MCAT Prep - 2

Instructions:

• Answer 50 questions in 15 minutes.
• If you are not ready to take this test, you can study here.
• Match each statement with the correct term.
• Don't refresh. All questions and answers are randomly picked and ordered every time you load a test.

This is a study tool. The 3 wrong answers for each question are randomly chosen from answers to other questions. So, you might find at times the answers obvious, but you will see it re-enforces your understanding as you take the test each time.

1. liver and blood glucose...
Ammonia; must be converted to urea by liver and excreted in urine by kidney
Liver is the control center for blood glucose; is fed by portal vein from sm intest
Arrested at primary oocyte; hypothalamus GnRH->FSH released at puberty stims granulosa cell development; granulosa secrete zona pellucida = primary follicle
Adrenocorticotropin; stims adrenal cortex release of glucocorticoids (eg cortisol - a steroid) stress hormones via second messenger system using cAMP


2. Gastrin from G cells stims parietal cells...
75% water/ 25% solid mass: of that solid mass: 10-20% fat = phospholipid bilayer of bacteria - slough - off enterocytes ie stomach lining (must be constantly rebuilt) 10-20% inorganic material 30% roughage = fiber = cellulose (indigestible) 2-3% prot
Fructose is a structural isomer of glucose
Tight regulation of parietal cells needed b/c gastric acid secretion is E- intensive; parietal cells are hi in mitochons
Many modern drugs are ligands for GPCRs


3. review: parietals secrete intrinsic factor...
Mediate complex cell processes thru eg phosphorylation via secondary messenger (G protein) systems = signal transduction pathway - GPCR (G protein coupled receptor)
Conjunction of cell body w/axon
Comes into play in the large intestine - where vitamin b12 is absorbed w/help of E. coli; thus; must travel thru bloodstream to large intestine
Hydrostatic pressure forces some plasma thru *fenestrations of the glomerular endothelium* and into Bowman's capsule; B.C. is continuous with lumen of nephron


4. Peritoneal refers to...
Sorts - modifies - concentrates proteins from the ER
Within the paravertebral ganglion - running parallel to spinal cord
Abdominal cavity - which is coated in serous fluid
RBCs - large proteins; What does enter is called the filtrate


5. Thus - central nervous sys is...
Smooth ER
**NO*** lipase digests fat; no bonds broken by bile; only opens up more SA for lipase
Sudiferous (sweat) - sebaceous - digestive (bile - pancreatic enzs) - mucosal
Interneurons working to integrate signals received from the peripheral nervous system (sense organs)


6. FLAT PG: LH
'visceral organs develop adjacent to a cavity and invaginate into the bag - like coelom'
Peptide; responsible for luteal surge (driven in part by LH-->testosterone -->estradiol -->LH positive feedback); results in ovulation (follicle bursting) - releasing egg into fallopian tube/oviduct
Estradiol
Testes>Semeniferous tubules>Sertoli cells; feedback on AP FSH production


7. Between meals most fats appear in blood as
Lipoproteins; albumin carries free fatty acids when fat is mobilized from adipose tissue - etc
Pepsin - secreted by chief cells in the stomach epithelial lining and active at low pH - breaks down proteins to polypeptides. Protein hydrolysis is aided by the highly acidic environment (hi gastric acid from parietal cells). Polypeptides are squirt
Chylomicrons are much bigger
Prod of steroid hormones in testes - ovaries


8. protein absorption at enterocyte
Amino acid monomers - di - tri absorbed by symport at enterocyte; each AA has slightly diff mechanism; from entero - AAs enter bloodstream where they are taken up by all cells of the body - esp the liver by active or facilitated transport (NEVER PASS
***nicotinic is ionotropic; muscarinic is GPCR
Micelles; micelles (made of bile) go back and forth between brush border and chyme
- parietal cells (**oxyntic= hi oxygen consumption - hi E??): have hi conc mito; need lots of energy to create proton gradient; thus - responsible for extremely harsh pH conditions in stom; denaturing conditions - chief cells (peptic): synthesize pep


9. pancreatic amylase is much stronger than
Via secondary active transport proteins (COSTS E TO FILTER BLOOD - ESTABLISH FLUID/ION BALANCE)
Fallopian tubes
Most absorption occurs in sm intestine
Salivary amylase; both hydrolyze glycosidic linkages


