Presentation on theme: "4.1 Chemical Energy and ATP KEY CONCEPT All cells need chemical energy."— Presentation transcript:
4.1 Chemical Energy and ATP KEY CONCEPT All cells need chemical energy.
4.1 Chemical Energy and ATP The chemical energy used for most cell processes is carried by ATP Adenosine Triphosphate adenine (nitrogen base) Ribose (sugar) Three phosphate groups
4.1 Chemical Energy and ATP The chemical energy used for most cell processes is carried by ATP. Molecules in food store chemical energy in their bonds. Starch molecule Glucose molecule
4.1 Chemical Energy and ATP phosphate 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.
4.1 Chemical Energy and ATP –Adenosine diphosphate (ADP) is a lower energy molecule that is created by the removal of the phosphate group.
4.1 Chemical Energy and ATP Fats store the most energy. –80 percent of the energy in your body Proteins are least likely to be broken down to make ATP. –amino acids not usually needed for energy Carbohydrates are the most common molecule to be broken down for ATP - 36 ATP from 1 glucose
4.1 Chemical Energy and ATP Organisms break down carbon-based molecules to produce ATP. Plants and animals use ATP for chemical reactions Plants are autotrophs (make their own carbohydrates) Animals are heterotrophs (consume carbohydrates) If plants didn’t have Mitochondria, they could make food, but wouldn’t be able to use it!
4.1 Chemical Energy and ATP 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 photosynthesis –uses chemical energy instead of light energy
4.1 Chemical Energy and ATP In photosynthesis, organisms make their own food using solar energy.
4.1 Chemical Energy and ATP Photosynthetic organisms are producers. Producers (Autotrophs) make their own source of chemical energy. Plants use photosynthesis and are producers. Photosynthesis captures energy from sunlight to make sugars.
4.1 Chemical Energy and ATP KEY CONCEPT The overall process of photosynthesis produces sugars that store chemical energy.
4.1 Chemical Energy and ATP Chlorophyll is a molecule that absorbs light energy. chloroplast leaf cell leaf In plants, chlorophyll is found in organelles called chloroplasts.
4.1 Chemical Energy and ATP Photosynthesis in plants occurs in chloroplasts. Photosynthesis takes place in two parts of chloroplasts. –grana (stacks of thylakoids) –Stroma (fluid around the grana) chloroplast stroma grana (thylakoids)
4.1 Chemical Energy and ATP The light-dependent reactions capture energy from sunlight. 1.take place in thylakoids 2.water and sunlight are needed 3.chlorophyll absorbs energy 4.energy is transferred along thylakoid membrane then to light-independent reactions 5.oxygen is released
4.1 Chemical Energy and ATP The light-independent reactions make sugars. 1.take place in stroma 2.needs 6 carbon dioxide molecules from atmosphere 3.use energy to build a sugar in a cycle of chemical reactions
4.1 Chemical Energy and ATP The equation for the overall process is: 6CO 2 + 6H 2 O C 6 H 12 O 6 + 6O 2 sunlight C 6 H 12 O 6 granum (stack of thylakoids) thylakoid sunlight 1 six-carbon sugar 6H 2 O 6CO 2 6O 2 chloroplast 1 2 43 energy stroma (fluid outside the thylakoids)
4.1 Chemical Energy and ATP Chlorophyll is the main pigment in plants Green light is reflected
4.1 Chemical Energy and ATP Chlorophyll is the main pigment in plants Chlorophyll a absorbs violet and red light Chlorophyll b absorbs blue and red
4.1 Chemical Energy and ATP Other pigments Carotene (Xanthophyll)
4.1 Chemical Energy and ATP Light Dependent Reaction The light-dependent reactions include groups of molecules called photosystems.
4.1 Chemical Energy and ATP Photosystem II captures and transfers energy. 1.chlorophyll absorbs energy from sunlight 2.energized electrons enter electron transport chain 3.water molecules are split 4.oxygen is released as waste 5.hydrogen ions are transported across thylakoid membrane
4.1 Chemical Energy and ATP Photosystem I captures energy and produces energy- carrying molecules. 6.chlorophyll absorbs energy from sunlight 7.energized electrons are used to make NADPH (e carrier) 8.NADPH is transferred to light-independent reactions
4.1 Chemical Energy and ATP The light-dependent reactions produce ATP. –hydrogen ions flow through a channel in the thylakoid membrane –ATP synthase attached to the channel makes ATP
4.1 Chemical Energy and ATP Light-independent reactions occur in the stroma and use CO 2 molecules. Calvin cycle (dark reaction)
4.1 Chemical Energy and ATP A molecule of glucose is formed as it stores some of the energy captured from sunlight. 1.carbon dioxide molecules enter the Calvin cycle 2.energy is added and carbon molecules are rearranged 3.some molecules are made into sugar 4.other molecules stay in cycle.