in collagen synthesis, a chain residues are glycosylated and hydroxylated in
golgi/ER
In collagen synthesis, procollagen triple-helix formation and secretion take place in
secretory vesicle
Which substance, under physiologic conditions, is essential to the transformation of G-actin to F-actin
ATP
Once F-actin is formed from G-actin what is it called
microfilament
In skeletal muscle, excitation-contraction coupling is mediated by what
release of calcium from sarcoplasmic reticulum
Calcium regulation of skeletal muscle contraction
1. action potential depolarizes membrane potential
2. SR releases Ca2+ which binds to troponin C
3. Troponin C modulates Troponin I conformation
4. myosin binding site on actin is exposed
5. Ca2+ is pumped back out to ER in msec
what modulates the troponin I conformation
troponin C
Sarcoplasmic reticulum release of Ca2+ binds what
Troponin C
During contraction, what does not change in width or length?
A band (thick)
Epinephrine causes an elevation in cAMP levels in muscle cells which in turn activate
protein kinase
What type of hormones bind to specific receptors on the cell surface, and a signal is transmitted to the interior of the cell as a result
hydrophilic hormones
in hydrophilic hormones, the interaction between hormones and their receptors is
reversible
As the hormone levels decline, the hormone action ________________ as the hormones dissociate from their receptors
declines
thyroid and steroid hormones are considered
lipophilic
what subunit of Gs protein exchanges GDP for GTP, dissociates from the G beta gamma subunits, and activates adenylate cyclase
G alpha
what G subunit is a GTPase and eventually hydrolyzes the GTP that is bound to it
G alpha
the hydrolysis of what inactivates the G alpha protein, which then reassociates with G beta-gamma where it remains until it is reactivated by a hormone-receptor complex
GTP
What G protein stimulates the enzyme adenylate cyclase
Gs
what G protein inhibits the enzyme adenylate cyclase
Gi
what G protein stimulates the enzyme phospholipase C
Gq
Levels of cAMP quickly declines because it is hydrolyzed by
cyclic nucleotide phosphodiesterase (PDEase)
Phospholipase C-beta cleaves IPI2 to form
IP3 and DAG (no cAMP is formed)
cAMP binds to the regulatory (R) subunits of cAMP-dependent protein kinase and causes them to be released from the
catalytic (C) subunits
the active ____ subunits phosphorylate specific proteins in the cell
C
Phospholipase C is a type of enzyme that hydrolyzes PIP2 to
IP3 and DAG
IP3 and DAG are ______________ _________________ , which means that they carry information from the hormone-receptor complex to molecules within the cell
secondary messangers
IP3 diffuses into what
cytosol
IP3 in the cytosol, causes the release of calcium ions from intracellular stores, and DAG activates
protein kinase C
IP3 is rapidly inactivated by
dephosphorylation
DAG is rapidly deactivated by
hydrolysis
what type of hormones have a longer duration of action
lipophilic hormones - interact with intracellular receptors, because they affect gene expression
insulin, glucagon, epinephrine, and epidermal growth factor (EGF) are considered
hydrophilic hormones
Insulin binds to a transmembrane receptor at the outer surface of the plasma membrane, which activates
tyrosine kinase receptor that is the cytosolic domain of the receptor
the binding of insulin to the alpha subunits causes a conformational change in
beta subunit
Beta subunit phosphorylate _____________ ______________ located in the cytoplasmic domain of the receptor
tyrosine residues
how is tyrosine kinase activated
by the binding of insulin
some hydrophilic hormones, such as glucagon and epinephrine, lead to the activation of _______________ ________________ through the Gs protein
adenylate cyclase
what can insulin not readily diffuse across the cell membrane
because it is hydrophilic
Plasminogen activator binds to fibrin clots and activates the conversion of plasminogen to
plasmin
what specifically degrades clots
plasminogen activator (plasminogen to plasmin)
thrombin is a procoagulant and can only
Increase clot formation
Heparin and hirudin are anticoagulants which
inhibits formation of clots
factors involved in the intrinsic pathway
XI, IX, and VIII
factors involved in the extrinsic pathway
III and VII
factors involved in the common pathway
I, II, V, and X
pertussis toxin is infectious disease which causes whooping cough by
