Quiz 10 Flashcards
Name the essential amino acids
Histidine Isoleucine Leucine Lysine Methionine Phenylalanine Threonine Tyrosine Valine
What are the four fates of dietary amino acids?
Protein synthesis
Energy production (citric acid cycle)
Biosynthesis
Urea excretion
Name the three drivers for protein oxidation
Protein rich diet
Normal synthesis and degradation
Diabetes
Dietary protein in the stomach leads to the release of what hormone?
Gastrin
What polypeptide bonds does pepsin hydrolyze?
Phe
Trp
Tyr
What does secretin do?
Stimulates the release of bicarbonate from the pancreas
What does cholecystokinin do?
Stimulates zymogen release from the pancreas and causes gall bladder contractions
What is the active form of the zymogen procarboxypeptidase a and b?
Carboxypeptidase a and b
Where does most catabolism of amino acids occur? What is the main strategy?
In the liver. Cleaves off the amine group and recycles the carbons
Name four amine group carriers
Glutamate
Glutamine
Alanine
Aspartate
The carbons fro amino acids will be turned into ____ once the amino group is removed. Then, what is it converted to?
Alpha keto acids (alpha ketogluterate)
Will then be turned into pyruvate
Amine groups are toxic in the body. How are they stabilized?
Converted to urea or Uric acid for excretion
How is ammonia toxic?
It disrupts sodium potassium ATPase on astrocytes to prevent their K uptake. This will get rid of the concentration gradient so GABA cant work to inhibit signals. Leads to seizures, loss of consciences and death
What are the two common amino acid catabolism reactions?
Transaminase reactions
One carbon transfers
In a transaminase reaction, the amine group from an amino acid will be put on _____ to make it _____. The amino acid is thus converted to a _____.
Alpha ketogluterate
Glutamate
Alpha keto acid
What enzyme aids in transaminase reactions?
Amino-transferases. They are specific to each amino acid transfer
What is a common coenzyme for amino-transferases?
PLP (pyridoxal phosphate)
This is also better known as vitamin B6
It is the carrier of amino groups and help stabilize the amino groups in the transfer
What carriers the amino groups through the blood to the liver?
Glutamine and glutamate
Intracellular ammonia is buffered by converting ____ to _____
Glutamate to glutamine
What enzyme is necessary for converting glutamate into glutamine?
Glutamine synthetase
It is an ATP dependent enzyme and adds another amino group to the molecule to make it glutamine
True or false… almost all cells in the body have glutamine synthetase
True
Other than amine groups getting to the liver by glutamine, what is another way it gets to the liver?
Glucose alanine cycle
Describe the glucose alanine cycle
Amino groups from amino acids are transferred to make glutamate. Glutamate transfers the amino group to pyruvate to form alanine. Alanine is transported throughout the blood and to the liver where it is converted back to pyruvate to undergo gluconeogenesis
True or false… the glucose alanine cycle occurs in aerobic states
False… it occurs in anaerobic states and coincides with the cori cycle
What amino acid is absolutly essential for the urea cycle to work?
Ornithine
The urea cycle involves enzymes from within what organelle?
Mitochondria
In the urea cycle, what enzyme takes the amine group off of glutamine to form a free ammonium and glutamate?
Glutaminase
The amine group on glutamate in the urea cycle is removed by what enzyme? Once the amine group is removed, the molecule is called ____ and will enter the _____ ____ _____
Glutamate dehydrogenase
Alpha keto gluterate
Citric acid cycle
The free ammoniums in the mitochondria of the urea cycle will be added to _____ (which involves ___ _____) to form ______. What enzyme facilitates this reaction?
Bicarbonate
2 ATP
Carbamoyl phosphate
Carbamoyl phosphate synthetase 1 carries this out
Alanine loses its amine group to become _____. The amine group is transferred to ______, which then becomes ______.
Pyruvate
Alpha ketogluterate
Glutamate
The amine group from carbamoyl phosphate is transferred to _____ to become ______
Ornithine
Citrulline
In the last step of the urea cycle, arginine is converted to _____ and forms _____ in the process
Ornithine
Urea
In the urea cycle, citruline + aspartate form ______
Argininosuccinate
Argininosuccinate is converted to _____ and releases _____ in the process
Arginine
Fumerate
How many amine groups are on urea. Where do they come from?
