Class: Name: Date: 21 Photosynthesis
Class:(Name:21)Date:Photosynthesis21.1 The basic concepts of photosynthesis(Book 3, p. 21-3)Plants and algae are autotrophs. They make their own food by (1) .Photosynthesis is the process by which (2) substances (such ascarbohydrates) are made from simple (3) substances (carbon dioxide and(4) ) using (5) energy. During the process, light energyis captured by (6) in plants and algae. Chlorophyll is found in(7) in most plants.The light energy captured is converted to (8) energy that is stored in thecarbohydrates produced. (9) is released as a by-product.Photosynthesis is a / an (10) (catabolic / anabolic) process.(11) and (12) are made from intermediates ofphotosynthetic reactions. Their production requires (13) absorbed from thesoil.sunoxygen(released to the air)lightcarbon dioxide(from ohydrateslipidsplant materials,e.g. enzymes,chlorophyll, cellmembrane andcell wallproteinswater(from soil) How plants make the materials they needNew Senior Secondary Mastering Biology(Second Edition)- 33 - Oxford University Press 2014
21.2 The site of photosynthesis(Book 3, p. 21-5)In plants, (1) are the main site of photosynthesis.AWhat are the adaptive features of leaves for photosynthesis?(Book 3, p. 21-5)StructureFeatureAdaptation for photosynthesisBroad and flatProvides a large (2)for absorbing sunlightLeaf bladeThinGases and light can reach thephotosynthetic cells easilyConsists of tightly packed cells thatPalisadecontain many (3)mesophyllLocated on the (4)Allows effective absorption of sunlight(upper / lower) side of the leafSpongymesophyllConsists of loosely packed cells withAllows gases to (6)many (5)freelyThe cells contain chloroplasts (fewerAllows absorption of sunlightthan palisade mesophyll)Covered by a thin layer of waxyReduce (8) loss(7)from the leaf, so that water is keptinside for photosynthesis and keepingthe cells turgidUpperepidermisContain numerousStomata open when the conditions areand lower(9) (more on lowerfavourable for photosynthesis. Theyepidermisepidermis)close when the conditions are lessEach stoma is surrounded by a pairfavourable. This regulates the passageof (10)of gases and water vapour into and outof the leafContain vascular bundles which areAllow efficient transport of materialsmade up of (11)into and away from the leafand (12)Support and spread the leaf bladeMidrib andveinsNew Senior Secondary Mastering Biology(Second Edition)- 34 - Oxford University Press 2014
BWhat are the adaptive features of chloroplasts forphotosynthesis? (Book 3, p. 21-7)A chloroplast is bounded by a (13) membrane and is filled with ajelly-like fluid called (14) (基質). The stroma contains (15) .It also holds (16) grains.A network of disc-like membranous sacs called (17) (類囊體) is suspendedin the stroma. The thylakoids are arranged in stacks called (18) (基粒).(19) is located on the thylakoid membranes.A chloroplast has about 50 grana, each consisting of about 50 thylakoids. This provides a large(20) to pack more chlorophyll for absorbing light. Thegrana are (21) by extensions from thylakoids. This allows efficient(22) of photosynthetic products within the chloroplast.thylakoidouter membranestromainner membranegranum 3-D drawing of a chloroplast showing grana and thylakoids21.3 The requirements for photosynthesisA1(Book 3, p. 21-9)How do we know if photosynthesis has occurred?(Book 3, p. 21-9)Detecting the presence of starchWe can carry out (1) test to test for the presence of starch in a plant.2Detecting the release of oxygenWe can test for oxygen in the gas produced by a plant using a (2) splint.Go toPractical 21.1Detection of starch produced in photosynthesis (the iodine test)(Book 3, p. 21-9; Practical Workbook for SBA 3 4, p. 21-1)Practical 21.2Detection of oxygen produced in photosynthesis(Book 3, p. 21-10; Practical Workbook for SBA 3 4, p. 21-5)New Senior Secondary Mastering Biology(Second Edition)- 35 - Oxford University Press 2014
