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MCAT Prep - 2

Subjects : mcat, science

Instructions:

Answer 50 questions in 15 minutes.
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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. What is a normal blood glucose range
Membrane - bound - endocytosed bodies
90-140 mg/dl
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)
Peptide; prolactin promotes milk production; prolactin release is stimulated by act of suckling - which in turn inhibits menstrual cycle

2. Mucus - digestive enzymes released thru
Posterior pituitary hormone; acts on uterus - mammary glands; causes uterine contractions - milk ejection
Glands w/ducts: Exocrine glands
Know that 90% digestion - absorption occurs in sm intestine --> fine breakdown of carbs - fat - prots
(diploid and haploid individuals = ALTERNATION of GENERATIONS) a fusion of gametic and zygotic life cycles

3. what happens when glycogen stores are saturated and blood sugar remains high?
Alpha cells; stims gluconeogenesis in liver; acts via cAMP second messenger
Night vision
Fat synthesis; carbs stored as free fatty acids - esterified to TAGs (requires small amount of E)
Nitrogen

4. What is the net effect of the distal tubule
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
An endogenous morphine
Nourishes follicle growth; stimulates granulosa cell growth around primary oocyte at puberty = primary follicle; also - stimulates Sertoli cells in males
Faces the lumen

5. During ejaculation - sperm...

6. Anatomy of the villi
Liposome has phospholipid bilayer
Contain capillary network - lymph vessels (lacteals)
At metaphase II of meiosis II (halted during reductional division); if fertilized - process continues toward haploid gamete
AAs can be burned for energy or converted to fat for storage

7. interneurons
sucrose (gluc+fruc) - lactose (gluc+galactose) - starch (gluc+gluc)
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
5
Transfer signals from neuron - neuron; 90% of neurons are interneurons

8. hypothalamus - AP - ACTH - cortisol release from adrenal cortex
Result: stress reaction; increase glycogenolysis - gluconeogenesis; fat/prot breakdown; increase blood glucose
Water flows from the tubule - concentrating the filtrate - raising BP
Peristalsis (esophagus) and segmentation (bi - directional=mixing)
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)

9. mitosis creates somatic cells
Sorts - modifies - concentrates proteins from the ER
Meiosis creates germ cells
Low because AAs are immediately used in translation
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

10. Path of urine

11. What is somatostatin
Arrested at primary oocyte; hypothalamus GnRH->FSH released at puberty stims granulosa cell development; granulosa secrete zona pellucida = primary follicle
Abdominal cavity - which is coated in serous fluid
Lots of water - minerals (electrolyte balance) - vitamins (aided by gut bacteria)
Secreted by delta cells of Islets of langerhans; inhibits insulin and glucagon; slows digestion

12. cAMP - cGMP - calmodulin...
Creates one ovum (23 N) and three polar bodies
Low because AAs are immediately used in translation
Mediate complex cell processes thru eg phosphorylation via secondary messenger (G protein) systems = signal transduction pathway - GPCR (G protein coupled receptor)
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

13. 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
In gastric pits; secretions combine into gastric juice
Moves down thru esophageal sphincter
= catecholamines; fight/flight; vasoconstrictors of internal organs - skin; vasodilators of skel musc; also considered stress hormones; epinephrine - norepinephrine
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

14. spermatogonia arise from
Ectoderm: outer coverings - nervous system Mesoderm: between covering ie musc - bone - etc - endoderm: digestive tract - viscera
Duodenum (wraps around pancreas; most digestion occurs here) - jejunum (pH 7-9; 2m) - ileum
Epithelial tissue near semniferous tubules
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

15. Fructose relates how structurally to glucose
Estrogen: steroid; stims LH in luteal surge; causes growth of female sex organs progesterone: prepares/maintains uterus for pregnancy
Gastrulation occurs: formation of three primary germ layers = differentiation
Fructose is a structural isomer of glucose
Nitrogen

16. size of chylomicrons (fat + apoproteins) vs lipoproteins ('cholesterol')
Chylomicrons are much bigger
Below hypothalamus
It targets liver conc of prothrombin - fibrinogen etc
1) by integral ion channels 2) transmitted by second messenger system

17. Kidney
Nuclear envelope reassembled in daughter cells; cytokinesis occurs; nucleoli reappear (site of rRNA synthesis)
(diploid organism) humans are part of gametic life cycle ie produce gametes; diploid germ - line stem cells undergo meiosis to form haploid gametes
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
Know that 90% digestion - absorption occurs in sm intestine --> fine breakdown of carbs - fat - prots

18. Anterior eye
cornea (1.4 refractory index; bends light) - pupil (size of pupil is determined by contraction state of the iris) - aqueous humor
Serous membrane (slick - reducing friction) that forms lining of the coelom --> secretes lubricating fluid
'visceral organs develop adjacent to a cavity and invaginate into the bag - like coelom'
Buildup of macromolecules in lysosome due to deficient lysosome enzymes

