Block 4 Flashcards
(559 cards)
1
Q
vitamin A is also known as
A
retinol
2
Q
the natural forms of vitamin A are __ and __
A
retinol
beta-carotene
3
Q
the active forms of vitamin A are __ and __
A
retinal
retinoic acid
4
Q
what are the 3 main functions of vitamin A
A
vision (retinal pigments)
gene transcription
differentiation of epithelial cells into specialized tissue
5
Q
what are the common food sources of vitamin A
A
liver/kidney
butter
egg yolks
orange/yellow fruits/veggies
dark green vegetables
6
Q
vitamin D is also known as
A
calciferol
When active in the kidneys= calcitriol
7
Q
the active form of vitamin D in the kidneys is
A
calcitriol aka 1,25 di (OH)- vitamin D3
8
Q
what is the storage form of vitamin D
A
calcidiol aka 25-hydroxy vitamin D2
9
Q
what are the main functions of vitamin D
A
Ca/PO4 homeostasis
10
Q
vitamin E is also called __
A
tocopherol
11
Q
the 2 forms of vitamin E are __ and __
A
tocopherol
tocotrienol
12
Q
the main function of vitamin E is to serve as a __
A
antioxidant
13
Q
what are the functions of vitamin K
A
activation of clotting factors II, VII, IX, and X
use in ETC
osteocalcin bone formation
14
Q
vitamin B1 is also known as __
A
thiamine
15
Q
vitamin B2 is also known as __
A
riboflavin
16
Q
vitamin B3 is also known as __
A
niacin
17
Q
vitamin B5 is also known as __
A
pantothenic acid
18
Q
vitamin B6 is also known as __
A
pyrixidine, pyridoxal, or pyridoxamine
19
Q
vitamin B7 is also known as __
A
biotin
20
Q
vitamin B9 is also known as __
A
folate
21
Q
vitamin B12 is also known as __
A
cyanocobalamin or methylcobalamin
22
Q
what 4 enzymes use vitamin B1 (thiamine)
A
alpha-ketoglutarate
transketolase
pyruvate dehydrogenase
branched chain ketoacid dehydrogenase
23
Q
what is the function of vitamin B2 (riboflavin)
A
used as a precursor to coenzymes FAD and FMN used in redox reactions (dehydrogenase and reductase enzymes)
24
Q
what is the function of niacin (vitamin B3)
A
a precursor of NAD and NADP
25
what is the function of vitamin B5 (pantothenic acid)
it's a precursor of coenzyme A for FA, cholesterol, and acetylcholine synthesis
26
what is the function of vitamin B6
the active form, pyridoxal phosphate, is used in the metabolism of alcohols, fats, and proteins
(heme and neurotransmitter synthesis, transamination, amino acid decarboxylation)
27
what is the function of vitamin B7 (biotin)
used as a cofactor with carboxylase enzymes
28
what is the function of vitamin B9 (folate)
precursor for methionine, purine, and pyrimidine synthesis, conversion between serine and glycine, and degradation of histidine to glutamate
29
what is the function of vitamin B12 (cobalamin)
methionine synthesis
folate metabolism
maintenance of myelin sheath
RBC maturation
30
what is the function of vitamin C (ascorbate)
used as a cofactor for hydroxylases
enhance iron absorption
norepinephrine formation
31
what amino acid load test is used to test for folate deficiency
histidine
32
what 2 vitamins are stored in the liver
B9 and B12
33
B12 absorption requires functioning __, __, and __ (what organs)
stomach
pancreas
ileum
34
what is produced in the stomach by parietal cells that is needed in the absorption of vitamin B12
intrinsic factor
35
before vitamin B12 is internalized for absorption, it binds to IF, forms a complex, then binds to __ receptor
cubilin
36
what is the main extracellular cation
Na+
37
what is the main intracellular cation
K+
38
what is the main extracellular anion
Cl-
39
what is the main intracellular anion
phosphate
40
what are the 3 main functions of sodium
nerve transmission
muscle function
control body osmolarity
41
the main function of potassium is to regulate __ and it is primarily regulated by __
heart rate
aldosterone
42
respiratory acidosis is caused by __
metabolic acidosis is caused by __
hypoventilation
uncontrolled diabetes, diarrhea, lactic acid, kidney disease (non-respiratory cause)
43
respiratory alkalosis is caused by __
metabolic alkalosis is caused by __
hyperventilation
antacids, vomiting, etc.
44
what is the main function of magnesium
regulate calcium
45
what are the 3 major iron containing proteins
hemoglobin
myoglobin
cytochromes
46
is heme iron Fe2+ or Fe3+
Fe2+
47
heme iron (Fe2+) is absorbed directly into intestinal cells. what must occur with non-heme iron before it is absorbed
it must be reduced to Fe2+ first
48
__ decreases absorption of iron
__ increases absorption of iron
calcium decreases
vitamin C increases
49
in low cellular iron cases, there is an increase in __ synthesis to help transport the iron into the cell
transferrin receptor
50
in high cellular iron cases, there is an increase in __ synthesis to bind the surplus iron and a decrease in __ synthesis
ferritin
transferrin receptor
51
what are the effects of excessive free iron
can lead to oxidative stress due to free radical generation
52
what is iodine required for
formation of thyroid hormone
53
what are the 6 trace elements/minerals
iron
iodine
selenium
sulfur
copper
zinc
54
what 4 enzymes use TPP (thiamine)
Alpha ketoglutarate dehydrogenase
Transketolase
Pyruvate dehydrogenase
Branched chain ketoacid dehydrogenase
55
what are the 3 main symptoms of infantile Beri Beri
cyanosis
tachycardia
cardiomegaly
56
what are the 3 main symptoms of wet Beri Beri
cardiomyopathy
pitting edema
tachycardia
57
what are the 3 main symptoms of dry Beri Beri
no edema
muscle atrophy
bilateral peripheral neuropathy
58
what are the 5 main symptoms of riboflavin (vitamin B2) deficiency
glossitis
cheilosis
seborreic dermatitis
stomatitis
normocytic normochromic anemia
59
what is the main symptom of high riboflavin
bright yellow-orange urine
60
what are the 3 main symptoms of niacin (vitamin B3) deficiency
dementia
diarrhea
dermatitis (scaly skin exposed areas)
61
a diet high in __ can lead to vitamin B3 deficiency
corn/maize
62
what are the 4 main symptoms of niacin (vitamin B3) toxicity
skin flushing
hyperglycemia
hypocholesterolemia
hyperuricemia
63
what are the 4 main symptoms of vitamin B6 deficiency
cheilosis
stomatitis
skin rash
hypochromic microcystic sideroblastic anemia
64
what are the 5 main symptoms of biotin (vitamin B7) deficiency
hair loss
scaly facial rash
depression
conjunctivitis
hypotonia/lethargy
65
what are the 6 main symptoms of folate (vitamin B9) deficiency
homocystinuria
atherosclerosis
hypersegmented PMN
glossitis
diarrhea
macrocytic/megaloblastic anemia
66
what are the 3 main symptoms of vitamin B12 deficiency
tingling/numbness in limbs
methylmalonic acid toxicity
macrocytic/megaloblastic anemia
67