10. micelles vs liposomes
Liposome has phospholipid bilayer
Travels vas deferens - urethra; mixes with prostate fluids - seminal vesicles - couper's gland - etc
Lumen (ie continuous w/body cavity) and cytosol
Ganglion


11. Examples of GPCRs in sensory systems/signal transduction: What is the ligand or messenger in each case? ...SIGHT - SMELL - MOOD - FIGHT/FLIGHT etc
**NO*** lipase digests fat; no bonds broken by bile; only opens up more SA for lipase
Peak at 1-2hr after meal; chylomicrons themselves have half - life of about 1hr after formation in enterocytes
visual (rhodopsin is receptor - derived from Vit A; conformation change occurs with photon to hyperpolarize rod cells; cone cells use photopsin for receptor) - olfactory - mood (NTs targeted by antidepressants - antipsychotics - etc; GABA is inhibit
Adrenocorticotropin; stims adrenal cortex release of glucocorticoids (eg cortisol - a steroid) stress hormones via second messenger system using cAMP


12. On what surface of the retina is the eye most sensitive
Fovea (highest amount of cones)
Small amounts of hydrolyzed phospholipids and cholesterol: like other fat mols these can diffuse thru enterocyte membrane
Steroid; target tissue is distal convoluted tubule of nephron and collecting duct; increases blood mineral concentration; potassium - protons secreted (blood pH increases); sodium - chloride reabsorbed (BP increases)
Oxytocin and ADH (aka vasopressin)


13. Which fats are not absorbed like this
An endogenous morphine
Smaller - more water soluble short - chain FAs go directly to bloodstream at villi capillaries
Glands w/ducts: Exocrine glands
Outermost layer of blood vessel


14. Seen in lysosomal storage diseases
RBCs - large proteins; What does enter is called the filtrate
Buildup of macromolecules in lysosome due to deficient lysosome enzymes
75% water/ 25% solid mass: of that solid mass: 10-20% fat = phospholipid bilayer of bacteria - slough - off enterocytes ie stomach lining (must be constantly rebuilt) 10-20% inorganic material 30% roughage = fiber = cellulose (indigestible) 2-3% prot
Contain rough ER and Golgi to make mucous; mucous is full of **glycoprots (sticky) and electrolytes*; protects epithelial tiss of stomach from low pH and lubricates stomach


15. After meiosis I - daughter cells are...

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16. Where are these exocrine glands located
In gastric pits; secretions combine into gastric juice
Called a tract in the CNS; bundling together of axons/dendrites thru which many diff signals pass; many many neurons are bundled together into a single nerve
Primitive streak - which consists of cells of the MESODERM ****
Buildup of macromolecules in lysosome due to deficient lysosome enzymes


17. What are the major carbohydrates
sucrose (gluc+fruc) - lactose (gluc+galactose) - starch (gluc+gluc)
Trypsin(- ogen; activates other panc enzymes after it is activated by enterokinase of sm intest); chymotrypsin - amylase - lipase
Increases surface area of food ball (bolus)
SYMP: spinal cord --->paravetebral ganglion PARA: spinal cord - brain; cell processes --->ganglion near effector organ (preganglionic neurons) extend outside of spinal cord to synapse at ganglia - go on along postganglionic neurons


18. Difference between euk and prok flagella
Digestion
Gall bladder - pancreatic secretions increase - arrive via ampulla of vater (duct glands); insulin secretion increases (fed state; ductless glands)
Bacterial flagellin: hollow filament (not microtub); euk: 9+2 microtubule w/dynein bridges
Amino acid monomers - di - tri absorbed by symport at enterocyte; each AA has slightly diff mechanism; from entero - AAs enter bloodstream where they are taken up by all cells of the body - esp the liver by active or facilitated transport (NEVER PASS


19. What is secreted into filtrate by cells of the proximal tubule?
Urine enters kidneys via artery - to arteriole - capillary bed - glomerulus - Bowman's capsule - proximal tubule - loop of henle (concentrates medulla) - distal tubule - collecting tubule - collecting duct (renal pyramids) - renal calyx - renal pelvi
Has memb - bound organelles - etc...
Drugs - toxins - bile pigments (color the urine) - uric acid - antibiotics
pericardial cavity - pleural cavity (contains lungs) - peritoneal cavity (abdominal)


20. What do the glomerulus and Bowman's capsule add up to...
Ectoderm: outer coverings - nervous system Mesoderm: between covering ie musc - bone - etc - endoderm: digestive tract - viscera
Somatic nervous sys - autonomic nervous sys
Via secondary active transport proteins (COSTS E TO FILTER BLOOD - ESTABLISH FLUID/ION BALANCE)
The renal corpuscle


