2 The chemical energy used for most cell processes is carried by ATP. Molecules in food store chemical energy in their bonds.Starch moleculeGlucose molecule
3 Energy is released when a phosphate group is removed. ATP transfers energy from the breakdown of food molecules to cell functions.Energy is released when a phosphate group is removed.ADP is changed into ATP when a phosphate group is added.phosphate removed
4 Organisms break down carbon-based molecules to produce ATP. Carbohydrates are the molecules most commonly broken down to make ATP.not stored in large amountsup to 36 ATP from one glucose moleculetriphosphateadenosinediphosphatetri=3di=2
5 Fats store the most energy. 80 percent of the energy in your bodyabout 146 ATP from a triglycerideProteins are least likely to be broken down to make ATP.amino acids not usually needed for energyabout the same amount of energy as a carbohydrate
6 A few types of organisms do not need sunlight and photosynthesis as a source of energy. Some organisms live in places that never get sunlight.In chemosynthesis, chemical energy is used to build carbon-based molecules.similar to photosynthesisuses chemical energy instead of light energy
7 KEY CONCEPT The overall process of photosynthesis produces sugars that store chemical energy.
8 Photosynthetic organisms are producers. Producers make their own source of chemical energy.Plants use photosynthesis and are producers.Photosynthesis captures energy from sunlight to make sugars.
9 Chlorophyll is a molecule that absorbs light energy. chloroplastleaf cellleafIn plants, chlorophyll is found in organelles called chloroplasts.
10 Photosynthesis in plants occurs in chloroplasts. Photosynthesis takes place in two parts of chloroplasts.grana (thylakoids)stromachloroplaststromagrana (thylakoids)
11 The light-dependent reactions capture energy from sunlight. take place in thylakoidswater and sunlight are neededchlorophyll absorbs energyenergy is transferred along thylakoid membrane then to light-independent reactionsoxygen is released
12 The light-independent reactions make sugars. take place in stromaneeds carbon dioxide from atmosphereuse energy to build a sugar in a cycle of chemical reactions
13 The equation for the overall process is: 6CO2 + 6H2O C6H12O6 + 6O2C6H12O6granum (stack of thylakoids)thylakoidsunlight1 six-carbon sugar6H2O6CO26O2chloroplast1243energystroma (fluid outside the thylakoids)
14 KEY CONCEPT Photosynthesis requires a series of chemical reactions.
15 The first stage of photosynthesis captures and transfers energy. The light-dependent reactions include groups of molecules called photosystems.
16 Photosystem II captures and transfers energy. chlorophyll absorbs energy from sunlightenergized electrons enter electron transport chainwater molecules are splitoxygen is released as wastehydrogen ions are transported across thylakoid membrane
17 Photosystem I captures energy and produces energy-carrying molecules. chlorophyll absorbs energy from sunlightenergized electrons are used to make NADPHNADPH is transferred to light-independent reactions
18 The light-dependent reactions produce ATP. hydrogen ions flow through a channel in the thylakoid membraneATP synthase attached to the channel makes ATP
19 The second stage of photosynthesis uses energy from the first stage to make sugars. Light-independent reactions occur in the stroma and use CO2 molecules.
20 A molecule of glucose is formed as it stores some of the energy captured from sunlight. carbon dioxide molecules enter the Calvin cycleenergy is added and carbon molecules are rearrangeda high-energy three-carbon molecule leaves the cycle
21 A molecule of glucose is formed as it stores some of the energy captured from sunlight. two three-carbon molecules bond to form a sugarremaining molecules stay in the cycle