riboflavin (vitamin B2) is used in what two types of enzymes
dehydrogenase
reductase
68
vitamin B6 is used for what 5 types of reactions
transamination
amino acid decarboxylation
heme synthesis
neurotransmitter synthesis
niacin (vitamin B3) synthesis from tryptophan
69
biotin (vitamin B7) is used with what type of enzymes
carboxylase
70
what are the 3 molecule requirements for hematopoiesis
iron
vitamin B12
folic acid
71
deficiency in 1 of what 3 molecules can lead to anemia
iron
vitamin B12
folic acid
72
what hormone directs the differentiation into erythrocytes
erythropoietin
73
what hormone directs the differentiation into platelets
thrombopoietin
74
what secondary condition is present in any kidney failure patient
anemia
75
erythropoietin is synthesized in the __ of the __ in response to __
peritubular capillaries
renal cortex
hypoxia
76
if a patient has kidney failure, what hormone level is going to be low
erythropoietin
77
erythropoietin uses what class of receptors
JAK/STAT (JAK2-STAT5)
78
what is supplemented in cases of renal failure
erythropoietin
79
how do immature erythrocytes differ from mature erythrocytes
immature have organelles
mature do not
80
why can RBC not use anything other than glucose for an energy source
they don't have the necessary organelles (mitochondria) to break down FA/ketones
81
what is the most predominant iron containing molecule
heme
82
what is the structure of a hemoglobin molecule
2 alpha chains
2 beta chains
4 heme groups
83
what is the structure of a heme molecule
Fe2+ in the center surrounded by 4 porphyrin rings
84
where does heme biosynthesis occur
mitochondria and cytoplasm
85
besides heme synthesis, what other process occurs in the mitochondria and cytoplasm
urea synthesis
86
what 2 main molecules build heme
succinyl CoA
glycine
87
what TCA cycle intermediate is needed for heme synthesis
succinyl CoA
88
what amino acid is needed for heme synthesis
glycine
89
what cofactor is used in heme synthesis
pyridoxal (B6)
90
what enzymes of heme synthesis are present in the mitochondria
ALA synthase
ferrochelatase
91
what is the rate limiting enzyme of heme synthesis
ALA synthase
92
a deficiency in what 3 molecules can lead to microcytic anemia
iron
B6
vitamin C
93
why can a deficiency in vitamin C lead to microcytic anemia
vitamin C is needed to reduce iron to an absorbable form
94
a deficiency in what 2 molecules can lead to macrocytic anemia
vitamin B12
folate (B9)
95
porphyira conditions involve a deficiency in what
enzyme in heme synthesis
96
in heme synthesis, what enzymes does lead inactivate
ferrochelatase (last enzyme)
ALA dehydratase (2nd enzyme)
97
what accumulates with defect in ALA dehydratase (can result due to lead poisoning)
aminolevulinic acid (ALA)
98
in lead poisoning, Fe is not added to form heme. what is added instead to whatever protoporphyrin IX that has already been made
zinc
99
what is the lab reading for someone with lead poisoning (3 results)
ALA in blood/urine
elevated zinc protoporphyrin levels
basophilic stippling (dots in RBC)
100
what exposure is associated with a risk in lead poisoning
urban, old house
lead based paint
101
what is the main symptom of lead poisoning
developmental delay or regression
*young children more susceptible due to under developed BBB and ingestion
102
What is a cause of iron deficiency anemia
lead poisoning
103
what enzyme is deficient in acute intermittent porphyria
porphobilinogen deaminase/hydroxymethylbilane synthase/uroporphyrinogen I synthase
(multiple names for the same enzyme)
104
what accumulates in acute intermittent porphyria
ALA
porphobilinogen
105
what are the 4 main symptoms of acute intermittent porphyria
abdominal pain (although all abdominal exams are normal)
neurological manifestations (incorrect psychiatric diagnosis)
no photosensitivity
portwine color urine on sitting
106
acute intermittent porphyria can be diagnosed through what method
urine dipstick
107
what medication is never given to those with acute intermittent porphyria
barbituates
108
what are the symptoms of porphyria cutanea tarde
photosensitivity
shearing of skin in areas exposed to skin (blistering)
109
what is the most common disorder of porphyrin synthesis
porphyria cutanea tarda
110
what enzyme is deficient in porphyria cutanea tarda
uroporphyrinogen decarboxylase
111
what accumulates in blood/urine with porphyria cutanea tarda
uroporphyrinogen III
112
what 2 molecules are negative regulators of heme synthesis
heme
glucose
113
heme and glucose act as negative regulators of heme synthesis by inhibiting what part of the synthesis
ALA synthase
114
how do barbiturates increase heme synthesis
cytochromes (cytochrome P450) are heme requiring so if you give a barbiturate, heme synthesis occurs leading to the buildup of an intermediate
115
what are the 2 main treatments for porphyrias
ingestion of carbohydrates (glucose)
administer hematin (heme)
116
a deficiency in __ or __can lead to sideroblastic anemia
ALA synthase
B6
117
what drug usage should be supplemented with B6
isoniazid for TB
118
why is B6 supplementation given with isoniazid usage
isoniazid inactivates B6
119
what is seen in a bloodsmear with someone with sideroblastic anemia
ring sideroblasts (iron accumulates around the developing RBC due to lack of ALA synthesis)
120
how does CO interfere with heme synthesis
CO competitively binds to iron in heme protein
with Fe2+ bound with CO, there is no O2 exchange
(CO binds with greater affinity than O2)
121
at the cellular level, CO binds to __, inhibiting aerobic metabolism, leading to tissue hypoxia (in ETC)
cytochrome oxidase (complex IV)
122
what is the classification of anemia based on
size of RBC (MCV)
123
what causes microcytic anemia in terms of cell divisions
more divisions= low MCV (low size) due to lack of availability of hemoglobin molecules
124
what are the 4 reasons for lack of available hemoglobin molecules
iron deficiency
thalassemia (globin chains)
sideroblastic anemia (B6 deficiency)
lead poisoning
125
what causes megaloblastic anemia in terms of cell divisions
vitamin B12 or B9 deficiency= inability to synthesize new bases= decreased cell divisions
126
strict vegans are at risk for what main vitamin deficiency
B12
127
methylfolate trap is due to deficiency in what vitamin
B12
128
how can B9 be differentiated from B12, when they both show megaloblastic anemia and hypersegmented neutrophils
B12 shows elevated homocysteine and methylmalonic acid
B9 only shows elevated homocysteine
129
what vitamin is needed for thymidylate synthase for pyrimidine and purine synthesis
