ATP

Question 1

Anabolism

Answer 1

synthetic reactions
genesis
glycogenesis

Question 2

Catabolism

Answer 2

breakdown reactions
lysis
glycolysis

Question 3

Why is metabolism important?

Answer 3

Energy is required for:
- motion
- transport
- biosynthesis
- thermoregulation

Question 4

Cells requires sources of free energy

Answer 4

maintaining life requires constant investment in energy, when a cell can no longer obtain energy it dies and decays

• free energy is energy available to perform work and is
  accquired from nutrient molecules

C6H12O6+6)2->6CO2+6H2O+ energy

Question 5

Enthalpy (H)

Answer 5

the heat content of the reacting system

Question 6

Entropy (s)

Answer 6

the randomness or disorder in a system

Question 7

Gibbs Free Energy

Answer 7

energy capable of doing work at a constant temp and pressure

Question 8

In cells the enthalpy change (deltaH) reflects

Answer 8

• the chemical bonds broken and formed
• delta H is positive when energy is absorbed by the
  reaction (endothermic)

Question 9

In cells the change in entropy (delta S) describes

Answer 9

the formation of large complex proteins from smaller molecules or vice verse

• delta S is positive when randomness increases
  (breaking a bigger molecule into smaller molecule)

Question 10

Gibbs free energy equation

Answer 10

Question 11

For a reaction to occur spontaneous delta G must be

Answer 11

negative (energy is released by the reaction)

Question 12

Catabolism is endergonic or exergonic

Answer 12

exergonic
products have less free energy and so are more stable than the reactants

Question 13

exergonic reactions

Answer 13

Question 14

endergonic reactions

Answer 14

Question 15

Coupling of reactions:

Answer 15

an endergonic reaction can be driven in the forward direction by coupling it to an exergonic reaction

the hydrolysis of ATP provides the energy to drive an unfavourable reaction

Question 16

ATP is the energy currency of the cell

Answer 16

achieved by phosphate group transfer

Question 17

Substrate level phosphorylation

Answer 17

• formation of ATP by the transfer of a phophoryl froup
  from a substrate to ADP
• distinguished from respiration linked phosphorlyation
• substrate level phosphorylation requires soluble
  enzymes and chemical intermediates
• respiration linked phosphorylates involve membrane
  bound enzymes and transmembrane gradients of
  protons and require oxygen

Question 18

Enzymes influence the delta G of the reaction.

True or False?

Answer 18

False
DOES NOT INFLUENCE DELTA G

Question 19

cofactors and coenzymes

Answer 19

Question 20

prosthetic groups

Answer 20

• non-protein cofactor that is covalently bound to the
  enzyme
• not released as part of the reaction
• acts as a temporary store for e—– or reaction
  intermediates

Question 21

What vitamin is a precursor for FAD/FMN coenzyme?

Answer 21

B2 (riboflavin)

Question 22

What vitamin is a precursor for NAD+?

Answer 22

Niacin

Question 23

Nicotinamide Adenine Dinucleotide (NAD+):

Answer 23

NAD+ and NADP+ accept PAIRS of e- to form NADH or NADPH

it is the nicotinamide that is the functional part of the molecule

Question 24

NADH for
NADPH for

Answer 24

• ATP synthesis
• reductive biosyntheses

Question 25

Recycling of NADH and FADH2 is via the

Answer 25

respiratory chain in the mitochondria OXIDATIVE PHOSPHORYLATION

Question 26

summary of energy metabolism

Answer 26

Question 27

glycolysis summary

Answer 27

Question 28

2 fates of pyruvate

Answer 28

- aerobic: oxidation and complete degradation - hypoxic: reduced to lactate

Question 29

structure of mitochondria

Answer 29

Question 30

Transport of pryuvate into the mitochondria:

Answer 30

- aerobic: pyruvate transport occurs via the specific carrier protein embedded in the mitochondrial membrane - pyruvate undergoes oxidative deccarboxylation by the ***pryuvate dehydrogenase complex to form acetyl CoA - reaction is irreversible and is the direct physical link link between glycolysis and the citric acid cycle

Question 31

Reaction equation the is the link between glycolysis and the citric acid cycle?

Answer 31

pyruvate +CoA + NAD+ -> acetyl CoA + CO2 + NADH + H+

Question 32

Glycolysis priming stages

Answer 32

Glucose-G3P is training stage because energy needs to be put in; ENERGY REQUIRED!!! Committed step is F6P to FBP; by phosphofructoskinase-1; want more G3P

Question 33

Glycolysis payoff stages

Answer 33

GAPDH changes G3P to 1,3 BGP by reducing 1 NAD to NADH **PGK uses substrate level phosphorylation to change 1,3 BGP to 3-phosphoglycerate Mutase changes 3-phosphoglycerate into 2-phospho-glycerate Enolase changes this into phosphophenolpyruvate ***Which is turned into pyruvate by PRYUVATE KINASE; also substrate level phosphorylation

Question 34

Fate of pyruvate: Why has this system of lactate production evolved?