irreversibly activating adenylate cyclase
pertussis toxin is an enzyme that modifies the
alpha subunit of Gi
during pertussis, the Gi modification prevents Gi from exchanging
GDP for DTP
normal serum calcium values
8.5-10.5 mg/dL
where does this reaction take place:
7-dehydrocholesterol --> cholecalciferol
skin
where does this reaction take place:
cholecalciferol --> 25-hydroxy-vitamin D3
liver
where does this reaction take place:
25-hydroxy-vitamin D3 --> 1,25-dihydroxy vitamin D3
kidney
what is a direct result of the parathyroid hormone
inhibition of osteoblasts apoptosis
what is the mechanism of action for the effect of estrogen on bone mineralization
inhibits osteoclast action
bone mineralization process
1. collagen fiber secretion
2. amorphous calcium phosphate deposition
3. hydroxyapatite crystal formation
4. growth of crystal lattice
ligand-gated ion channels in nerve cells open in response to
the binding of a neurotransmitter
proteins present in the saliva
IgA
EGF
lipase
mucin
what constitutes the largest family of cell-surface receptors
GPCRs
GPCRs activating mutations causes what even in the absence of ligand
GPCR signal transduction
ligand binding to the _________ causes a conformational change that allows them to directly interact with and activate G-proteins
GPCRs
Intracellular receptors regulate gene expression functioning as
transcription factors
what activate PKC leading to increase phosphorylation of PKCs target proteins
DAG and Calcium
what is the precursor of all steroid hormones
cholesterol
When a chemical messanger (or ligand) reaches a target cell, it binds to a receptor. A hydrophobic ligand binds to a _________________, whereas a hydrophilic ligand binds to a _______________
intracellular receptor; transmembrane receptor
calmodulin activates target proteins in the presence of
calcium
what muscle component can bind or sequester calcium ions
troponin C
Which type of cells is characterized by having limited cell to extracellular matrix contacts and abundant cell to cell contacts
epithelium
what type of cells is characterized by having abundant cell to extracellular matrix contacts and limited cell to cell contacts
connective tissue
the common pathway of coagulation begins with
activating of a clotting factor that converts prothrombin to thrombin
the final reaction of the common pathway is the conversion of what
fibrinogen to fibrin
what separates the epithelial cells from the underlying connective tissue
basal lamina
the enzyme responsible for forming the major storage form of energy needed for muscle contraction
creatine kinase
upon contraction, ATP concentration is maintained until phosphocreatine is depleted, then, more ATP is made by
adenylate kinase
creatine --------> phosphocreatine uses what enzyme
creatine kinase
what is the primary component of a stable blood clot
fibrin
what serine protease catalyzes the conversion of fibrinogen to fibrin
thrombin
proteins found in saliva
proline-rich proteins
mucin
epidermal growth factor
IgA
heparin, hirudin, coumarin, and warfarin are all examples of what
anticoagulant
what protein breaks F-actin filaments and caps the + end
gelsolin
saliva provides ____________ and ______________ for remineralization
calcium and phosphate
what inhibits the formation of primary and secondary calcium phosphate salts
statherin
what is the primary class of antibody found in secretions, such as tears and saliva
IgA
what saliva component has high elasticity, adhesiveness, low solubility and resists dehydration
mucins
Factor XII, plasma prekallikrein, coagulation Factor XI, and kininogen
intrinsic pathway
peptide hormones are _____________ in lipids
insoluble
what form rivet-like links between cytoskeleton and extracellular matrix components
hemidesmosomes
the metabolic changes in type 2 diabetes
1. hyperglycemia - increase plasma glucose
2. hypertriacylglycerolemia
the metabolic changes in type 1 diabetes
1. Hyperglycemia - increase plasma glucose
2. ketonemia - increase plasma ketone bodies
3. Hypertriacylglycerolemia - increase plasma TAG
normal range of plasma glucose
100 mg/dL
normal range of HbA1c
around 6%
what is the most abundant intracellular anion
phosphate
what is the most abundant mineral in the body
Calcium
parathyroid hormone and 1, 25 hydroxyl vitamin D3 - calcitriol both do what
increase serum calcium
parathyroid hormone main effects in bone
1. increases osteoblast proliferation and differentiation