B9
130
folate deficiency inhibits the synthesis of nucleic acids, particularly the formation of ___
deoxythymidine monophosphate (dTMP)
131
what 2 enzyme defects can lead to hemolytic anemia
G6PD
pyruvate kinase
132
pyruvate kinase is an enzyme of what pathway
glycolysis
133
in pyruvate kinase deficiency, what happens with the spleen
splenomegaly
134
G6PD is an enzyme of what pathway
pentose phosphate pathway
135
where does heme breakdown occur
reticuloendothelial system in the spleen and liver
136
what is the breakdown product of heme
bilirubin
137
what is the main enzyme of heme breakdown
heme oxygenase
138
heme is broken down into __ and __
Fe2+
bilirubin
139
when heme is being broken down, Fe is in what form
Fe2+
140
what part of heme is broken to form bilirubin
alpha bridge
141
heme oxygenase used in heme catabolism requires what 2 molecules
NADPH
O2
142
what 2 enzymes produce NADPH
what process are they involved in
G6PD- PPP
FA synthesis- malate dehydrogenase
143
what enzyme involves the physiological release of O2
heme oxygenase
144
heme oxygenase of heme catabolism produces what 3 molecules
Fe3+
CO
biliverdin
145
in heme breakdown, biliverdin is converted to bilirubin through use of what enzyme
biliverdin reductase
146
biliverdin reductase uses what cofactor
NADPH
147
bilirubin formation occurs in what organ
spleen
148
why must bilirubin be transported to the liver bound to albumin
it is insoluble (hydrophobic)
149
conjugation of bilirubin occurs where
liver
150
the 3 steps to bilirubin metabolism are
uptake by liver cells
conjugation
secretion in bile
151
what bilirubin accumulates in kernicterus
unconjugated (insoluble)
152
where does unconjugated bilirubin deposit in kernicterus
basal ganglia
153
what happens once the albumin-bilirubin complex reaches the liver
albumin unbinds and re-enters the blood
bilirubin enters the hepatocyte through the bilirubin transporter
154
once unconjugated bilirubin is in the liver, what is used to trap it and prevent efflux back to the blood
glutathione-S-transferase (GST)/protein Y/ligandin
155
unconjugated bilirubin in the liver is conjugated by what enzyme
bilirubin-UDP-glucuronosyltransferase (UGT1A1)
156
what is used to transport conjugated bilirubin into the bile duct
MRP (multi-drug resistant protein)
157
what molecule is added to conjugate bilirubin in the liver
UDP-glucuronic acid
158
what is the function of UDP-glucuronic acid in the liver
conjugate bilirubin to make it hydrophilic, allowing for excretion
also used for bond formation
159
how many time is UDP-glucuronic acid and bilirubin-UDP glucuronyltransferase used in the conjugation step
2
160
UDP is used in what 2 molecules
UDP glucose (glycogen synthesis)
UDP glucuronic acid (bilirubin metabolism)
161
what are the 3 causes of jaundice
1. hemolytic anemia- more bilirubin production than the liver can excrete due to hemolysis
2. defect in liver (no conjugation)
3. blockage of bile duct
162
what allows for reduction of conjugated bilirubin to urobilinogen in the small intestine
bacterial enzyme beta-glucuronidase
163
urobilinogens are ___
urobilins are __
(colored/colorless change)
urobilinogens- colorless change
urobilins- colored change
164
how can you assess for anemia/pallor by palpebral exam
pale lower palpebral conjunctiva
165
how can you assess for jaundice/icterus by palpebral exam
pale upper palpebral conjunctiva
166
where would you see jaundice most evident
sclera due to white background and high elastin content
167
pre-hepatic jaundice is caused by __
hemolytic anemia
(ex: sickle cell, G6PD deficiency, glutathione reductase deficiency)
168
hepatic jaundice is caused by __
liver disease
169
post-hepatic/obstructive jaundice is caused by __
gallstones or pancreatic cancer
170
is the level of direct (conjugated) or indirect (unconjugated) bilirubin higher in the serum
indirect (unconjugated)
171
is urinary bilirubin conjugated or unconjugated
conjugated
172
serum levels of what 2 enzymes indicate hepatitis
alanine aminotransferase (ALT)
aspartate aminotransferase (AST)
173
serum levels of what enzyme are increased in obstructive liver disease
alkaline phosphatase (ALP)
174
what is the stool presentation in obstructive liver disease/cholestasis
clay colored stool
175
why is alkaline phosphatase (ALP) level raised in post-hepatis jaundice
the liver pumps bile juices into the bile duct but they get blocked. this causes bile acids to form micelles and ALP is released
176
what are the 3 lab values for hemolytic jaundice
increased indirect (unconjugated) bilirubin
-->increased direct (conjugated) bilirubin
increased urine urobilinogen
increased fecal stercobilin (urobilinogen)
177
why is the urine dark yellow in both hemolytic jaundice and obstructive jaundice
bilirubin is in the urine
178
what color is the stool as a result of hemolytic jaundice
dark brown
179
what are the 3 lab values of obstructive/post-hepatic/cholestatic jaundice
increased direct (conjugated) bilirubin in blood and urine
low/no urine urobilinogen
low/no fecal stercobilin (urobilinogen)
180
what is the color of stool as a result of obstructive/post-hepatic/cholestatic jaundice
clay/pale colored (no fecal stercobilin/urobilinogen)
181
why can unconjugated bilirubin never appear in the urine
it is insoluble/lipophilic/hydrophobic and bound to albumin (large complex)
182
how does phenobarbital act on bilirubin metabolism
it's an enzyme inducer so it increases the enzyme activity of glucuronyltransferase in the liver to increase conjugation of bilirubin
183
what is the main concern of crigler najjar syndrome type I
it leads to encephalopathy that can lead to permanent brain damage within the first year of life
184
how does phototherapy work for treatment of jaundice
blue light isomerizes trans (unconjugated) bilirubin to soluble cis (conjugated) bilirubin that can be easily excreted
185
what are 2 processes involved in isomerization
methylmalonyl CoA-->succinyl CoA
trans bilirubin-->cis bilirubin
186
what process involves epimerization
galactose<-->glucose
187
what must be supplemented in a neonate receiving phototherapy for jaundrice
vitamin B2 (riboflavin)
B2 is degraded by light
188
what causes neonatal jaundice
low activity/immature bilirubin-UDP-glucuronyltransferase in the liver to conjugated bilirubin
189
what is neonate jaundice evident
2-3rd day of life
190
how can you differentiate Gilbert syndrome from physiological (neonatal) jaundice
Gilberts- later in life and requires a stimulus (stress/fasting/etc.)
