1
Q
Amylose
A
Linear polymer of glucose units
2
Q
Amylopectin
A
Branched polymer of glucose units
3
Q
SGLT found
A
On apical surface of GI epithelial cells
4
Q
Where does glycolysis occur in animals?
A
Cytoplasm
5
Q
Brain requires ___ g glucose per day
A
120 g
6
Q
NAD required for
A
Redox
7
Q
NAD derived from
A
Niacin (B3)
8
Q
Substrate level phosphorylation
A
Direct use of energy from substrate molecule to make ATP
9
Q
How many ATP made in glycolysis?
A
2
10
Q
CoA derived from
A
Pantothenic acid (B5)
11
Q
CoA function
A
Acyl chains
Fatty acids
12
Q
Two forms of CoA
A
CoASH - free
Acyl-CoA - acyl group attached
13
Q
Aerobic oxidation of pyruvate occurs
A
In mitochondrial matrix
14
Q
Fatty acid
A
Carbon chain connected to a carboxylic acid
15
Q
Oxidative phosphorylation is the coupled process of
A
Electron transport chain
Phosphorylation of ADP to ATP by ATP-synthase
16
Q
In oxidative phosphorylation, which part uses the proton gradient?
A
Phosphorylation of ADP to ATP by ATP-synthase
17
Q
Electrons in the ETC come from
A
NADH and FADH₂
18
Q
What happens at the end of the ETC?
A
Molecular oxygen is reduced to water
19
Q
Location of ETC
A
In the inner mitochondrial membrane
20
Q
In ETC the electrons are moved between complexes via
A
Mobile carriers
21
Q
Which mobile carrier sits in the inner mitochondrial membrane?
A
Ubequinone
22
Q
Which mobile carrier sits on the outer surface of the inner mitochondrial membrane?
A
Cytochrome c
23
Q
NADH goes to Complex __
A
Complex I
24
Q
FADH₂ goes to Complex __
A
Complex II
25
How many electrons does NADH and FADH₂ each drop off in ETC?
2 electrons
26
How many protons are pumped for each NADH oxidised?
4 protons
27
How many protons are pumped when FADH₂ is oxidised at Complex II?
None
28
Does UQ have to be oxidised or reduced to be carrying things?
Reduced
29
How many electrons do Complex I or Complex II pass on to UQ?
2 electrons
30
How many electrons at a time does UQ drop off to Complex III?
1 at a time
31
For each two electrons passed through Complex III, how many protons are pumped?
4 protons
32
How many electrons at a time does Complex III drop off to Cytochrome c?
1 at a time
33
How many electrons does Cytochrome c carry?
1
34
In Complex IV, how many protons does one NADH/FADH₂ pump?
2
35
In Complex IV, how many water molecules are made per one NADH/FADH₂?
1 water molecule
36
How many total protons pumped for each molecule of NADH?
10 protons
37
How many total protons pumped for each molecule of FADH₂?
6 protons
38
Dehydrogenases
Enzymes that catalyse redox reactions
39
ATP synthesis makes what other products?
CO₂ and H₂O
40
ATP hydrolysis is spontaneous/non-spontaneous
Spontaneous
41
Fuel molecules get reduced/oxidised
Oxidised
42
What is the reducing equivalent?
Hydrogen
43
Starch contains up to how many glucose units?
Up to 1 million
44
Amylopectin
Branched polysaccharide that is found in starch
45
Amylase hydrolyses
Glycosidic bonds
46
SGLT
Sodium glucose linked transporter
47
Body uses ___ g glucose per day
160 g
48
Traditional view of why glucose is preferred by the brain
Easily crosses blood-brain barrier, while fats don't
49
New hypothesis of why glucose is preferred by the brain
Safer
50
Favoured fuel of the eye
Glucose
51
White muscle cells preferred fuel source
Glucose
52
Red muscle cells preferred fuel source
Fats
53
Two ways for ATP synthesis
Substrate level phosphorylation - direct
Oxidative phosphorylation - indirect
54
Substrate level phosphorylation
Direct addition of phosphate from substrate to ADP
55
Oxidation of G-3-P done by
Glyceraldehyde-3-phosphate dehydrogenase
56
1st SLP in glycolysis done by
Phosphoglycerate kinase
57
Does CoA carry electrons (can be reduced/oxidised)?
