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MCAT Prep - 2

Subjects : mcat, science

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. In IBS - What is defective

2. How does the body mobilize fat stores
Glucose = aldose fructose = ketose
Apoproteins attach to outside of globules; these move to Golgi and are released into interstitial fluid via exocytosis as chylomicrons --->most go to lacteal system
Contains lysozyme - which regulates bacteria within intestine; breaks down peptidoglycans (**bact wall); innate immunity
***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

3. Kidney
Hormones --->stimulate exocrine glands - acetylcholine (increases all secretion of gastric pits) - gastrin (from G cells) - histamine (increases HCl secretion of parietals) ...Ach increases all secretions; gastrin increases gastric acid (parietal cel
Transfer signals from neuron - neuron; 90% of neurons are interneurons
Excretes waste products: urea - uric acid - ammonia - phosphate - maintains homeostasis: including body fluid volume (water reabsorption) and solute composition (mineral balance - nutrient reabsorption) - controls *plasma* pH: antiport of Na/K and pr
Serous membrane (slick - reducing friction) that forms lining of the coelom --> secretes lubricating fluid

4. What does peroxisome do
Oxidizes macromolecules; breaks down very long - chain FAs by beta - oxidation; products (acetyl - CoA) are shuttled to mitochondrion for citric acid cycle
Corpus luteum; secretes estradiol - progesterone throughout pregnancy OR if no pregnancy - for about 2 weeks (till menstruation = shedding of uterine lining)
Zygote (morula) composed of eight or more cells; All cells at this stage are TOTipOTENT STEM Cells: do not grow - form by cleavage
Glucose

5. Human chorionic gonadotropin...
Secreted by implanted egg; HCG prevents degeneration of the corpus luteum; HCG in blood/urine is first sign of pregnancy
Which is why lactase - maltase - dextrinase - sucrase are on brush border
On to the distal tubule where sodium - calcium are reabsorbed - protons - bicarbonate - potassium are secreted via membrane transport proteins
Contains lysozyme - which regulates bacteria within intestine; breaks down peptidoglycans (**bact wall); innate immunity

6. lysosome main function and derivation
The crypts of Lieberkuhn: sm intestine pH is not right; brush border enzs won't work right
Uncontracted: parasymp (eg opoid use)
Contains hydrolytic enzymes; thus - digests endocytosed substances; derived from golgi
Signal picked up by sensory cell - goes thru dorsal root ganglion to SC - may continue to interneurons in brain or simple reflex arc in SC - brain integrates info and decides (voluntary) response - travels back down SC to appropriate ventral root gan

7. What is endothelium?
Increase surface area of sm intestine; this improves digestion (enzymes adsorbed to villi) and absorption
Increases surface area of food ball (bolus)
Inner lining of blood vessels
Facilitated diffusion: no symport w/ secondary transport

8. oxytocin
Increases blood Calcium
sucrose (gluc+fruc) - lactose (gluc+galactose) - starch (gluc+gluc)
Sudiferous (sweat) - sebaceous - digestive (bile - pancreatic enzs) - mucosal
Posterior pituitary hormone; acts on uterus - mammary glands; causes uterine contractions - milk ejection

9. insulin secreted by
Number of centromeres - Not number of chromatids eg - two sister chromatids connected by one centromere = one chromosome
Beta cells
Ups bicarbonate secretion by pancreas; raises pH to 6.0
Break down TAGs to monoglycerides and free fatty acids

10. Seen in lysosomal storage diseases
Signal picked up by sensory cell - goes thru dorsal root ganglion to SC - may continue to interneurons in brain or simple reflex arc in SC - brain integrates info and decides (voluntary) response - travels back down SC to appropriate ventral root gan
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
The crypts of Lieberkuhn: sm intestine pH is not right; brush border enzs won't work right
Buildup of macromolecules in lysosome due to deficient lysosome enzymes

11. what else is located in the inner ear (not directly related to auditory)
Two perpendicular semicircular canals involved in balance - equilibrium
Lysosome
Collection of cell bodies; cell processes project out from both ends of ganglion; synapses with interneuron in spinal cord on one end and sensory receptor on other
Nitrogen

12. Where does blood to be filtered by kidney enter the nephron?

13. bundles of collecting ducts are called
Number of centromeres - Not number of chromatids eg - two sister chromatids connected by one centromere = one chromosome
Development of placenta begins with implantation; eventually - by end of first trimester - placenta will replace corpus luteum and its estrogen/progest secretions
Renal pyramids --->renal calyx-->renal pelvis -->ureter -->urethra
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.