physiological- 2-3 days after birth and resolves in 5-7 days
191
how can bilirubin form gallstones
formed by calcium salts of unconjugated bilirubin
192
what do you call the gallstones formed by bilirubin salts
pigment gallstones
193
what is the appearance and texture of pigment gallstones caused by unconjugated bilirubin
soft, dark brown/black
194
what causes pigmented gallstones to form
bacterial/helminthic infection that causes bacterial beta glucuronidase to be released hepatocytes
(this enzyme is usually only released in the small intestine)
195
what does beta glucuronidase do when it is released by hepatocytes during a bacterial or helminthic infection
unconjugates bilirubin in the liver after our enzymes have already worked to conjugate it
196
how does plasma differ from serum
plasma contains fibrinogen, serum does not
197
what is the main blood plasma protein
albumin
198
where are most plasma proteins synthesized
liver
199
most plasma proteins are synthesized in the liver with the exception of __ which is synthesized in __, and __ which is synthesized in __
von Willebrand factor
vascular endothelium
gamma globins
lymphocytes
200
most proteins are covalently modified by the addition of N or O linked oligosaccharide chains, or both. what plasma protein is an exception to this
albumin
201
what plasma protein is responsible for osmotic pressure of human plasma
albumin
202
what plasma protein contains disulfide bonds
albumin
203
what 3 molecules can be used to access liver function
AST and ALT liver enzymes
bilirubin
albumin
204
what 3 molecules can be used to access kidney function
creatinine
urea (make sure to account for protein diet history)
albumin
205
what is the best and 1st indicator of kidney disease
albumin in the urine
(typically, albumin is not filtered due to it being of the same charge and size of the glomerular filtration membrane. when there is an issue in the membrane, changing the charge, albumin is allowed to be filtered into the urine)
206
what are the 3 main functions of albumin
plasma osmotic pressure maintenance
transport
buffering
207
does albumin level relate to edema
decrease in plasma albumin= decreased in osmotic pressure= fluid buildup in tissues= edema
208
what is one of the main symptoms of kwashiorkor
decreased albumin-->edema
209
how is albumin able to act as a buffer
high histidine content
210
why is albumin more important than globins in the plasma
albumin has buffering capability
211
how does albumin relate to BBB maintenance
albumin binding to other molecules forms a large complex, preventing them from crossing the BBB
212
hypoalbuminemia in what 3 conditions leads to edema
malnutrition
nephrotic syndrome (any kidney disease)
liver cirrhosis
213
albumin is useful in treatment of __ and __
burns
hemorrhage
214
what is the normal albumin:globin ratio in blood plasma
1.2-1.5:1
215
what blood plasma protein protects the kidneys from damage by extracorpuscular hemoglobin/iron
haptoglobin
216
what type of protein is the plasma protein haptoglobin
acute phase
217
what are acute phase proteins
nonspecific proteins activated by inflammation
218
haptoglobin levels are low in what condition
hemolytic anemia
219
__ binds heme
__ binds hemoglobin
hemopexin binds heme
haptoglobin binds hemoglobin
220
what is the importance of high C reactive protein levels
it indicates inflammation
221
what are the 5 positive acute phase proteins (what plasma proteins are increased)
ferritin
fibrinogen
serum amyloid A
hepcidin
C reactive protein
222
what are the 2 negative acute phase proteins (what plasma proteins are decreased)
albumin
transferrin
223
why is CRP (C reactive protein) named with a C
it reacts with C polysaccharide
224
what is the significance of C reactive protein in diagnosis
biomarker of tissue injury, infection, and inflammation
225
what 2 molecules contain non-heme iron
transferrin
ferritin
226
what is the only non-globin protein plasma protein
albumin
227
where does absorption of dietary iron occur
proximal duodenum
228
what 2 molecules reduce ferric iron (3+) to ferrous iron (2+)
vit C
gastric acid
229
is iron absorbable in Fe2+ or Fe3+ form
Fe2+
230
when iron supplementation is given, what is always used as supplementation
vit C
So vit C can reduce iron to an absorbable 2+ form
231
transporters for absorption of metals such as iron into cells (ex: iron to enterocytes) enters through what transporter
divalent metal transporter
232
on the basal surface of enterocytes, what transporter is used for iron
ferroportin
233
when is iron in 2+ vs 3+
crossing membrane= 2+
storage/transport= 3+
234
what is the storage form of iron
ferritin
235
what is the shuttle protein used to bring iron to the site where it is needed
transferrin
236
what allows for entry of iron into enterocyte
divalent metal transporter
237
what protein oxidizes iron when it crosses into the blood
hephaestin
238
why is free iron toxic
it reacts with metabolites to make ROS (Fenton reaction)
239
transferrin shuttles how many irons from the intestines to the bone marrow
2
240
iron needs to be in 2+ or 3+ to be shuttled by transferrin
3+
241
what molecule represents the total iron binding capacity
transferrin
(transferrin is approx. 30% saturated with iron)
242
where is transferrin receptor 1 present
almost all cells, especially erythroid precursors in the bone marrow for uptake of iron
243
for cellular uptake of iron, what allows for iron to dissociate from transferrin
acidic pH of late endosome
it is internalized through a clathrin coated pit, forming an early endosome. pH decreases, forming a late endosome. low pH= dissociation
244
plasma level of what is an indicator of body iron stores
ferritin
245
what is a sensor of body iron stores
transferrin receptor 2
246
ferritin is an indication for iron __
transferrin is for iron __
ferritin= storage
transferrin= sensing
247
what is hemosiderosis
overstorage of iron in a partly degraded form of ferritin
248
what is the relationship between transferrin receptor 1 and ferritin
inversely
(when intracellular iron is low, receptor synthesis increases and ferritin decreases)
249
where are the coding regions for ferritin vs transferrin receptor 1 in mRNA
ferritin in 5' UTR
transferrin receptor 1 in 3' UTR
250
at high concentration of iron, is transferrin or ferritin synthesized
ferritin
251
when concentration of iron is high in the cell, ferritin is synthesized. what happens to the transferrin
mRNA of transferrin is degraded
252
what is the function of hepcidin
regulation of iron homeostasis
binds with ferroportin and degrades it, preventing iron absorption, so it continues to the small intestine (mucosal block)
253
the mucosal block is based on the relationship between what 2 molecules in iron homeostasis
hepcidin and ferroportin
254
is milk a low or high source of iron
low
255
in children, secondary to not eating after drinking milk, what condition is most common
iron deficiency anemia
256
when the Fe2+ iron that was released from heme breakdown is released from the macrophage through ferropotin, what molecule converts Fe2+ to Fe3+ (oxidation)
ceruloplasmin
257