BInvestigation of the requirements for photosynthesis (Book 3, p. 21-11)If we plan to use the presence of starch in leaves as the evidence that photosynthesis hasoccurred, any starch that is present in the leaves originally must be removed before theinvestigation.Plants used in such investigations must first be put in the (3) for at least(4) hours to remove all the starch. This process of removing starch is called(5) (脫澱粉).1ChlorophyllWe can carry out the investigation on plants with (6)leaves (斑葉). Chlorophyll is (7) (present / absent) inthe non-green parts of the leaves.The part of a leaf with chlorophyll is the (8)(experimental / control) set-up. Variegated leaf ofColeusThe part of a leaf without chlorophyll is the (9)(experimental / control) set-up.2Carbon dioxideWe can use (10) (氫氧化鉀) to remove carbon dioxidefrom the air inside the control set-up.The leaf exposed to normal air is the (11) (experimental / control) set-up.The leaf exposed to air without carbon dioxide is the (12) (experimental /control) set-up.3LightWe can use a piece of black paper or aluminium foil to mask part of a leaf.The unmasked part of the leaf is the (13) (experimental / control) set-up.The masked part of the leaf is the (14) (experimental / control) set-up.Go toPractical 21.3Investigation of the need for chlorophyll in photosynthesis(Book 3, p. 21-12; Practical Workbook for SBA 3 4, p. 21-7)Practical 21.4Investigation of the need for carbon dioxide in photosynthesis(Book 3, p. 21-13; Practical Workbook for SBA 3 4, p. 21-11)Practical 21.5Investigation of the need for light in photosynthesis(Book 3, p. 21-14; Practical Workbook for SBA 3 4, p. 21-14)New Senior Secondary Mastering Biology(Second Edition)- 36 - Oxford University Press 2014
21.4 The process of photosynthesis(Book 3, p. 21-16)Photosynthesis involves many reactions, each of which is controlled by a different enzyme.The reactions occur in two main stages: (1) (光反學反應)and (2) (碳固定).APhotochemical reactions (Book 3, p. 21-16)Photochemical reactions occur in the (3) of chloroplasts. The reactionsrequire (4) . Therefore, they are also called (5)(光反應).1Light absorptionWhen the chlorophyll molecule in the thylakoid captures (6) energy, some(7) of the chlorophyll molecule are raised to a higher energy level and areemitted from the chlorophyll molecule. These excited electrons then pass through a series ofelectron carriers of (8) (increasing / decreasing) energy levels in thethylakoid membrane. (9) is released in a step-wise manner. The series ofelectron carriers is called the (10)(電子傳遞鏈).An electron becomes‘excited’.higher energy levelenergysunThe ‘excited electron’releases energywhen it passesthrough an electrontransport chain.electrontransport chainLight energy isabsorbed bychlorophyll.initial energy levelchlorophyll molecule inthylakoid membranethylakoidchloroplast Absorption of light energy by a chlorophyll moleculeNew Senior Secondary Mastering Biology(Second Edition)- 37 - Oxford University Press 2014
2Synthesis of ATPSome of the energy released by the electrons in the electron transport chain is used to form(11) (adenosine triphosphate 腺苷三磷酸) by combining a phosphate with(12) (adenosine diphosphate 腺苷二磷酸). This process is called(13) (光磷酸化).In this way, (14) energy captured by the chlorophyll molecule is convertedto (15) energy stored in ATP. The ATP will provide energy to drive thereactions in carbon fixation.3Photolysis of waterThe light energy captured by chlorophyll molecules is also used to split (16)molecules to form (17) and (18) . This process is called(19) (光解) of water.-Hydrogen is accepted by (20) (nicotinamide adenine dinucleotidephosphate 菸酰胺腺嘌呤二核苷酸磷酸) to form (21) . NADPH is the(22) (oxidized / reduced) form of NADP. It will act as a(23) agent by donating (24) in carbon fixation.-Oxygen is a (25) in the reaction. It is released as a(26) to the atmosphere.sunSynthesis of ATP(photophosphorylation)to carbon fixationLight energycaptured bychlorophyllthylakoidmembranePhotolysisof waterthylakoidspacestromaoxygen releasedto atmosphere Photochemical reactionsNew Senior Secondary Mastering Biology(Second Edition)- 38 - Oxford University Press 2014
