Bioenergetics

Question 1

what is bioenergetics

Answer 1

QUANTITATIVE study of energy relationships and conversions.
(obeys law of thermodynamics)

Question 2

which instrument used to measure abilities of pigments to absorb different wavelengths of light

Answer 2

Spectrophotometer

Question 3

accesory pigments with colours

Answer 3

Cartenoids; yellow, red, orange [e.gCarotene]

Xanthophyls; yellow to orange

Question 4

chlorophyl found in eukaryotes and bacterias

Answer 4

eukaryotic; a, b, c, d

others in bacteria known as bacteriochlorophylls

Question 5

structure of chlorophyl

Answer 5

two main parts;
1. flat, light absorbing hydrophillic head
>complex poryphyrin ring made of 4 pyroles
>Mg present in center of porphyrin ring coordinated with 4 N.

2. Hydrophobic tail

Question 6

diff between chlorophyl a and b on functional groups

Answer 6

methyl group in Chlorophyl a is replaced by terminal carbonyl group in chlorophyl b

chlorophyll a: C55 H72 O5 N4 Mg
chlorophyll b: C55 H70 O6 N4 Mg

Question 7

are chlorophyl soluble?

Answer 7

Insoluble in water

Soluble in organic solvents (CCl4, alcohol)

Question 8

how much of total photosynthesis carried out by terrestial plants

Answer 8

10%

Question 9

Photosynthesis consists of two parts ;

Answer 9

1. light dependant reactions
   >light energy absorbed by chlorophyl
   >converted intoo chemical energy
   >NADPH & ATP formed

2.light independant reactions
>reduction of CO2

Question 10

Non cyclic phosphorylation

Answer 10

1. p2 absorbs light, electron excited to higher enrgy level.
2. photolysis occurs
3. excited e- passed to P1 via ETC.{Plastoquinone is an electron carrier of tw cytochromes and copper containing protein Pc}
4. e- moving down the chain, ATP produced[photophoshphorylation]
   5.NADP reductase transfers e- to NADP.

Question 11

Action spectrum

Answer 11

Graph of absorption by pigments

Question 12

Photosystems absorbance

Answer 12

Ps1 700nm
Ps2 680nm