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Energy in a Cell Photosynthesis & Cellular Respiration. Overview of P hotosynthesis and R espiration. SUN. RADIANT ENERGY. CELL ACTIVITIES. PHOTOSYNTHESIS. RESPIRATION. GLUCOSE. ATP (ENERGY). Cell Energy. Energy is essential for life
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Overview of Photosynthesis and Respiration SUN RADIANT ENERGY CELL ACTIVITIES PHOTOSYNTHESIS RESPIRATION GLUCOSE ATP (ENERGY)
Cell Energy • Energy is essential for life • Active transport, cell division, flagella movement, protein production • Some capture energy from light or chemicals • Autotrophs • Others eat those that capture energy • heterotrophs
So Where Is Energy Found? Energy is stored in chemical bonds of ATP • Adenosine Triphosphate (ATP) • Adenosine molecule with three phosphate groups • Energy carrier molecule of the cell
Question…? How do you release the energy stored in the bonds?
Answer Break the bond!
Forming and Breaking Down ATP • Adenosine monophosphate (AMP) • Adenosine diphosphate (ADP) • Adenosine triphosphate (ATP) • ATP ADP + P + Energy • Energy + P + ADP ATP
What is Photosynthesis? The process of photosynthesis is a chemical reaction. It is the most important chemical reaction on our planet.
What is the Equation for the Chemical Reaction of Photosynthesis in WORDS?
What is the Equation for the Chemical Reaction of Photosynthesis (SYMBOLS)?
Describe Photosynthesis • The process of changing light energy to chemical energy • Energy stored as sugar • Occurs in plants and some algae • Plants need light energy, CO2, and H2O • Takes place in the chloroplasts, using chlorophyll, the green pigment in plants
What Happens During Photosynthesis – An Overview • Plants capture light energy and use that energy to make glucose • Sunlight provides the energy needed by chlorophyll to change molecules of carbon dioxide and water into glucose • Oxygen is also released in this reaction
What Happens During Photosynthesis – More Specific? • Carbon dioxide enters the leaf through holes called stomata • CO2 combines with the stored energy in the chloroplasts through a chemical reaction to make glucose • The sugar is moved through tubes in the leaf to the roots, stems and fruits of the plants • Some of the sugar is used right away by the plant for energy; some is stored as starch; and some is built into plant tissue
The Importance… The Big Two Reasons: 1. We cannot make our own food (glucose, energy), we must get our food from plants. (Plants are the first step in the food chain.) 2. The oxygen released during photosynthesis is necessary for all living things.
Trapping Energy from Sunlight • Photosynthesis • Process that uses the sun’s energy to make simple sugars • Glucose, Fructose, Galactose • Light-dependent Reactions • Convert light into chemical energy (ATP) • Light-independent Reactions (Calvin Cycle) • Fueled by ATP • Produce simple sugars • 6CO2 + 6H2O C6H12O6 + 6O2
Chloroplasts and Pigments • Pigments • Molecules in thylakoid membranes that absorb specific wavelengths of sunlight • Cholorophyll is the most common pigment • Absorbs most wavelengths of light except for green.
Light-Dependent Reactions • Light energy hits thylakoid discs • Electrons are charged with energy and EXCITED! HOT! • Electron Transport Chain • Electrons travel through a series of proteins • Lose energy which is used to make ADP into ATP • Electrons reach a second photosystem (pigments) and are recharged • Travel down a 2nd transport chain
Light-Dependent Reactions • Electrons, at end of chain, transferred to a carrier molecule (NADP+ ) • NADP+ + electron + H = NADPH • Carries the electron to the Stroma • NADPH used in Calvin Cycle
Restoring Electrons • Photolysis (lysis = to break down) • Reaction where water is split H20 O + 2H+ + 2e • Oxygen released into air (O2) • The electrons are used by chlorophyll • Hydrogen ions are taken to thylakoid discs • Chemiosmosis H+ moves across membrane due to concentration gradient Creates charge / energy = used to make ATP
Light-Independent ReactionsThe DARK Reactions • Calvin Cycle • Series of reactions that uses CO2 to create sugars • Takes place in the Stroma • Named for Melvin Calvin
Summary of Calvin Cycle • 1. Co2 combines with RuBP to form 2 molecules of PGA • 2. Each molecule of PGA is converted into a molecule of PGAL • 3. Most of PGAL is converted back into RuBP, but some PGAL can be used to make a variety of organic compounds
What is this? • Guess?
A Summary of Photosynthesis + H2O CO2 Energy ATP and NADPH2 Which splits water Light is Adsorbed By Chlorophyll Calvin Cycle ADP NADP Chloroplast Used Energy and is recycled. O2 + C6H12O6 Light Reaction Dark Reaction
What is Cellular Respiration? The release of chemical energy for use by cells. Once the energy that was in sunlight is changed into chemical energy by photosynthesis, an organism has to transform the chemical energy into a a form that can be used by the organism. This process is cellular respiration.
1. The breakdown of glucose molecules to release energy 2. Takes place in all living things 3. Is a step by step process Describe Cellular Respiration
EQUATION FORRESPIRATION CARBON DIOXIDE ATP GLUCOSE C6H12O6 + 6O2 6CO2 + 6H2O + ENERGY OXYGEN WATER
Do You See The Relationship with Photosynthesis!? Respiration has the SAME formula as photosynthesis except it is backwards!
Cellular Respiration • Process by which mitochondria break down food molecules to produce ATP • Three Stages • Glycolysis – Anaerobic • Citric Acid Cycle – Aerobic • Electron Transport Chain - Aerobic
Glycolysis • Glucose gets broken into two three carbon pyruvic acids • 2 ATP used to start this reaction • Reaction produces 4 ATP • Net gain = 2 ATP • NAD+ = electron carrier = NADH when it accepts two electrons
Pyruvic molecules move into Mitochondria • IF OXYGEN IS PRESENT then the Citric Acid cycle takes place • Pyruvic acid loses one carbon (CO2) • Combines with Coenzyme A to create Acetyl-CoA
Fermentation • Times when there is not enough oxygen to do Citric Acid Cycle • Net Gain = 2 ATP • Two major types • Lactic Acid • Alcoholic
CYTOPLASMGLYCOLOSIS HAPPENS HERE! Respiration PROTEINS CARBO’S (SUGARS) FATS (LIPIDS) GLUCOSE C6H12O6 AMINO ACIDS MAKES 2 ATPS GLYCOLOSIS IN CYTOPLASM NO OXYGEN! ATP TOTALS GLYCOLOSIS=2 RESPIRATION=34 BOTH=36! PYRUVIC ACID CO2 IS RELEASED ACETYL-CoA O2 ENTERS HERE KREBS CYCLE AND ELECTRON TANSPORT MAKES 34 ATPS MITOCHONDRIARESPIRATION HAPPENS IN THIS ORGANELLE!
