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. E storage per unit mass
It targets liver conc of prothrombin - fibrinogen etc
Inactive: rhodopsin is activated by photons; activated rhodopsin hyperpolarizes rod cells - causes photobleaching
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
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

2. Different organs working together
All carbs absorbed at enterocytes are carried to liver by portal vein
1) by integral ion channels 2) transmitted by second messenger system
Peripheral nervous sys
Systems (eg digestive system consists of many organs)

3. from the loop of henle...
Duodenum (wraps around pancreas; most digestion occurs here) - jejunum (pH 7-9; 2m) - ileum
Buildup of macromolecules in lysosome due to deficient lysosome enzymes
Serous membrane (slick - reducing friction) that forms lining of the coelom --> secretes lubricating fluid
On to the distal tubule where sodium - calcium are reabsorbed - protons - bicarbonate - potassium are secreted via membrane transport proteins

4. 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.

5. What is a normal blood glucose range
'tones the bone'; decreases free Calcium conc; acts opposite to parathyroid hormone; thyroid polypeptide
90-140 mg/dl
Glycosaminoglycans - prots - AAs - lipids
Alpha 1-4 and 1-6 (branching) glycosidic linkages

6. when cells hit their limit for prot storage...
Bacterial flagellin: hollow filament (not microtub); euk: 9+2 microtubule w/dynein bridges
AAs can be burned for energy or converted to fat for storage
After morula - with blastocyst (+8 cell count)--->totipotent to embryonic stem cell and so on
Smaller - more water soluble short - chain FAs go directly to bloodstream at villi capillaries

7. What are phagosomes
Trypsin(- ogen; activates other panc enzymes after it is activated by enterokinase of sm intest); chymotrypsin - amylase - lipase
Adrenocorticotropin; stims adrenal cortex release of glucocorticoids (eg cortisol - a steroid) stress hormones via second messenger system using cAMP
Increases blood Calcium
Membrane - bound - endocytosed bodies

8. what else is located in the inner ear (not directly related to auditory)
Estrogen: steroid; stims LH in luteal surge; causes growth of female sex organs progesterone: prepares/maintains uterus for pregnancy
Salivary amylase; both hydrolyze glycosidic linkages
Chyme (by combined activity of exocrine glands)
Two perpendicular semicircular canals involved in balance - equilibrium

9. Difference between euk and prok flagella
On to the distal tubule where sodium - calcium are reabsorbed - protons - bicarbonate - potassium are secreted via membrane transport proteins
Bacterial flagellin: hollow filament (not microtub); euk: 9+2 microtubule w/dynein bridges
From lumenal (apical) to enterocyte to basolateral side of epithelial tissue
Ectoderm: outer coverings - nervous system Mesoderm: between covering ie musc - bone - etc - endoderm: digestive tract - viscera

10. What is the net effect of the loop of Henle
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)
Night vision
Only musc and esp ** liver can store large amounts
Creates one ovum (23 N) and three polar bodies

11. Adrenal medulla hormones (TYR- DERIVED)
An endogenous morphine
= catecholamines; fight/flight; vasoconstrictors of internal organs - skin; vasodilators of skel musc; also considered stress hormones; epinephrine - norepinephrine
Glucose and ketone bodies (not from glycogen stores)
Gall bladder - pancreatic secretions increase - arrive via ampulla of vater (duct glands); insulin secretion increases (fed state; ductless glands)

12. After meiosis II - Female

13. Embryology
Gall bladder - pancreatic secretions increase - arrive via ampulla of vater (duct glands); insulin secretion increases (fed state; ductless glands)
= catecholamines; fight/flight; vasoconstrictors of internal organs - skin; vasodilators of skel musc; also considered stress hormones; epinephrine - norepinephrine
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
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. After meiosis II...
Secondary spermatocyte (stim'd by FSH from Sertoli cells -->EQUATIONAL DIVISION-->spermatid - which matures further into spermatozoa; released into semeniferous tubule; transported to epididymis
Lipoproteins; albumin carries free fatty acids when fat is mobilized from adipose tissue - etc
Four 23 N daughter cells are formed from one 46 2N mother (germ - line) cell; four haploid gametes
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)

15. Glycogenolysis/gluconeogenesis
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
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
Beta cells
Note: enteric= small intestine - double layer of peritoneum that suspends jejunum/ileum from posterior abdominal wall = connective tissue

16. axon hillock physiology
Conjunction of cell body w/axon
Prod of steroid hormones in testes - ovaries
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
Result: stress reaction; increase glycogenolysis - gluconeogenesis; fat/prot breakdown; increase blood glucose

17. 80% of end product of carbohydrate metabolism is...
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
Glucose
In mouth - breakdown of starch into polysaccharides
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

18. Glucose is a .... sugar; fructose is a .... sugar
Glucose and ketone bodies (not from glycogen stores)
Glucose = aldose fructose = ketose
Prophase I: crossing over occurs; nuclear envelope is absorbed into ER; chromosomes condense)
- 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

