PhotosynthesisA. Photosynthesis occurs in chloroplasts

(organelles inside plants and algae)

Overview of Photosynthesis

B. Overview of Photosynthesis1. Uses light as the source of energy2. Uses water and carbon dioxide as reactants3. Makes glucose (C6H12O6)

Photosynthesis

4. Gives off oxygen as a by-product5. Equation:

6CO2 + 6H20 C6H12O6 + 6O2

6. Chlorophyll is the catalyst

Light Dependent Reaction •Occurs in the thylakoids•Energy from the sun used to break apart a water molecule

Light Independent Reaction (Calvin Cycle) •Occurs in the Stroma•“Carbon Fixation”- breaks apart carbon molecules to use the carbon atoms to assemble glucose

Food Stores Chemical Energy

Harvesting The Energy In Food

Many organisms harvest the energy stored in foods through

cellular respiration.

Cellular Respiration: Is a chemical process that uses

oxygen to convert the chemical energy stored in

glucose into another form of chemical energy called ATP.ATP: is the cells main energy supply.

Photosynthesis and cellular respiration are a cycle. There is a common set of chemicals.

1. Water2. Carbon Dioxide3. Oxygen4. Glucose

Cellular respiration converts the energy in food to energy in ATP.Relationship of cellular respiration to breathing.

Aerobic: means “Require Oxygen”.

Cellular respiration: the cell exchanges 2 gases.Takes in Oxygen Releases carbon dioxide.

Breathing is the following process.Blood stream delivers oxygen to cells.Blood stream takes away carbon dioxide from cells.

This takes place in tiny air sacs in the lungs.

Oxygen diffuses across the lungs lining into the blood stream.Carbon dioxide diffuses from blood stream to lungs and is exhaled.

In a molecule of ATP the “tail” is where the energy is stored (potential energy) Analogy: a tightly coiled spring

No, nothing like this…

The bond between two phosphate groups is broken and energy is released

Introduction to Energy

Energy: is the ability to do work. Energy cannot be created nor destroyed. Can be converted from one kind to another.

Work: is whenever an object is moved against an apposing force.

4 Types of Energy

1. Kinetic Energy: energy of motion. Any thing that is moving.

2. Potential Energy: is energy that is stored.

3. Chemical Energy: form of potential energy. There is a potential to form work. Chemical energy depends on the bonds & structure of molecules.

4. Thermal Energy: random molecular motion.Warmer objects > Cooler ones.

Putting Chemical Energy To Work

Within your cells Glucose (organic molecules) react with

oxygen, this process (cellular respiration) then exhausts

Carbon dioxide, water and heat.

40% of food is used for energy.

60% is thermal energy. This helps us maintain our body temperature.

Why do our bodies create heat after exercising?

There is an increase in cellular respiration.

Calories: Units of energy. Is the amount of energy required to raise the temperature of 1 gram of water by 1 degree C.

Kilocalories: 1,000 calories.1 KiloCalorie = 1 Food Calorie