14. Gland: ovaries
It is the animal counterpart of starch; it is more highly- branched - thus releases more glucose monomers upon repeated hydrolysis than starch
Creates one ovum (23 N) and three polar bodies
Estrogen: steroid; stims LH in luteal surge; causes growth of female sex organs progesterone: prepares/maintains uterus for pregnancy
REABSORPTION: draws off water and ions - increases osmolarity of the medulla while slightly lowering osmolarity of the filtrate -->medulla must have hi osmolarity in order to concentrate urine at collecting duct (final step in nephron)

15. Anterior eye
Posterior pituitary hormone; acts on uterus - mammary glands; causes uterine contractions - milk ejection
Cancer; apop can be programmed cell death; mitochon can play important role in apop
Direction of differentiation
cornea (1.4 refractory index; bends light) - pupil (size of pupil is determined by contraction state of the iris) - aqueous humor

16. 3 phases of menstrual cycle
Injury that does not sever SC (causes deep lesion from back - front) might cause loss of feeling without full loss of motion
Secreted by implanted egg; HCG prevents degeneration of the corpus luteum; HCG in blood/urine is first sign of pregnancy
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
Follicular phase: primary - secondary - ovulation (1 week) luteal phase: ovulation - thickening of uterine lining w/corpus luteum secretion - corpus luteum degrades (2 weeks) flow: shedding of uterine lining (4 days)

17. Sensory - motor neurons are part of which nervous system
Estrogen: steroid; stims LH in luteal surge; causes growth of female sex organs progesterone: prepares/maintains uterus for pregnancy
Peripheral nervous sys
= catecholamines; fight/flight; vasoconstrictors of internal organs - skin; vasodilators of skel musc; also considered stress hormones; epinephrine - norepinephrine
Prod of steroid hormones in testes - ovaries

18. cytosol pH
Digestion
Zygote (fertilization in fallopian tubes); morula (up to 8 cells - undifferentiated ie totipotent); blastocyst (4+ days - implants into uterus; HCG secretion stims corpus luteum; gradually placenta replaces HCG as estrogen/progest source; cells not t
About 7.2
Interneurons working to integrate signals received from the peripheral nervous system (sense organs)

19. golgi body
FAT=9 cal per gram Carbs=4.5 cal per gram - Prot=4 cal per gram - these seem to be for anhydrous forms
Albumin increases osmolarity of blood; increases osmotic pressure
Trypsinogen is activated by enterokinase in the brush border; in turn - it activates other enzymes
Sorts - modifies - concentrates proteins from the ER

20. what cannot cross the fenestrations of the renal corpuscle
Estradiol (estrogen - steroid horm); prepares uterine wall for pregnancy; just before ovulation - release of estradiol stims LH in pos feedback
Calcitonin (peptide; lowers blood Ca); T3/T4 (tyrosine - derived; increase basal metabolic rate); T4= thyroxine
HCl; secreted by parietal cells under stim by gastrin
RBCs - large proteins; What does enter is called the filtrate

21. testosterone can be aromatized to...
Serous membrane (slick - reducing friction) that forms lining of the coelom --> secretes lubricating fluid
Excretes waste products: urea - uric acid - ammonia - phosphate - maintains homeostasis: including body fluid volume (water reabsorption) and solute composition (mineral balance - nutrient reabsorption) - controls *plasma* pH: antiport of Na/K and pr
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
Estradiol

22. Tight junctions
Liver is the control center for blood glucose; is fed by portal vein from sm intest
Injury that does not sever SC (causes deep lesion from back - front) might cause loss of feeling without full loss of motion
Form barrier to extracellular fluid
Testosterone and estradiol

23. large intestine E. coli aid absorption of...
Estrogen: steroid; stims LH in luteal surge; causes growth of female sex organs progesterone: prepares/maintains uterus for pregnancy
- filtration occurs at the fenestrations of the renal corpuscle - most reabsorption and secretion occur in the proximal tubule - medulla is concentrated in the loop of henle - sodium and calcium are reabsorbed in the distal tubule -->collecting tubul
Vitamin K - b12 - thiamin - riboflavin
Where lipoprotein lipase hydrolyzes TAGs; products diffuse into target tiss (mostly liver - adipose tissue)

24. Inside the kidney: ...JGA (w/granular cells sensitive to hydrostatic pressure able to secrete renin - activate aldosterone - increase BP) is adjacent to distal tubule - monitors filtrate pressure
Albumin increases osmolarity of blood; increases osmotic pressure
Paracrine (local) - endocrine (longer distance)
Secrete intrinsic factor; important for absorbing vitamin B12 in sm intest
- filtration occurs at the fenestrations of the renal corpuscle - most reabsorption and secretion occur in the proximal tubule - medulla is concentrated in the loop of henle - sodium and calcium are reabsorbed in the distal tubule -->collecting tubul