No
58
CoASH made up of
β-mecaptoethyl-amine unit
Pantothenate unit
ADP
59
Acyl-CoA has acyl connected via
S (thioester)
60
Pyruvate → acetyl-CoA reaction type
Oxidative decarboxylation
61
Pyruvate → lactate reaction type
Reduction
62
Are phospholipids or sterols used as fuel?
Sterols
63
Cholesterol roles in the body
Membranes
Signalling
Bile salts
64
Cholesterol rough structure
Hydrophobic ring structure, with one small hydrophillic part
65
Dietary cholesterol rough structure
Cholesterol esters (have fatty acids attached)
66
Most dietary fat is in the form of
TAGs
67
VLDL function
Transports TAGs from the liver to peripheral tissues
68
LDL function
Transports cholesterol to cells
69
Chylomicron function
Transport dietary TAGs from the small intestine to peripheral tissues
70
Chylomicron remnant function
Deliver dietary cholesterol and lipids to the liver for processing
71
At which position does pancreatic lipase hydrolyse TAGs?
1 and 3, gives 2 FFAs and a monoacylglycerol
72
Bile salts rough structure
Ring structure of cholesterol with hydroxyl and/or carboxyl groups attached
73
Esterified
Fatty acid attached
74
Lipoprotein membrane made of
Phospholipids
Unesterified cholesterol
Apoproteins
75
Chylomicron protein to lipid ratio
1:50
76
VLDL protein to lipid ratio
1:9
77
Where are TAGs packaged into chylomicrons?
Epithelial cells
78
Where is LPL found?
Endothelial surface of capillaries
79
LPL function
Hydrolyses TAGs in lipoproteins, which then enter tissues
80
Where does LPL have highest activities?
Heart
Skeletal muscle
Adipose tissue
81
LPL activated by
Apoprotein ApoCII
82
What proportion of glycogen is water?
2/3
83
Adipose lipase regulated by
Hormones
84
What % of protein in blood is albumin?
50%
85
FFAs stay soluble inside cells using
FABP (fatty acid binding protein)
86
How are fatty acids activated before β-oxidation?
CoA attached to make fatty acyl-CoA
87
Fatty acyl-CoA
Carbon chain of any length
88
Acetyl-CoA
Two carbon chain
89
Where does activation of fatty acids occur?
Cytoplasm
90
Enzyme that activates fatty acids
Acetyl-CoA synthetase
91
Where does oxidation of fatty acids occur?
Matrix
92
What allows fatty acetyl-CoA through the outer membrane of the mitochondria?
Fatty acyl-CoA carrier
93
How does fatty acetyl-CoA get through the inner membrane of the mitochondria?
Transfers into fatty acetyl-carnitine
94
Cartnitine acyltransferase function
Swaps CoA and carnitine on a fatty acid
95
Carnitine transferase I location
Outer membrane of mitochondria
96
Carnitine transferase II location
Inner membrane of mitochondria
97
Which form of NAD and FAD holds onto energy?
Reduced
98
FAD derived from
Riboflavin (B2)
99
FAD/FADH₂ reduced form
FADH₂
100
How many reducing equivalents does FAD accept?
2
101
In what step of β-oxidation is acetyl-CoA released?
4 - cleavage
102
Reaction 4 in β-oxidation is a cleavage between which carbons?
ɑ and β
103
What is added to the end of the carbon chain in step 4 of β-oxidation?
CoASH
104
For each round of β-oxidation, how many NADH, FADH₂, and acetyl-CoA are produced?
