C1.3 Photosynthesis

Question 1

photosynthesis

Answer 1

production of glucose from carbon dioxide and water in presence of chlorophyll and enzyme

using light energy and produce oxygen

Question 2

what happens to glucose

Answer 2

it is temporarily stored and then used for metabolic activities

Question 3

photosynthesis formula

Answer 3

6co2 + 6H2O + light energy -> c6h12o6 + 6o2

Question 4

wider significance of photosynthesis

Answer 4

maintains composition of atmosphere

some oxygen converted into ozone in upper atmosphere

Question 5

what is light

Answer 5

form of electromagnetic radiation produced by sun

white light from spectrum - all colours which appear white

Question 6

pigments

Answer 6

coloured compounds produced by metabolism

Question 7

accessory pigments

Answer 7

light absorbing compounds that trap light energy and channel it to chlorophyll, which initiates photosynthesis

Question 8

biological pigments

Answer 8

coloured and produced by metabolism

Question 9

examples of biological pigments

Answer 9

chlorophyll

Question 10

what colour is reflected by plants

Answer 10

green which is why it is visible

orange and yellow as well but not as much

Question 11

what colour is absorbed by plants

Answer 11

red and blue

Question 12

how does Co2 get converted to glucose

Answer 12

1. light energy being used to split water
2. glucose being built of from co2

Question 13

photolysis

Answer 13

splitting of water molecules using light energy

Question 14

features of cyanobacteria

Answer 14

first organism to produce oxygen
contain photosynthetic pigments
have accessory pigments

chlorophyll and phycobilins

Question 15

2 organisms to produce oxygen as a by product

Answer 15

red/green algae and cyanobacteria

Question 16

red algae features in photosynthesis

Answer 16

have same pigments as cyanobacteria
get most their colour from phycoerythrin

Question 17

green and red algae features in photosynthesis

Answer 17

contains chloroplasts a and b which give them bright green colours
have accessory pigments which give red-orange and yellow colours

Question 18

chromatography

Answer 18

used to separate components of a mixture
involves letting soluble substances spread across filter paper

Question 19

what is chromatography used for

Answer 19

separation and identification of pigments in a mixture

separating biologically active molecules

Question 20

easy steps of chromatography

Answer 20

• leaves boiled
• grinded with sand
• propane added as solvent
• centrifuged
• solution created and stored

Question 21

chromatograms

Answer 21

patterns formed on an absorbent medium showing the result of separating the components of a mixture by chromatography

Question 22

what are chromatograms typically run on

Answer 22

adsorbent paper, powdered solid or thin film of dried solid

Question 23

features and steps of paper chromatography

Answer 23

liquid adsorbed om to the surface
papers pores adsorb and form molecules with water - stationary phase
pigments more soluble in solvent that water move rapidly up the paper

Question 24

Thin layer chromatography (TLC)

Answer 24

stationary phase of silica or alumina particles bonded to a thin layer of glass or plastic

separates a mixture of pigments based on how strongly they are adsorbed on stationary phase and dissolve in mobile phase

Question 25

mobile phase

Answer 25

liquid or mixture of liquids

Question 26

Rf Value

Answer 26

distance moved by substance / distance moved by solvent

Question 27

what does the Rf value depend on

Answer 27

compounds, solvent, temperature and other factors like nature of TLC plate

Question 28

absorption spectrum

Answer 28

a graph showing the relative absorbance of different wavelengths of light by a pigment

Question 29

how is absorption spectra of chlorophyll pigments obtained

Answer 29

by measuring their absorption of V B G Y O R

Question 30

Action spectrum

Answer 30

range of wavelengths of light within which a process like photosynthesis takes place

Question 31

what does the action spectrum graph record

Answer 31

amount of photosynthesis occurring at each wavelength

Question 32

limiting factors of photosynthesis

Answer 32

concentrations of CO2
light intensity
temperature

Question 33

experiment to measure the rate of photosynthesis

Answer 33

root of pondweed bubbling

Question 34

microburette

Answer 34

used in pondweed experiment to measure volume of oxygen given out in light by tracking of a bubble in capillary tube

Question 35

machines used in pondweed experiment

Answer 35

microburette
oxygen sensor probe
pH meter