Unit 6 Biology Photosynthesis

Photosynthesis

The process by which plant cells make glucose from carbon dioxide and water in the presence of sunlight.

Photosynthesis Equation

6CO2 + 6H2O → C6H12O6 + 6O2

Chlorophyll

The pigment found in the chloroplasts that is essential for photosynthesis.

Autotrophs

Organisms that produce their own food, such as plants.

Heterotrophs

Organisms that rely on autotrophs for food and cannot produce their own food.

Xylem

The tissue that transports water from the roots to the leaves.

Phloem

The tissue that carries glucose away from the leaves to the roots.

Stomata

Small openings on the leaf surface that allow the exchange of gases.

Transpiration

The process of water movement through a plant and its evaporation from aerial parts, especially leaves.

Gas Exchange

The process occurring in the spongy mesophyll where carbon dioxide enters and oxygen exits the leaf.

Palisade Mesophyll

Layer of tightly packed cells in the leaf that maximizes light absorption for photosynthesis.

Spongy Mesophyll

Layer of loosely packed cells in the leaf that facilitates gas exchange.

Guard Cells

Cells that control the opening and closing of stomata to regulate gas exchange and water loss.

Experiment with Elodea

An investigation of photosynthesis using pondweed to measure the rate of oxygen production by counting gas bubbles.

Role of Light in Photosynthesis

Light is crucial for photosynthesis, as it drives the process of converting carbon dioxide and water into glucose and oxygen.

Glucose Usage

The remaining glucose not used in respiration is converted into starch, cellulose, lipids, and amino acids.

Effect of Light Distance on Photosynthesis

As the distance between the light source and the plant increases, the rate of photosynthesis decreases.

Control Tube Purpose

A tube used in experiments to show what happens without photosynthesis for comparison.

Chemical Energy Conversion

Light energy is absorbed by chlorophyll and converted into chemical energy during photosynthesis.