1 of each, but when more than one round, there is n + 1 acetyl-CoA
105
Number of rounds in β-oxidation =
n(C)/2 - 1
106
Where does the citric acid cycle occur?
Mitochondrial matrix (apart from one enzyme)
107
Acetyl-CoA produced by
Glycolysis and β-oxidation
108
How does carbon enter the CAC?
Acetyl-CoA
109
How does carbon leave the CAC?
2CO₂
110
How many ATP, NADH and FADH₂ made per acetyl-CoA?
1 ATP
3 NADH
1 FADH₂
111
What does the rearrangement of citrate into isocitrate do?
Makes it susceptible to decarboxylation in CAC
112
Consequences of inhibiting the CAC
Increased acetyl-CoA
Decreased reduced coenzymes
Less ATP
113
Removal of the first carbon in CAC is what kind of reaction?
Oxidative decarboxylation (oxidation first)
114
Removal of the second carbon in CAC is what kind of reaction?
Oxidative decarboxylation
115
SDH (succinate dehydrogenase) found
In the inner mitochondrial membrane
116
What does SDH use as a coenzyme?
FAD
117
FAD reduced in which system? (CAC or ETC)
CAC
118
Where does the ETC occur?
Inner mitochondrial membrane
119
Endopeptidases function
Break peptide bonds within protein polymer
120
Exopeptidases function
Break peptide bonds near the end of the protein polymer
121
What side chains do pepsin and chymotripsin require to chop?
Aromatics
122
What does trypsin require as a side chain to chop?
Positively charged side chain
123
Endopeptidase specificity is determined by
Adjacent amino acid side chains in protein substrate
124
In what order do tripsin, pepsin and chymotripsin chop?
1. Pepsin
2. Tripsin
3. Chymotripsin
125
Exopeptidases release
Amino acids, di and tri peptides
126
Do exopeptidases or endopeptidases operate first?
Endopeptidases
127
Autolytic activation of peptidases
HCl unfolds zymogen, then it cuts off the inhibitory domain itself
128
Catalytic activation of peptidases
Active peptidase comes and cleaves inactive form to activate
129
What converts trypsinogen to trypsin?
Membrane-bound enterokinase
130
What converts chymotrypsinogen to chymotrypsin?
Trypsin and chymotripsin
131
What converts procarboxypeptidases into carboxypeptidases?
Trypsin
132
Absorption of di and tri peptides in the small intestine is via
Co-transport with H⁺ ions
133
What cleaves di and tri peptides into individual amino acids when they are absorbed into cells in the small intestine?
Cytoplasmic peptidases
134
Deamination of amino acids generates
Carbon skeleton
Free amino group
135
After deamination of amino acids, the carbon skeleton function is
Used as fuel
136
After deamination of amino acids, the free amino group is
Excreted
137
Transamination
Transferring an amino group with a keto group
138
PLP is a coenzyme that is required for
Transamination reactions, carries amino group from amino acid to keto acid
139
PLP derived from
Pyridoxine, vitamin B6
140
PLP form with no amino group
Pyridoxal phosphate
141
PLP form with amino group
Pyridoxamine phosphate
142
Oxidative phosphorylation is the coupled process of
ETC and phosphorylation of ADP to ATP by ATP-synthase
143
What makes the proton gradient?
ETC
144
What uses the proton gradient?
ATP-synthase
145
Oxidative phosphorylation is coupled by
Proton gradient
146
What system recycles coenzymes?
ETC
147
When mitochondria are treated with a strong detergent to solubilise all membranes, what happens to the ETC?
Stops working
148
When mitochondria are treated with a weak detergent to solubilise the outer membrane, what happens to the ETC and ATP production?
ETC still works
ATP not made
149
Which membrane is the barrier for the proton gradient?