19. What Changes - Doesn't Change as a result of movement of molecules across membranes in the proximal tubule
Many modern drugs are ligands for GPCRs
Which is why lactase - maltase - dextrinase - sucrase are on brush border
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
Changes: volume of filtrate does not change: osmolarity of filtrate --->reabsorbed ions like sodium carry water across membrane

20. What (typically - ie not pre - ovulation) feeds back to decrease LH - FSH production?
Testes>Semeniferous tubules>Sertoli cells; feedback on AP FSH production
Fat is insoluble in blood and requires a carrier like lipoproteins (vLDL...HDL) or albumins; ...vLDL has hi triglycerides - hi cholesterol
Testosterone and estradiol
Lipoproteins; albumin carries free fatty acids when fat is mobilized from adipose tissue - etc

21. liver receives blood from...
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
Thru tight junctions by favorable osmotic gradient
It targets liver conc of prothrombin - fibrinogen etc
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

22. What determines number of chromosomes?
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
Lipoproteins; albumin carries free fatty acids when fat is mobilized from adipose tissue - etc
= catecholamines; fight/flight; vasoconstrictors of internal organs - skin; vasodilators of skel musc; also considered stress hormones; epinephrine - norepinephrine
Number of centromeres - Not number of chromatids eg - two sister chromatids connected by one centromere = one chromosome

23. What is a toxic byproduct of gluconeogenesis from proteins
Alpha 1-4 and 1-6 (branching) glycosidic linkages
Via secondary active transport proteins (COSTS E TO FILTER BLOOD - ESTABLISH FLUID/ION BALANCE)
Ammonia; must be converted to urea by liver and excreted in urine by kidney
Processes: axons - dendrites

24. The apical side of the villi...
Synthesizes lipids (including steroids); detoxifies drugs; is continuous with lumen
Result: stress reaction; increase glycogenolysis - gluconeogenesis; fat/prot breakdown; increase blood glucose
Faces the lumen
Somatic sensory = dorsal root ganglia (outside spinal cord); somatic effector = ventral horns of spinal cord

25. 3 phases of menstrual cycle
Duodenum (wraps around pancreas; most digestion occurs here) - jejunum (pH 7-9; 2m) - ileum
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)
Organs
Trypsin(- ogen; activates other panc enzymes after it is activated by enterokinase of sm intest); chymotrypsin - amylase - lipase

26. Chewing does what?
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
ER
Four 23 N daughter cells are formed from one 46 2N mother (germ - line) cell; four haploid gametes
Increases surface area of food ball (bolus)

27. Four tissues
Nervous - muscle - epithelial (defines inner/outer) - connective (extensive matrices)
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
Testosterone upon stim by LH
Conjunction of cell body w/axon

28. 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
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
Visceral layer= parietal layer; serous membrane is the container of the coelom/peritoneal cavity
All carbs absorbed at enterocytes are carried to liver by portal vein

29. PNS review: SAME DAVE
Contain capillary network - lymph vessels (lacteals)
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
Sensory neurons are affector; motor neurons are effector // dorsal afferent (dorsal - Back- side of spinal cord carries sensory signals to brain; ventral effector
Nervous - muscle - epithelial (defines inner/outer) - connective (extensive matrices)

30. Where do pancreatic secretions take effect
On the chyme exiting the stomach and entering duodenum thru the pyloric sphincter
Polysaccharides w/proteoglycans attached = glycosaminoglycans; often give pliability
Corpus luteum degrades into corpus albicans
- 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

31. Luteal surge
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
Spike in estrogen - LH levels; secondary follicle bursts - releases into body cavity - swept along by fimbriae
Below hypothalamus
Fovea (highest amount of cones)

32. Meiosis I: REDUCTIONAL DIVISION Interphase: G1 (growth; enzymes - structural proteins needed for gametic production are synthesized); S (DNA of homologous chromosomes is duplicated; mother cell goes from 46 2N to 46 2N with sister chromosomes connect
Peptides
Pancreas; active at sm intestinal pH; hydrolyzes peptide bonds of (pepsin - digested) peptides
Prophase I: crossing over occurs; nuclear envelope is absorbed into ER; chromosomes condense)
Uncontracted: parasymp (eg opoid use)

33. Kidney physiology...

34. Liver Functions
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
Know that 90% digestion - absorption occurs in sm intestine --> fine breakdown of carbs - fat - prots
All carbs absorbed at enterocytes are carried to liver by portal vein
Fovea (highest amount of cones)

35. pancreatic amylase is much stronger than
Protein digestion begins in stomach; low pH denatures proteins - kills bacteria; mixes - stores food and destroys it to chyme (BOLUS-->CHYME)
Salivary amylase; both hydrolyze glycosidic linkages
It targets liver conc of prothrombin - fibrinogen etc
Oxytocin and ADH (aka vasopressin)

