Cell Power Slides
Grade 7 Life Science
Visual Science Series
CELLULAR ENERGY & ECOSYSTEMS
CELL POWER
How living organisms capture solar power, store chemical fuel, and unleash energy to survive.
Photosynthesis
Trapping Solar Energy
Respiration
Unlocking Stored Fuel
Mythbusters
3 Big Bio Misconceptions
Engage & Explore
Where Does Life Get Its Power?
The Big Question
Consumers (Animals)
Direct Food Intake
Animals cannot make their own food. When hungry, they eat other organisms to acquire glucose, fats, and essential nutrients.
Immediate source: Eating food directly from the environment.
Producers (Plants)
Self-Made Energy
Plants are stationary and have no mouths. They use sunlight, water, and invisible atmospheric gases to manufacture their own sugar.
Self-sufficient: Converting light into stable chemical sugar.
Turn & Talk Prompt:
"If a plant relies on sunlight to make its food, how does a tree stay alive on a dark night or all winter without leaves?"
Process 1 • Solar Synthesis
Photosynthesis: Making Stored Energy
In Chloroplasts
Carbon Dioxide
6 CO2 (from air)
Water
6 H2O (from soil)
Sunlight
Glucose (Sugar)
C6H12O6 (stored fuel)
Vital Byproduct: Also releases 6 Oxygen molecules (O2) into the atmosphere for living things to breathe.
Released Gas: O2
Definition: Photosynthesis combines carbon dioxide and water using sunlight energy to trigger a chemical reaction that creates sugar for plant growth and survival.
Process 2 • Chemical Release
Cellular Respiration: Burning the Fuel
In Mitochondria
Stored Fuel
Glucose (Sugar / Fat)
Oxygen
6 O2 (Inhaled / Absorbed)
Enzymes
Usable Energy
Cellular Work (ATP)
Byproducts: Cellular respiration breaks down sugars and produces Carbon Dioxide (CO2) and Water (H2O).
Released: CO2 + H2O
Definition: Cellular respiration is a multi-step chemical process where organisms break down stored energy to stay alive when immediate light or food isn't available.
Misconception #1 Common Biology Myth
Myth: "Only Animals Use Cellular Respiration!"
BUSTED!
During Daylight
Both Processes Running
Plants photosynthesize in their leaves to make and pack away sugars. But their living cells are also respiring at the exact same time to power basic cellular survival!
At Night & In Winter
Respiration Keeps Them Alive
When there is zero sunlight, or when deciduous trees drop all their leaves in autumn, photosynthesis stops. Trees survive by respiring stored starch and sugars!
Teacher Note & Discussion Check:
Remind students: "Plants don't just make food for animals. They make food for THEMSELVES! If plants couldn't respire, they would starve to death every single night."
Misconception #2 Classification Mystery
Myth: "Algae and Seaweed Are Plants!"
BUSTED!
Kingdom Protista
Algae does not belong to the plant kingdom (Plantae). It belongs to Kingdom Protista—a diverse group of simple eukaryotic organisms.
Giant Kelp = Algae
Massive ocean kelp forests reach over 100 feet tall! Even though they look like underwater trees, kelp and seaweeds are actually multicellular algae.
Has Chloroplasts
Like plants, algae possess chloroplasts and use photosynthesis to convert sunlight into food in aquatic environments.
Why isn't it a plant? Algae lack true stems, roots, leaves, and vascular tissue found in complex land plants.
Kingdom Protista
Misconception #3 Microbial Champions
Myth: "Only Plants Photosynthesize!"
BUSTED!
Kingdom Bacteria
Cyanobacteria
Often called "blue-green algae," cyanobacteria are actually bacteria that live in aquatic ecosystems.
Crucial Difference: They photosynthesize, but they have NO chloroplasts! They use special interior membrane folds.
Aquatic Microorganisms
Phytoplankton
A broad category of all photosynthetic ocean microorganisms: including algae, cyanobacteria, dinoflagellates, and diatoms.
Global Superpower: Generates over 50% of Earth's total oxygen supply!
Takeaway: Plants, algae (protists), and cyanobacteria (bacteria) all capture sunlight to make food!
3 Different Kingdoms
Big Picture Synthesis
The Great Energy Loop
Reciprocal System
Step 1: Stores Energy
Photosynthesis
Takes In: CO2 + H2O + Light
Gives Off: Glucose + O2
Creates stored chemical potential for the biosphere.
Step 2: Releases Energy
Cellular Respiration
Takes In: Glucose + O2
Gives Off: CO2 + H2O + ATP
Unlocks ATP to power muscle, root growth, and cell repair.
The Ultimate Connection: The chemical products of photosynthesis are the exact ingredients needed for cellular respiration!
Reciprocal Cycle
Interactive Review
Energy Detectives: Who Am I?
Quick Concept Check
Case #1
"I float in ocean water and have chloroplasts to photosynthesize. People mistake me for a plant, but I'm in Kingdom Protista!"
Answer: Algae / Kelp
Case #2
"I produce oxygen in the water through photosynthesis, but I have NO chloroplast organelles inside me. What kingdom am I in?"
Answer: Cyanobacteria (Bacteria)
Case #3
"I am an oak tree during a cloudy December night. Which chemical process is keeping my root cells alive right now?"
Answer: Cellular Respiration
Teacher Guidance: Have students hold up 1, 2, or 3 fingers or whisper their hypothesis to their table partner before revealing each answer.
Think-Pair-Share
Formative Assessment Independent Check
Exit Ticket: Prove Your Knowledge!
3 Questions
1
Why Do Plants Respire?
Why can't a plant survive on photosynthesis alone? Give one specific scenario when a plant must use cellular respiration to stay alive.
2
Beyond the Plants
Your friend claims: "Only plants can do photosynthesis." Name two non-plant organisms that photosynthesize to prove them wrong.
3
The Gas Trade
Which gas does photosynthesis release into the air that animals and plants need for cellular respiration? Which gas is returned?
Write your answers on your exit slip with your name and date. Turn it in before leaving!
Ready for Review
