respiration + photosyn

Question 1

where does glycolysis occur?

Answer 1

cytosol of the mitochondrion

Question 2

what are the products of glycolysis

Answer 2

two pyruvate molecule, 2NADH and 2 ATP

Question 3

during glycolysis, what are the 5 pdts in the pathway

Answer 3

glucose to fructose 1,6 biphosphate to G3P to 1,3 biphosphoglycerate to Glycerate phosphate to pyruvate

Question 4

what are the 5 main steps that occur in photosynthesis

Answer 4

phosphorylation of sugar
lysis
oxidation by dehydrogenation
substrate level phosphorylation
oxidative decarboxylation

Question 5

what happens in the link reaction (aerobic)

Answer 5

pyruvate enters the mitochondrial matric by an active process via a transport protein; 2 pyruvate molecules undergo oxidative carboylation and each combines with a coenzyme A moleucle to form 2 acetyl coA molecules; 2 NADH and 2CO2 is produced

Question 6

where does the link reaction occur in

Answer 6

mitochondrial matrix

Question 7

where does krebs cycle occur in

Answer 7

mitochondrial matrix

Question 8

outline the products of the krebs cycle

Answer 8

acetyl CoA to citrate to alpha ketoglutarate to oxaloacetate

Question 9

outline the process of the krebs cycle

Answer 9

OD –> OD –> 4 –> 6–> 6 ; 6NADH and 2 FADH and 2 atp +4 CO2 produced

Question 10

outline the process of oxidative phosphorylation
7steps: think movement of electrons

Answer 10

when molecular oxygen is available, nadh from glycolysis, the link rxna nd the krebs cycle, donates high energy electrons to the first electron carrier of the electron transport chain
the first e carrier is thus reduced and the NAD which is regenerated can pick up electrons and protons from glycolysis, the link reaction or the krebs cycle, the first electron carrier then transfers the electon to the next electron carrier and reduces it while the first carrier itself becomes reoxidised
the transfer of electrons continues in this manner until they combine with protons and molecular oxygen, the final electron acceptor to form metabolic H20 in the matrix. this reaction is catalysed by cytochrome oxidase.
as electrons are transferred down the increasingly electronegative electron carriers in the ETC, energy is released.
this energy is used to actively pump protons from the mitochondrial matrix to the intermembrane space via the electron carriers. this creates a proton gradient across the inner mitochondrial membrane as the charged protons cannot pass thru the hydrophobic core of the inner mitochondrial membrane. the energy stored in the form of a proton gradient across a membrane is known as a proton motive force.
as protons diffuse through ATP synthase down the proton gradient from the intermembrane space into the mitochondrial matrix, ATP synthase phosphorylates ADP to ATP in the matrix via chemiosmosis
FADH2 donates electrons further down the ETC compared to NADH. hence less energy is released form FADH2 during electron transfer. the regenerated FAD then can pick up electrons and protons from the krebs cycle.

Question 11

where does oxidative phosphorylation occur

Answer 11

on the inner mitochondrial membrane, H+ in the intermembrane space

Question 12

what is the total ATP from the oxidation of 1 glucose molecule

Answer 12

38.

Question 13

what is chemiosmosis

Answer 13

an energy coupling mechanism that uses energy stored in the form of proton gradient across a membrane to synthesise ATP

Question 14

`outline the process of anaerobic respiration (both)
10pts

Answer 14

in the absence of oxygen, there is no final electron acceptor to accept electrons from the ETC
electron carriers remain reduced and so NADH and FADH2 can no longer donate electrons to the ETC. hence OP cannot occur.
no regeneration of NAD and FAD thus link rxn and krebs cycle cannot occur
glycolysis can still occur as the NAD needed for glycolysis is regenerated from fermentation rxns
ATP is only produced from glycolysis.
in animals pyruvate is reduced by electrons from NADH in the presence of lactate dehydrogenase to lactate.
in yeasts pyruvate is converted to ethanal and CO2. it is then reduced by electrons from NADH in the presence of alcohol dehydrogenase to ethanol.
thus pyruvate or ethanal are the final electron acceptors during anaerobic respiration.
only 2 ATP produced per glucose molecule.

