The roles of ATP in living cells and the mechanisms of production of ATP Flashcards

1
Q

What is anabolism?

A
  • simple molecules put together to form complex molecules
  • complex molecules will then be stored as energy
  • think A = Adding molecules together
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What do anabolism terms end in?

A
  • genesis
  • e.g. glycogenesis (glucose to glycogen)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is an example of anabolism?

A
  • glycogenesis (glucose into glycogen)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is catabolism?

A
  • breakdown of complex molecules into simple molecules
  • think C for catabolism = Cut up molecules
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What is an example of catabolism?

A
  • glycogen to pyruvate
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What do all terms used to describe catabolism end in?

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

what is catabolims and anabolims together referred to as?

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

When catabolic reactions something is released and captured and used later in anabolic reactions, what is this?

A
  • adenosine triphosphate (ATP)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

If organisms do not work to produce energy what will happen to them?

A
  • they will die
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What are a few examples of how energy is requried in the body?

A
  • muscle contraction
  • ions/molecules transport across membranes
  • biosynthesis of essential metabolites, growth and replace damaged cells
  • thermoregulation
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Energy in the body, called free energy must come from somewhere, where is this?

A
  • nutrients that we consume.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What is Gibbs Free Energy?

A
  • thermodynamic calculation
  • used to calculate the maximum reversible work that may be performed by a thermodynamic system at a constant temperature and pressure.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

There are 3 parts to Gibbs Free Energy, what is enthalpy?

A
  • the heat content of the reacting system
  • referred to as H
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

There are 3 parts to Gibbs Free Energy, what is entropy?

A
  • the randomness or disorder in a system
  • referred to as S
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

There are 3 parts to Gibbs Free Energy, what is Gibbs Free Energy?

A
  • energy capable of doing work at constant temperature and pressure
  • referred to as G
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

In cells what does the change in enthalpy (/_H)_ relate to?

A
  • types and numbers of chemical bonds broken and formed
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

In cells if the change in enthalpy (_/_H) is positive (+ve) is this an endothermic or exothermic reaction? A positive change in energy indicates that energy is required to produce something. Ball rolling down or up a slide for example:

  • ball rolling down = reduced enthalpy (energy released from glucose through breaking the bonds of glucose)
  • ball rolling back up = increased enthalpy (energy required to make bonds, such as glucose to glycogen)
A
  • endothermic (anabolism = adding/building)
  • energy has to be invested to make new bonds
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

In cells what does the change in entropy (_/_S) refer to?

A
  • describes the formation of large complex molecules from smaller molecules or vice versa
  • (e.g. DNA formation/protein formation)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

In cells a postive (+ve) change in entropy (_/_S) refer to what?

A
  • when randomness increases (i.e. breaking up a big molecule to smaller molecules)
  • breaking fown glucose into ATP
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What is the formula for determining change in gibbs free energy?

A
  • _/_G = _/_H - T x _/_S
  • _/_G = Change in Gibbs Free Energy
  • _/_H = Change in enthalpy
  • _/_S = Change in entropy
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

When we are looking at Gibbs Free Energy, if a random reaction is to occur, what must the _/_G (Change in Gibbs Free Energy be?

A
  • negative (i.e. energy is released by the reaction)
  • also referred to as an exergonic reaction
  • catabolic reactions release energy
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What is an exergonic reaction in thermodynamics?

A
  • a chemical reaction where the change in the free energy is negative (there is a net release of free energy)
  • reactants are turned into products
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Following an exergonic reaction in thermodynamics, do products or reactants have more energy?

A
  • reactants
  • reactants become more stable than the reactants
  • formation of product is “downhill” (spontaneous)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

An example of an exergonic reaction is breaking down (burning) glucose into pyruvate, is this a anabolic or catabolic reaction?

A
  • catabolic
  • releasing energy
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

What is an endergonic reaction?

A
  • reactants are turned into products
  • glucose into glycogen is an example
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

In an endergonic reaction energy is invested to turn reactants into products, such as the formation of glucose into glycogen. Are the reactants or the products more stable?