Two amine groups
One from citrulline and one from aspartate… basically
75% of urea is moved to the ____ while 25% is moved to the_____
Kidneys to be excreted as urine
Gall bladder to be released as bile
Carbamoyl phosphate synthetase 1 is allosterically regulated by ____
ATP. More ATP = more urea
some other things that upregulate the urea cycle are increased synthesis of….
Ornithine transcarbomoylase
Arinosuccinate synthetase
Arginosuccinase
Arginase
How are the citric acid cycle and the urea cycle linked?
Argininosuccinate
It releases fumerate which is part of the citric acid cycle
(Aspartate-argininosuccinate shunt of citric acid cycle)
What is the difference between glucogenic and ketogenic?
Glucogenic = amino acids that can be converted to glucose
Ketogenic - amino acids that can be converted to ketone bodies
Amino acid catabolism produces enzyme substrates that fuel __ to ___ % of cellular energy production
10-15%
What are the nonessential amino acids?
Alanine Asparagine Aspartate Glutamate Serine
Aspartate and asparagine can give rise to _____
Oxaloacetate
Alanine, cysteine, glycine, serine, threonine, tryptophan, can give rise to ____ which in turn can give rise to ____
Pyruvate
Oxaloacetate
Isoleucine, leucine, threonine, tryptophan, can all give rise to _____
Acetyl coA
Leucine, lysine, phenylalanine, tryptophan, and tyrosine can all give rise to _____
Acetoacetyl-coA
Glutamate can give rise to _____
Alpha ketogluterate
Arginine, glutamine, histidine, and proline can all give rise to _____ which can in turn give rise to _____
Glutamate
Alpha ketogluterate
Isoleucine, methionine, threonine, and valine can all give rise to _____
Succinyl coA
Phenylalanine and tyrosine can all give rise to ____
Fumerate
Name three important one-carbon transfer reaction cofactors
S-adenosylmethionine
Biotin
Tetrahydrofolate
(These are one carbon group donors, often methyl groups, vitamins)
There is some overlap in what amino acids can be converted into. For example tyrosine can be converted to ____ or _____
Fumerate or acetyl coA
What amino acid is also a neurotransmitter?
Glutamate
The two amino acids ____ and ____ that feed into oxaloacetate, dont result in much energy because it enters late in the citric acid cycle
Asparagine and aspartate
What amino acids give rise to Pyruvate?
Serine Alanine Glycine Threonine Tryptophan Cysteine
What amino acids give rise to acetyl coA?
Tyrosine Leucine Isoleucine Lysine Threonine Phenylalanine Tryptophan
What amino acids give rise to alpha keto gluterate?
Glutamate Glutamine Proline Arginine Histidine
What amino acids give rise to succinyl coA?
Isoleucine
Methionine
Valine
Threonine
What two amino acids give rise to oxaloacetate?
Asparagine
Aspartate
What are the borders of the infratemporal fossa?
Zygomatic arch Maxilla Mastoid process/TMJ Lateral pterygoid plate Temporal sphenoid bones Pterygomaxillary fissure
What nerve goes through foramen ovale?
V3
What goes through the spinosum foramen? Nerve and vessel
Meningeal branch of the mandibular nerve
Middle meningeal artery and vein
What is the fissure that separates the infratemporal fossa and the pterygopalatine fossa?
Pterygomaxillary fissure
What is the structure that separates the pterygopalatine fossa and the nasal cavity?
Sphenopalatine foramen
What nerve goes through the petrotympanic fissure?
Chorda tympani nerve
The temporomandibular joint is located in what fossa?
Mandibular fossa of the temporal bone
What makes up the posterior border of the Infratemporal fossa?
TMJ
True or false, the temporalis posterior fibers assist in retraction of the mandible
True
during depression of the mandible, contraction of what muscle pulls both the consular head and articular disc anterioinferiorly?
Lateral pterygoid muscle
What are the four muscles of mastication?
Temporalis
Masseter
Medial pterygoid
Lateral pterygoid
The muscles of mastication are innervated by ____
V3
What portions of the maxillary artery are within the infratemporal fossa?
First and second portions.. give or take
What veins are seen in the infratemporal fossa?
Pterygoid plexus
Blood flows out of the ITF into the ____ and ____ veins and can go via ____ and _____ ____
Facial
Maxillary
Ophthalmic
Cavernous sinus
What are the boundaries of the pterygopalatine fossa?
Maxilla Pterygoid plate Pterygomaxillary fissure Sphenopalatine foramen Orbit
What structures are located within the pterygopalatine fossa?