what molecule of iron transport from heme breakdown has ferro-oxidase property
ceruloplasmin
258
ceruloplasmin is a __ containing globin of blood
copper
259
most plasma copper in the plasma are bound/stored where
in ceruloplasmin
(uses it for itself)
260
exchange of copper occurs through binding with what plasma protein
albumin (transfers it to where it's needed)
261
why is total iron binding capacity increased in iron deficiency anemia
there is less iron to bind but the transferrin binding capacity is still there
262
iron deficiency anemia causes what RBC morphology
microcytic
hypochromic
irregular
central pale coloring
263
what causes Wilson's disease
impaired incorporation of copper into ceruloplasmin due to ATP7B deficiency-->intracellular copper buildup
264
what 3 lab levels diagnose Wilson's disease
high urine copper
low urine ceruloplasmin
high free copper in urine
265
Kayser-Fleischer copper ring around eyes are caused by what disease
Wilson's
266
what receptor is used for copper transporting for incorporation into ceruplasmin
ATP7B
267
what is used for treatment of Wilsons disease
penicillamine
268
how does penicillamine work for Wilson's disease
chelates copper, causing it to be excreted in urine
269
what happens when ceruloplasmin is deficient
accumulation of iron in the liver
270
what causes "bronze diabetes"
accumulation of iron in tissue
leads to insulin dependent diabetes
271
what happens if the ferroxidase activity of ceruloplasmin, aceruplasminemia, is deficient
accumulation of iron
272
what causes multiple myeloma
abnormal Ig production (usually IgG)
273
the electrophoretic pattern in multiple myeloma shows what change
gamma band (M band) increase
274
what is involved in primary hemostasis
platelet plug formation
275
what is the function of glycoprotein Ia receptor in blood clotting
binds to collagen
276
what is the function of glycoprotein Ib receptor in blood clotting
binds von Willebrand factor
277
what is the function of glycoprotein IIb/IIIa
binds fibrinogen
278
what protein on the platelet surface allows for platelet aggregation
glycoprotein IIb/IIIa
279
what synthesizes von Willebrand factor used for blood clotting
endothelial cells
megakaryocytes
280
von willebrand factor is a carrier for what protein involved in secondary hemostasis
factor VIII
281
what does the ristocetin cofactor assay test
platelet agglutination
282
von willebrand factor is synthesized from __ in __ or __ in __
endothelial cells in Weibel Palade bodies
platelets in alpha granules
283
von willebrand factor is involved in __
fibrin is involved in __
plasmin is involved in __
platelet plug
fibrin mesh
dissolving of platelet plug
284
what clotting factor starts the extrinsic path way of fibrin clot formation
VII
285
what clotting factor starts the intrinsic path way of fibrin clot formation
XII
286
where do the fibrin clot formation pathways take place
activated platelet surface
287
what is the function of thrombin
convert fibrinogen to fibrin
288
what protein converts fibrinogen to fibrin
thrombin
289
what protein dissolves fibrin clots
plasmin
290
what is the function of plasmin
dissolve fibrin clots
291
the dissolving of fibrin (fibrinolytic system) is regulated by what protein
protein C
292
what is the function of protein C
regulate the fibrinolytic system (dissolving of fibrin clot)
293
what activates protein C, the protein that regulates the fibrinolytic system for dissolving fibrin clots
thrombomodulin
294
thrombin is involved in both fibrin formation and degradation. how is it involved in degradation
it complexes with thrombomodulin
295
what does protein C inactivate
clotting factor V and VIII
296
what are the products of fibrinolysis
D-dimers
297
what phase of clotting is bleeding time used to measure
primary hemostasis
298
what is prothrombin time a measure of
integrity of extrinsic and common pathway of coagulation
299
what clotting factors can be tested with a partial thromboplastin time test (aPPT)
XII (12)
XI(11)
IX (9)
VIII (8)
300
what clotting factor can be tested with a prothrombin time test
VII
301
hemophilia A is due to a deficiency of what clotting factor
VIII (8)
302
what stage of clotting is there an issue in those with hemophilia A
secondary hemostasis
303
what occurs in those with hemophilia A
lack of clotting factor VIII causes a weak platelet plug to form, allowing bleeding to continue
304
why is hemophilia A mainly seen in males
it's X linked recessive
305
what are the 4 lab findings in someone with hemophilia A
increased partial thromboplastin time (increased PTT because factor VIII that is affected by hemophilia A is part of the intrinsic coagulation cascade)
normal platelet count
normal prothrombin time
normal bleeding time
306
what is the main protein involved in iron homeostasis
transferrin
307
patients with hemophilia A often don't develop hematomas or hemarthroses until when
they begin to crawl or walk
308
what clotting factors require vitamin K for activation
II, VII, IX, X, protein C, protein S
309
II, VII, IX, X, protein C, and protein S undergo what kind of modification
(post-translational or post-transcriptional)
post-translational
310
II, VII, IX, X, protein C, and protein S undergo __ of __ amino acid residue
gamma carboxylation
glutamic acid
311
what is the function of gamma carboxylation of glutamic acid
allows for effective binding to Ca2+
312
what affect does vitamin K deficiency have on clot formation
decreased vitamin K= decreased clotting
313
how is vitamin K produced in the body
gut microflora
314
what is the effect of vitamin K deficiency in newborns
hemorrhagic disease of the newborn due to the neonate's gut being sterile
315
what are 2 main causes of vitamin K deficiency
long term antibiotic use
fat malabsorption
316
what is an example of a parental anticoagulants
what is an example of an oral anticoagulant
parental- heparin
oral- warfarin
317
what is the effect of heparin on anticoagulation
activates antithrombin III
318
what is the effect of warfarin on anticoagulation
inhibits vitamin K reductase (vitamin K epoxide reductase)
319
what enzyme, along with vit K as a cofactor, is needed to activate clotting factors II, VII, IX, X, protein C, and protein S
gamma glutamyl carboxylase
320
is vitamin K requires in the oxidized or reduced form for gamma glutamyl carboxylase, which allows for activation of clotting factors II, VII, IX, X, protein C, protein S
reduced
321
what enzyme reduces vitamin K to the reduced form needed for activation of clotting factors
vitamin K reductase (vitamin K epoxide reductase)
322
what is the function of antithrombin III
inactivates clotting factors IIa (thrombin) and Xa
323
what type of inhibitor is antithrobmin
serine protease
324
what 2 drugs are used to prevent further blood clotting
heparin
warfarin
325
what is the effect of liver failure on blood clotting
clotting factors are synthesized in the liver so there is a high risk of bleeding due to deficient synthesis of procoagulation factors
326
clot formation= increased __, decreased __
increased thrombin
decreased plasmin
327
what causes disseminated intravascular coagulation