21. For focal point that is nearby - what will the lens look like
Only musc and esp ** liver can store large amounts
23 N; 23 chromosomes and haploid (no homologous chromosomes); each chromosome has two sister chromatids Male: primary spermatocyte -->REDUCTIONAL DIVISION (first stim'd at puberty by GnRH - LH-->secondary spermatocyte Female: primary oocyte (arreste
Calcitonin (peptide; lowers blood Ca); T3/T4 (tyrosine - derived; increase basal metabolic rate); T4= thyroxine
Lens will be rounded; contraction of the lens (ie focusing) is done by ciliary muscle


22. overall - fatty - prot - rich food in duod causes
Peptide; prolactin promotes milk production; prolactin release is stimulated by act of suckling - which in turn inhibits menstrual cycle
Trypsinogen is activated by enterokinase in the brush border; in turn - it activates other enzymes
Arrested at primary oocyte; hypothalamus GnRH->FSH released at puberty stims granulosa cell development; granulosa secrete zona pellucida = primary follicle
Gastric inhibitory pep; increase of pancreatic - enz activating enzymes (which cleaves zymogens like trypsinogen); increased gall bladder contraction; decreases stomach mobility


23. what happens to bile secretions
Work together to emulsify fats: bile works as a detergent to increase SA of the fat; increased SA gives more substrate to lipase for digestion
Zygote - morula (first four days) - blastocyst (4 day+; implants in uterine lining) - gastrula (2 week) - neurula (3 week)...
Fat synthesis; carbs stored as free fatty acids - esterified to TAGs (requires small amount of E)
Mostly reabsorbed to liver


24. What controls release of LH - FSH from anterior pituitary
Gonadotropin releasing hormone - GnRH
Carbohydrates are highly hydrated: one water mol per carbon mol - fats are anhydrous: contain more reduced carbons per unit mass - altogether fats contain 6X energy per unit mass
(diploid and haploid individuals = ALTERNATION of GENERATIONS) a fusion of gametic and zygotic life cycles
Calcitonin (peptide; lowers blood Ca); T3/T4 (tyrosine - derived; increase basal metabolic rate); T4= thyroxine


25. what cannot cross the fenestrations of the renal corpuscle
Visceral layer= parietal layer; serous membrane is the container of the coelom/peritoneal cavity
Tight regulation of parietal cells needed b/c gastric acid secretion is E- intensive; parietal cells are hi in mitochons
RBCs - large proteins; What does enter is called the filtrate
Secondary oocyte (stim'd by LH stimulation of theca cells causing release of testosterone - converted to estradiol; eventually brings about luteal surge -->EQUATIONAL DIVISION-->ovum released during ovulation into fallopian tube; burst follicle becom


26. From that point...
AAs enter bloodstream for uptake by all cells (esp liver). If intracellular prot conc is at max AAs can be converted to fats or glucose via gluconeogenesis. Byproduct of gluconeo is ammonia --->urea.
Lens will be rounded; contraction of the lens (ie focusing) is done by ciliary muscle
Micelles; micelles transport lipase products to enterocytes for absorption at brush border
Outermost layer of blood vessel


27. How does the body mobilize fat stores
Processes: axons - dendrites
***starting with adipose tiss: FFAs are transported in the blood by albumin (major component of blood plasma); one albumin typically carries three fatty acid molecules but can hold up to 30 FAs
(diploid and haploid individuals = ALTERNATION of GENERATIONS) a fusion of gametic and zygotic life cycles
(diploid organism) humans are part of gametic life cycle ie produce gametes; diploid germ - line stem cells undergo meiosis to form haploid gametes


28. quote on cavities/viscera

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29. Beta - oxidation in liver produces...
Interstitial fluid (eg prostaglandins - cytokines)
Ketone bodies; thus excessive reliance on fat for energy (eg low carb diets) results in ketosis; blood acidity increases
The crypts of Lieberkuhn: sm intestine pH is not right; brush border enzs won't work right
Membrane - bound - endocytosed bodies