25. What are the major carbohydrates
Development of placenta begins with implantation; eventually - by end of first trimester - placenta will replace corpus luteum and its estrogen/progest secretions
sucrose (gluc+fruc) - lactose (gluc+galactose) - starch (gluc+gluc)
Glucose and ketone bodies (not from glycogen stores)
Glucose = aldose fructose = ketose

26. Adrenal cortex hormones (STEROIDS)
Uncontracted: parasymp (eg opoid use)
Trypsinogen is activated by enterokinase in the brush border; in turn - it activates other enzymes
Glucocorticoid (cortisol); mineralocorticoid (aldosterone)
Somatic sensory = dorsal root ganglia (outside spinal cord); somatic effector = ventral horns of spinal cord

27. lysosome pH
5
Adrenocorticotropin; stims adrenal cortex release of glucocorticoids (eg cortisol - a steroid) stress hormones via second messenger system using cAMP
Moves thru lymph sys; emptied into large veins (thus into bloodstream) of the neck at Thoracic duct
Protein digestion begins in stomach; low pH denatures proteins - kills bacteria; mixes - stores food and destroys it to chyme (BOLUS-->CHYME)

28. What if large intestine isn't working well
Diarrhea: excess water loss in feces; poor absorption of vitamins - minerals
Homologous chromosomes line up w/ attachment of spindle fibers/microtubule polymers to centromeres via kinetochores; identical in appearance under light microscope to metaphase of mitosis
- 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
***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

29. The bolus (chewing) is digested to what in the stomach
Chyme (by combined activity of exocrine glands)
Result is proton secreted into lumen - bicarbonate into interstitial fluid (diffuses into blood); result is also increased blood pH and decreased pH stomach
Pancreas; active at sm intestinal pH; hydrolyzes peptide bonds of (pepsin - digested) peptides
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

30. Think of spinal cord injury
Injury that does not sever SC (causes deep lesion from back - front) might cause loss of feeling without full loss of motion
Sudiferous (sweat) - sebaceous - digestive (bile - pancreatic enzs) - mucosal
Posterior pituitary hormone; acts on uterus - mammary glands; causes uterine contractions - milk ejection
Prophase I: crossing over occurs; nuclear envelope is absorbed into ER; chromosomes condense)

31. Exocrine GlandS: stomach
Fat synthesis; carbs stored as free fatty acids - esterified to TAGs (requires small amount of E)
Oxytocin and ADH (aka vasopressin)
- 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
Testes>Semeniferous tubules>Sertoli cells; feedback on AP FSH production

32. What Changes - Doesn't Change as a result of movement of molecules across membranes in the proximal tubule
Has memb - bound organelles - etc...
Changes: volume of filtrate does not change: osmolarity of filtrate --->reabsorbed ions like sodium carry water across membrane
Carry signals to musc OR Gland
Secreted by delta cells of Islets of langerhans; inhibits insulin and glucagon; slows digestion

33. serous membranes have a viscera - facing layer and a body wall - facing layer
Zygote (morula) composed of eight or more cells; All cells at this stage are TOTipOTENT STEM Cells: do not grow - form by cleavage
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
Visceral layer= parietal layer; serous membrane is the container of the coelom/peritoneal cavity
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.

34. Blastocyst
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
Glucocorticoid (cortisol); mineralocorticoid (aldosterone)
Lots of water - minerals (electrolyte balance) - vitamins (aided by gut bacteria)
Increases surface area of food ball (bolus)

35. medium for paracrine hormones
Vitamin K - b12 - thiamin - riboflavin
Changes: volume of filtrate does not change: osmolarity of filtrate --->reabsorbed ions like sodium carry water across membrane
Nitrogen
Interstitial fluid (eg prostaglandins - cytokines)

36. Posterior pituitary hormones (Small Peptides)
Oxytocin and ADH (aka vasopressin)
It targets liver conc of prothrombin - fibrinogen etc
Smooth ER
Injury that does not sever SC (causes deep lesion from back - front) might cause loss of feeling without full loss of motion

37. How is glucose absorbed in sm intest
Lower blood pH
Peptide; stims growth of nearly all cell of body; all other anterior pituitary horms have specific targets; upregulates anabolic pathways; use of fat for energy goes up (fat - burning); increases AA transport across cell membrane (nutrient uptake)
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
Stores blood: when expanded liver serves as blood reservoir for body - filters blood: Kupfer cells phagocytize bacteria picked up from intestines - destroys bad RBCs: also done by Kupfer cells - detoxifies blood: detoxified chemicals are excreted eit

