Chapter 8 Energy Flashcards
1
Q
What is kinetic vs potential energy? What is an example of potential energy? What is it called when you use both?
A
- kinetic: energy for movement
- potential: stored energy (ex. glycogen stored energy for glucose)
- work
2
Q
What is a kilocalorie/kcal/calorie?
A
energy required to raise temperature of 1 g water by 1 C
3
Q
What is the cal for carbs, lipids, proteins?
A
4, 9, 4
4
Q
where is energy stored in a nutrient?
A
chemical bonds
5
Q
_____ is needed to drive chemical reactions in cells that require input of energy
A
ATP
6
Q
photosynthesis vs aerobic respiration in terms of energy
A
photosynthesis = energy in
aerobic respiration = energy out
7
Q
What is metabolism?
A
sum of all chemical reactions occuring in body
8
Q
anabolic vs catabolic (4)
A
Anabolic
- reactions that involve building things like polymers
- synthesis
- endergonic (require energy) from catabolic reactions
- genesis (create)
Catabolic
- breakdown of polymer to monomer
- decomposition
- exergonic (release energy)
- lysis (breaking down)
9
Q
What 3 things does a metabolic pathway involve?
A
substrate/reactants, intermediates, products
10
Q
aerobic vs anaerobic
A
aerobic = requires O2 anaerobic = does not require O2
11
Q
metabolic pathways chart:
glycolysis, glycogenolysis, B oxidation, Proteolysis
vs
gluconeogenesis, glycogenesis, lipogenesis, protein synthesis
A
12
Q
Liver converts monosach, aa, glycerol, FA into ____ (3).
A
-new compounds, energy, or storage as glycogen and triglycerides
13
Q
The most metabolically active organ in the body? except for when ____. What does it do?(3)
A
- liver, except when exercising, the skeletal muscle
- metabolize, store, distribute nutrients after absorption
14
Q
Chart: Insulin, Glucagon, Epinephrine, Cortisol
Produced by, type of reaction, control of protein/carb/fat metabolism
A
15
Q
what is stored between phosphates? Which bonds?
A
- high energy sufficient enough to power a variety of cellular reactions and processes
- gamma (3rd) phosphate provides the most energy, then beta (2nd), then alpha (1st) phosphate provides little emergy
16
Q
what is the chemical composition of ATP? What does it stand for? ADP? AMP?
A
- adenine + ribose + 3 phosphate
- adenosine triphosphate
- adenosine diphosphate
- adenosine monophosphate
17
Q
What is the hydrolysis reaction of ATP?
A
ATP + H2O > ADP + Pi + energy
18
Q
What are the 3 stages of ATP production/cellular respiration/nutrient breakdown?
A
- Glycolysis for glucose, b oxidation for FA, amino acid catabolism
- Pyruvate oxidation and citric acid cycle
- Electron transport chain and ATP synthesis (oxidative phosphorylation)
19
Q
What do oxidation reactions involve? Do oxidized/reduced substances gain/lose electrons/energy? Are they the reducing/oxidizing agent?
A
- gain of oxygen or loss of hydrogen
- oxidized substances lose electrons and energy; reducing agent
- reduced substances gain electrons and energy; oxidizing agent
20
Q
What are the two enzymes involved in redox reactions?
A
dehydrogenase = catalyze removal of H atoms oxidases = catalyze transfer of O2
21
Q
What are the two coenzymes that act as a H (electron) acceptors?
A
NAD+, FAD
22
Q
In cellular respiration, what is oxidized and reduced?
A
- C6H12O6 oxidized to CO2
- O2 reduced to H2O
23
Q
NAD+ or FAD is a reducing or oxidizing agent? What about NADH and FADH2?
A
oxidizing agent, reducing agent
24
Q
What is the purpose of NADH?
A
-store energy used to synthesize ATP through the ETC
25
NADH has ___ more Hydrogen ions and ___ more electrons
1, 2
26
What hormone allows the glucose to enter the cell for glycolysis?
insulin
27
What is the importance of hexokinase?
phosphorylates glucose. glucose can no longer leave the cell because the negatively charged phosphate will not allow it to cross the hydrophobic interior
28
what are isomerases?