BCarbon fixation: Calvin cycle (Book 3, p. 21-19)ATP and NADPH formed in the photochemical reactions are used to fix (27)into organic compounds. This stage is called (28) . Itoccurs in the (29) of chloroplasts.This stage is also called (30) (暗反應) because it does notrequire (31) .This stage is also known as the (32) (卡爾文循環). Itinvolves a cyclic series of reactions and occurs in three main steps.1Carbon dioxide fixation and formation of a 3-C compoundUnder the action of enzymes, a molecule of (33)combines with a molecule of a 5-C compound to form (34) molecules of a3-C compound. The 5-C compound acts as a carbon dioxide (35) to ‘fix’carbon dioxide into an organic compound which starts the reactions in the cycle.2Reduction of the 3-C compound and formation of glucoseUsing energy from (36) and hydrogen from (37)produced in photochemical reactions, the 3-C compound is (38) (oxidized /reduced) to another 3-C compound called (39) (丙糖磷酸).ADP and NADP are formed in the process. They will be reused in (40)reactions.Triose phosphate is a sugar. It is the primary product of the Calvin cycle. Two molecules oftriose phosphate combine to form one molecule of (41) (6-C).New Senior Secondary Mastering Biology(Second Edition)- 39 - Oxford University Press 2014
3Regeneration of carbon dioxide acceptorMost triose phosphate molecules are used to (42) the original 5-C carbondioxide acceptor, so that the cycle can repeat itself to form more glucose. The regeneration ofcarbon dioxide acceptor requires (43) from ATP.Carbon dioxidefixation5-C compoundCalvin cycle3-C lreactionsRegeneration ofcarbon dioxideacceptortriose phosphate (3-C)Reduction of3-C compoundglucose (6-C) The Calvin cycleNew Senior Secondary Mastering Biology(Second Edition)- 40 - Oxford University Press 2014
COverall process of photosynthesis (Book 3, p. 21-22)Photochemical reactions and the Calvin cycle are linked by (44) and(45) .The equation of the overall process of photosynthesis:light captured6 CO2 6 H2Oby chlorophyllcarbon dioxide waterC6H12O6 glucose6 O2oxygenIt shows that (46) molecules of carbon dioxide and (47)molecules of water are required to form one molecule of (48) .The hydrogen and oxygen atoms in water molecules are found in the (49)and (50) produced calreactionsthylakoid(with chlorophyll)NADPstromaADP Pchloroplastglucose Summary of the process of photosynthesisNew Senior Secondary Mastering Biology(Second Edition)- 41 - Oxford University Press 2014
21.5 Factors affecting the rate of photosynthesis(Book 3, p. 21-24)Effect of light intensity (Book 3, p. 21-24)Initially, the rate of photosynthesis(1) proportionately with lightintensity as more (2) issupplied to the photochemical reactions.As the light intensity increases, the rate levels offwhen the light intensity reaches a(3) (飽和點).rate limited bylight intensityrate of photosynthesisArate limited byother factorssaturation pointThe rate is now (4) by otherlight intensityoptimum light intensityfactors. The light intensity at the saturation pointB Effect of light intensity on the rate ofphotosynthesisEffect of carbon dioxide concentration(Book 3, p. 21-25)Initially, the rate of photosynthesis (6)proportionately with carbon dioxide concentrationbecause more (7) are supplied to theCalvin cycle.As the carbon dioxide concentration further increases, therate (8) because therate becomes limited by other factors.rate of photosynthesisis called (5) light intensity.CO2 concentration Effect of CO2 concentrationon the rate of photosynthesisGo toPractical 21.6Investigation of the effect of light intensity on the rate of photosynthesis(Book 3, p. 21-24; Practical Workbook for SBA 3 4, p. 21-17)Practical 21.7Design an investigation of the effect of carbon dioxide concentration on the rate ofphotosynthesis(Book 3, p. 21-26; Practical Workbook for SBA 3 4, p. 21-22)New Senior Secondary Mastering Biology(Second Edition)- 42 - Oxford University Press 2014
