2 You get energy from the food you eat. 8-1 Energy and LifeYou get energy from the food you eat.Directly or indirectly, all of theEnergy in living systems needed forMetabolism comes from the sun.
3 Metabolism involves either using energy To build molecules or breaking Down molecules in which energyIs stored.Photosynthesis is the process by whichLight energy is converted toChemical energy.
4 Autotrophs are organisms that use Energy from sunlight or Inorganic substances to makeOrganic compounds.Like plants use sunlight toMake glucose.
5 Heterotrphs are organisms that Must get energy from food instead Of directly from sunlight.We are heterotrophs becauseWe can’t make our own foodIn our cells.Instead we use cellular respirationTo “burn” fuel in our bodies.
6 Almost all of the food we eat goes To heat, but some of the energy Goes into making ATP.ATP (adenosine triphosphate)Provides cells with the energy theyNeed to carry out life’s processes.
9 In the process of Photosynthesis, plants use 6CO2 + 6H2O + Light C6H12O6 + 6O2In the process of Photosynthesis, plants useThe energy of sunlight to convert water and carbon dioxideInto high energy carbohydrate and oxygen.
10 In the 1600’s, the Belgian, Jan van Helmont devised an Experiment to find out if plants got their mass out ofThe soil.After 5 years of taking data, he decided that plantsget most of their mass from water.
11 After more than 100 years, Joseph Priestly experimented With plants and candles.He learned that if you left a plant under a closed jar,That eventually it would be filled with oxygen.He tested for the oxygen by lighting candles under the jars.
12 Later, the Dutch scientist Jan Ingenhousz found that Plants only produced oxygen when exposed to light.The experiments performed by these three scientists led to work by other scientists who finally discovered that in the presence ff light, plants transform carbon dioxide and water into sugar and oxygen.
13 The plants principle pigment There are 2 types of chlorophyll, In addition to water and carbon dioxide, photosynthesis requires light and chlorophyll.Plants gather the sun’s energy with light absorbing molecules called pigments.The plants principle pigmentIs chlorophyll.There are 2 types of chlorophyll,a and b.
15 In stage 1, light energy is absorbed. 6CO2 + 6H2O + Light C6H12O6 + 6O2In stage 1, light energy is absorbed.Structures that will absorb lightContain pigments.Chlorophyll is the primary pigmentThat absorbs mostly blue and redLight and reflects green and yellow.
16 That reflection is why plants Are green. Plants contain 2 types of chlorophyll,a and b chlorophyll.Both types of chlorophyll play aRole in photosynthesis.
17 The pigments that produce yellow And orange colors in fall or In fruits and vegetablesAre called carotenoids.
18 Pigments involved in plant Photosynthesis are located in the Chloroplasts of leaf cells.Clusters of pigments are embeddedIn the membranes of diskShaped structures calledThylakoids.
19 When chlorophyll absorbs light this causes 1 pair of chlorophyll electrons to “bounce around”
20 Instead of being “trapped” in a wire they are stored in chemical bonds.
21 These “excited” electrons that leave The chlorophyll molecules are usedTo produce new molecules thatTemporarily store chemical energy,Including ATP.The series of molecules through whichExcited electrons are passed alongA thylakoid membrane are calledElectron transport chains.
22 -accepts electrons and is converted to NADPH NADP+ (in plants)-accepts electrons and is converted to NADPHNADPH is an electron carrier thatProvides the high-energy electronsNeeded to make C-H bonds in stage 3.
23 In the 1st and 2nd stages of Photosynthesis, light energy is used To make ATP and NADPH, whichTemporarily store chemical energy.In stage 3, energy is stored inOrganic molecules.
24 In the 3rd stage of photosynthesis, Carbon atoms from the CO2 in The air are used to makeOrganic compounds in whichChemical energy is stored.This energy is stored in the formOf sugar…Glucose.
26 The transfer of carbon dioxide To organic compounds is called Carbon fixation.The most common method forCarbon fixation is the Calvin Cycle.The Calvin cycle is a series of enzymeAssisted chemical reactions thatProduce 3 carbon sugars.