Test your basic knowledge |

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. Where would materials slated for digestion go?
Lysosome
Alpha 1-4 and 1-6 (branching) glycosidic linkages
Determined by whether in front of or behind the lens
Interstitial fluid (eg prostaglandins - cytokines)

2. pancreatic amylase is much stronger than
Micelles; micelles (made of bile) go back and forth between brush border and chyme
Paracrine (local) - endocrine (longer distance)
Liver is the control center for blood glucose; is fed by portal vein from sm intest
Salivary amylase; both hydrolyze glycosidic linkages

3. What is endothelium?
Processes: axons - dendrites
Glucose and ketone bodies (not from glycogen stores)
Inner lining of blood vessels
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

4. in the presence of ADH what happens to movement of water across nephron membr
Liposome has phospholipid bilayer
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
Lens will be rounded; contraction of the lens (ie focusing) is done by ciliary muscle
Water flows from the tubule - concentrating the filtrate - raising BP

5. Adrenal medulla hormones (TYR- DERIVED)
= catecholamines; fight/flight; vasoconstrictors of internal organs - skin; vasodilators of skel musc; also considered stress hormones; epinephrine - norepinephrine
90-140 mg/dl
Moves down thru esophageal sphincter
It is the animal counterpart of starch; it is more highly- branched - thus releases more glucose monomers upon repeated hydrolysis than starch

6. sporic life cycle
AAs can be burned for energy or converted to fat for storage
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
(diploid and haploid individuals = ALTERNATION of GENERATIONS) a fusion of gametic and zygotic life cycles
Fat synthesis; carbs stored as free fatty acids - esterified to TAGs (requires small amount of E)

7. components of interstitial fluid
Glycosaminoglycans - prots - AAs - lipids
To the organelle w/ lumen: smooth ER; they are resynthesized into TAGs
Tight regulation of parietal cells needed b/c gastric acid secretion is E- intensive; parietal cells are hi in mitochons
Paracrine (local) - endocrine (longer distance)

8. euk cell has two principal sides
Primitive streak - which consists of cells of the MESODERM ****
Contains lysozyme - which regulates bacteria within intestine; breaks down peptidoglycans (**bact wall); innate immunity
Lumen (ie continuous w/body cavity) and cytosol
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

9. What else do parietals do?
Secrete intrinsic factor; important for absorbing vitamin B12 in sm intest
'Increased absorptive area is useful because digested nutrients (including sugars and amino acids) pass into the villi through diffusion - which is effective only at short distances. In other words - **increased surface area (in contact with the flui
pericardial cavity - pleural cavity (contains lungs) - peritoneal cavity (abdominal)
Number of centromeres - Not number of chromatids eg - two sister chromatids connected by one centromere = one chromosome

10. sensory (afferent) neurons
Glycosaminoglycans - prots - AAs - lipids
Via secondary active transport proteins (COSTS E TO FILTER BLOOD - ESTABLISH FLUID/ION BALANCE)
Receive signals from receptor cell w/ ability to interact with its environment; 99% sensory input is discarded
Contains lysozyme - which regulates bacteria within intestine; breaks down peptidoglycans (**bact wall); innate immunity

11. Anterior eye
vitreous humor - retina - fovea
cornea (1.4 refractory index; bends light) - pupil (size of pupil is determined by contraction state of the iris) - aqueous humor
Needs time for bile - lipase - micelle migration - enterocyte uptake
Facilitated diffusion from hi to lo conc

12. Seen in lysosomal storage diseases
Maintains hi estrogen levels; body does not recognize luteal surge - ovulation does not occur; hi progesterone can lessen shedding by thickening the uterine lining
Buildup of macromolecules in lysosome due to deficient lysosome enzymes
Going up - water - impermeable: salt is actively pumped out - filtrate osmolarity goes down as salt leaves
Carry signals to musc OR Gland

13. ADH
PNS- Somatic - afferent (dorsal root ganglion) + efferent (ventral horns) PNS- ANS- afferent (sensors on viscera) + SYMP - PARA pre - post - ganglionic neurons
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
Di - tri - peptides; inside enterocytes are hydrolyzed to amino acids
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

14. What is the net effect of the distal tubule
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
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
Nervous - muscle - epithelial (defines inner/outer) - connective (extensive matrices)
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