rate of photosynthesisHow can we know which factor is limiting?high CO2 concentration(curve B)low CO2 concentration(curve A)light intensityWithout light, no photosynthesis takes place.At low light intensities, the rate (9) (increases / decreases) with increasinglight intensity. (10) is the limiting factor.At high light intensities, the rate in curve A (11) . Therate is limited by a factor other than light intensity.The rate (12) (increases / decreases) with higher CO2 concentration. Thisshows that (13) is the limitingfactor when curve A levels off.The rate in curve B levels off again. It is limited by a factor other than(14) .CRegulating the rate of photosynthesis (Book 3, p. 21-28)Farmers can build (15) (溫室) to monitorenvironmental factors such as temperature, light intensityand carbon dioxide concentration, so as to regulate the rateof photosynthesis of their crops.In this way, the productivity (生產力) and the quality of thecrops can be (16) . A greenhouseNew Senior Secondary Mastering Biology(Second Edition)- 43 - Oxford University Press 2014
21.6 The fate of photosynthetic products(Book 3, p. 21-31)(1) is the primary product of photosynthesis. Thismolecule and other intermediates of photosynthesis are synthesized into biomolecules essentialfor plant growth.1CarbohydratesTriose phosphate is quickly synthesized into (2) . Some of the glucose isused up in photosynthesizing cells as an (3) source.Most of the glucose formed is quickly built into (4) and is stored in cells. Itis a suitable form for storage because it is (5) . It can be stored in leaveswithout affecting the (6) of the cells.Starch can be broken down to form (7) , which is transported by the(8) to other parts of the plant. Sucrose is a suitable form for transportbecause it is soluble but relatively (9) .Some glucose molecules are built into (10) , which is a major component of(11) .2LipidsThe intermediates of photosynthesis can also be used to synthesize (12)and (13) . Glycerol and fatty acids then combine to formlipids.Lipids are used to form (14) . They are also stored asenergy reserve in some plants.3ProteinsThe intermediates of photosynthesis can also combine with (15) to form(16) , which are the building blocks of proteins.Proteins are important for (17) and repair, and for the synthesis ofenzymes. They are also the components of (18) .New Senior Secondary Mastering Biology(Second Edition)- 44 - Oxford University Press 2014
21.7 The significance of photosynthesis1(Book 3, p. 21-33)Providing the basic food source in ecosystemsMost organisms depend on plants for food. Plants are (1) in ecosystems.They serve as the basic food source for other organisms.2Maintaining energy flow in ecosystemsDuring photosynthesis, light energy from the (2) is captured by plants. Thelight energy is converted to (3) energy that is stored in plant bodies. Thechemical energy is transferred along (4) and iseventually lost as (5) to the surroundings.heatlight energyfrom sunheatproducers(e.g. plants)consumersdecomposersheat Energy flow in an ecosystem3Maintaining oxygen and carbon dioxide balance(6) of organisms consumes oxygen and releases carbon dioxide. Theoxygen consumed is replaced by the oxygen released by plants during (7) .Therefore, photosynthesis is important in maintaining the oxygen balance in the atmosphere.Plants take in carbon dioxide from the environment for (8) . This balancesthe increase in carbon dioxide concentration in the atmosphere due to (9) .taken up byplants duringphotosynthesiscarbon dioxidein atmospherereleasesreleasesoxygen inatmosphererespirationconsumedduring Balance of oxygen and carbon dioxide in the atmosphereNew Senior Secondary Mastering Biology(Second Edition)- 45 - Oxford University Press 2014
