Cell Metabolism 1+2 Flashcards
(84 cards)
1
Q
What is this process called?
A
Glycolysis
2
Q
Identify each type of reaction
A
3
Q
Identify enzyme, product, type of reaction
A
Step 1
4
Q
Identify enzyme, product, type of reaction
A
Step 2
5
Q
Identify enzyme, product, type of reaction
A
Step 3
6
Q
Identify enzyme, both products, type of reaction
A
Step 4
7
Q
Identify enzyme, product, type of reaction
A
Step 5
8
Q
Metabolic Disease:
Which glycolytic enzymopathy is fatal?
A
Deficiency in TPI is the only glycolytic enzymopathy that is fatal, with most sufferers dying within the first 6 years of their lives.
9
Q
Identify enzyme, product, type of reaction
A
Step 6
10
Q
Identify enzyme, product, type of reaction
A
Step 7
11
Q
Identify enzyme, product, type of reaction
A
Step 8
12
Q
Identify enzyme, product, type of reaction
A
Step 9
13
Q
Identify enzyme, product, type of reaction
A
Step 10 (Final Step)
14
Q
Which steps are irreversible in glycolysis?
A
Steps 1,3 and 10
(hexokinase, PFK, pyruvate kinase)
15
Q
Which step commits the cell to glycolysis and traps glucose inside the cell?
A
Step 1 - Phosphorylation of Glucose into Glucose 6-P
16
Q
What is the net change in ATP for glycolysis?
A
+2
(-2+4=+2)
17
Q
Which steps consume ATP?
A
Steps 1,3
(hexokinase, PFK)
18
Q
Which steps produce ATP?
A
Steps 7 and 10
(PG kinase and pyruvate kinase)
19
Q
Which step is a dehydration reaction?
A
Step 9
(Water and Phosphoenolpyruvate produced)
20
Q
How many NADH molecules produced in glycolysis and which steps?
A
2xNADH in Step 6
21
Q
What is the parallel pathway to glycolysis which is used in anabolic reactions to generate biosynthetic molecules called?
A
Pentose-Phosphate Pathway (PPP)
22
Q
What molecule does NADH reduce, which is also a vital antioxidant?
A
Glutathione
23
Q
Alcoholic Fermentation
Identify enzyme and product
A
Decarboxylation of Pyruvate
24
Q
Alcoholic Fermentation
Identify enzyme and product
A
Dehydrogenation of Acetaldehyde
25
Which organism performs alcoholic fermentation and under what conditions?
Yeast, under anaerobic conditions
26
# Generation of Lactate
Identify enzyme and product
Dehydrogenation of Pyruvate
27
# Generation of Lactate
Where in the Mammalian body does lactate generation occur and when?
In muscles, when oxygen is a limiting factor
28
What is the common purpose of alcoholic fermentation and lactate generation?
NAD+ Regeneration
29
Which molecule is used as an ATP buffer?
Creatine phosphate
30
Identify enzyme and product
31
What is the order of main ATP storage in muscles during a long exercise?
stored ATP-> CP-> Anaerobic metabolism-> Aerobic metabolism
32
Identify enzyme and all three products
33
Why is addition of CoA necessary for TCA cycle?
Thioester bond is readily hydrolysed enabling acetyl CoA to donate acetate easily
34
What are the cofactors of PDH complex?
Thiamine (B1) pyrophosphate, Lipoic Acid and FAD
(in addition to NAD+ and CoA which are also substrates)
35
What is the cause of Beri-Beri disease?
Thiamine deficiency affecting PDH complex causes symptoms such as peripheral nerve damage, muscle weakness and reduced cardiac output.
36
Which 3 amino acids can be substrates of kinases?
Serine, threonine and tyrosine
37
What type of phosphorylation is glycolysis?
Substrate-level phosphorylation
38
What does high serum LDH indicate?
Possible stroke or MI
39
What is this cycle called and where does it take place?
TCA or Kreb's or Citcric Acid Cycle
- takes place in mitochondrial matrix
40
What is the total production of TCA cycle per one glucose?
Two turns per glucose:
6xNADH
2XGTP
2XFADH2
4XCO2
41
What reaction is this and which group of molecules react?
Transamination (Group Transfer)
An amino acid and a keto acid react
42
What is the purpose of this transamination reaction?
Alanine is converted into pyruvate, so it can join the TCA cycle (through link reaction)
43
Identify enzyme and one product
44
Name all the substrates of TCA cycle respectively, starting with Acetyl CoA
Acetyl Coa + Oxaloacetate → Citrate → Isocitrate → a-Ketoglutarate → Succinyl CoA → Succinate → Fumarate → Malate → Oxaloacetate
45
Identify enzyme and product
46
Name the enzymes
47
Name the enzymes
48
Which steps produce NADH in TCA cycle?
Isocitrate → a-Ketoglutarate
a-Ketoglutarate → Succinyl CoA
Malate → Oxaloacetate
49
Which step produces GTP in TCA cycle (later converted to ATP)?
