Part of GED® Science: Life Science
GED® Science: Cellular Energy (Deep Dive)
A deep dive into how living things get, store, and use energy, expanding the single 'Cellular Energy' lesson from the GED® Life Science course into a full mini-course. You'll meet ATP (the cell's energy currency), follow photosynthesis as it captures sunlight into sugar and cellular respiration as it releases that energy, see how the two processes form a cycle, learn how cells make energy without oxygen (fermentation), and practice reading energy data. Plain language, all-new labeled diagrams, common-misconception warnings, and GED®-style practice with full explanations throughout.
📚 Course Curriculum
Every living thing needs energy to grow, move, and repair itself. In biology, energy shows up mainly as kinetic energy (the energy of motion) and …
🔒 Enroll to unlock this session.
Cells do not spend the energy stored in glucose directly. Instead, they convert it into a smaller, more convenient molecule called ATP (adenosine triphosphate), which …
🔒 Enroll to unlock this session.
Metabolism is the sum of all chemical reactions happening inside an organism. Biologists sort these reactions into two broad categories based on the direction energy …
Open trial session →Even reactions that release energy usually need a small push to get started. That initial push is called activation energy — the energy required to …
🔒 Enroll to unlock this session.
Photosynthesis is the process plants, algae, and some bacteria use to convert light energy into chemical energy stored in sugar. The overall reaction can be …
🔒 Enroll to unlock this session.
The light-dependent reactions are the first stage of photosynthesis, and as the name suggests, they require light to run. Light strikes pigment complexes called photosystem …
🔒 Enroll to unlock this session.
The Calvin cycle, also called the light-independent reactions, uses the ATP and NADPH produced by the light-dependent reactions to build sugar. It does not require …
Open trial session →Several environmental conditions influence how fast photosynthesis proceeds, and each can become the process's limiting factor — the one condition currently holding back the rate, …
🔒 Enroll to unlock this session.
Cellular respiration is the process cells use to release the energy stored in glucose and convert it into ATP. Its overall equation is essentially the …
🔒 Enroll to unlock this session.
Glycolysis ("sugar splitting") is the first stage of both aerobic respiration and fermentation, and it takes place in the cell's cytoplasm rather than inside the …
🔒 Enroll to unlock this session.
When oxygen is available, the pyruvate from glycolysis enters the mitochondrion and is converted into a two-carbon compound that feeds into the Krebs cycle (also …
🔒 Enroll to unlock this session.
Comparing the ATP output of each stage of aerobic respiration shows why the electron transport chain matters so much. Glycolysis nets about 2 ATP directly. …
🔒 Enroll to unlock this session.
Photosynthesis and cellular respiration are, in a real sense, mirror images of each other. Photosynthesis takes in carbon dioxide and water and, using light energy, …
🔒 Enroll to unlock this session.
Because photosynthesis and respiration are opposite processes, the gases each one produces become the gases the other one consumes, both within a single plant and …
🔒 Enroll to unlock this session.
The law of conservation of energy states that energy cannot be created or destroyed, only transformed from one form to another. Following that energy through …
🔒 Enroll to unlock this session.
Ecosystems depend on a division of labor built directly on the relationship between photosynthesis and respiration. Producers (mainly plants and algae) make their own food …
🔒 Enroll to unlock this session.
When oxygen is not available, cells cannot run the Krebs cycle or electron transport chain, since both ultimately depend on oxygen as the final electron …
🔒 Enroll to unlock this session.
Human muscle cells use lactic acid fermentation when they cannot get oxygen fast enough to keep up with demand, such as during intense, short bursts …
🔒 Enroll to unlock this session.
Yeast and some other microorganisms use alcoholic fermentation instead of lactic acid fermentation when oxygen is unavailable. In this pathway, the pyruvate from glycolysis is …
🔒 Enroll to unlock this session.
With aerobic respiration, lactic acid fermentation, and alcoholic fermentation all covered, this session focuses on comparing the three directly. All three pathways begin with the …
🔒 Enroll to unlock this session.
The GED® Science test frequently presents cellular energy concepts through graphs of metabolic rate, oxygen consumption, or carbon dioxide production, rather than through direct questions …
🔒 Enroll to unlock this session.
This session works through a sample experiment measuring photosynthesis rate, such as counting oxygen bubbles released by aquatic plants under different light intensities, and uses …
Open trial session →Beyond graphs, the GED® Science test also uses labeled diagrams of cell structures and flowcharts of multi-step biological processes. This session practices two diagram types. …
🔒 Enroll to unlock this session.
This final session brings together everything covered across Units 1 through 5 in a single cumulative review, followed by a practice set built in the …
🔒 Enroll to unlock this session.
Course Syllabus
This self-paced GED® Science course follows a 6-lesson sequence. Work through the modules in order so that each skill supports the next.
Course sequence
Module 1 - Lessons 1-3
- Energy for Life: ATP & Metabolism
- Photosynthesis: Storing Sunlight in Sugar
- Cellular Respiration: Releasing the Energy
Module 2 - Lessons 4-6
- Two Processes, One Cycle
- Fermentation: Energy Without Oxygen
- Reading Cellular-Energy Data
Practice and completion
- Use worked examples and lesson practice to check understanding after each module.
- Review incorrect answers, explain the correction, and repeat weak skills.
- Complete the available mixed or final course practice to demonstrate readiness.
Course Outcomes
By the end of this course, learners will be able to:
- Explain the key scientific ideas and vocabulary in Energy for Life: ATP & Metabolism.
- Interpret observations, data, models, or evidence related to Photosynthesis: Storing Sunlight in Sugar.
- Apply scientific reasoning to questions involving Cellular Respiration: Releasing the Energy.
- Evaluate explanations and identify common errors about Fermentation: Energy Without Oxygen.
- Connect Reading Cellular-Energy Data with other course concepts in mixed practice.
- Use feedback and answer explanations to diagnose and correct mistakes.
- Complete mixed, exam-style practice with clearer reasoning and greater independence.
📝 Practice Questions
240 interactive questions with instant feedback and explanations.
Enroll for free to unlock the full practice bank after the trial sessions.