AnswersCh 21 ygen10anabolic11Proteins / Lipids12lipids / proteins13minerals21.21leaves2surface area3chloroplasts4upper5air spaces6diffuse7cuticle8water9stomata10guard cells11xylem / phloem12phloem / 18grana19Chlorophyll20surface l9control10Potassium ntrol2carbon rgy21.41photochemical reactions5light reactions10electron transport ical16water17hydrogen / oxygen 18oxygen / hydrogen ogen25by-product26gas27carbon28carbon fixation29stroma30dark reactions31light32Calvin cycle33carbon e rgy44ATP / NADPH45NADPH / ATP46six47six48glucose49glucose50oxygen gas6lightNew Senior Secondary Mastering Biology(Second Edition)- 46 - Oxford University Press 2014
21.51increases2energy3saturation point4limited5optimum6increases7substrates8levels off9increases10Light intensity11levels off12increases13carbon dioxide concentration14carbon dioxide concentration15greenhouses16improved21.61Triose phosphate2glucose3energy4starch5insoluble6water potential7sucrose8phloem9inactive10cellulose11cell walls12glycerol13fatty acids14cell membranes15minerals16amino acids17growth18cell membranes5heat21.71producers2sun3chemical4food espirationNew Senior Secondary Mastering Biology(Second Edition)- 47 - Oxford University Press 2014
New Senior Secondary Mastering Biology Oxford University Press 2014 (Second Edition) - 33 - 21 Photosynthesis 21.1 The basic concepts of photosynthesis (Book 3, p. 21-3) Plants and algae are autotrophs. They make their own food by (1) _. Photosynthesis
Photosynthesis takes place in autotrophs. [brown] Oxygen is a product of photosynthesis. [black] Photosynthesis takes place in the nucleus of plantcells. [blue] 12. Which of the followingstatements is true? Photosynthesis takes place primarily in plant leaves. [light red] Plants obtain their ”food” from the soil. [red] Photosynthesis .
photosynthesis 1/2-5/2 8/2 S1-5 Picnic Day 9/2-19/2 Lunar New Year Holiday photosynthesis 11A 4/6 Chapter 21 Photosynthesis o Basic concepts of photosynthesis o Requirements for photosynthesis o Site of The process of photosynthesis oPre Lesson Worksheet o Communication s
Photosynthesis Chapter 8 2 Photosynthesis Overview Energy for all life on Earth ultimately comes from photosynthesis. 6CO 2 12H 2O C 6H 12O 6 6H 2O 6O 2 Oxygenic photosynthesis is carried out by: cyanobacteria, 7 groups of algae, all land plants 3 Photosynthesis Overview Photosynt
UNIT 1 PHOTOSYNTHESIS AND RESPIRATION Photosynthesis is the process whereby plants use carbon dioxide, water and light energy in a series of chemical reactions to produce glucose (food). Photosynthesis Microorganisms Interactions and interdependencies Life and living Photosynthesis and respiration Photosynthesis Respiration
photosynthesis of an aquatic plant [Elodea]. The rate of photosynthesis can be determined by measuring the concentration of dissolved oxygen as the plant undergoes photosynthesis. There are multiple methods for measuring the rate of photosynthesis including: The uptake of CO 2 The production and release of O 2
In this live Gr 11 Life Sciences show we take a look at Photosynthesis. In this lesson we study the process of photosynthesis looking at the light and dark phases. We discuss the importance of photosynthesis as well as consider the effects of varying amou nts of light, carbon dioxide and temperature on the rate of photosynthesis.
LAB 8 – Photosynthesis . Objectives. 1. Assess CO 2 consumption and O 2 production during photosynthesis. 2. Analyze the role of light in photosynthesis. 3. Examine the effect of different wavelengths of visible light on photosynthesis. Introduction . In order to , organisms require a source of
Photosynthesis Song. Create a photosynthesis project! Directions for Project You can create a play, rap, poem, song, diagram, or commercial explaining photosynthesis. You must use all of the following terms correctly: –Photosynthesis, sunlight, carbon dioxide,
