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. What controls release of LH - FSH from anterior pituitary
Lipoproteins; albumin carries free fatty acids when fat is mobilized from adipose tissue - etc
Gonadotropin releasing hormone - GnRH
Chylomicrons are much bigger
Prod of steroid hormones in testes - ovaries

2. sensory (afferent)/interneurons/motor (efferent)
Nourishes follicle growth; stimulates granulosa cell growth around primary oocyte at puberty = primary follicle; also - stimulates Sertoli cells in males
Neurons may perform one of three functions....
Lipoproteins; albumin carries free fatty acids when fat is mobilized from adipose tissue - etc
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.

3. lining of abdominal cavity=
Synthesizes lipids (including steroids); detoxifies drugs; is continuous with lumen
Serous membrane (slick - reducing friction) that forms lining of the coelom --> secretes lubricating fluid
Night vision
From lumenal (apical) to enterocyte to basolateral side of epithelial tissue

4. smooth ER main function
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)
Synthesizes lipids (including steroids); detoxifies drugs; is continuous with lumen
PNS- Somatic - afferent (dorsal root ganglion) + efferent (ventral horns) PNS- ANS- afferent (sensors on viscera) + SYMP - PARA pre - post - ganglionic neurons
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

5. What do villli do
Inactive: rhodopsin is activated by photons; activated rhodopsin hyperpolarizes rod cells - causes photobleaching
Increase surface area of sm intestine; this improves digestion (enzymes adsorbed to villi) and absorption
Corpus luteum degrades into corpus albicans
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

6. What does peptic refer to in general
Vitamin K - b12 - thiamin - riboflavin
Prod of steroid hormones in testes - ovaries
Digestion
Trypsinogen is activated by enterokinase in the brush border; in turn - it activates other enzymes

7. Where is bile produced
Sensory neurons are affector; motor neurons are effector // dorsal afferent (dorsal - Back- side of spinal cord carries sensory signals to brain; ventral effector
Parathyroid hormone (peptide; increases blood Ca); thus - might increase osteoclast/decrease osteoblast activity
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**
Receive signals from receptor cell w/ ability to interact with its environment; 99% sensory input is discarded

8. What hormones affect the stomach?
Formed in kidney (nephron) - sent thru renal pelvis - down ureter to bladder - drained by urethra'
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
RBCs - large proteins; What does enter is called the filtrate
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

9. Anterior eye vs. posterior eye
Notochord (mesoderm) induces ectoderm to thicken into neural plate --->neural tube --->spinal cord
Ammonia; must be converted to urea by liver and excreted in urine by kidney
Determined by whether in front of or behind the lens
Form barrier to extracellular fluid

10. What determines number of chromosomes?
Night vision
Number of centromeres - Not number of chromatids eg - two sister chromatids connected by one centromere = one chromosome
Tight regulation of parietal cells needed b/c gastric acid secretion is E- intensive; parietal cells are hi in mitochons
Micelles; micelles (made of bile) go back and forth between brush border and chyme

11. in the dark is rhodopsin active or inactive?
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
It is the animal counterpart of starch; it is more highly- branched - thus releases more glucose monomers upon repeated hydrolysis than starch
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**
Inactive: rhodopsin is activated by photons; activated rhodopsin hyperpolarizes rod cells - causes photobleaching

12. What is feces composed of...
cornea (1.4 refractory index; bends light) - pupil (size of pupil is determined by contraction state of the iris) - aqueous humor
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
An endogenous morphine
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**

13. pancreatic amylase is much stronger than
Four 23 N daughter cells are formed from one 46 2N mother (germ - line) cell; four haploid gametes
Salivary amylase; both hydrolyze glycosidic linkages
Interstitial fluid (eg prostaglandins - cytokines)
cornea (1.4 refractory index; bends light) - pupil (size of pupil is determined by contraction state of the iris) - aqueous humor

14. Bile salts and lipase
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
It targets liver conc of prothrombin - fibrinogen etc
'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
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

15. What is main difference is signal transmission in nicotinic vs muscarinic?
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
***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
***nicotinic is ionotropic; muscarinic is GPCR
Notochord (mesoderm) induces ectoderm to thicken into neural plate --->neural tube --->spinal cord

16. What if large intestine isn't working well
Diarrhea: excess water loss in feces; poor absorption of vitamins - minerals
Sympathetic: dilates pupil (for night hunting)
Meiosis creates germ cells
Glucose = aldose fructose = ketose

17. parathyroid hormones
Liver is the control center for blood glucose; is fed by portal vein from sm intest
Micelles; micelles transport lipase products to enterocytes for absorption at brush border
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)
Parathyroid hormone (peptide; increases blood Ca); thus - might increase osteoclast/decrease osteoblast activity

18. What is the pH at the entrance to the duodenum
Arrested at primary oocyte; hypothalamus GnRH->FSH released at puberty stims granulosa cell development; granulosa secrete zona pellucida = primary follicle
PNS- Somatic - afferent (dorsal root ganglion) + efferent (ventral horns) PNS- ANS- afferent (sensors on viscera) + SYMP - PARA pre - post - ganglionic neurons
(diploid organism) humans are part of gametic life cycle ie produce gametes; diploid germ - line stem cells undergo meiosis to form haploid gametes
PH 6.0; this accomplished by pancreatic secretion of bicarbonate which ups pH