15. motor (efferent) neurons --> VENTRAL
Lots of energy; eg neurons have hi glucose need for 3Na out 2K in ATPase; stomach epithel tiss needs E for parietal cells to pump protons into lumen and bicarbonate into blood
Ganglion
Hydrostatic pressure forces some plasma thru *fenestrations of the glomerular endothelium* and into Bowman's capsule; B.C. is continuous with lumen of nephron
Carry signals to musc OR Gland

16. A group of cell bodies in CNS is nucleus - outside CNS is...
Ganglion
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
Lysosome
Secondary spermatocyte (stim'd by FSH from Sertoli cells -->EQUATIONAL DIVISION-->spermatid - which matures further into spermatozoa; released into semeniferous tubule; transported to epididymis

17. Aldosterone (sodium uptake - potassium secretion)
Somatic sensory = dorsal root ganglia (outside spinal cord); somatic effector = ventral horns of spinal cord
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)
Travels vas deferens - urethra; mixes with prostate fluids - seminal vesicles - couper's gland - etc
Development of placenta begins with implantation; eventually - by end of first trimester - placenta will replace corpus luteum and its estrogen/progest secretions

18. Stomach has no lacteals
Spike in estrogen - LH levels; secondary follicle bursts - releases into body cavity - swept along by fimbriae
Adrenocorticotropin; stims adrenal cortex release of glucocorticoids (eg cortisol - a steroid) stress hormones via second messenger system using cAMP
Lysosome
Most absorption occurs in sm intestine

19. Polypeptides are formed with what kind of reaction?
Renal pyramids --->renal calyx-->renal pelvis -->ureter -->urethra
Inner lining of circulatory system
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
Dehydration reaction; broken apart with enzyme - catalyzed hydrolysis

20. from the loop of henle...
Alpha cells; stims gluconeogenesis in liver; acts via cAMP second messenger
An ether phospholipid; hi conc in myelin; thus - hi conc in heart tiss - nervous tiss
Liposome has phospholipid bilayer
On to the distal tubule where sodium - calcium are reabsorbed - protons - bicarbonate - potassium are secreted via membrane transport proteins

21. Chewing does what?
Polysaccharides w/proteoglycans attached = glycosaminoglycans; often give pliability
sucrose (gluc+fruc) - lactose (gluc+galactose) - starch (gluc+gluc)
Increases surface area of food ball (bolus)
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

22. Fructose relates how structurally to glucose
Fructose is a structural isomer of glucose
Most absorption occurs in sm intestine
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
Going up - water - impermeable: salt is actively pumped out - filtrate osmolarity goes down as salt leaves

23. What kind of cells make up epithel tiss of stom - then sm intest?
Stom= G cells (gastrin) - parietal (oxyntic); chief (peptic); mucous cells (hi ER - Golgi to make sticky glycoprots) - sm intest= enterocytes (w/brush border of maltase - sucrase - lactase - dextrinase; peptidase; lipase; nucleases); goblet cells (mu
Lots of water - minerals (electrolyte balance) - vitamins (aided by gut bacteria)
Sorts - modifies - concentrates proteins from the ER
To the organelle w/ lumen: smooth ER; they are resynthesized into TAGs

24. A pinpoint iris is contracted or uncontracted
'Increased absorptive area is useful because digested nutrients (including sugars and amino acids) pass into the villi through diffusion - which is effective only at short distances. In other words - **increased surface area (in contact with the flui
Mediate complex cell processes thru eg phosphorylation via secondary messenger (G protein) systems = signal transduction pathway - GPCR (G protein coupled receptor)
Uncontracted: parasymp (eg opoid use)
From lumenal (apical) to enterocyte to basolateral side of epithelial tissue

25. Induction affects...
Direction of differentiation
Photon (hv)- rhodopsin - conformation change - GPCR- Na less permeable - hyperpolarized rod cells - generates AP= photobleaching at visible light wavelengths (390-700nm)
= catecholamines; fight/flight; vasoconstrictors of internal organs - skin; vasodilators of skel musc; also considered stress hormones; epinephrine - norepinephrine
Lots of energy; eg neurons have hi glucose need for 3Na out 2K in ATPase; stomach epithel tiss needs E for parietal cells to pump protons into lumen and bicarbonate into blood