A
  • reactants are more stable
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

Why is coupling of reactions important in metabolism?

A
  • endergonic reactions can be driven in the forward direction by coupling it to an exergonic reaction
  • anabolic reactions can drive catabolic reactions
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

Coupling of reactions is important in metabolism. Endergonic reactions can be driven in the forward direction by coupling it to an exergonic reaction (catabolic reactions can drive anabolic reactions). An example of this is:

A
  • coupled with a exergonic reaction (catabolic)
  • ATP + H2O = ADP + Pi
  • this provides _/_G of -30.5 kJ/mol
  • -30.5 - 13.8 = -16.7 meaning reaction will occur as _/_G is negative and it will be spontaneous
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

What is the principle of coupling reactions?

A
  • couple a reaction that requires energy with one that produces energy
  • catabolic = produces energy
  • anabolic = requires energy
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

In thermodynamics the hydrolysis of ATP is able to drive the an unfavourable reaction, which is essentially one where Gibbs Free Energy is not negative. What does the hydrolysis of ATP do then to help?

A
  • releases free energy
  • energy released ensures Gibbs Free Energy is negative
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

Adenosine triphosphate has 3 phosphate groups, hence the tri in its name. If it has one or two phosphate groups attached, what are these called?

A
  • one = adenosone monophosphate
  • two - adenosine diphosphate
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

Adenosine triphosphate has 3 phosphate groups. What are the names of these phosphate bonds moviong away from the adenosine?

A
  • first = alpha
  • second = beta
  • third = gamma
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

Adenosine triphosphate has 3 phosphate groups. The generation of energy from ATP is driven by breaking the bonds between the alpha (1st), beta (2nd) and gamma (3rd) phosphates. Which bond is generally broken providing the majority of energy for the cell?

A
  • gamme bond
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

What is phosphorylation?

A
  • adding a phosphate group to a molecule
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

What is substrate level phosphorylation (SLP)?

A
  • adding a phosphate group direclty to ADP
  • phosphate provided by a substrate
  • ADP + phosphate group = ATP
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

Substrate level phosphorylation (SLP) involves adding a phosphate group direclty to ADP from a substrate, which then forms ATP. What is required for this process to take place?

A
  • soluble enzymes and chemical intermediates
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

What is an enzyme?

A
  • biological catalysts that accelerate the rate of chemical reaction
  • creates a new pathway for the reaction; one with a lower activation energy
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

In the image below, the _/_G requires an enzyme to accelerate the rate of reaction to get it over the hump. What is the energy known as that the enzyme will release that will determines if the substrate is able to spontaneously roll down the hill becoming the products?

A
  • Ea = activation energy provided by enzymes
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

Do enzymes influence the Gibbs free energy (_/_G) of a reaction as depicted in the image below?

A
  • no _/_G remains constant
  • enzymes lower the activation energy
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

Are enzymes able to react and act alone or do they require something else?

A
  • they require co-factors
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

The iron in heme is a metal ion, and is an example of what?

A
  • a co-factor
42
Q

Co-factors can be co-enzymes. What are the 2 main groups of co-enzymes?

A

1 - Co-substrates

2 - Prosthetic groups

43
Q

Where do most co-enzymes come from?

A
  • vitamins in the diet
44
Q

What are non-protein cofactors?

A
  • metal cations
  • iron and sodium
45
Q

Co-substrates, which are a subgroup of cofactors are able to diffuse between enymes and generally carry what?

A
  • electrons
46
Q

Co-substrates, which are a subgroup of cofactors able to diffuse between enymes carry electrons. Becuase they carry electrons they co-substrates flux between oxidised and reduced forms, what does oxidised and reduced mean in terms of electrons?

A
  • oxidation = loss of electron (NAD+)
  • reduced = addition of electron (NADH)
47
Q

Prosthetic groups are a subgroup of co-enzymes, what are they?

