Photosynthesis Lesson 6 PDF

Capturing Solar Energy: PHOTOSYNTHESIS  What is a PHOTOSYNTHESIS ? Is the process by which light energy is captured and then stored as chemical energy in bonds of organic molecules such as sugar.  the process by which plants, algae, and some microorganisms harness...

Capturing Solar Energy: PHOTOSYNTHESIS  What is a PHOTOSYNTHESIS ? Is the process by which light energy is captured and then stored as chemical energy in bonds of organic molecules such as sugar.  the process by which plants, algae, and some microorganisms harness solar energy and convert it into chemical energy.  What is a PHOTOSYNTHESIS ?  In lakes and oceans, photosynthesis is performed primarily by photosynthetic protists and certain bacteria, and on land, mostly by plants.  Life depends on  Photosynthesis builds Carbohydrates out of CO2 and H2O. The reaction of photosynthesis are summarized as follows: Light energy 6 CO + 6H O 2 2 C H O + 6O 6 12 6 2  Photosynthesis is an oxidation-reduction (redox) process. OXIDATION means that electrons are removed from an atom or molecule. REDUCTION means electrons are added.  Leaves and Chloroplasts are adaptations for photosynthesis. EPIDERMIS consist of a layer of transparent cells found both the upper and lower surfaces of a leaf. It protects the inner part of the leaf while allowing light to penetrate.  Leaves and Chloroplasts are adaptations for photosynthesis. CUTICLE a transparent, waxy, waterproof covering found in the outer surface of the epidermis that reduces the evaporation of water from the leaf.  Leaves and Chloroplasts are adaptations for photosynthesis. STOMATA (singular: stoma) adjustable pores where leaf obtains carbon dioxide (CO2) necessary for photosynthesis from the air.  Leaves and Chloroplasts are adaptations for photosynthesis. MESOPHYLL (Gk: meso-middle) a layer of cells where most chloroplasts are located. Mesophyll cells in the leaf’s center are loosely packed, allowing air to circulate around them and CO2 and O2 to be exchanged through their moist membranes.  Leaves and Chloroplasts are adaptations for photosynthesis. CHLOROPLASTS it is where photosynthesis takes place and most of which are contained within mesophyll cells. STROMA a semifluid substance found inside the chloroplast.  Sunlight is the energy source for photosynthesis.  What is LIGHT ? Visible light is a small sliver of a much larger electromagnetic spectrum, the range of possible frequencies of radiation.  The electromagnetic spectrum  Photosynthetic pigments capture light energy. Different types of pigments: o Chlorophyll a- the most abundant, a green photosynthetic pigment in plants, algae and cyanobacteria. o Accessory Pigments- Chlorophyll b and Carotenoids  Photosynthesis occurs in 2 stages: Light Reaction o Happens on daytime in the thylakoids of the chloroplast. Dark Reaction (Calvin Cycle) o May happen during daytime or nighttime in the stroma of the chloroplast.  The relationship between the light reactions and the Calvin cycle.  The Light Reaction process. Composed of Photosystem (II) and Photosystem (I) linked by Electron Transport Chain (ETC)  captured kinetic energy from photons were stored as potential energy in the chemical bonds of two molecules: ATP and NADPH (Nicotinamide Adenine Dinucleotide Phosphate-Hydrogen).  The Calvin cycle. Is the metabolic pathway that uses NADPH and ATP to assemble CO2 molecules into three-carbon carbohydrates molecules. The pathway is named in honor of its discoverer, American biochemist Melvin Calvin.  The Calvin cycle. Also known as Calvin-Benson cycle.  Discovered in 1950s by Melvin Calvin together with his fellow chemists Andrew Benson and James Bassham.  The Calvin cycle. Composed of three (3) stages: o Carbon Fixation o Synthesis of G3P* o Regeneration of RuBP *Glyceraldehyde 3-Phosphate  The Calvin cycle. Important Key Components: o CO2 o RuBP- Ribulose bisphosphate o Rubisco- an enzyme that combines three CO2 molecules with three RuBP. CO2 + RuBP PGA Phosphoglyceric acid  The Calvin cycle.