Energy transfers in and between organisms

Question 1

Photosystems

Answer 1

structures that photosynthetic pigments are arranged in

Question 2

where are photosystems found

Answer 2

thylakoid membranes

Question 3

accessory pigments

Answer 3

absorb the wavelengths of light that are not easily absorbed by chlorophyll and are not directly involved in the light dependent reactions. They channel more captured light energy to chlorophyll so more electrons can be excited.

Question 4

where is p680 chlorophyll a

Answer 4

photosystem 2

Question 5

where is p700 chlorophyll b

Answer 5

photosystem 1

Question 6

primary pigment centre

Answer 6

where chlorophyll a is at the base of the photosystem

Question 7

p700 absorption peak

Answer 7

700nm

Question 8

p680 absorption peak

Answer 8

680nm

Question 9

how do photosystems work

Answer 9

The energy from absorbing light is passed from 1 accessory pigment to another
until it reaches the primary pigment. The energy is then used to excite pairs of electrons in the reaction centre
pigment. The electrons move up to a higher energy level, ready to be used in the
light dependent reactions

Question 10

why is it useful for plants to have different pigments

Answer 10

so more wavelengths of light can be absorbed

Question 11

Thylakoid adaptations for photosynthesis

Answer 11

contain photosynthetic pigments, large SA to increase absorption, contains ATP synthase to make ATP

Question 12

Oxidation

Answer 12

loss of electrons, energy released

Question 13

Reduction

Answer 13

gain of electrons, energy taken in

Question 14

where does the light dependant reaction of photosynthesis take place

Answer 14

thylakoid membranes

Question 15

light independant reaction

Answer 15

-CO2 combines with RUBP
-produces 2, 3GPs
-GP is reduced to form TP
-requires reduced NADP and energy from ATP
-TP is converted to glucose

Question 16

light dependant reaction

Answer 16

-light energy breaks down water forming H+, e- and oxygen
-forms H+ gradient
-electrons travel through electron transport chain
-reduced NADP produced (NADP+H+)
-ATP produced by phospholyration

Question 17

phospholyration equation

Answer 17

ADP + Pi = ATP

Question 18

Photolysis equation

Answer 18

H2O = H+ + e- + O2

Question 19

electron carriers

Answer 19

proteins which transfer electrons

Question 20

Glycolysis

Answer 20

~Glucose phospholyrated to hexose biphosphate
~hexose biphosphate converted to 2 Triose Phosphates
~The TPs are oxidised to form pyruvate
~produces NADH

Question 21

Link reaction

Answer 21

~Pyruvate enters mitochondria
~Pyruvate combines with coenzyme a to form acetylcoenzyme a
~CO2 and Hydrogen are removed from pyruvate

Question 22

Krebs cycle

Answer 22

~acetylcoenzyme a combines with oxaloacetate to form a 6C compound
~CO2 released, hydrogen reduces NAD and FAD to NADH and FADH
~oxaloacetate regenerates to be used again
~2 ATP molecules produced

Question 23

Electron Transport Chain (respiration)

Answer 23

~NADH and FADH oxidised to NAD and FAD
~ H removed splits into proton and e-
~electrons pass through electron carriers, releasing energy which is used to pump H+ ions from matrix to intermembrane space through ATPase
~converts ADP to ATP
~water is formed by combining of proton, e- and O2

Question 24

What stages happen in anaerobic respiration

Answer 24

Just Glycolysis

Question 25

Nitrogen cycle

Answer 25

~ammonification- nitrogen containing compounds broken down by saprobionts to produce ammonia
~nitrification- ammonia converted to nitrite then nitrate ions
~denitrification- bacteria convert nitrate ions to nitrogen gas
~nitrogen fixation- nitrogen gas converted to nitrogen containing compounds