increased fibrin formation--> clotting-->deficiency in clotting factors--> bleeding and visible petechiae
328
what are the 3 main causes of disseminated intravascular coagulation (which is the main)
sepsis
trauma
*obstetric complications
329
what lab value is of importance for any blood clotting
d-dimer
330
what is the cause of factor V leiden
mutation that leads to resistance to clotting factor V degradation by protein C
331
how do enzymes for blood clotting work
activate plasminogen-->plasmin to dissolve clot
332
what is the function of streptokinase in blood clotting
dissolves fibrin in blood clots
333
where does platelet differentiation occur
bone marrow
334
platelet production is signaled through what receptor pathway
JAK2 STAT5 (which regulates Bcl-xl expression)
335
what are petechiae a symptom of in terms of blood clotting
decreased platelet function
336
all platelet disorders have what lab value
increased bleeding time
337
if there is an increased bleeding time, this tells us there is an issue with __ or __
von wilebrand factor
platelets
338
what is the defect in Bernard Soulier syndrome
defect in GpIb for platelet adhesion
339
what is the defect in Glanzmann thrombasthenia
defect in GpIIa/IIIb for platelet adhesion
340
what is the defect in immune thrombocytopenia
anti-GpIIb/IIIa antibodies
341
when platelet circulate through vessels with intact epithelium, the platelets remain in their inactive state due to release of __ from intact epithelium
prostacyclin (PGI2)
342
when platelets encounter a break in epithelium, what triggers the platelet activation
thromboxanes (TxA2)
343
what signalling pathway do thromboxanes (TxA2) use
G protein mediated signaling
344
how does aspirin work
irreversibly inhibits COX (which therefore inhibits thromboxane (TxA2) synthesis)
345
what amino acid does aspirin acetylate
serine
346
at low dose, aspirin inhibits COX-_
1
347
all eicosanoids originate from __ with __ carbons
polyunsaturated fatty acids (arachidonic acid)
20
348
is linoleic acid essential or nonessential
essential
349
do eicosanoids act locally or far
locally
350
eicosanoids are known as __ because they exert their effect primarily in the tissue in which they are produced
autocoids
351
what type of receptor do eicosanoids use
G protein coupled
352
what series is the predominant type of prostaglandins in the body
2
353
arachidonic acid is made from what molecule
linoleic acid
354
arachidonic acid is made from dietary linoleic acid by what 2 processes
elongation
desaturation
355
arachidonic acid is broken down to produce prostaglandins through what 2 enzyme
cyclo-oxygenase
peroxidase
*these together are called PGH synthase
356
cyclo-oxygenase and peroxidase (PGH synthase) used for prostaglandin synthesis are present where
ER membrane, bound
357
is COX-1 or COX-2 present in most tissues
COX-1 (platelet/gastric/renal integrity)
*always present
358
is COX-1 or COX-2 inducible
COX-2
stimulus needed
359
COX-2 is inducible in response to what 5 things (5 signs of inflammation/infection)
pain
heat
redness
swelling
fever
360
the 5 signs of inflammation are mediated by what enzyme
COX-2
361
thromboxane A2 is a COX-1 or 2 product
COX-1
362
thromboxane A2 is produced where
in platelets
363
what are the 3 function of thromboxane
vasoconstriction
platelet aggregation
mobilizes calcium
364
prostacyclin (PGI2) is a product of COX-1 or COX-2
COX-2
365
prostacyclin (PIG2) is produced where
endothelium of blood vessels
366
what are the 2 main functions of prostacyclin (PGI2)
vasodilation
inhibition of platelet aggregation
367
what is the main function of prostaglandin E2 (PGE2)
induce labor (uterine contraction)
368
the 2 products of the lipoxygenase pathway are
leukotrienes
lipoxins
369
what enzyme converts leukotrienes to 5-HPETE (parent intermediate)
5-lipoxygenase
370
what is the main function of leukotrienes
bronchoconstrictors
371
what is the main molecule involved in asthma
leukotrienes
372
what 3 leukotrienes are involved in the mediation of asthma
LTC4
LTD4
LTE4
373
what causes aspirin induced asthma
overproduction of leukotrienes with NSAID use
374
cortisol inhibits what enzyme of prostaglandin synthesis
phospholipase A2
375
aspirin and other NSAIDs inhibit what enzyme
COX-1 and COX-2
376
does aspirin inhibit COX-1 and COX-2 reversibly or irreversibly
irreversibly
377
COX-2 inhibitors have been associated with __ due to __
heart attacks
decreased PGI2 (thromboxane) synthesis
378
what type of modification does aspirin make
acetylation
379
can the inhibition of COX-1 or COX-2 be overcome
by what cells?
COX-2
endothelial cells
380
at low dose of aspirin, is COX-1 or COX-2 more affected (inhibited)
COX-1
*COX-1 makes thromboxane, decreasing activity of platelets
381
do platelets have COX-1 or COX-2
COX-1
382
what enzyme of prostaglandin synthesis can inactivate itself
cyclooxygenase
383
where is the site of neurotransmitter synthesis
some (cell body)
384
what 2 structures are within the axon
neurofilaments
microtubules
385
acetylcholine is synthesized in what type of neurons
cholinergic
386
acetylcholine is synthesized using what enzyme
choline aceyltransferase
387
what toxin blocks the release of acetylcholine
botulinum
388
what toxin causes release of acetylcholine
spider venom
389
acetylcholine is degraded by what enzyme
acetylcholinesterase
390
what are the 3 main symptoms of myasthenia gravis
muscle fatigue
muscle weakness
drooping of eyelids as the day progresses
391
where is acetylcholine released
neuromuscular junction at post synaptic terminal
392
myasthenia gravis is what type of condition
autoimmune
*antibodies are produced against the acetylcholine receptor
393
what are the 2 main treatments for myasthenia gravis
competitive reversible inhibitor of acetylcholinesterase
immunosuppressants
394
what do organophosphates do
irreversibly inhibit acetylcholinesterase
395
how do organophosphates inhibit acetylcholinesterase irreversibly
irreversible covalent bond
396
what type of receptor are muscarinic
G protein coupled
397
what type of receptor are nicotinic
ion channel
398
how does immunosuppression work for myasthenia gravis
activates apoptosis
399
are acetylcholinesterase inhibitors reversible or irreversible
reversible
400
do organophosphates inhibit reversibly or irreversibly
irreversible
401
serotonin is synthesized from what amino acid
tryptophan
402
catecholamines (dopamine, epinephrine, norepinephrine) are synthesized from what amino acid
phenylalanine/tyrosine
403
in the CNS, what cell synthesizes the myelin sheath
what about in the PNS
CNS- oligodendrocytes
PNS- schwann
404
organophosphate poisoning in common in what groups of patients
farmers
405
what is the predominant phospholipid present in myelin
sphingomyelin
406
brain and bone marrow are only able to synthesize nucleotides by what pathway
salvage
407
Multiple sclerosis and guillain barre syndrome are associated with what disorders
demyelination of CNS
408
oligoclonal antibodies are associated with what condition
multiple sclerosis
409
what type of hormones are glucagon and insulin
peptide
410
insulin in produced by what cells in the __
beta
endocrine portion of the pancreas
411