Maxillary artery (3rd part) Maxillary nerve (V2) Pterygopalatine ganglion
What portion of the maxillary artery branches and runs anteriorly? What structure does it run through?
Infraorbital artery
Runs through the inferior orbital fissure
What artery branches off of the maxillary artery in the pterygopalatine fossa to run medically? What structure does it run through?
Sphenopalatine artery
Runs through the sphenopalatine foramen
V2 runs into the pterygopalatine fossa via ____ _____
Foramen rotundum
Why dont synapses occur in the trigeminal ganglion?
These are all sensory, no synapses because they are pseudounipolar neurons
The greater and lesser palatine nerves exit the pterygopalatine fossa through the _____
Greater palatine canal (inferior)
True or false.. you can see the posterior superior alveolar nerve in the pterygopalatine fossa
True.. the others you cannot however because they branch off later
You can see the zygomatic nerve in the pterygopalatine fossa. This nerve will then split into what two nerves?
Zygomaticotemporal
Zygomaticofacial
The infraorbital nerve will give rise to what two nerves?
Middle superior alveolar nerve
Anterior superior alveolar nerve
Vidian’s nerve is made up of what two nerves?
Greater petrosal and deep petrosal
What types of neurons are in the deep petrosal nerve?
Sympathetics
What cranial nerve is the greater petrosal nerve from?
Facial (7)
Vidian’s nerve goes through what canal to enter the pterygopalatine fossa?
Vidian’s canal (pterygoid canal)
Where would you find the palatovaginal canal?
In between the vomer and pterygoid
What two things run through the palatovaginal canal?
Pharyngeal branch of the maxillary nerve and the pharyngeal artery (ascending pharyngeal)
Name all of the branches of V2 that are from the pterygopalatine fossa
Zygomatic Nasopalatine Posterior superior alveolar Greater/lesser palatine Pharyngeal
Name the four parasympathetic ganglia in the head
Ciliary
Pterygopalatine
Optic
Submandibular
What branch of trigeminal gives rise to the ciliary ganglion?
What about submandibular?
What about otic?
Ciliary - opthalmic
Submandibular - mandibular
Otic - mandibular
how does the pharyngeal nerve enter the pterygopalatine fossa
?
Palatovaginal canal
____ provides carbon backbone for amino acid synthesis
Glucose
DNA is primarily in the _____ form
Nucleosome
Not chromosomes!!! Thats for division
Which, introns or exons are spliced out?
Introns. “Exons are expressed”
Roughly what percent of mammalian DNA codes for proteins?
1.5%
Approximately how many genes do humans have?
25,000
What are the two components of the regulatory region of DNA?
Enhancer/silencer - binding of proteins that promote or inhibit transcription
Promoter region - transcription factor and RNA polymerase binding
Describe the UTR
Untranslated region located at the 5’ and 3’ end of the open reading frame necessary for RNA processing
What do each of the following synthesize?
RNA pol. 1
RNA pol. 2
RNA pol. 3
RNA pol. 1 - rRNA
RNA pol. 2 - mRNA
RNA pol. 3 - tRNA
DNA is read in what direction? What direction is RNA synthesized as?
Read 3’ - 5’
Synthesized as 5’ to 3’
Negative regulation of transcription involves ____ whereas positive regulation of transcription involves. _____
Represses
Activators
What are the three RNA processing steps? List them in chronological order
Addition of a 5’ cap
Intron splicing
Adding of a 3’ poly A tail
What are the three functions of the 5’ cap?
Protects mRNA in the cytoplasm
Bound by ribosomes to initiate translation
Cap-binding complex tethers the mRNA until transcription is complete
Where does a ribosome bind to mRNA
On the 5’ cap
There are four classes of introns. Describe these classes
Two are self spliced
The other two involve splicesomes (most common)
True or false…. splicing variance creates different mRNAs and products
True true true
The AAUAAA is the upstream signal for _____.
Cleavage
It sits about 20-15 nucleotides before actal cleaveage occurs
The actual cleavage site (where RNA pol. Is removed from the DNA) is rich in what two nucleotides?
G and U
What enzyme adds the poly A tail to the end of the mRNA
Polyadenylate
What functions does the poly A tail serve?
Protects mRNA tail in cytoplasm
Anchors mRNA during translation
True or false… in order for mRNa to be exported into the cytoplasm via nuclear pore complexes, proteins must be bound to the mRNA
True
What is the first step of translation?