19. Contrast PNS- Somatic with PNS- Autonomic
PNS- Somatic - afferent (dorsal root ganglion) + efferent (ventral horns) PNS- ANS- afferent (sensors on viscera) + SYMP - PARA pre - post - ganglionic neurons
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
Mostly reabsorbed to liver
Thru tight junctions by favorable osmotic gradient

20. Thus inhibiting parietal cells could do What to blood pH
Diarrhea: excess water loss in feces; poor absorption of vitamins - minerals
Contains hydrolytic enzymes; thus - digests endocytosed substances; derived from golgi
Lower blood pH
Duodenum (wraps around pancreas; most digestion occurs here) - jejunum (pH 7-9; 2m) - ileum

21. 3 phases of menstrual cycle
- 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
Posterior pituitary hormone; acts on uterus - mammary glands; causes uterine contractions - milk ejection
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)
Low because AAs are immediately used in translation

22. Cell determination begins At what stage of development
Alpha cells; stims gluconeogenesis in liver; acts via cAMP second messenger
After morula - with blastocyst (+8 cell count)--->totipotent to embryonic stem cell and so on
Synthesizes lipids (including steroids); detoxifies drugs; is continuous with lumen
Fallopian tubes

23. What force is acting upon chyme to move it forward down sm intestine
Peristalsis (esophagus) and segmentation (bi - directional=mixing)
- 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
***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
ER

24. A pinpoint iris is contracted or uncontracted
Micelles; micelles (made of bile) go back and forth between brush border and chyme
Uncontracted: parasymp (eg opoid use)
Peptides
Salivary amylase; both hydrolyze glycosidic linkages

25. almost all exocytosed proteins pass through this
Lower blood pH
Smooth ER
Focuses light thru the vitreous humor onto retina; acts as a converging lens (image is real - inverted)
Adrenocorticotropin; stims adrenal cortex release of glucocorticoids (eg cortisol - a steroid) stress hormones via second messenger system using cAMP

26. Morula (...totipotent)
Zygote (morula) composed of eight or more cells; All cells at this stage are TOTipOTENT STEM Cells: do not grow - form by cleavage
It is the animal counterpart of starch; it is more highly- branched - thus releases more glucose monomers upon repeated hydrolysis than starch
Moves thru lymph sys; emptied into large veins (thus into bloodstream) of the neck at Thoracic duct
Estrogen: steroid; stims LH in luteal surge; causes growth of female sex organs progesterone: prepares/maintains uterus for pregnancy

27. axon hillock physiology
Conjunction of cell body w/axon
Water flows from the tubule - concentrating the filtrate - raising BP
Normally contracted
Renal pyramids --->renal calyx-->renal pelvis -->ureter -->urethra

28. After meiosis II...
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)
Four 23 N daughter cells are formed from one 46 2N mother (germ - line) cell; four haploid gametes
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
Gastric inhibitory pep; increase of pancreatic - enz activating enzymes (which cleaves zymogens like trypsinogen); increased gall bladder contraction; decreases stomach mobility

29. euk cell has two principal sides
AAs can be burned for energy or converted to fat for storage
Lumen (ie continuous w/body cavity) and cytosol
Membrane - bound - endocytosed bodies
Abdominal cavity - which is coated in serous fluid

30. Path of food entering body...
- 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
Mouth - esophagus - stomach - duodenum - jejunum - ileum - ascending colon - transverse colon - descending colon - sigmoid colon - rectum - anus
HCl; secreted by parietal cells under stim by gastrin
Digestion

31. review: parietals secrete intrinsic factor...
Diarrhea: excess water loss in feces; poor absorption of vitamins - minerals
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
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
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

32. FLAT PG: TSH aka thyrotropin
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
Increases solute conc and osmotic pressure of the ***medulla
Contain capillary network - lymph vessels (lacteals)
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.

33. What are the memb - bound enzymes of the brush border?
In gastric pits; secretions combine into gastric juice
Fat synthesis; carbs stored as free fatty acids - esterified to TAGs (requires small amount of E)
Prod of steroid hormones in testes - ovaries
CARB- Digesting: dextrinase (polysachs produced by hydrolysis of starch) - maltase (glucose - glucose) - sucrase (glucose - fructose) - lactase (galactose - glucose) - Protein- Digesting: peptidases - NUCLEOTIDE- Digesting: nucleosidases

34. How long are peptides when absorbed at brush border
Di - tri - peptides; inside enterocytes are hydrolyzed to amino acids
Injury that does not sever SC (causes deep lesion from back - front) might cause loss of feeling without full loss of motion
Moves down thru esophageal sphincter
Fat is insoluble in blood and requires a carrier like lipoproteins (vLDL...HDL) or albumins; ...vLDL has hi triglycerides - hi cholesterol

35. when cells hit their limit for prot storage...
Has memb - bound organelles - etc...
pericardial cavity - pleural cavity (contains lungs) - peritoneal cavity (abdominal)
Digestion
AAs can be burned for energy or converted to fat for storage

