BIOL 2050 1nd Edition Lecture 15 Outline of Last Lecture I. Fermentationa. Types of Fermentationb. Anaerobic and Aerobic RespirationOutline of Current Lecture II. Photosynthesisa. Processb. PhotosystemsCurrent LecturePhotosynthesis: the process that converts solar energy into chemical energy- Nourishes almost all of the living world- Autotrophs: sustain themselves without eating anything derived from other organismso Producers of the biosphereo Plants, algae, and some bacteria- Heterotrophs: obtain organic material from other organismso Consumers of the biosphereo Depend on photoautotrophs for food and oxygenProcess- Chloroplasts: allow for chemical reaction of photosynthesiso Chlorophyll: provides green color within chloroplastso Found mainly in cells of mesophyllo Stomata: pores of the leaf where CO2 enters and O2 leaveso Thylakoids: connected sacs in the chloroplast, stacked in columnso Stroma: dense interior fluid- Equation:o Carbon Dioxide + Water + Light Energy -> Glucose + Oxygen + Water- Splitting Water: Water is split into hydrogen and oxygen and hydrogen contributes to the production of sugar, while oxygen is released- Redox Processo Reverse direction of electron flow compared to cellular respirationThese notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute. Water is oxidized and CO2 is reduced- Stages:o Light Reactions Splits water Releases oxygen Reduces NADP+ to NADPH Generates ATP by photophosphorylationo Calvin Cycle Occurs in the stroma Forms sugar using ATP and NADPH Begins with carbon fixation- Incorporates CO2 into organic molecules- Light Reactionso Thylakoids transform light energy into chemical energy of ATP and NADPHo Wavelength determines the type of electromagnetic energyo Visible Light: consists of wavelengths that produce colors we can seeo Photons: discrete particles of lighto Leaves appear to be green because they absorb every color besides green.o Light Receptors: Light hits chlorophyll Reflects and transmits green light Absorbs blue light- Excited State: an unstable state that occurs when a pigment absorbs lighto Photons boost electrons into an excited state Releases energyPhotosystems- Consists of a reaction-center complex surrounded by light-harvesting complexeso Light-harvesting complexes transfer the energy of photons to the reaction centero Primary electron acceptor: accepts excited electrons and is reduced as a result- Photosystem II: functions first and is the best at absorbing a wavelength of 680 nm- Photosystem I: absorbs wavelength 700 nm- Linear electron flow: primary pathway that involves both photosystems and produces ATP and NADPH using light energy.o Photon hits a pigment and energy is passed among pigment molecules and excites P680o An excited electrons from P680 is transferred to the primary electron acceptoro Water is split and oxygen is releasedo Electron Transport Chaino H+ diffuse across the membrane and drives ATP synthesiso Transferred light energy then excites P700 Leads to the production of NADPH Transported to the Calvin Cycle- Cyclic Electron Flow: uses only photosystem I o Produces ATP but not NADPHo No oxygen is releasedo Evolved before linear electron flowo May protect cells from light-induced damageauto
View Full Document
Unlocking...