Activation of amino acids (charging the tRNAs with amino acids)
Which ribosomal subunit binds to the mRNA first the small or large?
Small subunit
True or false… ATP/GTP is not needed for the inition phase of translation
False!
In translation, the mRNA is read in what direction? Which end of the polypeptide is produced first N or C?
5’ to 3’
N to C
True or false, in elongation, making the bond for new amino acids requires GTP/ATP
False
True or false… the stop codon codes for a final amino acid
False.. instead, eukaryotic releasing factor is put in and causes everything to disintegrate
What is the role of the signal recognition particle?
It is like a flag that tells the protein where to complete translateion
Where are the two locations where translation may occur?
ER
Cytoplasmic space
Proteins that are produced in the ER will be what kind of proteins?
Integral membrane proteins
Intravesicular proteins
Secreted proteins
Where do most post-translational modifications occur? What are some of these post-translational modifications?
In the ER.
Protein folding
Proteolytic cleavage
Glycosylation Acetylation Phosphorylation Methylation Acyl action
Where is a likely site where glycoproteins are formed?
In the ER
What kind of proteins are produced from those translated in the cytoplasmic space?
Nuclear proteins
Structurally associated proteins (like tubulin)
Membrane associated proteins
What post-translational modification signals the protein for destruction?
Ubiquitin
What are the two primary organelles responsible for molecular degradation?
Proteosomes and lysosomes
Proteosomes degrade ___ while lysosomes degrade ____
Cytoplasmic proteins
Vesicular and membrane proteins
True or false… in order for translation to occur, the 5’ and 3’ ends must be bound
True
The majority of fluid in the body is ______
Inside cells
How many liters = total body fluid?
how many in blood?
how many in plasma?
how many in RBCs?
42
5
3
2
In general, waste products are ____ filtered and _____ reabsorbed
highly
Poorly
True or false… the kidneys can deal with nonvolatile acids
True
Kidneys regulate pH by regulating their secretion/reabsorption of what?
HCO3. Although they can also deal with H+, HCO3 is more important
If the blood was too alkaline, what would the kidneys do?
Retain H+ and get rid of HCO3
The kidneys also can increase HCO3 by metabolising glutamine. What other product results form this?
NH4
What are some other renal functions? 3
Production of erythropoietin (increase RBCs)
Gluconeogenesis
Adrenal glands
Nephrons are located in the ____ ____ wich is located within the ____ of the kidney
Renal pyramids
Medulla
Where does filtration occur?
In the glomerular capillaries into the nephron. This whole structure is called bowmans capsule
The efferent arterioles will give rise to the ___ ____ in which ____ and _____ occurs
Peritubular capillaries
Reabsorption and secretion
Plasma containing salutes passes out of the glomerulus into the nephron and enters the ____ ______, then passes through the _____, then the _____ _____, then finally the ______. This is deposited into the ____ ____ and then _____
Proximal tubule Loop of henlie Distal tubule Collecting duct Renal pelvis Ureter
What are the only portions of the nephron that can be regulated?
Distal tubule and collecting duct
Which runs deeper into the medulla, the cortical or juxtamedullary nephrons?
Juxtamedullary
Which are more abundant, cortical or juxtamedullary nephrons?
Corical (70%)
Juxtamedullary (30%)
In the juxtamedullary nephron, the ______ extend part of the way down the loop of henlie and form specialized peritubular capillaries called the ______
Efferent arterioles
Vasa recta
Around what percent of the blood plasma presented to the glomerulus enters the proximal tubule via bowman’s capsule?
20%
True or false… the filtration rate is equal to rate of urine formation
False
What is the urinary excretion rate formula?
Filtration rate - reabsorbtion + secretion
A normal GFR is about how many liters per day?
180
The membranes of the glomerular capillaries is slightly specialized. It is selective and only will allow what things to pass through
Small and/or positively charged molecules
What are the three layers of the glomerular capillary membrane (have one extra)
Endothelium (fenestrated, negatively charged)
Basement membrane (collagen/proteoglycan mesh, negatively charged)
Podocytes (specialized epithelial cells)
What is the effect of the negatively charged endothelium and basement membrane?
Repelled negatively charged molecules and large molecules like albumin
What do podocytes do?
