SQA (c) Making Food

1. SQA (c) MakingFood

2. Photosynthesis reen • G_____ plants make their own food which they store as s_____. • Green leaves contain c________. • Chlorophyll converts l______ energy to c_______ energy • Equation of photosynthesis • CO2 + H20 + light glucose + oxygen energy tarch hlorophyll ight hemical aterials R___ m___ aw roducts P_

3. Equation of aerobic respiration Glucose + oxygen CO2 + + energy H20

4. Photosynthesis Photosynthesis CANNOT work without: • Carbon dioxide • Water • Chlorophyll • Sunlight If any of the above are in short supply they are said to be Limiting Factors”.

5. Starch Test ater ill • Boil leaf in w_____ to k____ the cells • Boil in a________ to remove c___________ • Rinse in h__ water • Add i________ s______ to test for s________ • Rinse leaf in c_____ water lcohol hlorophyll ot olution odine tarch old

6. Starch Test Results black Leaf from light brown Leaf from dark brown yellow green black Variegated leaf black Leaf with CO2 brown Leaf without CO2

7. Fate of CO2 in Photosynthesis(C) • During photosynthesisCO2 gas is taken in by plants and made into glucose • Glucose provides energy for cellular processes e.g. cell growth, cell division • Glucose can also be converted • to the storage carbohydrate called starch • Or to the structural carbohydrate called cellulose ( makes up the plant cell wall)

8. Stored as starch and converted back when glucose is needed for energy by plant. Structural Carbohydrate (e.g. cellulose in cell walls) glucose CO2 Used immediately for energy Fate of CO2 in Photosynthesis(C) 1 Photosynthesis 2 5 6 8 3 7 4

9. cellulose glucose starch

10. B CO2 D A C cellulose starch glucose

11. Used for energy / respiration Made into cellulose /plant cell walls Stops light reaching leaf

13. Elodea Bubbler reen reen • When g_____ plants photosynthesise they produce o__. • In a______ plants, this oxygen is given off as b_____ which are easily seen. • The n______ of bubbles produced every m______, i.e. the rate, gives us an idea of how f____ the plant is p____________. quatic ubbles umber inute ast hotosynthesing

14. Limiting Factors (C) arbon • Photosynthesis depends on c______ d_______, w_____, l_____ i_______ and t__________. • If they are in s_____ supply, they cut down or L_____ the rate of photosynthesis. • Light, water, carbon dioxide and temperature can act as “L Factors”. ioxide ater ight ntensity emperature hort IMIT imiting

15. Limiting Factors – light (C) ight At point X on the graph l______ intensity is limiting the rate of photosynthesis. At pointX - as light intensity increases. the r____ of photosynthesisi________ At point Y on the graph light intensity is n__ l_____ l________ as photosynthesis slows down even though light intensity is still i___________. ate Y ncreases X o onger imiting ncreasing

16. Limiting Factors – CO2 (C) At ACO2 concentration is the limiting factor as the rate of photosynthesis is increasing as the concentration of CO2 is increasing At BCO2 concentration is not the limiting factor as photosynthesis is slowing down even though the concentration of CO2 is still increasing At Bthere must be another limiting factor e.g. light intensity or temperature B A

17. Limiting Factors –temperature (C) At X the rate of photosynthesis is increasing as the enzymes of photosynthesis are working faster At Y the rate of photosynthesis is at its highest because the enzymes of photosynthesis are at their optimum temperature At Z photosynthesis slows down because enzymes are being d enatured Y Z X

18. Limiting Factors (C) • At X the limiting factor is light intensity • At Y temperature is limiting • At ZCO2 concentration is limiting Z Y

19. Light intensity temperature CO2 concentration Mass of sugar produced (g)

20. Light intensity Rate of photosynthesis increases Rate of photosynthesis increases

22. Plant transport – what you should know wo • The transport system of a plant does t___ jobs. • One is to t________materials needed for photosynthesis. • W____ from r_____ to l______ • The other is to transport n________ produced by photosynthesis. S_____ from l____ to roots and fruits and all parts of the plant ransport ater oots eaves utrients ugar eaves

23. Plant transport – what you should know • Tubes, in the stem, called x_____ carry the w_____ and m_______ from the r_____ to the l______ • Tubes called the phloem carry the s______ made in p__________ from the leaves to all other parts of a plant • Up to y______ leaves and f______ • Down to r______ and t_______ ylem ater inerals oots eaves hotosynthesis ugar oung ruits oots ubers

24. Xylem structure ead • D____ cells – no cell c_______ • Contains l______ • Carries w_____ and m______ up to leaves • S________ plant ontents ignin ater inerals upports

25. Phloem structure iving • Made of l_____cells • T___ cell types • S_____ cells and c___________ cells • Has sieve p______ • Carries n_______ from leaves to r____, f______ and y_______ leaves wo 1 ieve Sieve plate ompanion lates 2 Sieve cell utrients ruits oots 3 Companion cell oung

26. Leaf hin road lat • Leaves are f____, t_____ and b_____ • Leaves don’t o_______ so they don’t block s_______ needed for photosynthesis • Leaves have s_______ on their e_______ • Plants take in CO2 from the a___ through stomata which can o____ and c_____ • W_____ v______ is l____ through the stomata verlap unlight pidermis tomata ir pen lose ater apour ost

27. Cross section of leaf (c) chloroplasts

29. 0.5 stomata Gas exchange/ gases in / out

30. More on lower surface ylem Water would evaporate into the air

31. D phloem B CO2 and water

32. cuticle upper epidermis Palisade mesophyll Leaf vein xylem Spongy mesophyll Moist air space Guard cells stoma

33. Xylem/ leaf vein B F C

34. 1 3 2 4 5 Transport minerals support

36. Sieve plate Companion cell Transports food / nutrients /sugar epidermis Guard cells