ENERGY FLOWPHOTOSYNTHESIS AND CELLULAR

RESPIRATION

Energy FlowLight from the sun is our ultimate source of

energyAutotrophs take energy from the sun and turn

it into chemical energy via PhotosynthesisPlants convert solar energy into chemical

energy in the form of carbohydratesOrganisms take in carbohydrates and convert

to it ATP (usable energy) via Cellular Respiration

Photosynthesis

CO2 + H2O + Light energy Glucose + O2 + H2O

Cellular Respiration

Glucose + O2 + H2O O2 + H2O + Usable Energy

(36 ATP)

Photosynthesis and Cellular Respiration are opposite processes…

PhotosynthesisOccurs in the Chloroplast of green plantsContains Chlorophyll a pigment needed to

absorb light and begin photosynthesis

Occurs in a series of steps:

1. Light Reactions2. Calvin Cycle

Photosynthesis ProcessesSTEP 1: LIGHT REACTIONChlorophyll molecules within the chloroplast

trap light and convert its energy to ATP

STEP 2: CALVIN CYCLECarbon atoms from CO2 get recombined to

form glucose (C6H12O6) with the help of ATP

Cellular RespirationProcess in which chemical energy stored in

glucose (carbohydrates) is turned into usable energy (ATP)

2 Types:1. Aerobic uses O2 and produces a lot of ATP2. Anaerobic no O2 used and produces little

ATP

Aerobic Cellular RespirationOccurs in 2 stages:

1. Glycolysis breakdown of glucose into smaller molecules of

pyruvate (C3H6O3) Occurs in the cytoplasm Produces 2 ATP

2. Oxidative Phosphorylation production of ATP from the breakdown of pyruvate Occurs in the mitochondria Produces 34 ATP

Creating usable energy: ADP ATPAdenosine Diphosphate Adenosine

TriphosphatePhosphorylation

The MitochondrionSite of oxidative

phosphorylationProduces 34 ATP for

1 glucose moleculePowerhouseMitochondrial cell

membranes contain proteins vital to ATP production

Anaerobic RespirationWhen O2 is not available, ATP may still be

produced via Fermentation

2 Types of Fermentation:1. Ethanol occurs in yeast2. Lactic Acid occurs in humans

Ethanol Fermentation1. Glucose enters

Glycolosis (produces 2 ATP) and produces pyruvate

2. Breakdown of pyruvate into ethanol

Occurs in the Cytoplasm

Used in breads, wine, beer production

Lactic Acid Fermentation1. Glycolysis – breakdown

of glucose pyruvate (2 ATP)

2. Enzymes in the cytoplasm breakdown pyruvate into lactate

Occurs when oxygen is not readily available (exercise)

Accumulation of lactic acid causes soreness, stiffness and fatigue