26. Exocrine GlandS: stomach
- 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
Meiosis creates germ cells
Epithelial tissue near semniferous tubules
Night vision

27. sensory (afferent)/interneurons/motor (efferent)
Neurons may perform one of three functions....
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
vitreous humor - retina - fovea
ER

28. gradual increase in FSH typical of primary follicle development;
Secondary follicle: Theca cells differentiate from interstitial tissue - surround follicle - secrete testosterone when stimd by LH (compare to Leydig cells)
Liver breaks down glycogen (glycogenolysis); at hi blood sugar it builds up glycogen (glycogenesis)
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
Increases surface area of food ball (bolus)

29. almost all cells can store Some glycogen - but...
Albumin increases osmolarity of blood; increases osmotic pressure
Only musc and esp ** liver can store large amounts
Lots of energy; eg neurons have hi glucose need for 3Na out 2K in ATPase; stomach epithel tiss needs E for parietal cells to pump protons into lumen and bicarbonate into blood
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

30. How is the follicle developed during oogenesis
Testes>Semeniferous tubules>Sertoli cells; feedback on AP FSH production
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
Arrested at primary oocyte; hypothalamus GnRH->FSH released at puberty stims granulosa cell development; granulosa secrete zona pellucida = primary follicle
Trypsin(- ogen; activates other panc enzymes after it is activated by enterokinase of sm intest); chymotrypsin - amylase - lipase

31. is intracellular AA conc hi or low?
From lumenal (apical) to enterocyte to basolateral side of epithelial tissue
Low because AAs are immediately used in translation
Paracrine (local) - endocrine (longer distance)
- enterocytes w/ *microvilli brush border*: membrane - bound digestive enzymes for carbs - fats - nucleic acids - goblet cells: secrete mucous - Deep between villi are the intestinal exocrine glands - the crypts of Lieberkuhn - which secrete pH 7.6 i

32. What is the net effect of the loop of Henle
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
Conjunction of cell body w/axon
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)
Creates one ovum (23 N) and three polar bodies

33. When 'coumadin targets liver enzymes to act as anticoagulant'...
Creates one ovum (23 N) and three polar bodies
It targets liver conc of prothrombin - fibrinogen etc
Fat synthesis; carbs stored as free fatty acids - esterified to TAGs (requires small amount of E)
Water flows from the tubule - concentrating the filtrate - raising BP

34. Glucose is a .... sugar; fructose is a .... sugar
Receive signals from receptor cell w/ ability to interact with its environment; 99% sensory input is discarded
Glucose = aldose fructose = ketose
Increase surface area of sm intestine; this improves digestion (enzymes adsorbed to villi) and absorption
Trypsinogen is activated by enterokinase in the brush border; in turn - it activates other enzymes

35. How do parietal cells work ** (involves CO2)
Result is proton secreted into lumen - bicarbonate into interstitial fluid (diffuses into blood); result is also increased blood pH and decreased pH stomach
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)
Peptide; prolactin promotes milk production; prolactin release is stimulated by act of suckling - which in turn inhibits menstrual cycle
CARB- Digesting: dextrinase (polysachs produced by hydrolysis of starch) - maltase (glucose - glucose) - sucrase (glucose - fructose) - lactase (galactose - glucose) - Protein- Digesting: peptidases - NUCLEOTIDE- Digesting: nucleosidases

36. review: parietals secrete intrinsic factor...
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
Lots of water - minerals (electrolyte balance) - vitamins (aided by gut bacteria)
Prophase I: crossing over occurs; nuclear envelope is absorbed into ER; chromosomes condense)
Albumin increases osmolarity of blood; increases osmotic pressure

37. Three stages of the menstrual cycle
Lumen (ie continuous w/body cavity) and cytosol
Follicular (proliferative)= 8d - Luteal (post - ovulation; corpus luteum secretions)= 13d - Menstruation (shed uterine lining if no implantation)= 5
Systems (eg digestive system consists of many organs)
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

38. FLAT PG: ACTH
Ventrally (picture skeletal vertebrae)
Prod of steroid hormones in testes - ovaries
Adrenocorticotropin; stims adrenal cortex release of glucocorticoids (eg cortisol - a steroid) stress hormones via second messenger system using cAMP
Dehydration reaction; broken apart with enzyme - catalyzed hydrolysis