Answer 34

RBC do not have mitochondria so no Kreb cycle so always make lactacte, which is taken to liver

Question 35

A hydride ion

Answer 35

Is a proton with two electrons

Question 36

Kerbs/Citric acid cycle

Answer 36

Question 37

Kerbs/Citric acid cycle: 2 carbon acetyl groups are fed into the cycle which

Answer 37

Enzymatically oxidises them to CO2; the energy released is stored as either ATP, NADH, FADH2

Question 38

What are the 9 steps of the critic acid cycle?

Answer 38

1) oxaloacetate joins Acetyl CoA to form citrate 2) citrate is converted to isocitrate 3) isocitrate id decarboxylated to alpha ketoglutarate (NADH produced) 4) succinate CoA is added to alpha ketoglutarate by oxidative decarboxylation (NADH produced) 5) succinyl CoA converted to succinate (ATP) 6) succinate is dehydrogenated to fumarate (FADH2) 7) fumurate hydrated to malate 8) malate dehydrogenated to oxoaloacetate (NADH) 9) Citric acid cycle begins again

Question 39

Step 1 of the citric acid cycle:

Answer 39

- acetyl CoA and oxaloacetate joined by enzyme citric synthesis in a condensation reaction to form citrate

Question 40

Step 2 of the citric acid cycle

Answer 40

Aconitase enzyme converts citrate into isocitrate

Question 41

Step 3 of the citric acid cycle

Answer 41

Enzyme isocitrate dehydrogenase -> Isocitrate is decarboxylated to alpha ketoglutarate using NAD and creating NADH

Question 42

Step 4 of the citric acid cycle:

Answer 42

Alpha-ketoglutarate dehydrogenase -> alpha ketoglutarate and succinate CoA join to form succinyl CoA, CO2 and uses NAD and forms NADH

Question 43

Step 5 of the citric acid cycle

Answer 43

Enzyme succinyl-CoA synthetase converts succinate to succinyl CoA via substrate level phosphorylation producing ATP

Question 44

Step 6 of the citric acid cycle:

Answer 44

Enzyme Succinate dehydrogenase -> Succinate is dehydrogenated to fumurate generating FADH2

Question 45

Step 7 of the citric acid cycle

Answer 45

Enzyme fumurase hydrates fumurate to malate

Question 46

Step 8 of the citric acid cycle

Answer 46

Enzyme Malate dehydrogenase -> Malate is dehydrogenated to oxaloacetate generating NADH

Question 47

THE CITRIC ACID CYCLE PRODUCT TALLY:

Answer 47

1 turn of cycle: 2 carbons enter (acetyl CoA), 2 carbons leave (CO2 x2) For one glucose molecule: Glycolysis: 4 ATP, NADH Citric acid cycle: - 3 x NADH x2 = 6NADH - 1x ATP x2 = 2 ATP - 1 x FADH2 x 2 = 2 FADH2

Question 48

Regulation of the citric acid cycle

Answer 48

- flow of carbon atoms from pyruvate into and through the citric acid cycle is tightly regulated at 2 levels: 1) conversion of pyruvate into acetyl Co-A (PDH reaction) 2) entry of acetyl-CoA into the TCA cycle (citrate synthase reaction) 3) isocitrate dehydrogenase to alpha ketoglutarate dehydrogenase reaction

Question 49

Regulation of the TCA cycle

Answer 49

Question 50

The electron transport chain

Answer 50

- NADH and FADH2 are re-oxidised using electron transport proteins - series of coupled oxidation and reduction reactions - electron transport chain or respiratory chain - terminal acceptor of electrons is O2 which is REDUCED to H20

Question 51

ATP synthesis via oxidative phosphorylation utilises ——- energy and ——— ——- energy caused by a difference in the ———— provided by ——- pumping from the ——- to the ———- ——- by complexes —-, ——-, ——. The ——- motive force (the separation of charge between the ———— and the ———— ———) drives the synthesis of ATP using the enzyme ——— ————-

Answer 51

- electrical - chemical potential - proton concentration - proton pumping - mitochondrial matrix - inter membrane space - 1 - 3 - 5 - proton motive force - intermembrane space - mitochondrial matrix - ATP synthase

Question 52

ATP synthase

Answer 52

- composed to structures F0 and F1 - F0 resides in the innner membrane of mitochondria - F1 projects into the matrix - as H+ flows through the membrane, the cylinder within F0 and the y shaft rotate - as the y shaft interacts with each of the beta subunits of F1, they change conformation and facilitate the formation of ATP from ADP and Pi