Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

104 Theme 2 > The roles of ATP in living cells and mechanisms of production part 1 > Flashcards

The roles of ATP in living cells and mechanisms of production part 1 Flashcards

1
Q

what is metabolism

A

integrated set of enzymatic reactions comprising both anabolic and catabolic reactions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

what is anabolism

A

synthesis of complex molecules from simpler ones (necessary energy usually derived from ATP)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

what is catabolism

A

breakdown of energy rich molecules to simpler ones (CO2 H20 NH3)
(energy released is captured as ATP and stored for later use in anabolic reactions)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

how can anabolic and catabolic reactions be told apart

A

Anabolic – synthetic reactions (pathways end in genesis eg glycogenesis)
Catabolic – breakdown reactions (pathways end in lysis eg glycolysis)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

why are bioenergetics important

A

Living cells and organism must perform work to stay alive
Energy required for motion (muscle contraction), transport (of ions/molecules across membranes), biosynthesis of essential metabolites), thermoregulation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

why are storage forms of energy needed

A

Timing of processes doesn’t necessarily coincide with feeding times

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

why do cells require sources of free energy

A

Cells are isothermal systems so heat flow can’t be used as energy so free energy (energy available to perform work is acquired from nutrient molecules

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

what are important thermodynamic quantities

A

Gibbs free energy (G) – energy capable of doing work at constant temp and pressure
Enthalpy (H) – the heat content of reacting system
Entropy (S) – the randomness or disorder of a system

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

how goes G relate to H and S in cells

A

G=H-T S (change in all, ex T)
G of reaction – max energy that can be obtained from a reaction at a constant temp and pressure
H reflects the kinds and numbers of chemical bonds broken and formed (positive when energy absorbed by reaction)
S is formation of large complex molecules from smaller ones and vice versa (positive when randomness increases such as breaking up a larger molecule into smaller ones)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

how does free energy change

A

A->B
Greater conc of B than A at equilibrium
Spontaneous or exergonic reaction, free energy defined as negative (G<0), energy liberated by reaction
Greater conc of A
Unfavourable or endergonic reaction, free energy positive, energy input required to start reaction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

what are exergonic reactions

A

Products have less free energy than reactants and are more stable, formation downhill
change in G negative
catabolism

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

what are endergonic reactions

A

Products have more free energy than reactants so are less stable, uphill reaction
change in G positive
anabolism

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

how do endergonic reactions occur

A 
Endergonic reaction coupled to exergonic to drive it forward, via common intermediate 
eg Glucose+Pi>G6P+H20 (exo)
ATP+H2O>ADP+Pi (endo)
overall
ATP+Glucose>ADP+G6P
change in G negative
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

what is ATP

A

Provides most of free energy required for endergonic reactions
ATP currency of cell, achieved by phosphate group transfer

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

How does ATP link to G

A

energy derived from oxidation of dietary fuels to generate ATP, energy conserved as ATP and transduced into useful work

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

How does ATP link to Mg2+

A

ATP/ADP Mg2+ complexes
ATP in cytosol is present as a complex with Mg2+
Mg2+ interacts with oxygens of triphosphate chain making it susceptible to cleavage in the phosphoryl transfer reactions

Mg2+ deficiency impairs virtually all metabolism

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

what is substrate level phosphorylation

A

Formation of ATP by phosphate group transfer from substrate to ADP
Require soluble enzymes and chemical intermediates

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

how is SLP different to Respiratory linked phosphorylation

A

resp linked phosphorylation involves membrane bound enzymes and transmembrane gradients of protons and require oxygen

19
Q

what are enzymes

A

Biological catalysts that accelerate rate of chemical reactions by creating a new pathway with a lower activation energy
Does not influence G of reaction

20
Q

what enzymes are important to know for SLP

A

Oxidoreductases - transfer of electrons

transferases - transfer of functional groups

21
Q

what are coenzymes an cofactors

A

Cofactors – non protein molecules necessary for enzyme activity eg metal cations and coenzymes