36. Gastrulation: ectoderm/mesoderm/endoderm
Focuses light thru the vitreous humor onto retina; acts as a converging lens (image is real - inverted)
Vitamin K - b12 - thiamin - riboflavin
Ectoderm: outer coverings - nervous system Mesoderm: between covering ie musc - bone - etc - endoderm: digestive tract - viscera
Oxytocin and ADH (aka vasopressin)

37. Local vs long - distance mediators
Paracrine (local) - endocrine (longer distance)
From lumenal (apical) to enterocyte to basolateral side of epithelial tissue
Salivary amylase (weak); sm intest amylase (breaks down large polysaccharides)
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

38. Some epithelial cells are... others...
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
Determination is a pre - programmed fate - differentiation is the actual materialization of that fate
Maintains hi estrogen levels; body does not recognize luteal surge - ovulation does not occur; hi progesterone can lessen shedding by thickening the uterine lining
- 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

39. Different organs working together
From lumenal (apical) to enterocyte to basolateral side of epithelial tissue
Systems (eg digestive system consists of many organs)
Food is digested from mouth to stomach (denaturation by gastric acid - digested by pepsin) to duodenum (more digestion); then absorption occurs in jejunum and ileum
Low because AAs are immediately used in translation

40. main point of fat transport...
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
Fat is insoluble in blood and requires a carrier like lipoproteins (vLDL...HDL) or albumins; ...vLDL has hi triglycerides - hi cholesterol
On the chyme exiting the stomach and entering duodenum thru the pyloric sphincter
Membrane - bound - endocytosed bodies

41. Think of spinal cord injury
Development of placenta begins with implantation; eventually - by end of first trimester - placenta will replace corpus luteum and its estrogen/progest secretions
(diploid and haploid individuals = ALTERNATION of GENERATIONS) a fusion of gametic and zygotic life cycles
Injury that does not sever SC (causes deep lesion from back - front) might cause loss of feeling without full loss of motion
Increases surface area of food ball (bolus)

42. Where would materials slated for digestion go?
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
Lysosome
Increases surface area of food ball (bolus)
Peptides

43. How does birth control work?
Glands w/ducts: Exocrine glands
Maintains hi estrogen levels; body does not recognize luteal surge - ovulation does not occur; hi progesterone can lessen shedding by thickening the uterine lining
Notochord (mesoderm) induces ectoderm to thicken into neural plate --->neural tube --->spinal cord
Zygote - morula (first four days) - blastocyst (4 day+; implants in uterine lining) - gastrula (2 week) - neurula (3 week)...

44. What are the major carbohydrates
sucrose (gluc+fruc) - lactose (gluc+galactose) - starch (gluc+gluc)
AAs can be burned for energy or converted to fat for storage
Spike in estrogen - LH levels; secondary follicle bursts - releases into body cavity - swept along by fimbriae
Fovea (highest amount of cones)

45. In effect LH - FSH stimulate
Prophase I: crossing over occurs; nuclear envelope is absorbed into ER; chromosomes condense)
Uncontracted: parasymp (eg opoid use)
In mouth - breakdown of starch into polysaccharides
Prod of steroid hormones in testes - ovaries

46. sensory (afferent) neurons
Receive signals from receptor cell w/ ability to interact with its environment; 99% sensory input is discarded
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
Renal pyramids --->renal calyx-->renal pelvis -->ureter -->urethra
Nuclear envelope reassembled in daughter cells; cytokinesis occurs; nucleoli reappear (site of rRNA synthesis)

47. How do parietal cells work ** (involves CO2)
At the collecting duct: becomes more permeable to water which passively diffuses *into the medulla* concentrating the urine
Result is proton secreted into lumen - bicarbonate into interstitial fluid (diffuses into blood); result is also increased blood pH and decreased pH stomach
sucrose (gluc+fruc) - lactose (gluc+galactose) - starch (gluc+gluc)
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)

48. What kind of cells make up epithel tiss of stom - then sm intest?
Faces the lumen
Somatic nervous sys - autonomic nervous sys
Estradiol (estrogen - steroid horm); prepares uterine wall for pregnancy; just before ovulation - release of estradiol stims LH in pos feedback
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

49. 80% of end product of carbohydrate metabolism is...
Gall bladder - pancreatic secretions increase - arrive via ampulla of vater (duct glands); insulin secretion increases (fed state; ductless glands)
Lipoproteins; albumin carries free fatty acids when fat is mobilized from adipose tissue - etc
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
Glucose

50. What hormones affect the stomach?
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
Liver breaks down glycogen (glycogenolysis); at hi blood sugar it builds up glycogen (glycogenesis)
Nuclear envelope reassembled in daughter cells; cytokinesis occurs; nucleoli reappear (site of rRNA synthesis)
'visceral organs develop adjacent to a cavity and invaginate into the bag - like coelom'