enzymes that do not add/subtract from the structure but rearrange
29
The energy investment stages of glycolysis
1. hexokinase phosphorylates glucose using ATP = glucose-6-phosphate
2. phosphoglucose isomerase = fructose-6-phosphate
3. phosphofructose kinase phosphorylates using ATP = fructose-1, 6-biphosphate
30
The energy generation stages of glycolysis
4. Aldolase cleaves frctose-6-phosphate into 2 3 carbon molecules
5. isomerase transforms DHAP to form 2 molecules of glyceraldehyde-3-phosphate
6. oxidation of glyceraldehyde-3-phosphate extract electrons picked up by NAD+. Anohter phosphate added producing 1, 3 biphosphoglycerate (P attached to the 1st and 3rd Carbon) *does not require ATP*
7. 1, 3-biphosphoglycerate donates phosphate to ADP to form ATP. Carbonyl group oxidized to carboxyl group and form 3-phosphoglycerate. Catalyzed by phosphoglycerate kinase
8. phosphate group moves from 3rd to 2nd carbon producing 2-phosphoglycerate
9. Enolase causes water loss (dehydration rxn) and formation of a double bond that increases PE in remaining phosphate bond. produces PEP
10. pyruvate kinase takes the P group to make ATP from ADP and as a result, pyruvic acid/pyruvate is formed
31
What limits the pathway from fructose-6-phosphate to fructose-1, 6-biphosphate?
phosphofructose kinase
32
What is a mutase?
like isomerase, rearranges structure
33
Which enymes are involved in the regulatory steps of glycolysis?
hexokinase, phosphofructokinase, pyruvate kinase
34
Which enzymes are involved in ATP production in glycolysis?
1. hexokinase
2. phosphofructokinase
3. phosphoglycerate kinase
4. pyruvate kinase
35
Which enzyme is involved in the reduction of NAD+ to NADH during glycolysis?
glyceraldehyde-3-phosphate dehydrogenase
36
What are the products of glycolysis? (4) worksheet
2 NADH, 2 ATP (4 gross, 2 net), 2 pyruvates, 2 water
37
Why is it necessary to convert pyruvate into Acetyl CoA?
not lipid soluble so cannot enter mitochondria
38
When is oxidizaion of glucose complete?
when pyruvate (acetyl coA) enters mitochondria
39
What links glycolysis and the citric acid cycle?
Acetyl CoA
40
3 steps of the pyruvate dehydrogenase complex
reactant and product
1. Carboxyl group removed to release CO2. This creates a 2 C hydroxyethyl group bound to an enzyme (pyruvate dehydrogenase)
2. NAD+ reduced to NADH by oxidizing the hydroxyethyl group to an acetyl group
3. Acetyl group transferred to CoA to make Acetyl CoA
2 pyruvate > 2 NADH + 2 acetyl CoA
41
What are the other names for the citric acid cycle (2)
krebs cycle, TCA cycle
42
How is the Krebs cycle a cycle?
acetyl group of acetyl CoA combines with oxaloacetate to form citrate then go through 8 decomposition steps to produce oxaloactate again
43
NADH and FADH2 accounts for most of the ____ extracted from food
energy
44
What do the electrons in NADH and FADH2 do? Which powers ____ through _____.
donate to te ETC that powers ATP synthesis through oxidative phosphorylation
45
Where is the electron transport chain located?
inner membrane called cristae
46
What are the proteins of the electron transport chain called? What happens to them as it accepts and donates electrons? What happens to the electron energy as they go down the chain? Where does it finally land?
- complexes
- alternate between reduced and oxidized states
- electrons drop in free energy
- passed to O2 forming H2O
47
Which complex does not go across/completely through the inner mitochondrial membrane?
complex 2
48
What is complex 5 also called?
ATP synthase
49
NADHs are transported to which complex?
complex 1
50
FADH2s are transported to which complex?
complex 2
51
What is the general summary of the oxidative phosphorylation process? (7)
1. NADH and FADH2 goes to complex 1 and 2
2. Complexes binds the NADH/FADH2 and strips off the H
3. H is split to remove the e-, creating H+
4. The protein complexes are reduced as e- are accepted, opening up the channel to let H+ through. The protein complexes are then oxidized as e- is removed and passed onto the next complex.
5. Electrochemical gradient is established as H+ accumulates, making the intermembrane space more acidic and electrically positive
6. Complex 5 (ATP synthase) senses build-up of H+ ions in the intermembrane space
7. Protons pumped through ATP synthase (protein) to combine ADP with Pi to form ATP
52
ETC Complex 1:
Where does it receive its e-? How many? How many H+ does it pump? What does this do?
- 2 e- carried to complex 1 via NADH
| - pumps 4 H+ ions into the intermembrane space to establish ion gradient
53
ETC Complex 2 & Q:
From what does it accept H? What is it also called? What is it made of? What does this allow Q to do? What happens to Q when FADH2 donates its H atoms? What does it then do? Which complexes does Q recieve its electrons from? What is unique about complex 2?
