GB1 Q2 L3 Energy In Living Systems; Photosynthetic Pigments PDF
Document Details
2021
Miss Robeemane B. Balisi
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Summary
These lecture notes cover the topics of energy in living systems, redox reactions, electron carriers, NAD, FAD, ATP, energy from ATP, photosynthetic pigments, and spectrophotometer. The notes were presented on December 14, 2021.
Full Transcript
Energy in Living Systems Miss Robeemane B. Balisi December 14, 2021 Redox Reactions Oxidation Reaction Reduction Reaction Strips an electron from The addition of the an atom in a compound stripped electron to another compound...
Energy in Living Systems Miss Robeemane B. Balisi December 14, 2021 Redox Reactions Oxidation Reaction Reduction Reaction Strips an electron from The addition of the an atom in a compound stripped electron to another compound Loss of electron and loss of potential energy Gains electron and potential energy Electron Carriers Bind and carry high-energy electrons between compounds in metabolic pathways Easily reduced (added to a compound) or oxidized Important carriers often derived from the B vitamin group and nucleotides. NAD Nicotinamide adenine dinucleotide Derived from vitamin B3, niacin NAD+ – oxidized form of the molecule NADH – reduced form of the molecule FAD + Flavin adenine dinucleotide Derived from vitamin B2, riboflavin FADH2 – reduced form of the molecule ATP Adenosine triphosphate Often called the “energy currency” of the cell A compound used to fill an energy needed by the cell When ATP is broken down, usually by the removal of its terminal phosphate group, energy is released. Energy from ATP Hydrolysis – the process of breaking down complex macromolecules apart by splitting water into hydrogen atom (H+) and a hydroxyl group (OH-) Hydrolysis of ATP -> ADP + P1 + Free energy ADP -> Reattachment of third phosphate group -> ATP Energy for this process comes from metabolism of glucose Photosynthetic Pigments Miss Robeemane B. Balisi December 14, 2021 Pigments - light-absorbing molecules in photosynthetic organisms that absorb only specific wavelengths of visible light, while reflecting others PIGMENTS * Chlorophyll a and Chlorophyll b - found in higher plant chloroplasts; green pigments found in chloroplasts * Carotenoid - found in fruit – red of tomato (lycopene), yellow of corn seeds (zeaxanthin), orange of an orange peel (β-carotene); to attract seed dispersers - photosynthetic pigment; for disposal of excess energy Absorption Spectrum - Each type of pigment can be identified by the specific pattern of wavelengths it absorbs from visible light - Chlorophyll a – absorbs wavelengths from either end of the visible spectrum (blue and red), but not green - Green is reflected or transmitted - Carotenoids – absorbed in the short- wavelength blue region; reflect the longer yellow, red, and orange wavelengths Spectrophotometer - An instrument that can differentiate which wavelengths of light a substance can absorb - Measures transmitted light and compute from it the absorption