are the effects of insulin catabolic or anabolic
anabolic (making)
412
what is the structure of insulin
2 polypeptide chains linked by 2 disulfide bridges
413
what are the 3 classes of eicosanoids
prostaglandins
thromboxanes
leukotrienes
414
from arachidonic acid, prostaglandins are synthesized through the __ pathway
cyclooxygenase
415
from arachidonic acid, prostaglandins are synthesized through the __ pathway
cyclo-oxygenase
416
phospholipase A2 acts on what to release arachidonic acid from the plasma membrane
phosphatidylinositol (PI)
417
what is the function of the c-peptide in insulin
proper folding
418
what is used as an indication of insulin production/secretion
c-peptide
419
signal sequence of insulin is present at what terminal
N terminal
420
what does the insulin signal sequence do
transport from ribosomes to rER
421
once insulin reaches the ER, it is __ which is then transported to __
proinsulin
golgi
422
in pre/pro form,
pre-=__
pro-=__
(signal or zymogen)
signal
zymogen
423
what is the half life of insulin
6 minutes
424
what is the primary stimulus for insulin secretion
carb-rich meal
425
what 3 molecules (stimuli) determine how much insulin will be released
glucose
amino acids
GI peptide hormones
426
GLUT2 is located in what cells
hepatocytes
427
what 2 aspects of the beta islet cells of the pancreas serve as glucose sensor for insulin release
GLUT2
glucokinase
428
GLUT4 is in what 2 tissues
adipose tissue
muscle
429
what is the affect of ATP production in pancreatic beta cells following initial glucose entry
potassium ATP channel closes
VGCaC open
430
what intracellular concnetration causes insulin release
calcium
431
How do sulfonylureas work
close ATP K+ channels
432
what is the main amino acid (protein) that causes insulin secretion
arginine
433
does oral or IV glucose cause a greater release of insulin
oral
434
what is the function of intestinal peptides in terms of glucose/insulin
increases sensitivity of beta cells to glucose and cause anticipatory release of insulin
435
what 2 molecules are known as incretins
glucagon-like protein 1
gastric inhibitory peptide
436
what is the main function of gastric inhibitory polypeptide
stimulate insulin secretion by increasing the sensitivity of beta cells to glucose
437
what 2 states decrease insulin release
decrease in food
stress
438
what is the main function of insulin in terms of fatty acids
inhibit hormone sensitive lipase to decrease release of fatty acids
439
insulin uses what receptor
tyrosine kinase
440
what type of bonds does the insulin receptor have
disulfide bonds (tetramer structure)
441
how does the alpha domain differ from the beta of the insulin receptor
alpha- extracellular insulin binding
beta- tyrosine kinase residues
442
when insulin binds to the alpha subunit of the insulin receptor, what happens
autophosphorylation of tyrosine residues on each beta subunit
443
after insulin receptor is autophosphorylated, what is initiated
insulin receptor substrates
444
autophosphorylation of the insulin receptor makes the receptor __
dephosphorylation makes it __
active or inactive
autophosphorylation- active
dephosphorylation- inactive
445
phosphorylated insulin receptor substrate tyrosine phosphorylation can take 2 pathways. what are they
phosphoinositide 3 kinase
RAS/MAP
446
PKB/Akt is under the effect of what molecule
insulin
447
the activation of PKB/Akt by insulin is under the effect of what 2 amino acids
threonine
serine
448
what is the main phosphatase involved in insulin action
protein phosphatase-1
449
anything under affect of insulin is active in what state
(phosphorylated or dephosphorylated)
active in dephosphorylated state
450
glucagon is secreted by what cells, where
alpha cells of the pancreas
451
GLUT4 is what type of transport
facilitative
452
glucagon signals what state
hypoglycemia
453
glucagon prevents __ that would occur as a result of insulin secretion that occur after meals
hypoglycemia
454
when are insulin and glucagon both released
after a protein rich meal
455
glucagon binds to what type of receptor
G protein coupled
456
GLT4 translocation in skeletal muscle is stimulated by exercise. this is independent of insulin, and involves __
5' AMP activated kinase
457
is the post meal absorptive state an anabolic or catabolic process
anabolic
458
insulin stops all __ processes
(lysis or synthesis)
lysis
459
glycogenolysis and gluconeogeneis is increased with insulin or glucagon
glucagon
460
in a well-fed post-prandial state, what is used as an energy source for:
liver, muscle, brain, and adipose
glucose
461
in a fed state, what is the main enzyme acting to trap glucose in the liver
glucokinase (with GLUT2)
462
in the liver, excess glucose is __ or __
stored as glycogen
converted to triacylglycerol and packaged into VLDL
463
endogenous fat (glucose) is converted into __
VLDL
464
exogenous fat is packaged into __
chylomicrons
465
RBC only use what as an energy source, why
glucose
no mitochondria
466
lactate is taken up by what organ
liver
467
lactate is taken up by what process
gluconeogenesis
468
how does the fed state increase the rate of glycolysis in the liver
increase insulin=increase PFK2=increased fructose 2,6-bisphosphate=increased PFK-1= increased glycolysis
469
fructose 2,6-bisphosphate increases __ by __, decreases __
(what 2 processes)
increases glycolysis by PFK1
decreases gluconeogenesis
470
what is the effect of the fed state on lipid metabolism
increases TAG synthesis
decreases TAG degradation
471
what enzyme of lipid metabolism is active in the fed state
lipoprotein lipase
472
what enzyme of lipid metabolism is inactive in the fed state
hormone sensitive lipase
473
what enzyme of lipid metabolism is active in the fasting state, under effect of what hormone
hormone sensitive lipase (increased degradation of TAG)
glucagon
474
what enzyme of lipid metabolism is inactive in the fasting state, under effect of what hormone
lipoprotein lipase
insulin
475
what organs use glucokinase after meal
liver
pancreas
476
in the absorptive state, there is increased uptake of what amino acids
branched chain
477
what is the primary fuel source of the brain
glucose
478
what are the 2 possible energy sources for the brain
glucose
ketone bodies
479
the main target organ of glucagon is what
liver
480
what are 2 ways in which glucagon inhibits glycogen synthesis in the early fasting state
activation of phosphorylase
inhibition of glycogen synthase
481
in the early fasting state, there is a decrease in __, increase in __
decrease insulin
increase glucagon
482
what us the fuel source of muscle during early fasting, what is it for liver
fatty acids for both
483
why do liver and muscle shift to using fatty acid as a fuel source during early fasting
to save glucose
484
what enzyme can be used by the liver to release glucose into the blood
glucose 6 phosphate
485
in starvation what are the 3 sources of energy reserves
liver/muscle glycogen
muscle protein
adipose triglycerides
486
liver glycogen is used up after how long of a fast
24 hours
487
liver or muscle glycogen can be used as a fuel source
liver
(muscle keeps it for itself)
488