Question 15

what is ATP

Answer 15

adenosine triphosphate; it is actually a carrier of energy. can also be used to form RNA

Question 16

outline the differences between photosynthesis and aerobic respiration

Answer 16

features: anabolic/catabolic
energy storage
oxygen
CO2 and h20
dry mass
conditions
organelle
electron carrier
high H+ location
major reactions

Question 17

outline the differences between photophosphorylation and oxidative phosphorylation

Answer 17

features:
location
involvement of light
source of energy for ATP synthesis
energy conversion
electron donors
electron acceptors
by-product
proton gradient

Question 18

distinguish between the krebs and calvin cycle

Answer 18

features: location
redox reaction
carbon dioxide
ATP
substance regenerated

Question 19

functions of NAD and FAD

Answer 19

coenzymes that serve as mobile electron carrier which transport the high-energy electrons from organic molecules to the ETC in the mitochondrial membrane

Question 20

functions of ETC

Answer 20

generate PMF to produce ATP and regenerate NADH and FADH2 from NAD and FAD

Question 21

importance of oxygen

Answer 21

acts as the final electron acceptor at the end of the ETC where it combines with electrons and protons to form water, o2 reoxidises the ETC so that the electron carreir NADH and FADH2 can continue donating their electrons to the chain, allowing electron flow, thereby allowing OP to continue to generate ATP by chemiosmosis.
the NAD and FAD are regenerated when NADH and FADH donate electrons to the ETC, allowing NAD and FAD to pick up more electrons and protons from glycolysis, link rxn and krebs cycle, allowing these processes to continue.
reduction of oxygen to water removes H+ from the matrix, contributing to the generation of a proton gradient across the inner mitochondrial membrane.

Question 22

OUTLINE NONCYCLIC PHOTOPHOSPHORYLATION

Question 23

OUTLINE CYCLIC PHOTOPHOSPHORYLATION

Answer 23

In cyclic photophosphorylation, electrons displaced from P700 if PS1 accepted by the primary electron acceptor Y are transferred to the middle of the 1st ETC. the elctron is transported down the ETC and is finally recycled back to PS1. energy lost during electron transfer is coupled to the formation of ATP in a manner similar to non-cyclic photophosphorylation. only PS1 is involved and only ATP is produced.

Question 24

outline light independent reaction process

Answer 24

1: carbon fixation: CO2 combines with RuBP in the presence of the enzyme ribulose biphosphate carboxylase
2: reduction and sugar formation: GP is reduced to G3P; ATP and NADH is required
3 regeneration of RUBP . g3p is either converted to sugars or regenerate RuBP

Question 25

define photophosphorylation

Answer 25

formation of ATP from ADP + inorganic phosphate using light energy in photosyn

Question 26

define resonance transfer

Answer 26

when a chlorophyll molecule absorbs light, the energy from light raises one of its electrons to a higher energy level. and vice versa

Question 27

define photoactivation

Answer 27

when a chlorophyll molecule absorbs light, the energy from this light raises one of its electrons to a higher energy level. that chlorophyll molecule is said to be photoactivated

Question 28

what is the compensation point

Answer 28

light intensity at which rate of photosynthesis is equal to rate of respiration

Question 29

what is the absorption spectrum and action spectrum

Answer 29

amount of light absorbed vs effectiveness of different wavelengths of light in stimulating photosynthesis

Question 30

distinguish between light dependent and light independent reactions

Answer 30

features: location
conditions
reactions involved
reactants
products
by-products

Question 31

difference between noncyclic and cyclic photophosphorylation

Answer 31

features: similarities : energy lost; both take place on membranes, ADP is phosphorylated to ATP via chemiosmosis.
conditions
pathway of electrons
photosystems involved
first electron donor
last electron acceptor
products
high H+ in thylakoid space

Question 32

what is the role of NADP in photosyn

Answer 32

coenzyme that carries both protons and high energy electrons
final electron acceptor in the non-cyclic light dependent reaction in the thylakoid membrane

Question 33

what contributes to high H+ conc in the thylakoid space

Answer 33

1) proton pump
2)photolysis of water
3)lack of permeability of thylakoid membrane
4) reduction of NADP to NADPH

Question 34

Describe the function of the thylakoid membrane in photophosphorylation

Answer 34

1) it provides a large SA to embed many photosynthetic pigments for light absorption
2) maintains the sequential arrangement of the electron carrier of ETC for the flow of electrons
3) maintains proton gradient for ATP synthesis since the hydrophobic core of the membrane is impermeable to protons and is essential for chemiosmosis
4) allows of many ATP synthase to be embedded so ATP can be produced as protons flow down their gradient via chemiosmosis from thylakoid space to stroma.