Energy in a Cell ATP: Energy in a Molecule Photosynthesis: Trapping Energy Cellular Respiration: Getting Energy to Make ATP

ATP: Energy in a Molecule Cell energy Organisms and their cells need an endless supply of energy in order to function Energy to walk, talk, bend, exercise Cells get energy from the food you eat Organisms break down food into small nutrient molecules that can enter your bloodstream Cells then break down the food molecules Cells use some of the ATP from the food molecules, then store the rest

ATP: Energy in a Molecule ATP is known as the cell’s “money” Cells must have plenty of ATP “money” to spend whenever the cell needs to work Without a constant supply of ATP, the cell will die Cells use to ATP for many things make ribosomes help with cell division for active transport Maintain homeostasis

The ATP molecule

ATP: Energy in a Molecule Forming and breaking down ATP Cells store energy by adding a phosphate group to a ADP ADP + P  ATP (energy) Adenosine diphosphate  adenosine triphosphate When cells use energy, the process works in reverse ATP  ADP + P (energy is released) The process is then ready to start all over again

Redox Reactions Most of the important energy changes in organisms involve chemical reactions known as oxidation reduction reactions. Photosynthesis & cellular respiration are oxidation reduction reactions.

Oxidation Involves the : Releases Energy Combining with Oxygen Loss of Electrons Loss of Hydrogen

Reduction Involves the: Absorption of Energy Separation from Oxygen Gain of Electrons Gain of Hydrogen

LEO the Lion goes GER Loss of Electrons is Oxidation Gain of Electrons is Reduction

Photosynthesis: Trapping Energy Autotrophs/the producers of the planet Autotrophs are organisms that can make their own food (plants) Autotrophs make their own food through the process of photosynthesis They make simple sugars that other organisms can break down into ATP Autotrophs trap energy from sunlight and use the energy to build carbohydrates (sugars)

Photosynthesis: Trapping Energy The green pigment chlorophyll absorbs sunlight Found in the chloroplasts Plants also have other colored pigments that help trap sunlight These pigments give plants their bright colors

Chlorophyll

Photosynthesis The process by which plants use light energy to make food molecules from CO2 & H2O

Larry the Sun Light Reaction H+ Light O2- H2O ATP chlorophyll zapped within chloroplast H2O ATP Light Reaction

Calvin the Moon Calvin Cycle (Dark Reaction) CO2 glucose or C6H12O6 or sugar H+ ATP (from light reaction) (Dark Reaction) Calvin Cycle

Photosynthesis: Trapping Energy Photosynthesis: the basic steps 1st step – chloroplasts trap sunlight 2nd step – light energy is converted to chemical energy (sugar) and then stored Water and carbon dioxide are also required for this step The general equation for photosynthesis is: 6CO2 + 6H2O + light energy  C6H12O6 + 6O2 carbon dioxide plus water plus light produces sugar and oxygen (in the presence of chlorophyll)

Photosynthesis: Trapping Energy There are 2 main groups of reactions that take place during photosynthesis Light reactions Calvin cycle (formerly called the dark reaction) Light reactions occur when light energy is converted to chemical energy This is the photo part of photosynthesis These reactions split water molecules and provide the energy for the Calvin cycle

Photosynthesis: Trapping Energy The Calvin cycle The series of reactions that form simple sugars using carbon dioxide and hydrogen (from water) The Calvin cycle is the synthesis part of photosynthesis

Photosynthesis: Trapping Energy The Light Reactions Light strikes chlorophyll Electrons gain energy and jump out of chlorophyll The electrons move down the electron transport chain The electrons give off energy, which is used to make ATP Electrons from water move to the chlorophyll, to replace the lost electrons

Photosynthesis: Trapping Energy The Light Reactions Water breaks up into hydrogen and oxygen Light causes the electrons to gain energy and leave the chlorophyll again Electrons and hydrogen are added to NADP+, which produces NADPH + H+ The ATP made in the light reactions will be used in the 2nd stage of photosynthesis – the Calvin cycle

Electron transport chain

Photosynthesis: Trapping Energy The Calvin Cycle This is a complex chemical reaction that uses ATP to make simple sugars A 5 carbon sugar is formed It breaks into two 3 carbon sugars The two 3 carbon sugars go through some chemical reactions and finally make a 5 carbon sugar The process starts again when a carbon from CO2 is used to turn the 5 carbon sugar into a 6 carbon sugar This is called carbon fixation

The Calvin Cycle

Photosynthesis: Trapping Energy/Locations Overview :Light reaction and Calvin cycle Light reactions take place in the thylakoids The Calvin cycle takes place in the stroma The light reactions make the ATP that is used to make sugar (food) during the Calvin cycle Animals then eat the sugars to get energy they need to survive & thrive

Now….Add the Photosystems (PSII) Light is absorbed by ?? or other pigments in photosystem II. This E from ?? is then transferred to electrons which are then passed down the ??. Separately enzymes break apart ?? Into electrons & of ?? Ions & ??. (ETC) Electrons from ?? move though the ETC to photosystem I. E from this process are used to transport ?? ions from the stroma into the inner ??. (PSI) As in PSI, pigments add E from light to the electrons. The high E electrons are then picked up by NADP+ to form ??.

And then… d) (H ion movement) The inside of the ?? fills with H + ions, giving the membrane an overall charge. The difference in charges provides the E to make ATP. e) (ATP formation) A protein called ??? allows the H ions to pass through & it rotates (like a turbine with water running over it at a hydroelectric power plant). As this happens the protein binds ADP & PO4 to produce ???.

Photosynthesis: Trapping Energy Life without light Some organisms are able to energy without sunlight Mainly bacteria They are chemosynthetic – they are autotrophs that can use different chemicals to produce methane These types of bacteria live near deep cracks in the ocean floor

Chemosynthetic vent worms