mitochondria and chloroplasts 2

Question 1

Function of chloroplasts

Answer 1

Harvest energy from sunlight, convert it to chemical energy to fix carbon from the atmosphere (CO2) into sugars

Question 2

Features of phosphorylation

Answer 2

Electrons passed along ETC are from water, but unlike NADH, H2O is a poor donor of electrons, so requires energy input from light to extract electrons

Question 3

How does light raise energy of electrons

Answer 3

Sunlight absorbed by chorophyll and electrons interact with photons, raising them to higher energy level

Question 4

What does chlorophyll look like

Answer 4

Haem, except metal ion at the centre is Mg not Fe

Question 5

in depth explanation of electron transfer from panopto

Answer 5

When chlorophylls in antenna complex absorb light they channel it into electrons in special pair of chlorophylls- get excited to higher energy level, can be donated to electron acceptor
If electrons are low energy can’t be passed onto electron acceptor (See diagram)

Question 6

Mobile electrons carriers: Plastoquinone

Answer 6

resembles ubiquinone of mitochondria

Question 7

Plastocyanin

Answer 7

small copper containing protein

Question 8

Ferredoxin

Answer 8

Small protein containing a Fe-S centre

Question 9

How is ATP generated

Answer 9

BY proton gradient across thylakoid membrane, same as in mitochondria

Question 10

What are high energy electrons passed onto form at the end of the ETC

Answer 10

high energy NADPH, strong reducing agent

Question 11

What are high energy electrons passed onto form at the end of the ETC

Answer 11

high energy NADPH, strong reducing agent

Question 12

What are the NADPH and ATP generated by light dependent PS used for?

Answer 12

Energy sources to fix carbon from CO2 into sugars (by calvin cycle)

Question 13

RUBISCO

Answer 13

Ribulose biphosphate carboxylase

Question 14

Function RUBISCO

Answer 14

Catalyses initial reaction in carbon fixation
Very slow enzyme, so a lot is required to fix a lot of carbon
Catalyses addition of one carbon (CO2) onto a 5C (ribulose biphosphate) molecule to make a 6C intermediate, then cleaved to produce 2 3C molecules

Question 15

Calvin cycle overview (add to from panopto)

Answer 15

For every three carbons that are fixed a 3C molecule can be removed from the cycle
glyceraldehyde 3-phosphate

Question 16

For every 3 carbon sugar produced what is required

Answer 16

9 ATP and 6 NADPH

Question 17

Thylakoid contents

Answer 17

PS I and II, ATP synthases and NADP reductase

Question 18

Stroma processes

Answer 18

ATP synthesised, NADPH synthesised, carbon fixation, DNA

Question 19

Similarities between processes in mitochondria and chloroplasts

Answer 19

Both use proton gradients across membranes to make ATP using ATP synthase
Electron transport along an ETC drives proton pump
Some components of ETC same- cytochrome bc and b6f similar and ubiquinone and plastoquinone resemble one another

Question 20

Photosystems

Answer 20

Antenna complex and reaction centre

Question 21

What do electrons extracted from water replace

Answer 21

electrons lost from PSII

Question 22

Other products of splitting of water

Answer 22

O2

H+- contributes to proton gradient across thylakoid membrane

Question 23

order in thylakoid membrane

Answer 23

PS II, cytochrome b6-f, (similar to bc-1) PS I, NADP reductase

Question 24

What is energy lost from electrons used for

Answer 24

pumping protons

Question 25

What is energy lost from electrons used for

Answer 25

pumping protons into thylakoid lumen

Question 26

Light energy harnessed to produce

Answer 26

ATP and NADPH

Question 27

What does the electrochemical gradient produced by protons do

Answer 27

Generate ATP, protons flow through ATP synthase same way as in mitochondria

Question 28

NADPH

Answer 28

high energy compound, good electron donor

Question 29

Where is water split

Answer 29

thylakoid lumen

Question 30

order in thylakoid membrane including mobile electron carriers

Answer 30

PS II,
plastoquinone
cytochrome b6-f, (similar to bc-1)  
plastocycanin
PS I
ferredoxin
NADP reductase

Question 31

direction protons are pumped in chloroplasts

Answer 31

stroma into thylakoid

Question 32

direction protons are pumped in mitochondria

Answer 32

intermembrane space

Question 33

where ATP made in chloroplasts/mitochondria

Answer 33

chloroplasts: stroma
mito: matrix