19. Path of urine

Warning: Invalid argument supplied for foreach() in /var/www/html/basicversity.com/show_quiz.php on line 183

20. when cells hit their limit for prot storage...
AAs can be burned for energy or converted to fat for storage
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
Inner lining of circulatory system
Parathyroid hormone (peptide; increases blood Ca); thus - might increase osteoclast/decrease osteoblast activity

21. spermatogonia arise from
Prophase I: crossing over occurs; nuclear envelope is absorbed into ER; chromosomes condense)
Transfer signals from neuron - neuron; 90% of neurons are interneurons
Epithelial tissue near semniferous tubules
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

22. going down the loop of Henle - water - permeable - filtrate osmolarity goes up as water leaves...
Going up - water - impermeable: salt is actively pumped out - filtrate osmolarity goes down as salt leaves
Lens will be rounded; contraction of the lens (ie focusing) is done by ciliary muscle
Lysosome
Testosterone upon stim by LH

23. is intracellular AA conc hi or low?
Zygote - morula (first four days) - blastocyst (4 day+; implants in uterine lining) - gastrula (2 week) - neurula (3 week)...
Low because AAs are immediately used in translation
CARB- Digesting: dextrinase (polysachs produced by hydrolysis of starch) - maltase (glucose - glucose) - sucrase (glucose - fructose) - lactase (galactose - glucose) - Protein- Digesting: peptidases - NUCLEOTIDE- Digesting: nucleosidases
Most absorption occurs in sm intestine

24. Important aspect of crypt of Lieberkuhn - secreted intestinal juice
'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
Contains lysozyme - which regulates bacteria within intestine; breaks down peptidoglycans (**bact wall); innate immunity
Follicular (proliferative)= 8d - Luteal (post - ovulation; corpus luteum secretions)= 13d - Menstruation (shed uterine lining if no implantation)= 5
Needs time for bile - lipase - micelle migration - enterocyte uptake

25. mitosis creates somatic cells
Uncontracted: parasymp (eg opoid use)
Lots of water - minerals (electrolyte balance) - vitamins (aided by gut bacteria)
An endogenous morphine
Meiosis creates germ cells

26. How do monoglycerides and ffas get to brush border?
Liver is the control center for blood glucose; is fed by portal vein from sm intest
Contains hydrolytic enzymes; thus - digests endocytosed substances; derived from golgi
Micelles; micelles (made of bile) go back and forth between brush border and chyme
90-140 mg/dl

27. How is glucose absorbed in sm intest
Micelles; micelles (made of bile) go back and forth between brush border and chyme
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
Polysaccharides w/proteoglycans attached = glycosaminoglycans; often give pliability
Glands w/ducts: Exocrine glands

28. Where else does ADH act
At the collecting duct: becomes more permeable to water which passively diffuses *into the medulla* concentrating the urine
Result: stress reaction; increase glycogenolysis - gluconeogenesis; fat/prot breakdown; increase blood glucose
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**
Inner lining of blood vessels

29. Tight junctions
ER
Form barrier to extracellular fluid
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
Increases surface area of food ball (bolus)

30. Energy from fat - prot - gluc
FAT=9 cal per gram Carbs=4.5 cal per gram - Prot=4 cal per gram - these seem to be for anhydrous forms
Processes: axons - dendrites
Most absorption occurs in sm intestine
The crypts of Lieberkuhn: sm intestine pH is not right; brush border enzs won't work right

31. How do nutrients move?
Primitive streak - which consists of cells of the MESODERM ****
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
From lumenal (apical) to enterocyte to basolateral side of epithelial tissue
- 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

32. energy source of neurons
Secondary spermatocyte (stim'd by FSH from Sertoli cells -->EQUATIONAL DIVISION-->spermatid - which matures further into spermatozoa; released into semeniferous tubule; transported to epididymis
Glucose and ketone bodies (not from glycogen stores)
Smaller - more water soluble short - chain FAs go directly to bloodstream at villi capillaries
CARB- Digesting: dextrinase (polysachs produced by hydrolysis of starch) - maltase (glucose - glucose) - sucrase (glucose - fructose) - lactase (galactose - glucose) - Protein- Digesting: peptidases - NUCLEOTIDE- Digesting: nucleosidases

33. chylomicron concentration in blood after meal
Peak at 1-2hr after meal; chylomicrons themselves have half - life of about 1hr after formation in enterocytes
Trypsinogen is activated by enterokinase in the brush border; in turn - it activates other enzymes
Below hypothalamus
Outermost layer of blood vessel

34. What is the mesentery?
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
Note: enteric= small intestine - double layer of peritoneum that suspends jejunum/ileum from posterior abdominal wall = connective tissue
Only musc and esp ** liver can store large amounts
- 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