Form slit pores which size and charge restrict filtrate
Describe the pressure seen in the glomerulus
High hydrostatic pressure
High osmotic pressure (pulling water back in)
Bowmans capsule has a much lower hydrostatic pressure
Bowmans capsule should not have any osmotic pressure because there shouldn’t be any proteins in there
Constriction of the afferents arteriole will ____ GFR whereas constriction of the efferent arteriole will _____ GFR
Decrease
Increase
How can major constrion of the efferent arteriole cause a decrease of GFR?
It will build up to conc. Of proteins, increasing the osmotic pressure thus decreasing GFR.
Describe the effect of sympathetic nervous system on GFR
Decreases GFR
Constricts afferents
Describe the effect of catecholamines (norepinephrine) on GFR
Decreases GFR
Constricts afferents arteriole
Describe the affects of angiotensin 2 on GFR
Prevents a decrease in GFR
Describe the affect of prostaglandins/endothelial derived NO on GFR
Increases GFR
Dilates the afferents arteriole
Describe tubuloglomerular feedback
Essential links the sodium chloride conc. Of the DISTAL TUBULE with the constriction state of the arterioles.
What is the role of the macula densa
The macula densa is in the distal tubule and forms the juxtaglomerular complex
Detects NaCl levels in distal tubule to alter GFR
What changes does the macula densa do to alter GFR?
Initiates dilation of the afferents arteries and increases release of renin and angiotensin 1 and 2 which causes constrictor of the efferent artiorle
True or false… the scaring of kidneys due to poor control of blood pressure and/or blood glucose levels can permanently lower the GFR
True
When the body osmolarity is high, the kidney will form _____ urine
Concentrated
True or false… glucose is flirted through the glomerulus
True but it is quickly reabsorbed in the proximal tubule
Where is most volume reabsorbed?
Proximal tubule
How are hydrogen ions excreted into the filtrate?
Counter-transport with sodium
In the distal end of the proximal tubule, what is mostly reabsorbed?
Chloride ions. Here, the glucose and amino acids should have already been depleted by reabsorption in the proximal end of the proximal tubule
Sodium amount decreases as we proceed down the nephron but not concentration so much… why?
Because water is being pulled out proportionally
What are the two functionality distinct regions in the loop of henlie?
Thin descending segment and thick ascending segment
What are the thin descending and thick ascending portions of the loop of henlie responsible for?
Thin descending - highly permeable to water
Thick ascending - not permeable to water but lots of active transporters to reabsorbed sodium, chloride, and potassium
In the thick ascending segment, what is the primary pump that pumps sodium out of filtrate
Sodium, chloride, potassium cotransporter
The transporters in the thick ascending segment only have a capacity to maintain a _____ mOsm/L difference, but can overcome this by ____ ____
200
Counter current exchange
Where would you find the macula densa (thus the juxtaglomerular apparatus)?
Distal tubule
What are the two distinct cell types found in the distal half of the distal tubule?
Principal cells and intercalated cells
What do principal cells do?
Reabsorb sodium and water from the lumen and secretes potassium into the filtrate. This favors an outward flow of sodium (out of filtrate)
What do intercalated cells do?
Reabsorb potassium and bicarbonate and secrete hydrogen ions into the tubule and can therefore regulate pH
The permeability of the late distal tubule is controlled by ___
ADH
The collecting duct cells are regulated by ____ and are also very efficient at pumping ____ into the lumen
ADH
Hydrogen ions
Thus they can regulate pH
True or false… the collecting duct is impermeable to urea
False. Some can be reabsorbed thus helping pull water out in the thick ascending segment
What percent of osmotic force is due to urea?
~40%
When ADH levels are high, is more or less urea reabsorbed in the collecting duct? Also… can urea be reabsorbed in the proximal tubule?
More
Yes
What cycle links the urea cycle and the citric acid cycle?
Aspartate argininosuccinate shunt of citric acid cycle
Name three pancreatic protease enzymes
Trypsin
Chymotrypsin
Carboxypeptidase a and b
What kinds of animals get rid of their ammonia by urea, uric acid, or ammonia?
Urea - mammals and sharks
Uric acid - birds and reptiles
Ammonia - fish and amphibians
Describe the action of glutamine synthase.
Adds a phosphate group by ATP. The. Replaces it with ammonia group m
What enzyme is responsible for converting pyruvate to alanine by converting glutamate to alpha ketogluterate?
Alanine aminotransferase
True or false… the urea cycle is ATP dependent
True
