CURB THE CARB Flashcards
(95 cards)
1
Q
per mole of glucose, ilang ATP meron?
A
36 or 38 moles of ATP
2
Q
CHO can generate reducing equivalents in the form of
A
NADPH
3
Q
RIBOSE: nucleic acids
_______: milk
A
galactose
4
Q
glucose is major fuel for fetus by the ____ trimester
A
3rd, max transfer of nutrients from mother to baby
5
Q
dietary fibers: ___ & ___ binds lipid compounds such as cholesterols
A
Pectin and Lectin
Thus, these lower blood cholesterol levels
6
Q
Pyruvate converted to Alanine by what pathway?
A
Gluconeogenesis (AA to glucose)
7
Q
30 to 40% of CHO digestion happens in the
A
mouth by salivary amylase (ptyalin)
linkages: 1,4 glycosidic ng amylose and amylopectin
pH: 6-7 pH at mainactivate siya by less than 4 pH
end products: dextrin, maltose
8
Q
Sa small intestine naman ang final digestion of CHO by enzymes _______
A
pancreatic amylase (amylopsin) oligosaccharides from brush border of small intestine
9
Q
enzyme -> CHO sucrase: sucrose lactase (beta-galactosidase): lactose maltase (alpha-glucosidase): maltose isomaltase (alpha 1,6 glucosidase): \_\_\_\_\_\_\_
A
alpha 1,6 glycosidic bonds
10
Q
What part of the small intestine is CHO absorbed?
A
jejunum
11
Q
What is the most rapidly absorbed CHO?
A
Galactose
12
Q
What is the most LEAST rapidly absorbed CHO?
A
Pentoses
13
Q
Fate of 50% glucose?
A
ENERGY (glycolysis)
14
Q
Fate of 30-40% glucose?
A
FATS
15
Q
Fate of 10% glucose?
A
GLYCOGEN (muscles, liver)
16
Q
Insulin facilitates the entry of glucose inside cell EXCEPT in
A
LIVER
17
Q
possible ang conversion ng G6P to glucose using ____
A
GLUCOSE-6-PHOSPHATASE pero nasa liver lang siya
18
Q
why is hexokinase used first in the pathway?
A
kasi pwede siya gamitin kahit mababa levels ng glucose mo
19
Q
bakit tinawag na “specific enzyme” ang glucokinase?
A
ACTS ONLY ON GLUCOSE
(induced by insulin) -> high levels of glucose
20
Q
Oxidative degradation to CO2
A
energy formation by krebs cycle from glycolysis
21
Q
FATES OF G6P?
A
uronic acid pathway krebs cycle/TCA glycolysis HMP shunt (degradation) blood glucose, energy, FA, cholesterol, glycogen
22
Q
aerobic: glucose -> pyruvate
anaerobic: glucose -> _____
A
LACTATE
23
Q
GLYCOLYSIS happens where in the cell?
A
CYTOSOL (exergonic to ah. energy producing MOSTLY)
24
Q
What does RBC and cornea, lens, retina in relation to glycolysis?
A
lack mitochondria, anaerobic glycolysis
25
In the absence of glucose in the brain, the _____ is metabolized by brain tissue
ketone bodies
26
① Glucose 🡆G6P (first priming reax)
| enzyme: ________
hexokinase
uses ATP
start of preparatory phase
1ST irreversible step
27
② G6P 🡆 F6P
| enzyme: ________
phosphohexose isomerase (PHI)
aldose 🡆 ketose
REVERSIBLE
ISOMERIZATION
28
③ F6P 🡆 F1,6BP (second priming reax)
| enzyme: ________
PFK1 (phosphofructokinase 1)
uses ATP
rate-limiting enzyme
2ND irreversible step
29
④ F1,6BP 🡆 GD3P + DHAP
| enzyme: ________
```
Aldose - cleavage enzyme
2 sugars to 3 carbons each
GD3P - aldose
DHAP - ketose
ISOMERIZATION
```
30
⑤ GD3P 🡆 G3P(2)
| enzyme: ________
Triosephosphate isomerase (TPI)
31
⑥ G3P(2) 🡆 1,3BPG(2)
| enzyme: ________
G3PDH
start of pay off phase
oxidoreduction-phosphorylation
NADH 🡆 NAD 🡆 oxidation (H+ enter ETC in mitochondria to produce ATP)
32
⑦ 1,3BPG(2) 🡆 3PG(2)
| enzyme: ________
PGK (phosphoglycerate kinase)
1st ATP forming reaction
transferase reax
substrate level phosphorylation
33
⑧ 3PG(2) 🡆 2PG(2)
| enzyme: ________
PGM (phospho-glycerate mutase)
phosphate change from pos. 3 🡆 pos. 2
ISOMERIZATION
34
⑨ 2PG(2) 🡆 PEP(2)
| enzyme: ________
Enolase (inhibited by fluoride)
releases H2O(2)
DEHYDRATION
35
⑩ PEP(2) 🡆 Pyruvate(2)
tautomerizes into its KETO FORM
enzyme: ________
PK (Pyruvate Kinase)
3rd irreversible step
2nd ATP forming reaction
substrate level phosphorylation
36
1 mol glucose 🡆 aerobic glycolysis by MAS 🡆 total ATPs would be?