30. Meiosis II: EQUATIONAL DIVISION
Testosterone upon stim by LH
Combined via conjunction of pancreatic duct and common bile duct; common bile duct originates at **cystic duct where gall bladder and liver secretions combine ..cystic duct+common bile duct+pancreatic duct --->into duodenum
Prophase II: no crossing over b/c there are no homologous chromosomes; nuclear envelope dissolves Metaphase II: chromosomes line up at metaphase plate Anaphase II: sister chromatids separate - migrate to opp poles Telophase II: nuclear envelope reap
**only para effectors have muscarinic receptors; symp effectors are adrenergic (epi - norepi); **neuromuscular junction uses nicotinic receptors


31. Human chorionic gonadotropin...
Inactive: rhodopsin is activated by photons; activated rhodopsin hyperpolarizes rod cells - causes photobleaching
Interstitial fluid (eg prostaglandins - cytokines)
Liposome has phospholipid bilayer
Secreted by implanted egg; HCG prevents degeneration of the corpus luteum; HCG in blood/urine is first sign of pregnancy


32. main point of fat transport...
Fat is insoluble in blood and requires a carrier like lipoproteins (vLDL...HDL) or albumins; ...vLDL has hi triglycerides - hi cholesterol
Development of placenta begins with implantation; eventually - by end of first trimester - placenta will replace corpus luteum and its estrogen/progest secretions
Needs time for bile - lipase - micelle migration - enterocyte uptake
Can be saturated; conc of a solute is called the transport maximum --->excess goes into urine


33. important because in meiosis germ - line cells begin as 46 2N w/ 23 pairs of homologous chromosomes which are replicated in S phase of interphase to 23 pairs of sister chromatids = still 46 2N
Growth 1 (G1) phase: STRUCTURAL ProteinS - ENZYMES; This is a very active period - where the cell synthesizes its vast array of proteins - including the enzymes and structural proteins it will need for growth. In G1 stage each of the chromosomes cons
Stomach - sm intest - spleen - pancreas from the hepatic portal vein...all blood that passes thru liver go thru flattened spaces called the ***hepatic sinusoids -->hepatic vein --->vena cava
Carry signals to musc OR Gland
In liver (RBC recycling of heme); stored in gall bladder; released via cystic duct to common bile duct (shared w/liver); common bile duct joins up with panc duct...everything feeds into the sm intest at the ampulla of vater**


34. Where does the bolus go after mouth chews food
5
Urine enters kidneys via artery - to arteriole - capillary bed - glomerulus - Bowman's capsule - proximal tubule - loop of henle (concentrates medulla) - distal tubule - collecting tubule - collecting duct (renal pyramids) - renal calyx - renal pelvi
Moves down thru esophageal sphincter
Four 23 N daughter cells are formed from one 46 2N mother (germ - line) cell; four haploid gametes


35. In IBS - What is defective

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36. Blastocyst
Lowers osmolarity of the filtrate (IONS - Water Are Taken Back Up By The Kidney)--->at the end of the distal tubule (the collecting tubule) is where aldosterone acts - along with the JGA
Prophase II: no crossing over b/c there are no homologous chromosomes; nuclear envelope dissolves Metaphase II: chromosomes line up at metaphase plate Anaphase II: sister chromatids separate - migrate to opp poles Telophase II: nuclear envelope reap
After 4 day+ - morula cells have formed fluid - filled ball (blastocyst); this implants in uterus at day 5-7; blastocyst is made up of EMBRYONIC STEM Cells; once implanted w/blastocyst - female is pregnant
At the first capillary bed of the nephron called the glomerulus which is encased by ***Bowman's capsule


37. albumin has What affect on blood osmotic pressure
Duodenum (wraps around pancreas; most digestion occurs here) - jejunum (pH 7-9; 2m) - ileum
Albumin increases osmolarity of blood; increases osmotic pressure
cornea (1.4 refractory index; bends light) - pupil (size of pupil is determined by contraction state of the iris) - aqueous humor
Nourishes follicle growth; stimulates granulosa cell growth around primary oocyte at puberty = primary follicle; also - stimulates Sertoli cells in males


38. in the dark is rhodopsin active or inactive?
Notochord (mesoderm) induces ectoderm to thicken into neural plate --->neural tube --->spinal cord
Posterior pituitary hormone; acts on uterus - mammary glands; causes uterine contractions - milk ejection
Inactive: rhodopsin is activated by photons; activated rhodopsin hyperpolarizes rod cells - causes photobleaching
**only para effectors have muscarinic receptors; symp effectors are adrenergic (epi - norepi); **neuromuscular junction uses nicotinic receptors