36. Most important nutrients absorbed by large intestine
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)
Drugs - toxins - bile pigments (color the urine) - uric acid - antibiotics
**only para effectors have muscarinic receptors; symp effectors are adrenergic (epi - norepi); **neuromuscular junction uses nicotinic receptors
Lots of water - minerals (electrolyte balance) - vitamins (aided by gut bacteria)

37. During ejaculation - sperm...

38. cholinergic receptors: NICTONIC and MUSCARINIC Nicotinic: neuromuscular effectors (ionotropic) Muscarinic: PARA effectors (GPCRs) Adrenergic: SYMP effectors (GPCRs)
Corpus luteum; secretes estradiol - progesterone throughout pregnancy OR if no pregnancy - for about 2 weeks (till menstruation = shedding of uterine lining)
'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
Fovea (highest amount of cones)
**only para effectors have muscarinic receptors; symp effectors are adrenergic (epi - norepi); **neuromuscular junction uses nicotinic receptors

39. PNS is broken down into
Gall bladder - pancreatic secretions increase - arrive via ampulla of vater (duct glands); insulin secretion increases (fed state; ductless glands)
RBCs - large proteins; What does enter is called the filtrate
Somatic nervous sys - autonomic nervous sys
Normally contracted

40. signal transduction occurs by 2 paths
'Microvilli function as the **primary surface of nutrient absorption in the gastrointestinal tract**. Because of this vital function - the microvillar membrane is packed with enzymes that aid in the breakdown of complex nutrients into simpler compoun
1) by integral ion channels 2) transmitted by second messenger system
Secondary follicle: Theca cells differentiate from interstitial tissue - surround follicle - secrete testosterone when stimd by LH (compare to Leydig cells)
After morula - with blastocyst (+8 cell count)--->totipotent to embryonic stem cell and so on

41. calcitonin

42. pancreas secretes enzymes via
Peristalsis (esophagus) and segmentation (bi - directional=mixing)
Most absorption occurs in sm intestine
Pancreatic duct (made of acinar cells?)
Oxidizes macromolecules; breaks down very long - chain FAs by beta - oxidation; products (acetyl - CoA) are shuttled to mitochondrion for citric acid cycle

43. overview of prot digestion
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
Pancreas; active at sm intestinal pH; hydrolyzes peptide bonds of (pepsin - digested) peptides
Via secondary active transport proteins (COSTS E TO FILTER BLOOD - ESTABLISH FLUID/ION BALANCE)
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

44. remaining secondary follicle becomes
Contain capillary network - lymph vessels (lacteals)
Eg spinal nerve - cranial nerve; Not All Nervous Tissue In Brain - SC Is CNS Tissue
Corpus luteum; secretes estradiol - progesterone throughout pregnancy OR if no pregnancy - for about 2 weeks (till menstruation = shedding of uterine lining)
Many modern drugs are ligands for GPCRs

45. Embryology
Zygote - morula (first four days) - blastocyst (4 day+; implants in uterine lining) - gastrula (2 week) - neurula (3 week)...
Result is proton secreted into lumen - bicarbonate into interstitial fluid (diffuses into blood); result is also increased blood pH and decreased pH stomach
Somatic nervous sys - autonomic nervous sys
Glands w/ducts: Exocrine glands

46. week three: neurulation; mesoderm induces ectoderm; thus - NEURULATION INVOLVES SC Development - at week three
Contain capillary network - lymph vessels (lacteals)
Oxidizes macromolecules; breaks down very long - chain FAs by beta - oxidation; products (acetyl - CoA) are shuttled to mitochondrion for citric acid cycle
Via secondary active transport proteins (COSTS E TO FILTER BLOOD - ESTABLISH FLUID/ION BALANCE)
Notochord (mesoderm) induces ectoderm to thicken into neural plate --->neural tube --->spinal cord

47. main point of fat transport...
Peripheral nervous sys
Determination is a pre - programmed fate - differentiation is the actual materialization of that fate
Fat is insoluble in blood and requires a carrier like lipoproteins (vLDL...HDL) or albumins; ...vLDL has hi triglycerides - hi cholesterol
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

48. What is the function of the loop of Henle
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
Increases solute conc and osmotic pressure of the ***medulla
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
Prod of steroid hormones in testes - ovaries

49. How does glycogen compare to starch
Sudiferous (sweat) - sebaceous - digestive (bile - pancreatic enzs) - mucosal
Somatic nervous sys - autonomic nervous sys
It is the animal counterpart of starch; it is more highly- branched - thus releases more glucose monomers upon repeated hydrolysis than starch
An ether phospholipid; hi conc in myelin; thus - hi conc in heart tiss - nervous tiss

50. Alpha - amylase found where
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
In mouth - breakdown of starch into polysaccharides
Follicular (proliferative)= 8d - Luteal (post - ovulation; corpus luteum secretions)= 13d - Menstruation (shed uterine lining if no implantation)= 5
Fructose is a structural isomer of glucose