38. cholinergic receptors: NICTONIC and MUSCARINIC Nicotinic: neuromuscular effectors (ionotropic) Muscarinic: PARA effectors (GPCRs) Adrenergic: SYMP effectors (GPCRs)
**only para effectors have muscarinic receptors; symp effectors are adrenergic (epi - norepi); **neuromuscular junction uses nicotinic receptors
Facilitated diffusion from hi to lo conc
Vitamin K - b12 - thiamin - riboflavin
Liver breaks down glycogen (glycogenolysis); at hi blood sugar it builds up glycogen (glycogenesis)

39. interneurons
Focuses light thru the vitreous humor onto retina; acts as a converging lens (image is real - inverted)
Transfer signals from neuron - neuron; 90% of neurons are interneurons
Contains lysozyme - which regulates bacteria within intestine; breaks down peptidoglycans (**bact wall); innate immunity
Raises BP; causes collecting ducts at end of nephron (kidney) to become permeable to water - which concentrates urine; coffee - beer block ADH and increase urine volume

40. Important of villi (='shaggy hair') More fluid makes contact with the epithelial tissue: thus nutrients in solution have less distance to travel to diffuse into villi.

41. hypothalamus - AP - ACTH - cortisol release from adrenal cortex
Moves down thru esophageal sphincter
Number of centromeres - Not number of chromatids eg - two sister chromatids connected by one centromere = one chromosome
Result: stress reaction; increase glycogenolysis - gluconeogenesis; fat/prot breakdown; increase blood glucose
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

42. examples of different cavities... (compartments for viscera)
The crypts of Lieberkuhn: sm intestine pH is not right; brush border enzs won't work right
pericardial cavity - pleural cavity (contains lungs) - peritoneal cavity (abdominal)
Processes: axons - dendrites
Water flows from the tubule - concentrating the filtrate - raising BP

43. What is the net effect of the loop of Henle
Sorts - modifies - concentrates proteins from the ER
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.
ER
REABSORPTION: draws off water and ions - increases osmolarity of the medulla while slightly lowering osmolarity of the filtrate -->medulla must have hi osmolarity in order to concentrate urine at collecting duct (final step in nephron)

44. The apical side of the villi...
Interneurons working to integrate signals received from the peripheral nervous system (sense organs)
Two perpendicular semicircular canals involved in balance - equilibrium
Faces the lumen
Glucose = aldose fructose = ketose

45. What is a plasmalogen?
RBCs - large proteins; What does enter is called the filtrate
An ether phospholipid; hi conc in myelin; thus - hi conc in heart tiss - nervous tiss
PNS- Somatic - afferent (dorsal root ganglion) + efferent (ventral horns) PNS- ANS- afferent (sensors on viscera) + SYMP - PARA pre - post - ganglionic neurons
**NO*** lipase digests fat; no bonds broken by bile; only opens up more SA for lipase

46. Mucus - digestive enzymes released thru
Fructose is a structural isomer of glucose
Stores blood: when expanded liver serves as blood reservoir for body - filters blood: Kupfer cells phagocytize bacteria picked up from intestines - destroys bad RBCs: also done by Kupfer cells - detoxifies blood: detoxified chemicals are excreted eit
Glands w/ducts: Exocrine glands
Has memb - bound organelles - etc...

47. zygotic life cycle
Direction of differentiation
Peptide; stims growth of nearly all cell of body; all other anterior pituitary horms have specific targets; upregulates anabolic pathways; use of fat for energy goes up (fat - burning); increases AA transport across cell membrane (nutrient uptake)
(haploid organism) many fungi and protozoa; individuals are typically haploid; fertilization may occur with immediate meiosis back to haploid state
Nitrogen

48. from the loop of henle...
Result is proton secreted into lumen - bicarbonate into interstitial fluid (diffuses into blood); result is also increased blood pH and decreased pH stomach
Collection of cell bodies; cell processes project out from both ends of ganglion; synapses with interneuron in spinal cord on one end and sensory receptor on other
Estradiol
On to the distal tubule where sodium - calcium are reabsorbed - protons - bicarbonate - potassium are secreted via membrane transport proteins

49. Morula (...totipotent)
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
Zygote (morula) composed of eight or more cells; All cells at this stage are TOTipOTENT STEM Cells: do not grow - form by cleavage
Testosterone and estradiol
Interstitial fluid (eg prostaglandins - cytokines)

50. The EYE
Focuses light thru the vitreous humor onto retina; acts as a converging lens (image is real - inverted)
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
The renal corpuscle
Corpus luteum degrades into corpus albicans