Biosc&0150:&Foundations&of&Biology&I.& & Review&chapters&10,11,&&&12& &Adel,&Anthony,&Kathleen,&Megan,&Dr.&Swigonova& & Page&1&of&18&Review&chapter&10:&Photosynthesis&&1. How&would&you& describe&photosynthesis&in&general&terms&to&a&nonBbiologist?&The&use&of&sunlight&to&manufacture&sugars.&State& a& general& description& of& photosynthesis& in& biological& terms?& Transformation& of& light& energy&into&che m ic a l&en e rg y&in &c a rb ohydrates.&a. ________________&make&all&of&their&own&food&from&ions&and&simple&molecules.&Give&three&examples.&Autotrophs;&plants,&cyanoba c te r ia ,&green&algae.&b. ________________& have& to& obtain& sugars& and& many& other& m acromolecules& from& other&organisms.&Give&three&examp le s.&Heterotrophs;&fungi,&animals,&bacteria.&c. Balance&the&equation&for&photosynthesis&____&CO2&+&____ &H2O&+&light&energy&&____&C6H12O6&+&____&O2&+&____ &H2O&6&CO2&+&12&H2O&+&light&energy&&1&C6H12O6&+&6&O2&+&6&H2O&d. Photosynthesis&is&an&(endergonic&/&exergonic)&suite&of&reactions&that&reduces&_________&to&_________.&Cellular&respiration&is&an&(endergonic&/&exergonic)&suite&of&reactions&that&oxidizes&________& to& _________& and& results& in& the& production& of& _________.& Endergonic;& CO2;&glucose;&exergonic;&glucose;&CO2;&ATP&e. What&is&source&of&O2&produced&during&photosynthesis?&H2O.&&2. List&the& three&main& things&that& can& happen& to&electrons&when & light&hits& chlorophyll.&The&electrons&can&drop&back&to&a&lower&ene rgy&state&causing&flu ore sce n ce,&e xcite &a n&electron&in&a&ne arb y&pigment&to&induce&reson an ce ,&or&be&tra nsfe rred &to&an &electro n&ac cep tor&in&a &redo x&rea ction .&a. Describe&the&phenomena&“fluorescence.”&If&an&excited&electron&falls&back&to&its&ground&state,&some&of&the&absorbed&energy&is&released&as&heat&and &light.&This&results&in&color&that&we&can&see.&b. What&does&it&mean&for& an&electron&to&be& in&a&higher&energy&state&when&it&is&“excited”?&The&electron&is& elevated& to&an&energy& level&above&the& ground&state.&This&m eans&that&the&electron&has&moved&up&an&orbital&so&suppose&you&had&Hydrogen;&it&would&be&kicked&up&to&2s&or&6p.&&c. Explain&the&process&of&resonance&the&moment&light&hits&chlorophyll.&Light&hits&chlorophyll&the&energy&is&absorbed&and&an&electron&is&excited&to&a&higher&energy&state.&The&energy&(not&the&electron)& is& passed& to& nearby& chlorophyll& which& sets& a& chain& reaction& for& the& same& thing&happening&until&the&energy& reaches&the&reaction&center&where&the&excited& electron’s&energy&is&perma n e n tly &tra n sfo rmed&from&electr omagnetic&energ y& to&ch em ica l&ene rgy.&d. What&is&the&significance&of&having& a&lot&of&chlorophyll&surrounding&a&reaction&center?& More&chlorophyll&equates&to& more&opportunities&for&electrons&to&become& excited&and&have& their&energy& passed& to& reaction& centers.& This& allows& for& a& more& efficient& transformation& of&electromagnetic&energy&to&chemical&energy.&&3. What&are&the&two&linked&sets&of&reactions&of&photosynthesis?&The&lightBcapturing&reaction&and&the&Calvin&Cycle&a. Which&reaction&is&dependent&on&the&other?&Explain.&The&Calvin&cycle&requires&the&products&(ATP&and&N A DP H )&o f&the&lightBcapturing&reactions.