- receives from FADH2
- Q molecule (also called ubiquinone B) connects 1st and 2nd complexes to the 3rd
- Q is lipid soluble
- can freely move through the hydrophobic core of membrane
- Q reduced to QH2 and delivers e- to the next complex
- Q receives electrons from NADH in complex 1 and FADH2 in complex 2
- fewer ATP molecules made from FADH2 because it does not energize the proton pump/does not span through the membrane
54
ETC Complex 3 & cytochrome C:
What is this complex also called? What does it have? What does it carry? Does complex 3 pump e-? To where does it pass its electrons?
What is the difference between cytochrome C and Q?
- cytochrome oxidoreductase
- has prosthetic group of heme (similar to heme in hemoglobin but carries e- not O2)
- yes, pumps e-
- passes e- to cytochrome C for transport to the fourth complex
-Q carries pairs of e- and cytochrome c accepts 1 at a time
55
ETC Complex 4:
What 3 proteins is the fourth complex made of? What do they do? What does it pick up from the surrounding medium? What does it form?
- cytochrome proteins c, a, a3
- cytochrome hold O2 molecule tightly until completely reduced by gaining 2 e-
- picks up 2 H+ ions from surrounding medium to make H2O
56
What does the series of redox reactions from complex 1 to 4 create? What is chemiosmosis? What do the H+ ions pass through? What is it also called? What does it do?
- electrochemical gradient (pH + voltage gradient)
- movement of H+ ions back into the mitochondrial matrix
- pass through ATP synthase (complex 5)
- small rotary motor that drives addition of Pi to ADP to create ATP
57
What is oxidative phosphorylation?
ETC + chemiosmosis
58
Which complexes of the ETC pumps H+ ions into the intermembrane space?
complex 1, 3, 4
59
****Where do triglycerides and protein fit into cellular respiration?
- glycerol goes into glycolysis
- FA converted into Acetyl CoA and go through citric acid cycle
- amino acids go into citric acid cycle
60
What is gluconeogenesis? When does it occur? Where does it occur?
- formation of glucose from non-carbohydrate sources (aa and FA)
- takes place with blood glucose level low
- takes place in the liver
61
When is NADH produced in the citric acid cycle? (3)
Isocitrate > a ketoglutarate (also where CO2 released)
a ketoglutarate > succinyl CoA (CO2)
malate > oxaloacetate
62
When is CO2 released in the citric acid cycle? (2) What is this reaction called?
Isocitrate > a ketoglutarate
a ketoglutarate > succinyl CoA
decarboxylation reaction
63
When is FADH2 produced in the citric acid cycle? (1)
Succinate > fumarate
64
When is H2O required in the citric acid cycle? (2)
acetyl CoA > citrate
| fumarate > malate
65
citric acid cycle diagram
66
Citric acid cycle step (8)
1. 2C acetyl group + 4C oxaloacetate > 6C citrate
- citrate synthase
- HIGLY EXERGONIC RXN
2. citrate > isomer, isocitrate
- aconitase
3. isocitrate + NAD+ > 5C a-ketoglutarate + 2e- (which produces NADH) + CO2
- isocitrate dehydrogenase
- isocitrate is oxidized, NAD+ is reduced
4. a-ketoglutarate + succinal group > succinal CoA + CO2 + NADH
- 4C molecule oxidized, NAD+ reduced
- made reactive by adding CoA
5. succinal coA > succinate
- P substituted for coenzyme A = high energy bond formed.
- energy used in substrate-level phosphorylation to form GTP or ADP
- succinyl CoA synthetase
6. succinate > fumarate
- 2 H transferred to FAD to produce FADH2
- succinate dehydrogenase
7. fumarate + H2O > malate
- fumarase
8. malate + NAD+ > oxaloacetate + NADH
- malate oxidized
- malate dehydrogenase
67
Which step in the citric acid cycle is higly exergonic?
oxaloacetate > citrate
68
when do redox reactions occur in the citric acid cycle
when NADH is produced
69
What are the reactants and products of glycolysis?
reactants: glucose,
products: 2 pyruvate, 2 net ATP, 2 NADH
70
What are the reactants and products of the TCA cycle?
reactants: 2 oxaloacetate, 2 acetyl CoA,
products: 2 oxaloacetate, 6 NADH, 2 FADH2, 2 ATP
71
What are the reactants and products of the pyruvate dehydrogenase complex?
reactant: 2 pyruvate
products: 2 acetyl coA, 2 NADH
72
What are the products and reactants of the ETC?
reactants: 10 NADH, 2 FADH2, 6 O2
products: 10 NAD+, 2 FADH, 6 H2O
73
Where does glycolysis, pyruvate dehydrogenase complex, TCA cycle, and ETC take place?
glycolysis: cytoplasm
PDH: cytoplasm
TCA: mitochondria matrix
ETC: intermembrane (cristae) of mitochondria