Gross ATP: 9
Net ATP: 7
[reax #6 = 5 ATP]
37
1 mol glucose 🡆 aerobic glycolysis by G3PS 🡆 total ATPs would be?
Gross ATP: 7
Net ATP: 5
[reax #6 = 3 ATP]
38
1 mol glucose 🡆 anaerobic glycolysis 🡆 total ATPs is?
Gross ATP: 4
Net ATP: 2
[no ATP on reax #6]
reax #7 and #10 lang meron
39
Starting at F1,6BP, it will produce how many NET ATPs?🡆 aerobic glycolysis by MAS
Gross ATP: 9
Net ATP: 9
tandaan, reax #6 siya nag start so walang bawas na ATP
40
If ang reaction #6 sa glycolysis ay anaerobic, ano fate ng NADH?
pyruvate 🡆 lactate
| enzyme: lactate dehydrogenase
41
What inhibits pyruvate kinase?
ATP, alanine, FA, acetyl-coA
42
What stimulates pyruvate kinase?
F1,6BP
43
pyruvate 🡆 transamination = ?
pyruvate + NH2 = alanine
44
pyruvate 🡆 oxidative carboxylation = ?
acetyl coA (recall: Pyruvate dehydrogenase complex)
45
quickie: 3 enzymes ng PDH complex?
Pyruvate dehydrogenase ①
Dihydrolipoyl Transacetylase ②
Dihydrolipoyl Dehydrogenase ③
46
R group ng pyruvate dehydrogenase?
① Thiamine pyrophosphate (TPP)
| vit B1
47
R group ng DHLT?
| Transfer of acetyl group to coA
② Lipoamide CoASH
| vit B5
48
R group ng DH dehydrogenase?
| regeneration of oxidized lipoamide
③ FAD = vit B2
| NAD = vit B3
49
If any of the enzymes in PDH complex is blocked, what happens?
lactic acid will accumulate 🡆 lactic acidosis
50
what is the importance of b vitamins in the fate of pyruvate?
pyruvate cannot be converted to acetyl-coA w/o B vitamins 🡆 beri-beri
51
These inhibit PDH complex
Arsenite & Mercuric ions - reacts with the -SH of lipoic acid
Thiamine deficiency - alcoholics
52
In the cori cycle or lactic acid cycle, lactate is produced by ______ glycolysis in the muscles 🡆 liver 🡆 converted to glucose 🡆 muscles 🡆 lactate
anaerobic glycolysis
53
The cori cycle includes both
glycolysis and gluconeogenesis
54
80% of acetyl coA 🡆 ______ 🡆 maximize ATP production
krebs cycle (reuires insulin to enter)
55
Triglyceride 🡆 _____ 🡆 free FA 🡆 beta-oxidation 🡆 acetyl coA
lipolysis
56
Protein 🡆 _______ 🡆 AA 🡆 deamination & oxidation 🡆 acetyl coA
proteolysis
57
glycogen 🡆 glycogenolysis 🡆 glucose 🡆 glycolysis 🡆 pyruvate 🡆 ______ 🡆 acetyl coA
oxidation
58
What happens when there is no insulin?
acetyl coA cannot enter krebs
➀ formation ketone bodies
② formation cholesterol
59
α-ketoglutarate is a precursor of
glutamic acid
60
oxaloacetate is a precursor of
aspartic acid
61
1st reaction of the kreb cycle depends on
availability of acetyl coA
availability of oxaloacetate
concentration of succinyl coA
62
succinyl coA inhibits ______
citrate synthase
63
① Acetyl coA + oxaloacetate =
citrate
1st rate limiting step
𝕔𝕠𝕟𝕥𝕣𝕠𝕝 𝕡𝕠𝕚𝕟𝕥
CONDENSATION
64
② Citrate 🡆 Isocitrate
enzyme: Aconitase
what reaction is this?
dehydration/rehydration reaction
| REVERSIBLE
65
③ Isocitrate 🡆 α-ketoglutarate
enzyme: isocitrate dehydrogenase
what reaction is this? what does it release?