A
  • non-protein cofactors that are covalently bound to the enzyme
48
Q

Prosthetic groups are a subgroup of co-enzymes, that are non-protein cofactors that are covalently bound to the enzyme. During the enzymatic reaction are they released from the enzyme?

A
  • no
  • they act as a temporary store for electrons or reaction intermediates
49
Q

B2 also referred to as Riboflavin is an important vitamin that is consumed in the diet and is important for maintaining energy pathways withing the cells. What are the 2 co-enzymes that are required to extract energy from the dietary source of B2?

A
  • FAD – flavin adenine dinucleotide
  • FMN – flavin mononucleotide
50
Q

B2, also referred to as Riboflavin is an important vitamin that is consumed in the diet and is important for maintaining energy pathways withing the cells. Flavin adenine dinucleotide (FAD) and flavin mononucleotide (FMN) are the 2 co-enzymes that are required to extract energy from the dietary source of B2. Are FMN and FAD classed as a prosthetic group or co-substrate?

A
  • prosthetic group
51
Q

Niacin is an important vitamin that is consumed in the diet and is important for maintaining energy pathways withing the cells. What is the co-enzymes that is required to extract energy from the dietary source of niacin?

A
  • Nicotinamide adenine dinucleotide (NAD+)
52
Q

Niacin is consumed in the diet. Nicotinamide adenine dinucleotide (NAD+) is the co-enzymes that is required to extract energy from the dietary source of niacin. Is NAD+ classed as a Prosthetic group or Co-substrate?

A
  • Co-substrate
53
Q

Hydrogens and electrons are transferred to co-factors that does what to them?

A
  • reduces co-factors
54
Q

What is the major difference between NAD+ and NADH vs. NADPH and NADP+?

A
  • NAD+ and NADH do not contain a phosphate group

-

55
Q

Out of NAD+, NADH, NADPH and NADP+, which are used for anabolic reactions?

A
  • NADPH and NADP+?
56
Q

Out of NAD+, NADH, NADPH and NADP+, which are used for catabolic reactions?

A
  • NAD+ and NADH
57
Q

Is NADH or NADPH used for ATP synthesis?

A
  • NADH
58
Q

Is NADH or NADPH used for reductive biosyntheses

A
  • NADPH
59
Q

What is oxidative phosphorylation?

A
  • metabolic pathway in which cells use enzymes to oxidize nutrients (removal of electron produces energy)
  • stored chemical energy in the nutrients is released producing adenosine triphosphate
60
Q

How do cells cecycle NADH and FADH2?

A
  • via the respiratory chain in the mitochondria
61
Q

For every NADH and FADH2, how many ATP are synthesised?

A
  • NADH = 2.5 ATP molecules
  • FADH2 = 1.5 ATP molecules
62
Q

What is glycolysis?

A
  • metabolic pathway that converts glucose (C₆H₁₂O₆) into pyruvic acid (CH₃COCOOH)
  • free energy is released forming ATP and reduced NAH+
63
Q

Does glycolysis take place in the cells cytoplasm or in the mitochondria?

A
  • cytoplasm
64
Q

What does glucose-6-phosphate (G-6-P) actually mean?

A
  • a glucose molecule has been phosphorylated
  • phosphorylation occurs at carbon 6
65
Q

What enzyme converts glucose to glucose-6-phosphate (G-6-P) in the priming phase of glycolysis?

A
  • hexokinase
66
Q

Hexokinase is the enzyme that converts glucose to glucose-6-phosphate (G-6-P) in the priming phase of glycolysis, but what else is required to initiate this reaction?

A
  • ATP is converted to ADP releasing a phosphate group
  • phosphate group is added to glucose at 6th carbon
  • glucose-6-phosphate (G-6-P) is formed and can no longer leave the cell
67
Q

In glycolysis the second priming step is the conversion of glucose-6-phosphate through phosphorylation into what?

A
  • fructose-6-phosphate
  • isomerase is used to do this
68
Q

In glycolysis what is the step where the cell is commited to glycolysis?

