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KEY CONCEPT The cells of all organisms need chemical energy to carry out their life sustaining processes. What do the cells need chemical energy for? To move To reproduce To grow To actively transport materials across the cell membrane
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KEY CONCEPT The cells of all organisms need chemical energy to carry out their life sustaining processes.
What do the cells need chemical energy for? • To move • To reproduce • To grow • To actively transport materials across the cell membrane (Ex. Endocytosis, exocytosis, sodium-potassium pumps) • To carry out chemical reactions –Activation Energy Ex. Photosynthesis, respiration , All metabolism
Energy is stored in Food Molecules • Chemical E is stored in the organic molecules found in food.
Carbohydrates and lipid molecules are the most important energy containing molecules in foods we eat.
1. AUTOTROPHS – MAKE THEIR OWN FOOD MOLECULES USING ENERGY AND CARBON DIOXIDE (CO2) gas FROM THE ENVIRONMENT *
2 Groups of Autotrophs • Photoautotrophs • Chemoautotrophs
Photoautotroph – use light E to make their food through Photosynthesis CyanoBacteriaProtists (Algae) Plants
Chemoautotrophsuse chemical E to make their food through Chemosynthesis Ex. Archaebacteria
Autotrophs make the organic compounds that serve as food for themselves and all other organisms on Earth
2. Heterotrophs –Organisms that eat other organisms (or their products) to obtain energy and carbon compounds • Animals • Fungus • Some Protists • Most Bacteria ANIMALS
Law of Conservation of EnergyEnergy cannot be created or destroyed but it can be changed from one form to another
Two processes are needed to convert the sun’s light energy into chemical energy the cell can use. PHOTOSYNTHESIS and CELL RESPIRATION
In photosynthesis, sunlight E is transformed into chemical E stored in food molecules Starch Glucose
In cell respiration, the chemical E stored in food molecules is released and repackaged into high energy molecules called ATP the cells can use.
What happens to the E released from food in cellular respiration? It is used to make high energy molecules called ATP
What is ATP? ATP stands for the molecule Adenosine Triphosphate
ATP is a high energy containing molecule used by all cells to carry out cellular functions.. • Sodium-Potassium Pump • Muscle contraction
adenosine triphosphate adenosine diphosphate ATP – ADP ATP – Adenosine Triphosphate ADP – Adenosine Diphosphate
phosphate removed The ATP – ADP cycle ATP –High energy molecule ADP –Low energy molecule
When ATP loses a phosphate molecule it gives off E and becomes ADP. • The E given off is used to power chemical reactions in the cell
When ADP gains E and a phosphate molecule, it becomes “recharged” to form ATP. • The E source to “recharge” ADP comes from the breakdown of food through respiration.
This process is called the ATP – ADP Cycle
Removing a Phosphate - Release Energy “use the battery” ATP Energy + P + ADP Adding a Phosphate – Stores Energy “recharge battery” ADP + Energy + P ATP
This is constantly occuring in every cell of your body, millions of times a minute! • The E given off is used to power every chemical reaction occuring in the cell
ATP to ADP Recharging your body’s batteries