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Step 1: Light energy is absorbed by chlorophyll in plant cells
Step 2: Water molecules are split into hydrogen and oxygen
Step 3: Carbon dioxide from the air is captured
Step 4: Hydrogen and CO₂ combine to form glucose (sugar)
Step 5: Oxygen is released as a byproduct into the atmosphere
Result: The plant now has glucose for energy and growth

Supply and demand determines prices in a market. Here are everyday examples:

• Concert tickets: When a popular artist announces a show (high demand, limited supply), prices increase. Scalpers charge even more because demand exceeds supply
• Seasonal produce: Strawberries are cheap in summer (high supply) but expensive in winter (low supply)
• Technology: New phones start expensive (high demand, limited supply), then prices drop as newer models come out (demand shifts to new product)
• Housing: In popular cities, limited housing (low supply) and many people wanting to live there (high demand) drives up rent prices

Picture a cell membrane as a semi-permeable fence with tiny gates. On one side of the fence, imagine lots of water molecules (dilute solution) bouncing around freely. On the other side, picture water molecules mixed with large sugar molecules that can't fit through the gates (concentrated solution). The water molecules constantly bump against the fence. Because there are more free water molecules on the dilute side, more of them pass through the gates from that side. The sugar molecules are too big to pass through. Over time, water flows from where there's more of it (dilute) to where there's less of it (concentrated), trying to balance things out. Think of it like a crowded room with two doors - people naturally move from the packed side to the emptier side until both sides are equally crowded.

Electrical current is like water flowing through pipes:

• Voltage is like water pressure → Higher pressure pushes more water through
• Current is like the flow rate → How much water actually moves through the pipe
• Resistance is like pipe width → Narrow pipes restrict flow, wide pipes allow more
• A battery is like a water pump → Creates the pressure that pushes everything through
• A switch is like a valve → Opens or closes to control the flow

Just like you need water pressure to push water through pipes, you need voltage to push electrons through wires. And just like narrow pipes slow down water flow, high resistance materials slow down electrical current.