A
  • conversion of fructose-6-phosphate into fructose1,6-bisphosphate
  • ATP phosphorylated into ADP
  • phosphate group added to fructose-6-phosphate at the first carbon becoming fructose1,6-bisphosphate )phosphate at number 1and 6 carbons of the glucose
69
Q

In glycolysis the commited step where the cell is committed to the glycolysis pathway is the conversion of fructose-6-phosphate into fructose1,6-bisphosphate. What enzyme is responsible for this conversion?

A
  • Phosphofructoskinase-1
70
Q

In the priming (investing) phase of glycolysis how many ATP are needed?

A
  • 2 ATPs
71
Q

In glycolysis the commited step where the cell is committed to the glycolysis pathway is the conversion of fructose-6-phosphate into fructose1,6-bisphosphate. Phosphofructoskinase-1 is responsible for this conversion. Fructose1,6-bisphosphate is then broken down into two 3 carbon molecules called dihydroxyacetone phosphate (DHAP) and glyceraldehyde-3-phosphate (G-3-P). Out of these 2 which is the only one that continues on in the glycolysis pathway?

A
  • G-3-P
72
Q

In glycolysis the commited step where the cell is committed to the glycolysis pathway is the conversion of fructose-6-phosphate into fructose1,6-bisphosphate. Phosphofructoskinase-1 is responsible for this conversion. Fructose1,6-bisphosphate is then broken down into two 3 carbon molecules called dihydroxyacetone phosphate (DHAP) and glyceraldehyde-3-phosphate (G-3-P). Onlp G-3-P continues on in glycolysis, what happens to DHAP?

A
  • isomerase re-arranges it into G-3-P
73
Q

In the glycolysis payoff reactions how is the first ATP produced?

A
  • Glyceraldehyde-3-phosphate (G-3-P) from the priming stage of glycolysis is converted into 1,3-bisphosphoglycerate (1,3 BPG)
  • 1,3 BPG has 2 phosphate groups so 1 is added to ADP forming ATP
74
Q

In the glycolysis payoff reactions the first ATP is produced during the conversion of glyceraldehyde-3-phosphate (G-3-P) from the priming stage of glycolysis, into 1,3-bisphosphoglycerate (1,3 BPG). 1,3 BPG has 2 phosphate groups and therefore donates 1 to ADP forming ATP. But what enzyme is responsible for converting G-3-P into 1,3 BPG?

A
  • Phosphoglycerate kinase (PGK)
75
Q

Although it occurs in glycolysis there are 2 instances where a phosphate group is added to ADP forming ATP. What is this process referred to as?

A
  • substrate level phosphorylation
76
Q

Pyruvate is fromed from phosphoenolpyruvate. What enzyme is responsible for this?

A
  • pyruvate kinase
77
Q

Pyruvate kinase is responsible for converting phosphoenolpyruvate into pyruvate. During this conversion what does pyruvate also do?

A
  • takes phosphate group from phosphoenolpyruvate
  • then phosphorylates ADP, creating an ATP molecule
78
Q

During the glycolysis payoff reactions why do we need to multiply what we create by 2?

A
  • becuase each molecule of glucose creates 2 lots of Glyceraldehyde-3-phosphate (G-3-P)
  • each G-3-P molecule enters the glycolysis payoff reaction
79
Q

At the end of the glycolysis payoff reaction how many ATP and NADH molecules will we create?

A
  • 4 ATP (2 per cycle)
  • 2 NADH (1 per cycle)
80
Q

In glycolysis how many ATP are required to initiate the reaction?

A
  • 2 ATP
81
Q

Pyruvate is the end product of glycolysis. Here there are 2 things that can happen to pyruvate, what are they?

A
  • aerobic conditions it is oxidation and complete degradation in the Krebs cycle
  • hypoxic (anaerobic) conditions, it can be reduced to lactate
82
Q

How many membranes does the mitochondria have?