&b. What& are& the& products& of&each&set&of&reactions?& The&products&of&the&lightBdependent&reaction&are&ATP,&NADPH&and&O2;&the&products&of&the&Calvin&Cycle&is&3&carbon&sug ar &(G 3 P ) .&&Biosc&0150:&Foundations&of&Biology&I.& & Review&chapters&10,11,&&&12& &Adel,&Anthony,&Kathleen,&Megan,&Dr.&Swigonova& & Page&2&of&18&c. How& are& the& two& sets& o f& reactions& linked& to& one& anothe r?& The& reactions& are& linked& by&electron&carrier,&NADPH,&transporting&electro ns&released&by&H2O&splitting&to&re action&ce nter&of&photosystem&II.&&4. Where&does&photosynthesis&take&place&in&a&cell?&Chloroplasts&a. Name& the& components& of& this& organelle& and& how& they& relate& to& one& another.& Use& the&following& terms:& th yla ko ids,& grana,& s trom a .& The& interior& of& a& chloroplast& in& dominated& by&thylakoids,& which& often & occur& in & stacks& ca lle d & grana.& Th e& space& insid e& the& thlyakoid& is& its&lumen .&Th e &fluid Bfilled&space&betw e en &the &thyla koid s&an d&th e&inn er&m e m b ran e&is&the & strom a&b. True&or& False:&Pigments&have& colors&because& we& see& the&w avelengths&they&absorb.& FALSE!&They&have&colors&because&we&see&the&wavelengths&they&do&not&absorb&&c. The& most& common& pigment& in& chloroplasts& is& ___chlorophyll__,& whose& function& is&to__absorb&photon’s&energy__.&&d. Additional,& but& less& common& pigments& include& a& class& of& compounds& called&___carotenoids___.&What& is& their& function?&These&are&accessory&pigments& that& absorb& light& in& ranges&complimentary& to& chlorophyll.& Carotenoids& absorb& in& the& blue& and& green& parts& of& visible&spectrum,& w idening& the& action& spectrum& for& photosynthesis.& T hey& also& play& a& protective&role,&quenchin g&free &radic als&by &acce ptin g&or&stab ilizing&un pa ired &electro ns .&&5. What&is&the&first&molecule&that&reacts&with&CO2&in&the&Calvin&cycle?&How&many&carbon&atoms&does&this& m ole cule & contain?& What& is& the & product& of& th is& reaction?& RuBP,& 5,& two& molecules& of& 3Bphosphoglycerate&(3PG)&a. In&the &second&step&of&the&calvin&cycle,&3Bphosphoglycerate&(3PG)&is&phosphorylated&by&ATP&and& reduced& by& NAD PH& to& form& which& molecule?& Does& this& molecule& have& m ore& or& less&energy&than&3PG?&&Glycerald eh y d e B3Bphosphate&(G3P),&it&has&much&more&energy&b. What&is&the&fate& of&the&majority&of&the&glyceraldehydeB3Bphosphate&(G3P)&that&is&generated&in&the&sec o n d &st ep &o f&th e &C a lvin &c yc le? &&It&is&used &to &r e ge n e r a te &R u B P&c. For&every&6&molecules&of&G3P&that&are&produced,&how&many&go&toward&production&of&sugars?&One.&&6. Explain&why& photorespiration&occurs&in& competition&with& carbon&fixation.&You& should&mention&the&affinity&of&rubisco&to&CO2&and&O2.&Rubisco& is& an& enzyme& which& catalyzes& the& addition& of& both& carbon& dioxide& and& oxygen& to& RuBP.&Ideally,&you &w ould&on ly&w a n t &car b o n &dioxide&to&be&fixed&to&Ru BP &so&this&interm e diate &could &be&use d&in&the&C a lvin &cycle.&In&so me&case s,&oxygen&is&fixed&to&R u B P&by&rubisco ,&le a d in g&to&photo re sp ira tio n .&Photorespiration& “undoes”& photosynthesis& by& producing& intermediates& which& consume& ATP& and&release&carbon &diox ide .&&&7.