ENERGY IN THE CELL ENERGY CONVERSIONS PHOTOSYNTHESIS CELLULAR RESPIRATION ATP for cell usage Is about Starting with Transformed by Converted to

Plants & photosynthesis

Photosynthesis Photosynthesis takes place in specialized structures inside plant cells called chloroplasts Light absorbing pigment molecules e.g. chlorophyll

Photosynthesis Method of converting sun energy into chemical energy usable by cells Autotrophs: self feeders, organisms capable of making their own food Photoautotrophs: use sun energy e.g. plants photosynthesis-makes organic compounds (glucose) from light Chemoautotrophs: use chemical energy e.g. bacteria that use sulfide or methane chemosynthesis-makes organic compounds from chemical energy contained in sulfide or methane

Equation for photosynthesis 6CO H 2 O C 6 H 12 O 6 + 6O 2 light

Overall Reaction 6CO H 2 O + light energy → C 6 H 12 O 6 + 6O 2 + 6H 2 O The Carbohydrate made is glucose Water appears on both sides because 12 H 2 O molecules are required and 6 new H 2 O molecules are made Water is split as a source of electrons from hydrogen atoms releasing O 2 as a product Electrons increase potential energy when moved from water to sugar therefore energy is required (endergonic reaction)

Harvesting Chemical Energy So we see how energy enters food chains (via autotrophs) we can look at how organisms use that energy to fuel their bodies. Plants and animals both use products of photosynthesis (glucose) for metabolic fuel Heterotrophs: must take in energy from outside sources, cannot make their own e.g. animals When we take in glucose (or other carbs), proteins, and fats-these foods don’t come to us the way our cells can use them

ENERGY FOR LIFE PROCESSES RADIANT ENERGY CHEMICAL ENERGY

PHOTOSYNTHESIS & CELLULAR RESPIRATION CONVERTS RADIANT SOLAR ENERGY INTO CHEMICAL ENERGY STORED IN THE BONDS OF ORGANIC COMPOUNDS ( GLUCOSE) ENERGY FOR MOST LIVING ORGANISMS COMES FROM THE SUN AND IS CONVERTED TO USABLE FORM THROUGH PHOTOSYNTHESIS & CELLULAR RESPIRATION. SUN Photosynthesis By autotrophs Respiration by autotrophs & heterotrophs Cell activities

Cellular respiration: IS A SET OF CHEMICAL REACTIONS THAT OCCUR INSIDE EVERY ORGANISM’S CELLS. DURING CELLULAR RESPIRATION, FOOD MOLECULES ARE BROKEN DOWN TO RELEASE THE ENERGY IN THEIR BONDS. (EXCERGONIC REACTION). THE ORGANIC COMPOUNDS MADE BY PLANTS ( CALVIN CYCLE) DURING PHOTOSYNTHESIS ARE THE FOOD THAT SUPPLIES THE ENERGY USED BY AUTOTROPHS & HETEROTROPHS FOR LIFE.

CELLULAR RESPIRATION 2 TYPES OF CELLULAR RESPIRATION: - ANAEROBIC – DOES NOT NEED OXYGEN - AEROBIC – NEEDS OXYGEN. CYTOPLASM GLYCOLYSIS ANAEROBIC MITOCHONDRIA AEROBIC LACTIC ACID ETHYL ALCOHOL + CO 2 GLUCOSE 2 PYRUVIC ACID ALCOHOLIC FERMENTATION LACTIC ACID FERMENTATION KREB’S CYCLE ELECTRON TRANSPORT CHAIN ELECTRON TRANSPORT CHAIN CO2 H 2 O ATP

CELLULAR RESPIRATION GLYCOLYSIS: BOTH ANAEROBIC AND AEROBIC RESPIRATION BEGINs WITH GLYCOLYSIS OCCURS IN CYTOPLASM PRODUCES ATP - adenosinetriphosphate FERMENTATION: THE PROCESS OF BREAKING DOWN PYRUVIC ACID WITHOUT THE USE OF OXYGEN DOES NOT PRODUCE ATP LACTIC ACID FERMENTATION: ANAEROBIC respiration CONVERSION OF PYRUVIC ACID TO LACTIC ACID. EX. MUSCLE SORENESS ALCOHOLIC FERMENTATION : ANAEROBIC respiration SOME PLANT CELLS AND UNICELLULAR ORGANISMS CONVERT P YRUVIC ACID TO ETHYL ALCOHOL. BEER AND WINE DEPEND ON YEASTS TO PRODUCE ALCOHOL THROUGH FERMENTATION.

AEROBIC RESPIRATION REQUIRES OXYGEN OCCUR INSIDE THE MITOCHONDRIA KREBS CYCLE RESULTS IN THE FORMATION OF ATP CO 2, H 2 O, ATP ARE ALL PRODUCTS OF AEROBIC RESPIRATION

FORMULA FOR CELLULAR RESPIRATION: C 6 H 12 O O 2 6CO2 + 6H 2 O + 36 ATP