A
  • 2
  • inner and outer membrane
83
Q

The mitochondrian has folds designed to increase the surface area of the mitochondria. What is this called?

A
  • cristae
84
Q

What is the area within the mitochondria that is contained within the inner membrane?

A
  • matrix
85
Q

Where does the respiration chain sit within the mitochondria?

A
  • on the innner membrane
86
Q

What is decarboxylation?

A
  • a chemical reaction that removes a carboxyl group and releases carbon dioxide
87
Q

How does pyruvate cross the mitochondrial membrane?

A
  • undergoes oxidative decarboxylation
  • pyruvate dehydrogenase complex facilitates this
  • Acetyl CoA is formed
88
Q

The pyruvate dehydrogenase complex converts pyruvate into Acetyl CoA so that is can cross the mitochondrial membrane. This is the link between glycolysis and the citric acid cycle. Is this reaction reversible?

A
  • no
  • it is irreversible, so it a rate limiting step
89
Q

During each cycle of the Krebs cycle, how many GTP (ATP), NADH and FADH2 are created?

A
  • 3 NADH
  • 1 GTP
  • 1 FADH
90
Q

During each cycle of the Krebs cycle, 3 NADH, 1 GTP and 1 FADH are created. Why do we need to multiply all of these by 2, meaning we have 6 NADH, 2 GTP and 2 FADH for each molecule of glucose?

A
  • glycolysis creates 2 glyceraldehyde-3-phosphate (G-3-P)
  • each G-3-P creates 1 pyruvate, so 2 pyruvate in total
  • each pyruvate enters the citric acid cycle
91
Q

What are the 2 key regulation steps of the TCA cycle?

A

1 - conversion of pyruvate to acetyl-CoA by pyruvate dehydrogenase complex allowing entry into mitochondria matrix

2 - citrate synthase reaction controls entry of acetyl-CoA into the TCA cycle

  • BOTH ARE IRREVERSIBLE
92
Q

Once NADH & FADH2 leave the citric acid cycle, how are they re-oxidized?

A
  • through a series of coupled oxidation & reduction reactions occuring whilst electrons are passed along a series of carriers
  • carriers are in the electron transport chain (ETC)
  • essentially donating their electrons to the ETC
93
Q

How many complexes are in the electron transport chain?

A
  • 4
94
Q

Once NADH and FADH have released their electrons into the electron transport chain, what are the 2 electron carrier proteins which facilitate the electon transport chain?

A

1 - ubiquinone also known as Coenzyme Q

2 - cytochrome C

95
Q

As electrons move along the electron transport chain, what do they pump into the intermembrane space?

A
  • H+ protons
  • creates concentration of H+ protons
96
Q

In the electrong transport chain, what 2 things are used that are also very important for maintaining membrane potential to create ATP?

A

1 - electrical energy (positive electrical charge gradient created)

2 - chemical potential energy (concentration gradient created)

97
Q

What is the proton motive force?

A
  • build up of protons (H+)
  • separation of charge between the intermembrane space and mitochondrial matrix
  • drives the synthesis of ATP using ATP synthase
  • low H+ proton concentratio in matrix
  • high H+ proton concentration in intermembrane space
98
Q

What is ATP synthase?

A
  • a protein on the inner membrane of the mitochondria
  • catalyzes the formation of the energy storage molecule ATP using ADP and inorganic phosphate (Pi)
99
Q

ATP Synthase is composed of 2 structures. In the image below, which number denotes the F0 and F1 portions of ATP synthase?

A

1 = F1 projects into matrix of mitochondria

2 = F0 resides in the inner membrane of the mitochondria

100
Q

What happens when H+ protons flow from the intermembrane space through the membrane, the cylinder within the F0 portion of the ATP synthase?

A
  • the g-shaft rotates
  • the turning causes conformational changes in the F1 part of the ATP synthase
101
Q

As the y-shaft interacts with each of the B subunits of F1 portion, they change conformation and facilitate the formation of what?

A
  • ATP from ADP and Pi