35. Posterior eye
Uncontracted: parasymp (eg opoid use)
Organs
5
vitreous humor - retina - fovea

36. Posterior pituitary hormones (Small Peptides)
Oxytocin and ADH (aka vasopressin)
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
The renal corpuscle
Small intestine; duodenum is smallest and does most DIGESTION; jejunum is medium and does most ABSORPTION; ileum is biggest and does most absorption along with jejunum

37. Interaction of corpus luteum/placenta
Determined by whether in front of or behind the lens
Mediate complex cell processes thru eg phosphorylation via secondary messenger (G protein) systems = signal transduction pathway - GPCR (G protein coupled receptor)
Development of placenta begins with implantation; eventually - by end of first trimester - placenta will replace corpus luteum and its estrogen/progest secretions
Meiosis creates germ cells

38. cAMP - cGMP - calmodulin...
Hydrostatic pressure forces some plasma thru *fenestrations of the glomerular endothelium* and into Bowman's capsule; B.C. is continuous with lumen of nephron
Mediate complex cell processes thru eg phosphorylation via secondary messenger (G protein) systems = signal transduction pathway - GPCR (G protein coupled receptor)
Small intestine; duodenum is smallest and does most DIGESTION; jejunum is medium and does most ABSORPTION; ileum is biggest and does most absorption along with jejunum
Smaller - more water soluble short - chain FAs go directly to bloodstream at villi capillaries

39. What is the function of the loop of Henle
Trypsin(- ogen; activates other panc enzymes after it is activated by enterokinase of sm intest); chymotrypsin - amylase - lipase
Increases solute conc and osmotic pressure of the ***medulla
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
Peptide; prolactin promotes milk production; prolactin release is stimulated by act of suckling - which in turn inhibits menstrual cycle

40. Morula (...totipotent)
Most absorption occurs in sm intestine
Ventrally (picture skeletal vertebrae)
Zygote (morula) composed of eight or more cells; All cells at this stage are TOTipOTENT STEM Cells: do not grow - form by cleavage
Mediate complex cell processes thru eg phosphorylation via secondary messenger (G protein) systems = signal transduction pathway - GPCR (G protein coupled receptor)

41. gametes are haploid
Zygotes are diploid
Hypothalamus --->AP--->target tissues eg TSH - thyroid - T3/T4 release - increase basal metabolic rate
Chylomicrons are much bigger
PNS- Somatic - afferent (dorsal root ganglion) + efferent (ventral horns) PNS- ANS- afferent (sensors on viscera) + SYMP - PARA pre - post - ganglionic neurons

42. position of AP...
Oxytocin and ADH (aka vasopressin)
Lots of water - minerals (electrolyte balance) - vitamins (aided by gut bacteria)
Below hypothalamus
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

43. In effect LH - FSH stimulate
Adrenocorticotropin; stims adrenal cortex release of glucocorticoids (eg cortisol - a steroid) stress hormones via second messenger system using cAMP
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
Eukaryotes
Prod of steroid hormones in testes - ovaries

44. euk cell has two principal sides
Lumen (ie continuous w/body cavity) and cytosol
Night vision
Fructose is a structural isomer of glucose
To the organelle w/ lumen: smooth ER; they are resynthesized into TAGs

45. What else do parietals do?
Secrete intrinsic factor; important for absorbing vitamin B12 in sm intest
Via secondary active transport proteins (COSTS E TO FILTER BLOOD - ESTABLISH FLUID/ION BALANCE)
Pancreatic duct (made of acinar cells?)
In gastric pits; secretions combine into gastric juice

46. large intestine E. coli aid absorption of...
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
Four 23 N daughter cells are formed from one 46 2N mother (germ - line) cell; four haploid gametes
At the first capillary bed of the nephron called the glomerulus which is encased by ***Bowman's capsule
Vitamin K - b12 - thiamin - riboflavin

47. light detection via GPCRs
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
Where lipoprotein lipase hydrolyzes TAGs; products diffuse into target tiss (mostly liver - adipose tissue)
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
Photon (hv)- rhodopsin - conformation change - GPCR- Na less permeable - hyperpolarized rod cells - generates AP= photobleaching at visible light wavelengths (390-700nm)

48. Difference between euk and prok flagella
Bacterial flagellin: hollow filament (not microtub); euk: 9+2 microtubule w/dynein bridges
Normally contracted
Peptide; prolactin promotes milk production; prolactin release is stimulated by act of suckling - which in turn inhibits menstrual cycle
Serous membrane (slick - reducing friction) that forms lining of the coelom --> secretes lubricating fluid

49. What do lipases do
Smooth ER
Note: enteric= small intestine - double layer of peritoneum that suspends jejunum/ileum from posterior abdominal wall = connective tissue
Break down TAGs to monoglycerides and free fatty acids
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

50. A pinpoint iris is contracted or uncontracted
Facilitated diffusion: no symport w/ secondary transport
Uncontracted: parasymp (eg opoid use)
'The hepatic portal vein is not a true vein - because it does not conduct blood directly to the heart. It is a vessel in the abdominal cavity that drains blood from the gastrointestinal tract and spleen to capillary beds in the liver.'
Cancer; apop can be programmed cell death; mitochon can play important role in apop