Matter and Energy in Ecosystems

Photosynthesis The process used by plants that has two pathways to capture sunlight and converting it to chemical energy

Photosynthesis Every living thing needs energy in order to survive. Cells use energy to: Grow Reproduce Respond to the environment Metabolize Maintain homeostasis Evolve Many organisms get their energy from the food that they eat. However, plants are different. They lack the ability to graze or hunt so they obtain their energy in a different way.

They make their food using… !! Photosynthesis They make their food using… !!

Energy Source of Life on Earth The process by which a cell captures energy in sunlight and uses it to make food is called photosynthesis

Plants have a specialized organelle in charge of capturing sunlight and converting it to chemical energy: Chloroplast

Two Pathways of Photosynthesis Pathway 1: Light Dependent Reaction (capturing the Sun’s Energy) Pathway 2: Calvin Cycle (Converting Light Energy to Chemical Energy)

Pathway 1: Capturing the Sun’s Energy In chloroplasts called the Thylakoid (it contains chlorophyll) (a special energy-capturing molecule that makes plants green) has a similar function as solar panels. It captures energy Chlorophyll captures light energy and uses it to power the second pathway of photosynthesis.

Pathway 1- Light Dependent Reaction Occurs in Chloroplasts— (thylakoid, which contains chlorophyll) Reactants: Sunlight, 6 H2O Products: 6 O2, 1 ATP, and NADPH (a special energy carrying molecule found in plants, used in Pathway 2)

Pathway 2-Calvin Cycle Occurs in Chloroplasts – specifically the stroma (jelly like fluid in chloroplasts) Reactants: 6 CO2, NADPH, ATP Products: C6H12O6

Model: Process of Photosynthesis

How do CO2 and O2 get into and out of a plant? CO2 enters and O2 exits the leaf through the stomata (small openings on underside of leaves).

The Photosynthesis Equation

Photosynthesis vs. Respiration Cellular Respiration Chemical formula is opposite Cellular Respiration How Energy Changes: Sunlight changes into Chemical Energy (in glucose) How Matter Changes: Turns CO2 and H2O into C6H12O6 and O2 Chemical formula is opposite photosynthesis How Energy Changes: Chemical Energy changes into Motion and Heat Energy How Matter Changes: Turn C6H12O6 and O2 into CO2 and H2O

Photosynthesis vs. Respiration

Photosynthesis and Cellular Respiration

Fermentation Some cells are able to obtain energy from food without using oxygen ----anaerobic respiration Organisms who do this: Single celled organisms who live in places that contain no oxygen Mud Deep ocean

Fermentation Organisms who obtain their energy through fermentation, an energy-releasing process that does not require oxygen. The amount of energy released during fermentation, however, is much lower than the amount released during respiration.

Types of Fermentation Two Examples of Fermentation: Alcohol fermentation Lactic acid fermentation

Alcohol Fermentation One type of fermentation occurs when yeast and some other singled-celled organisms break down sugars. This is sometimes called alcohol fermentation because this is one product that is produced. The products of alcohol fermentation are carbon dioxide and a small amount of energy.

Alcohol Fermentation

Alcohol Fermentation CO2 in bread caused by yeast causes it to rise. CO2 is the source of bubbles in beer

Lactic Acid Fermentation Lactic Acid Fermentation occurs when your cells use up oxygen faster than it can be replaced. Because your cells lack oxygen, fermentation occurs.

Lactic Acid Fermentation The fermentation supplied your cells with energy One product of this type of fermentation is an acid called lactic acid. When lactic acid builds up you feel pain in your muscles