```
NAD dependent
ATP = 2.5
release of CO2
𝕔𝕠𝕟𝕥𝕣𝕠𝕝 𝕡𝕠𝕚𝕟𝕥
OXIDATIVE DECARBOXYLATION
```
66
TOP 3 importance of the Krebs cycle?
synthesis of NADH
precursors for amino acids
release of stored energy through oxidation of acetyl coA
67
mnemonics for the krebs cycle/citric acid cycle/tricarboxylic acid cycle
```
Our - Oxaloacetate
City - Citrate
Is - Isocitrate
Kept - alpha-ketoglutarate
Safe and - succinyl-coA
Sound - succinate
From - fumarate
Malice - malate
```
68
What reaction in the krebs cycle is energy conserving?
Reax ⑤ Succinyl-coA 🡆 Succinate
enzyme: Succinyl coA synthase
1 ATP is produced
subtrate level phosphorylation
69
④ α-ketoglutarate 🡆 succinyl-coA
enzyme: α-KGD complex
How many ATPS are produced?
2.5 ATP
NAD dependent
𝕔𝕠𝕟𝕥𝕣𝕠𝕝 𝕡𝕠𝕚𝕟𝕥
release of CO2
70
⑥ succinate 🡆 fumarate
| enzyme: succinate dehydrogenase
1.5 ATP
𝕔𝕠𝕟𝕥𝕣𝕠𝕝 𝕡𝕠𝕚𝕟𝕥
dehydrogenation
H+ pass through FAD (complex II ng ETC)
71
⑦ fumarate 🡆 malate
| enzyme: fumarase
addition of H2O
| HYDRATION
72
⑧ Malate 🡆 Oxaloacetate
| enzyme: Malate dehydrogenase
2.5 ATP
NAD dependent
DEHYDROGENATION
73
Total ATP produced by one cycle of krebs cycle?
[Oxidative phosphorylation - 9 ATP]
[Substrate phosphorylation - 1 ATP]
Add 2 mol pyruvate that entered = 10 x 2
20 ATP
74
glucose 🡺 complete oxidation 🡺 G3PS 🡺 total ATPs?
Gross ATP: 32
| Net ATP: 30
75
glucose 🡺 complete oxidation 🡺 MAS 🡺 total ATPs?
Gross ATP: 34
| Net ATP: 32
76
glucose 🡺 complete oxidation 🡺 MAS 🡺 total ATPs through oxidative phosphorylation?
Gross ATP: 23
| Net ATP: 21
77
1 mol of α-ketoglutarate 🡆 krebs cycle 🡆 total ATPS produced?
```
7.5 ATP
4th = 2.5
5th = 1
6th = 2.5
8th = 2.5
total = 7.5 ATP
```
78
F1,6BP 🡆 complete oxidation 🡆 G3PS 🡆 total ATPs produced?
Gross ATP: 32
| Net ATP: 32
79
Vitamins that play important role in krebs cycle?
B1, B2, B3, B5
80
Glycolysis and Glycogenesis 🡆 _______ pathways
| Stimulated by insulin
HYPOglycemic (blood sugar lower than normal)
81
Glycogenolysis and Gluconeogenesis 🡆 ______ pathways
| Stimulated by glucagon
HYPERglycemic (blood sugar higher than normal)
82
```
Major gluconeogenic precursors:
Lactate
Glycerol
Glucogenic AA
_______ sa animals
```
Propionate
83
What is LIPOLYSIS?
breakdown of fats into fatty acids and glycerol
84
What is GLYCOGENOLYSIS?
breakdown of glycogen to glucose
85
what are the 3 steps in glycolysis that should be reversed?
PEP 🡆 Pyruvate
F6P 🡆 F1,6BP
Glucose 🡆 G6P
86
Why is there a need for pyruvate to be converted to malate first before exiting the mitochondria?
There is no OXALOACETATE TRANSPORTER in there.
87
Oxaloacetate 🡆 PEP
| what is the enzyme used?
PEPCK (Phospho-enol-pyruvate Carboxykinase
88
Remember that F2,6BP:
stimulates ______
inhibits _______
glycolysis
| gluconeogenesis
89
Fact! what is the most potent ALLOSTERIC ACTIVATOR of PFK1?
F2,6BP
90
HMP shunt occurs in what part of the cell?
CYSTOSOL
| It is the oxidation of G6P 🡆 pentose phosphates
91
2 Major functions of HMP shunt:
➀ generation of _____ for reductive synthesis
➁ production of _____ for nucleotide & nucleic acid biosynthesis
NADPH (nicotinamide adenine dinucleotide phosphate)
| Ribose-5-Phosphate
92
In the oxidative stage of HMP shunt,
| NADPH is produced as _____
G6P 🡆 ribose-5-phosphate
93
In the non-oxidative stage of HMP shunt,
| R-5-P 🡆 F6P + _____
GD3P
94
ano ang glycogenesis?
intracellular synthesis of glycogen occurs in the liver and muscle
95
ano naman ang glycogenolysis?
intracellular degradation of glycogen
main rate-limiting enzyme: glycogen phosphorylase