2. decreases osteoblast apoptosis
3. enhances the Wnt-B catenin pathway, central to osteogenesis and bone formation, inhibiting sclerostin
what is the primary component of bone, dentin, and enamel
inorganic biological apatite (hydroxyapatite)
bone and dentin are 30% organic which is mostly
type 1 collagen
what pump in the osteoclast membrane lowers the pH in the space between the osteoclast and the bone
ATP-driven proton pump
what mineral is the most resistant to the enamel dissolving acid produced by bacteria in the mouth
fluoroapatite
where is insulin synthesized
B cells
where is glucagon synthesized
alpha cells
Where is the body are insulin and glucagon produced
pancreas
where does glycogen synthesis take place
skeletal muscle
where does TAG synthesis take place
adipose
where does catecholamine synthesis take place
adrenal glands and sympathetic nervous system
stages of insulin synthesis
1. transcribed, mRNA moves to cytosol
2. on rough E.R. translated to preproinsulin
3. in E.R. lumen, cleaved to proinsulin
4. In golgi, cleaved to insulin and C-peptide
glucose
amino acids
G.I hormones
all promote
insulin secretion
catecholamines
scarcity of dietary fuels
all decrease
insulin secretion
decreased blood glucose - fasting / increased glucagon prevents hypoglycemia
amino acids
catecholamines
all increase
glucagon secretion
high blood glucose
insulin
all decrease
glucagon secretion
metabolic effects of insulin
- increased glycogen synthesis
- decreased glycogenolysis and gluconeogenesis
- reduces fatty acid release and promotes fatty acid storage
metabolic effects of glucagon
- increases gluconeogenesis
- increased glycogenolysis
what is the by product of ethanol metabolism causes a decrease in liver gluconeogenesis
NADH
what is the most common type of hypoglycemia
postprandial (period of time after a meal)
what state does insulin increase and glucagon secretion decreases
Absorptive or well-fed state
the anabolic period where there is an increase of TAG, glycogen, and protein occurs in what state
absorptive (feed state)
4 regulatory mechanisms in the feed-fast cycle
1. availability
2. allosteric regulation
3. covalent enzyme modification
4. enzyme synthesis
what promotes dephosphorylation, and activation of glycogen synthase (an enzyme for glycogen synthesis)
Insulin
what promotes phosphorylation, and activation of glycogen phosphorylation (a enzyme degradation; glycogenolysis)
glucagon
what regulatory mechanism in the feed-fast cycle is most common that is involved in phosphorylation/dephosphorylation
covalent enzyme modification
increased glucose phosphorylation to glucose-6-phosphate by glucokinase leads to
1. increased glycogenesis
2. increased pentose phosphate pathway
3. increased glycolysis --> leads to increased acetyl CoA
what is the source of fatty acids for TAG synthesis in the liver during the absorptive state
Acetyl CoA
Chylomicron
where is TAG synthesis packaged and sent to adipose and muscle tissue
VLDL
Increased glucose uptake by __________ transporters - glucose phosphorylated by _______________
GLUT-4 ; hexokinase
what is the 1st source of glucose - about 2-3 hours after a meal
glycogenolysis
Next - gluconeogenesis (2-4) hours after a meal)
in the fasting state, what are the byproducts of fatty acid oxidation
Acetyl CoA and NADH
major fuel source in resting muscle
fatty acids
Type 1 diabetes results from an autoimmune attack on pancreatic ___ cells
Beta
which diabetes has a environmental stimulus
type !
type 1 diabetes metabolic changes
1. hyperglycemia - increase plasma glucose
2. Ketonemia - increase plasma ketone bodies
3. hypertriacyglycerolemia - increase plasma TAG
what is the most common complication of insulin therapy
insulin-induced hypoglycemia
what results from the combination of insulin resistance and dysfunctional Beta cells
Type 11 diabetes
Insulin resistance increases with
weight gain
what is the most common cause of insulin resistance
obesity
obesity causes adipose to secrete
- proinflammatory cytokines
- increased amounts of leptin
- decreased amounts of adiponectin
type 2 diabetes metabolic changes
1. hyperglycemia - increase plasma glucose
2. hypertriacylglycerolemia
what type of adipose is the most metabolically active - high rates of lipolysis, free fatty acid mobilization
visceral adipocytes
what receives the venous drainage of visceral and abdominal adipocytes
liver
_________ gene mutations cause hyperphagia and obesity
leptin