Succinyl CoA → Succinate
50
Which step produces FADH2?
Succinate → Fumarate
51
What are the ketogenic amino acids?
Leucine
Lysine
Isoleucine
Tryptophan
Tyrosine
Phenylalanine
52
What do ketogenic amino acids form?
Ketone bodies
53
Through what do the ketogenic amino acids enter TCA cycle?
Through Acetly CoA or Acetoacetyl CoA (which is then converted into Acetoacetyl CoA)
54
How do the glucogenic amino acids enter TCA cycle?
Pyruvate, Oxaloacetate, Fumarate, Succinyl coA, a-Ketoglutarate
55
How are the electrons from NADH transferred inside the mitochondrion?
The Glycerol phosphate shuttle and the Malate-Aspartate shuttle
56
Where in the body are the specific electron shuttles used?
The Glycerol phosphate shuttle – skeletal muscle, brain
The Malate-Aspartate shuttle – liver, kidney and heart
57
Which enzyme transfers electrons from NADH to which molecule?
Cytosolic glycerol 3-phosphate dehydrogenase transfers electrons from NADH to DHAP to generate glycerol 3-phosphate
58
What is Step 2 of the Glycerol phosphate shuttle?
Mitochondrial glycerol 3-phosphate dehydrogenase transfers the electrons to FAD. These then get passed to co-enzyme Q, part of ETC
59
What types of reactions are happening in the Malate-Aspartate shuttle?
Redox reactions
60
What are the enzymes and protein channels in the Malate-Aspartate shuttle called?
Enzymes:
AT = aspartate transaminase
MDH = malate dehydrogenase
Protein Channels:
Glutamate-aspartate antiporter
Malate-α-ketoglutarate antiporter
61
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Which molecule reacts with aspartate in a transamination reaction and what are the products?
reactant is α-ketoglutarate
products are glutamate and oxaloacetate
62
How many ATP molecules produced per NADH and FADH2?
3x ATP per NADH
2x ATP per FADH2
63
What type of reaction is this?
Transamination reaction
64
What is the first step of β-oxidation of fatty acids?
Fatty acids are converted into an Acyl CoA species converting ATP to AMP
65
Mutations in which TCA cycle enzymes might favour aerobic glycolysis (supporting malignancy)?
Isocitrate dehydrogenase, Succinate dehydrogenase and Fumarase
66
How does the Acyl CoA generated from β-oxidation enter mitochondrial matrix?
Couples with carnitine
67
What are the enzymes and protein channel called in the carnitine shuttle?
68
What happens inside the cells in primary carnitine deficiency?
Reduced carnitine transporter activity causes carnitine levels inside the cells to drop which further prevents β-oxidation of fatty acids.
69
What are the products of one turn of β-oxidation cycle?
1X NADH
1X FADH2
1X Acetyl CoA
1X Acyl CoA species, 2 carbons shorter than the original
70
What are the products of β-oxidation of palmitoyl CoA (16C)?
In 7 β-oxidation cycles:
8 Acetyl CoA+7NADH+7FADH2
71
What does Acetyl CoA from β-oxidation produce when fasting and what are they collectively. known as?
Ketone Bodies: Acetoacetate, D3HB and. Acetone
72
Which two enzymes does fatty acid biosynthesis involve?
Acetyl CoA Carboxylase and Fatty Acid Synthase
73
What is the growing fatty acid chain linked to in lipogenesis?
Acyl Carrying Protein (ACP)
74
Carriers, Reducing power and Locations of Lipogenesis vs β-oxidation
Lipogenesis: ACP, NADPH and cytoplasm
β-oxidation: CoA, NAD+/FAD+ and mitochondrial matrix
75
Which two molecules react in decarboxylative condensation reactions of lipogenesis?
Acetyl CoA and Malonyl CoA
76
What are the reactants of lipogenesis that give palmitate (16C) as a product?
Acetyl CoA (2C) + 7 Malonyl CoA (3C) + 14 NADPH
77
What are the byproducts of lipogenesis of palmitate (16C)?
7 CO2 + 6 H2O + 8 CoA + 14 NADP+
78
Where does elongation of acyl group to make fatty acids longer than 16C occur in the cell?
Mitochondria and ER
79
What is the group of enzymes required for desaturation of fatty acids?
Fatty acyl CoA desaturases
80
Which enzyme turns palmitate and stearate into palmitoleic acid and oleic acid?
∆-9 desaturase as it generates a double bond on the 9th C
81
Which parts of the adult human body perform de novo fatty acid biosynthesis?
Liver, adipose tissue and lactating breast
82
Why is lipogenesis reactivated in some cells unusually?
To act as an energy source for cancer cells
83
How chain lengths separated in acyl CoA dehydrogenases?
Short-chain 1-6C
Medium-chain 6C-12C
Long-chain 13C-21C
Very long-chain >22C
84
What is affected in patients with Medium-chain acyl CoA dehydrogenase deficiency (MCADD)?
Fatty metabolism is affected, so they should rely highly on carbohydrates and avoid fasting for long periods