22
Q

what are coenzymes

A

Most are organic molecules derived from vitamins
Participate in enzymatic reactions
Cycle between oxidised and reduced forms
made of cosubstrates and prosthetic groups
CE and CS loose association to enzyme and diffuse between enzymes carrying e-

23
Q

what are prosthetic groups

A

non protein cofactor that is covalently bound to enzyme so not released as part of reaction, acts as temporary e- store or intermediates

24
Q

what are coenzymes and prosthetic groups

A

vitamin precursors

eg B2 > FAD/FMN or Niacin > NAD+

25
Q

What do redox coenzymes and prosthetic groups do

A

Major redox coenzyme/prosthetic groups involved in transduction of energy from dietary foods to ATP – NAD+/FAD/FMN
Electrons are transferred from dietary material to these carriers – coenzymes reduced
In each case 2 e- transferred but H+ moved varies
Eg NAD+ reduced to NADH but FAD reduced to FADH2

26
Q

what is Nicotinamide adenine dinucleotide

A

NAD+
NAD+ and NADP+ accept pairs of e- to form NADH or NADPH
Nicotinamide is functional part
NADH for ATP synthesis and NADPH for reductive biosynthesis

27
Q

what happens to redox coenzymes after they’re used

A

re-oxidation
Recycling of NADH and FADH2 is via resp chain in mitochondria
Coupled to ATP synthesis – process of oxidative phosphorylation

28
Q

where does cellular energy metabolism occur

A

Proteins/carbs/lipids to AA/glucose/FA and glycerol
glycolysis to pyruvate - cytosol
rest in mitochondria
Pyruvate to Acetyl-CoA - CAC-CO2- Oxidative phosphorylation

29
Q

what is glycolysis

A

glucose to glucose-6-phosphate
to fructose-6-phosphate
to fructose-1,6-biphosphate
to dihydroxyacetone phosphate or glyceraldehyde-3-phosphate

30
Q

what converts glucose to G6P

A

Hk
ATP to ADP
PRIMING REACTION

31
Q

what converts G6P to F6P

A

isomerase

32
Q

what converts F6P to F1,6BP

A

PFK-1
ATP to ADP
PRIMING REACTION
COMMITTED STEP

33
Q

What converts F1,6BP to DHAP/G3P

A

Aldolase
DHAP to G3P interconverted by isomerase
G3P continues to glycolysis

34
Q

what are payoff reactions

A 
G3P
1,3 biphosphoglycerate
3 phosphoglycerate
2 phosphoglycerate
phosphoenolpyruvate
pyruvate
35
Q

what steps of payoff reactions are SLP

A

3P to pyruvate

36
Q

what converts G3P to 1,3BPG

A

GAPDH

NAD+ - NADH

37
Q

what converts 1,3BPG to 3P

A

PGK

ADP to ATP

38
Q

what converts 3P to 2P

A

Mutase

39
Q

what converts 2P to PP

A

ENOLASE

40
Q

what converts PP to pyruvate

A

PK

ADP to ATP

41
Q

What key enzymes are involved in priming

A

Hexokinase - phosphorylation
PFK-1 - phosphorylation
Pyruvate kinase - phosphorylation

42
Q

what is a summary of priming

A

investment of ATP at the hexokinase and PFK-1 reaction

uses2 ATP and produces to C3 molecules (interconvertible DHAP and GAP)

43
Q

What is a summary of payoff

A

recovery of ATP by SLP in 1,3BPG and pyruvate reactions

generates 4 ATP and 2 NADH and various intermediates

44
Q

what is pyruvate converted to

A

Pyruvate formed from glucose via glycolysis
Aerobic – oxidised and degraded to CO2 and H20
Hypoxic – reduced to lactate (lactate dehydrogenase, canoe reduced back with O2)

104 Theme 2 (22 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions