Energy Transformations: Photosynthesis & Respiration

What do you remember from Friday? What is energy? List 2 processes (in the cell) that require energy (the ability to do work). What is the difference between an autotroph and a chemotroph? What is metabolism? What are the reactants of photosynthesis? What are the products of photosynthesis?

ATP & ADP ATP: Adenosine triphosphate adenine + ribose + 3 phosphates Energy storing molecule, only stores energy for a few minutes Source of all cell energy When one phosphate group breaks off, energy is released Adenine 3 Phosphate groups Ribose

ADP: Adenosine diphosphate Adenine + ribose + 2 phosphates Molecule that results from ATP losing one P Another P may be added later ADP ATP Energy Energy Adenosine diphosphate (ADP) + Phosphate Adenosine triphosphate (ATP) Partially charged battery Fully charged battery

Describe organelles involved in energy transformation Energy transformation is when energy is converted from one form to another. Energy transformations involve photosynthesis and respiration.

Photosynthesis

CHLOROPLASTS: Found in plant cells, some protists & bacteria not animal cells Contain pigment called chlorophyll (green) Allows plants to go through photosynthesis by converting light into energy for the cell

Overview Photosynthesis Photosynthesis: process using energy from sunlight to convert water and CO2 into oxygen and carbohydrates (sugar) Two parts: Light dependent reactions: produce O2 & converts ADP to ATP Calvin cycle (dark reactions): use ATP from light reactions to produce sugars Light Energy Chloroplast CO2 + H2O Sugars + O2

Chlorophyll: green pigment in cells that absorbs blue & red light energy Moves energy to electrons that drive reactions Equation for photosynthesis: 6CO2 +6H2O + energy  C6H12O6 + 6O2

MITOCHONDRIA: “powerhouse” of cell Releases energy from food molecules Found in both animal and plant cells A cell that needs more energy has more mitochondria Ex: muscles, growing cells, areas of repair

Overview cellular respiration Respiration: process that releases energy by breaking down food when oxygen is present Equation for Respiration: C6H12O6 + 6O2  6CO2 + 6H2O + energy

Anaerobic respiration: (fermentation) occurs without oxygen present Two types: Alcoholic: form ethyl alcohol and CO2 as waste products; used to make bread rise Lactic acid: produces lactic acid in muscles when exercising without enough oxygen

Photosynthesis Respiration Function Energy storage Energy release Location Chloroplasts Mitochondria Reactants Carbon dioxide water Glucose oxygen Products Equation 6CO2 +6H2O + energy  C6H12O6 + 6O2 C6H12O6 + 6O2  6CO2 +6H2O + energy