Inner mitochondrial membrane
150
Two mobile carriers in ETC
Ubiquinone (UQ)
Cytochrome c (cyt c)
151
UQ is the same as
CoQ (coenzyme Q)
152
Rotenone effect on ETC
Inhibits electron transfer from Complex I to Co-Q
153
Cyanide effect on ETC
Binds to a carrier in Complex IV
154
Carbon monoxide effect on ETC
Binds where oxygen would normally
155
Where is UQ located/where does it move?
Inner mitochondrial membrane
156
UQ is required by
The last carrier in Complex I and the first carrier of Complex III
157
Where is cyt c located/where does it move?
Outer surface of the inner mitochondrial membrane
158
Proton gradient results in which two energetic gradients?
Chemical/pH gradient
Electrical gradient
159
Proton motive force
Electrochemical gradient created by proton gradient
160
Function of 2,4-dinitrophenol (DNP)
Uncoupler of proton gradient, shuttles protons from the intermembrane space to the matrix
161
What happens to the ETC and ATP production is the presence of 2,4-dinitrophenol (DNP)?
ETC functions
No ATP produced
162
F₁ of ATP synthase is located
In the matrix
163
Fₒ of ATP synthase is located
In the inner mitochondrial membrane
164
In ATP synthase, what drives rotor movement?
Proton gradient
165
In ATP synthase, what does rotor movement cause?
Conformational changes in the stator ɑ and β subunits
166
In ɑ and β subunits, O means
Open
ATP release/ADP and Pᵢ binding
167
In ɑ and β subunits, L means
Loose
Holds ADP and Pᵢ in preparation for catalysis
168
In ɑ and β subunits, T means
Tight
Catalysis, ATP formation
169
How many protons used per 1 ATP made?
4
170
How many ATP are made per one NADH?
2.5
171
How many ATP made per one FADH₂?
1.5
172
What is bacteriorhodopsin?
Proton pump when light is shone onto it
173
Which organ can't use ketones?
Liver
174
Can RBCs use fatty acids as fuel?
No, they don't have mitochondria
175
Resting skeletal muscle fuel stores
Glycogen
176
Exercising skeletal muscle fuel stores
None
177
Resting skeletal muscle preferred fuel
Fatty acids
178
Exercising skeletal muscle preferred fuel
Fatty acids
Glucose
Branch-chain amino acids
179
Heart preferred fuel source when exercising
Fatty acids
180
Resting skeletal muscle fuels exported
None
181
Exercising skeletal muscle fuels exported
Lactate
Alanine
182
Adipose tissue fuels exported
Fatty acids
Glycerol
183
Adipose tissue preferred fuel
Fatty acids
184
Liver fuels exported
TAGs (VLDL)
Glucose
Ketone bodies
185
RBCs fuels exported
Lactate
186
Which organs does insulin act on?
Liver
Muscle
Adipose tissue
187
Underlying cause of T1D
Pancreas can't secrete insulin
188
T1D a.k.a
Insulin-dependent or juvenile diabetes
189
In diabetes, fruity breath is due to
Ketone bodies
190
Incretin effect
Oral glucose triggers a higher insulin response than IV due to the release of GLP-1 in the intestine
191
Which cells cleave proglucagon into glucagon?
Pancreatic alpha cells
192
Which cells cleave proglucagon into GLP-1?
L-cells
Brain
193
GLP-1 synthesised in response to
Nutrients
194
GLP-1 is which type of hormone?
Peptide
195
Which enzyme cleaves proglucagon?
Convertase
196
GLP-1 effect on heart
Increased cardioprotection and heart rate
197
GLP-1 effect on stomach
Decreased gastric emptying
198
GLP-1 effect on brain
Increased neuroprotection and adversive responses
199
GLP-1 effect on islets
Decreased glucagon secretion from alpha cells, increased insulin secretion and decreased apoptosis in beta cells, and increased somatostatin secretion in delta cells
200
Where is GLUT4 found in adipose and muscle cells?
Intracellular storage vesicles
201
What type of receptor is the insulin receptor (INSR) on muscle and fat cells?