how long can the brain use glucose before switching to ketone bodies+glucose
2-3 days
489
in the early fasting state, what 3 factors allow for blood glucose to be kept at a steady level
mobilization of glycogen
release of fatty acids
shift from glucose use to fatty acid use by muscle and liver
490
in a starvation state, what molecule do we try to preserve by shifting the fuel use from glucose to fatty acids and ketones
protein
491
what is the effect of using fatty acids and ketone bodies for fuel during starvation instead of glucose
to spare protein
492
what is the activity of the liver during starvation
generate glucose through glucose 6 phosphatase in glycogenolysis and gluconeogenesis to
493
gluconeogenesis production of glucose is derived from what 3 molecules
glucogenic amino acids in muscle
lactate in muscle
glycerol in adipose
494
what is the main enzyme that allows for the progression of gluconeogenesis during starvation
fructose 1,6-bisphosphatase
495
with fatty acid oxidation increased during periods of starvation, what enzyme of FA synthesis is inhibited
acetyl CoA carboxylase
496
what 2 molecules are produced in FA oxidation that are needed in gluconeogenesis
NADH
ATP
497
what organ synthesizes and releases ketone bodies, but does not use ketone bodies
liver
498
what are the 3 ketone bodies
acetoacetate
beta- hydroxybutyrate
acetone
499
why can the liver not use ketone bodies
it lacks thiophorase (succinyl CoA acetoacetate
500
what causes ketoacidosis
high concentration of ketone bodies
501
are ketone bodies water or fat soluble
water
502
what process uses the glycerol produced from TAG degradation
gluconeogenesis
503
during fasting, what enzyme is low in adipose tissue due to decreased level of insulin
lipoprotein lipase
504
what is the fuel source of skeletal muscle during fasting
how does this change after 3 week
fatty acids
oxidizes fatty acids almost exclusively after 3 weeks
505
what 2 molecules do ketone bodies spare
glucose
muscle protein
506
after how long of starvation will the brain begin to use more ketone bodies than glucose
3-5 days
507
what causes Kwashiorkor
insufficient intake of proteins as the child is weaning
508
what is the typical age group of Kwashiorkor
1-5 years
509
what are the 3 main presentations of Kwashiorkor
pitting edema of hands and legs
moon face
large belly that sticks out
510
how does a low protein diet and albumin relate to edema
low protein diet= low albumin= decreased osmotic pressure/balance= edema
511
how can you test for Kwashiorkor
decreased plasma albumin
512
if a patient is consuming protein with a low biological value, will they enter into positive or negative nitrogen balance
negative
513
what occurs with marasmus
inadequate energy in all forms, including protein
514
how can you differentiate marasmus from kwashiorkor
marasmus does not show edema or decreased concentration of plasma albumin
515
what is the typical age for marasmus to be present
weaned infants less than 1 year
516
use of what can lead to Reyes syndrome (hepatic mitochondrial damage)
aspirin during illness
517
what histological changes are seen with Reyes syndrome
fatty vacuolization in hepatocytes
loss of neurons in the brain
edema and fat deposition of proximal lobules in the kidneys
518
the use of what medication during what infections can lead to mitochondiral liver damage (Reyes syndrome)
aspirin during influenza or varicella zoster virus
519
what fuel do muscles use during endurance marathon training
fatty acids
520
ATP can be stored for seconds in the muscle as __
phosphocreatine
521
in initial phases of contraction, we require __ for contraction
phosphocreatine
522
type I skeletal fibers are __ and __
type II are __ and __
slow vs fast
oxidative (contain mitochondria) vs glycolytic
I= slow twitch, oxidative
II= fast twitch, glycolytis
523
do type I or II skeletal fibers perform aerobic metabolism
I
524
do type I or II skeletal muscle fibers sustain contractions for a longer period
I
525
sprinters use type I or II skeletal fibers
II (short term)
526
marathon runners use type I or type II skeletal fibers
I (longer term)
527
what is a downside of using BMI index
it does not differentiate between lean and fat mass
528
what is the calculation for BMI
(weight in kg)/(height in meters)^2
529
does a pear shpe body indicate a higher or lower risk for metabolic disease
lower
530
what anatomical deposition increases health risks associated with obesity
excessive fat in visceral and abdominal subcutaneous stores
531
does the upper or lower body mobilize fatty acid more slowly
lower
532
what adipocytes are the most metabolically active
visceral
fat enters the bloodstream more readily
533
is there higher or lower risk for health issues in those with upper or lower body obesity
upper
534
does white or brown adipose tissue have an endocrine regulatory function
white
535
white adipose tissue regulates the release of what 2 hormones
leptin
adiponectin
536
what is the function of leptin
regulate appetite
537
what is the function of adiponectin
reduce the levels of free fatty acid in the blood
538
leptin __ food intake and __ expenditure of energy
(increases or decreases)
decreases
increases
539
what cell signalling does leptin use
JAKSTAT
540
what type of hormone is leptin
peptide
541
besides leptin, what other molecule acts on the hypothalamus to decrease appetite
insulin
542
what part of the brain controls hunger and satiety
hypothalamus
543
where in the brain is the satiety center
ventromedial nuclei
544
where in the brain regulates food intake
arcuate nuclei
545
what is orexigenic
increase feeding
(opposite of anorexigenic)
546
what is a normal BMI
18-25
547
does insulin release following a meal elicit anorexigenic or orexigenic neurons
anorexigenic
548
does leptin release following a meal elicit anorexigenic or orexigenic neurons
elicit anorexigenic, inhibit orexigenic
*unless it is a protein meal, in which leptin will be release along with insulin
549
what is the leptin pathway to signal satiety
adipocytes release leptin
leptin activates POMC in the arcuate nucleus
POMC in paraventricular nucleus produces MSH
MSH acts on MC4R receptor
MC4R receptor decreases food intake
550
genetic disruption in what receptor causes severe obesity
MC4R (melanocortin 4 receptor)
551
G cells are stimulated by high or low glucose
G cells are secreted from what organ
G cells secrete what hormone
low glucose
stomach
ghrelin
552
is ghrelin orexigenic or anorexigenic
orexigenic (appetite stimulating)
553
ghrelin has a direct affect on what part of the brain
arcuate nucleus
554
what is the effect of ghrelin acting on the arcuate nucleus
stimulates the feeding center that drives hunger and inhibits the satiety center
555
the orexigenic action of ghrelin is suppressed following food by what 3 anorexigenic hormones
CCK
peptide YY
insulin
556
anorexigenic increases or decreases satiety
increases
557
what 2 molecules produced by fat cells exert long term effects of appetite/satiety
leptin
adiponectin
558
when is peptide YY released from the ileum and colon
post-meal signaling fullness
559
what 2 molecules increase feeding (orexigenic)
neuropeptide Y
ghrelin