39. What does lipase attack exactly
Stims release of tyrosine - derived horms T3/T4 (increase basal metabolic rate); TSH increases thyroid cell size - number - rate of T3/T4 synth -----> thus - iodine deficiency causes swollen thyroid due to lack of neg feedback onto TSH in anterior pi
TAGS--->FFAs; remember that FFAs are broken down for energy in mito matrix by beta - oxidation
Nitrogen
Ventrally (picture skeletal vertebrae)


40. parathyroid hormones
Paracrine (local) - endocrine (longer distance)
Parathyroid hormone (peptide; increases blood Ca); thus - might increase osteoclast/decrease osteoblast activity
Know that 90% digestion - absorption occurs in sm intestine --> fine breakdown of carbs - fat - prots
Water flows from the tubule - concentrating the filtrate - raising BP


41. Polypeptides are formed with what kind of reaction?
via symport - secondary transport (ie by pre - established - ATP- intensive) with Na gradient into enterocyte......with no Na gradient (ie without ATP) carbohydrate monomers could not be transported in
Dehydration reaction; broken apart with enzyme - catalyzed hydrolysis
Water flows from the tubule - concentrating the filtrate - raising BP
Urine enters kidneys via artery - to arteriole - capillary bed - glomerulus - Bowman's capsule - proximal tubule - loop of henle (concentrates medulla) - distal tubule - collecting tubule - collecting duct (renal pyramids) - renal calyx - renal pelvi


42. Kidney physiology...

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43. What is the pH at the entrance to the duodenum
Secrete intrinsic factor; important for absorbing vitamin B12 in sm intest
PH 6.0; this accomplished by pancreatic secretion of bicarbonate which ups pH
Sorts - modifies - concentrates proteins from the ER
Paracrine (local) - endocrine (longer distance)


44. PNS is broken down into
Most absorption occurs in sm intestine
Normally contracted
Spinal cord ventral horns; somatic motor neurons use acetylcholine for NTs (voluntary)
Somatic nervous sys - autonomic nervous sys


45. Path of urine

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46. Interaction of corpus luteum/placenta
Inner lining of circulatory system
Development of placenta begins with implantation; eventually - by end of first trimester - placenta will replace corpus luteum and its estrogen/progest secretions
Peptide; prolactin promotes milk production; prolactin release is stimulated by act of suckling - which in turn inhibits menstrual cycle
Contain rough ER and Golgi to make mucous; mucous is full of **glycoprots (sticky) and electrolytes*; protects epithelial tiss of stomach from low pH and lubricates stomach


47. Where would materials slated for digestion go?
Mostly reabsorbed to liver
Sorts - modifies - concentrates proteins from the ER
Abdominal cavity - which is coated in serous fluid
Lysosome


48. Fructose relates how structurally to glucose
Fructose is a structural isomer of glucose
AAs enter bloodstream for uptake by all cells (esp liver). If intracellular prot conc is at max AAs can be converted to fats or glucose via gluconeogenesis. Byproduct of gluconeo is ammonia --->urea.
Adrenocorticotropin; stims adrenal cortex release of glucocorticoids (eg cortisol - a steroid) stress hormones via second messenger system using cAMP
Lowers osmolarity of the filtrate (IONS - Water Are Taken Back Up By The Kidney)--->at the end of the distal tubule (the collecting tubule) is where aldosterone acts - along with the JGA


49. Anterior eye
Stims release of tyrosine - derived horms T3/T4 (increase basal metabolic rate); TSH increases thyroid cell size - number - rate of T3/T4 synth -----> thus - iodine deficiency causes swollen thyroid due to lack of neg feedback onto TSH in anterior pi
cornea (1.4 refractory index; bends light) - pupil (size of pupil is determined by contraction state of the iris) - aqueous humor
Development of placenta begins with implantation; eventually - by end of first trimester - placenta will replace corpus luteum and its estrogen/progest secretions
About 7.2


50. FLAT PG: TSH aka thyrotropin
Facilitated diffusion: no symport w/ secondary transport
About 7.2
SYMP: spinal cord --->paravetebral ganglion PARA: spinal cord - brain; cell processes --->ganglion near effector organ (preganglionic neurons) extend outside of spinal cord to synapse at ganglia - go on along postganglionic neurons
Stims release of tyrosine - derived horms T3/T4 (increase basal metabolic rate); TSH increases thyroid cell size - number - rate of T3/T4 synth -----> thus - iodine deficiency causes swollen thyroid due to lack of neg feedback onto TSH in anterior pi