Tyrosine kinase receptor
202
70 kg adult uses ___ g ATP per day
90 kg
203
Energy value of ATP (kJ/mol and kJ/g)
57 kJ/mol
0.11 kJ/g
204
Weight and energy equivalent of TAGs stored in 70 kg adult
15 kg
590,000 kJ
205
Weight and energy equivalent of glycogen stored in 70 kg adult
0.223 kg
3,800 kJ
206
DNL
De novo lipogenesis
Body synthesises fatty acids from excess CHO
207
What transports glucose into the liver?
GLUT2
208
Are both GLUT2 and GLUT4 stimulated by insulin?
GLUT2 isn't, GLUT4 is
209
Where is glycogen made?
Liver and muscle
210
What does insulin activating PKB do?
Inactivates glycogen synthase kinase (GSK3)
211
What does inactivation of glycogen synthase kinase (GSK3) do?
Prevents glycogen synthase from being phosphorylated which keeps it active
212
What does phosphatase PP1do?
Dephosphorylates glycogen synthase, keeping in active
213
Energy inputs required for glycogen synthesis
ATP
UTP
214
___ g glycogen can be stored in liver
100 g
215
___ g glycogen can be stored in muscle
280 g
216
Adrenaline synthesised from _______ in ________
From tyrosine in adrenal glands
217
Does the liver have glucagon or adrenaline receptors?
Both
218
Does muscle have glucagon or adrenaline receptors?
Adrenaline
219
Glycogen phosphorylase function
Breaks down glycogen
220
How much glucose can gluconeogenesis add per day?
80-200 g
221
How much protein in the body?
10-15 kg
222
ATP generation in aerobic exercise
Glucose from blood (or from glycogen as glucose-6-phosphate) undergoes oxidative metabolism, as does fatty acids
223
ATP generation in anaerobic exercise
Glycogen to glucose-6-phosphate and anaerobic glycolysis, and phosphocreatine system
224
20 μmol of phosphocreatine per g muscle provides ~___ s worth of ATP
~ 10 s
225
Ketones in blood increased/decreased during starvation
Increased substantially
226
FFAs in blood increased/decreased during starvation
Increased
227
FoxO1 function
Transcription factor that activates gluconeogenic genes
228
PEPCK
Branch point in gluconeogenesis where the reaction is not the same as the reverse of glycolysis
229
PEPCK switched on by
Glucagon
230
What happens when PEPCK is switched on?
We get gluconeogenesis
231
G6Pase
Branch point in gluconeogenesis (compared with glycolysis)
232
Where does gluconeogenesis occur?
Mainly in the liver, some in the kidneys
233
What provides the energy and reducing power for gluconeogenesis?
Fatty acid oxidation
234
For every molecule of alcohol, how many NADH are produced?
2
235
Ketone body concentration during fed state
<0.1 mmol/L
236
Ketone body concentration during fasted state
0.3 mmol/L
237
Ketone body concentration during starvation
10 mmol/L
238
Ketone body concentration for T1D and ketoacidosis
>30 mmol/L
239
Diabetes fasting glucose levels
>7 mmol/L
240
Diabetes random glucose levels
>11.1 mmol/L
241
Diabetes HbA1c levels
≥50 mmol/mol
242
Main diagnostic marker for diabetes
HbA1c
243
Ketonemia
High ketones in blood
244
What do AGE products do?
Promote inflammation and atherosclerosis
245
Insulin resistance
Reduced response to the same amount of insulin
246
Underweight BMI
<18.5
247
Normal BMI
18.5 - 24.9
248
Overweight BMI
25 - 29.9
249
Obese BMI
30 - 34.9
250
Extremely obese BMI
35 +
251
Xenical function and what is
Pancreatic lipase inhibitor, reduces fat absorption
252
Leptin is released from ____ and promotes ____
Released from adipose, promotes reduced appetite
253
Ghrelin released from _____ and signals _____
Released from stomach, signals that gut is empty
254
ATP synthase moves protons from
Intermembrane space to matrix
BIOC192
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