39. PNS is broken down into
Somatic nervous sys - autonomic nervous sys
Smaller - more water soluble short - chain FAs go directly to bloodstream at villi capillaries
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)
Glycosaminoglycans - prots - AAs - lipids

40. glucagon secreted by
Secrete intrinsic factor; important for absorbing vitamin B12 in sm intest
Alpha cells; stims gluconeogenesis in liver; acts via cAMP second messenger
Low because AAs are immediately used in translation
Carry signals to musc OR Gland

41. 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
Break down TAGs to monoglycerides and free fatty acids
Spinal cord ventral horns; somatic motor neurons use acetylcholine for NTs (voluntary)
- 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
Contains hydrolytic enzymes; thus - digests endocytosed substances; derived from golgi

42. What is the path of a sound wave that enters the ear?
Somatic nervous sys - autonomic nervous sys
Outer ear= pinna (auricle)- external auditory canal - eardrum (tympanic membrane) inner ear= malleus - incus - stapes - ...oval window - cochlea - where sound is transduced into neural signal...enters cochlea at scala vestibuli - where pressure chang
Determination is a pre - programmed fate - differentiation is the actual materialization of that fate
Four 23 N daughter cells are formed from one 46 2N mother (germ - line) cell; four haploid gametes

43. What is a toxic byproduct of gluconeogenesis from proteins
Sympathetic: dilates pupil (for night hunting)
Ammonia; must be converted to urea by liver and excreted in urine by kidney
Outermost layer of blood vessel
Corpus luteum degrades into corpus albicans

44. amylase acts where on carbs
Salivary amylase (weak); sm intest amylase (breaks down large polysaccharides)
Night vision
sucrose (gluc+fruc) - lactose (gluc+galactose) - starch (gluc+gluc)
Development of placenta begins with implantation; eventually - by end of first trimester - placenta will replace corpus luteum and its estrogen/progest secretions

45. Beta - oxidation in liver produces...
Interneurons working to integrate signals received from the peripheral nervous system (sense organs)
Ketone bodies; thus excessive reliance on fat for energy (eg low carb diets) results in ketosis; blood acidity increases
Determined by whether in front of or behind the lens
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

46. Meiosis I Anaphase I
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
'Increased absorptive area is useful because digested nutrients (including sugars and amino acids) pass into the villi through diffusion - which is effective only at short distances. In other words - **increased surface area (in contact with the flui
Homologous chromosomes separate - migrate towards opposite poles/centrioles
Liver is the control center for blood glucose; is fed by portal vein from sm intest

47. FSH - LH - HCG - inhibin are...
Going up - water - impermeable: salt is actively pumped out - filtrate osmolarity goes down as salt leaves
Gastrulation occurs: formation of three primary germ layers = differentiation
Peptides
Presence of fat - prot in duodenum causes release of **gastric inhibitory peptide**; result is slower stomach contraction; slower emptying into duod thru pyloric sphincter (slower chyme secretion); more time to properly digest - absorb nutrients

48. Different organs working together
Only musc and esp ** liver can store large amounts
Diarrhea: excess water loss in feces; poor absorption of vitamins - minerals
Number of centromeres - Not number of chromatids eg - two sister chromatids connected by one centromere = one chromosome
Systems (eg digestive system consists of many organs)

49. What force is acting upon chyme to move it forward down sm intestine
Normally contracted
Nuclear envelope reassembled in daughter cells; cytokinesis occurs; nucleoli reappear (site of rRNA synthesis)
Peristalsis (esophagus) and segmentation (bi - directional=mixing)
Di - tri - peptides; inside enterocytes are hydrolyzed to amino acids

50. Spinal cord horns (thick knobs) point
Ventrally (picture skeletal vertebrae)
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)
Hydrostatic pressure forces some plasma thru *fenestrations of the glomerular endothelium* and into Bowman's capsule; B.C. is continuous with lumen of nephron
Liver Functions pt. 2 - Carb metabolism: blood is sent straight to liver from sm intest thru portal vein; liver is control center for blood glucose; _______________ - fat metabolism: oxidizes fat for energy by beta - oxidation - forms most lipoprotei