (which acts as a source of CO2), no bubbles will form, suggesting CO2 is necessary for photosynthesis. The end goal is for students to make claims regarding the inputs and outputs of photosynthesis based on data.
Extension ideas: Could the glucose produced by the disks during the experiment be detected somehow?
Where Does the Mass of a Plant Come From?
Explore the misconception that a growing plant gets most of its mass from soil and water, rather than from CO2 produced by photosynthesis.
Before beginning this activity, students should be able to produce independently the correct equation for photosynthesis. This activity helps explore the common misconception that growing plants gain most of their dry mass from soil or water, when in fact most of their dry mass comes from CO2 absorbed from the air during photosynthesis. Even though students know the inputs and outputs of photosynthesis (and that there is no soil in that equation) they often predict that the mass of a plant comes from the soil.
Respiration in Yeast
Explore the inputs required for cellular respiration using this lab.
This laboratory activity can be used to test various factors that affect the rate of cellular respiration. For example, if the yeast sample is given no sugar, little CO2 is produced. Or, if a student chooses to double the amount of sugar, more CO2 is formed. The end goal is for students to make claims regarding the inputs and outputs of cellular respiration based on data.
Extension ideas: Could a test be devised to test the amount of sugar or alcohol produced by the yeast?
Science and Engineering Practices
Developing and Using Models
Develop a model based on evidence to illustrate the relationships between systems or components of a system. (HS-LS2-5)
Using Mathematics and Computational Thinking
Use mathematical representations of phenomena or design solutions to support claims. (HS-LS2-4)
Constructing Explanations and Designing Solutions
Construct and revise an explanation based on valid and reliable evidence obtained from a variety of sources (including students’ own investigations, models, theories, simulations, peer review) and the assumption that theories and laws that describe the natural world operate today as they did in the past and will continue to do so in the future. (HS-LS1-6),(HS-LS2-3)
Disciplinary Core Ideas
- The process of photosynthesis converts light energy to stored chemical energy by converting carbon dioxide plus water into sugars plus released oxygen. (HS-LS1-5)
- The sugar molecules thus formed contain carbon, hydrogen, and oxygen: their hydrocarbon backbones are used to make amino acids and other carbon-based molecules that can be assembled into larger molecules (such as proteins or DNA), used for example to form new cells. (HS-LS1-6)
- As matter and energy flow through different organizational levels of living systems, chemical elements are recombined in different ways to form different products. (HS-LS1-6),(HS-LS1-7)
- As a result of these chemical reactions, energy is transferred from one system of interacting molecules to another. Cellular respiration is a chemical process in which the bonds of food molecules and oxygen molecules are broken and new compounds are formed that can transport energy to muscles. Cellular respiration also releases the energy needed to maintain body temperature despite ongoing energy transfer to the surrounding environment. (HS-LS1-7)
PS3.D: Energy in Chemical Processes
The main way that solar energy is captured and stored on Earth is through the complex chemical process known as photosynthesis. (secondary to HS-LS2-5)
Systems and System Models
Models (e.g., physical, mathematical, computer models) can be used to simulate systems and interactions—including energy, matter, and information flows—within and between systems at different scales. (HS-LS2-5)
- Changes of energy and matter in a system can be described in terms of energy and matter flows into, out of, and within that system. (HS-LS1-5), (HS-LS1-6)
- Energy cannot be created or destroyed—it only moves between one place and another place, between objects and/or fields, or between systems. (HS-LS1-7),(HS-LS2-4)
This work was supported by the Office of the Director, National Institutes of Health under Science Education Partnership Award Number R25OD016525. The content is solely the responsibility of the authors and does not necessarily represent the official views of the NIH.