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Test your basic knowledge |
MCAT Prep - 2
Start Test
Study First
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. Glycogenolysis/gluconeogenesis
Calcitonin (peptide; lowers blood Ca); T3/T4 (tyrosine - derived; increase basal metabolic rate); T4= thyroxine
- 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
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
- 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
2. Creating gradients requires what?
Parathyroid hormone (peptide; increases blood Ca); thus - might increase osteoclast/decrease osteoblast activity
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
TAGS--->FFAs; remember that FFAs are broken down for energy in mito matrix by beta - oxidation
Oxidizes macromolecules; breaks down very long - chain FAs by beta - oxidation; products (acetyl - CoA) are shuttled to mitochondrion for citric acid cycle
3. Chewing does what?
PH 6.0; this accomplished by pancreatic secretion of bicarbonate which ups pH
Glands w/ducts: Exocrine glands
Increases surface area of food ball (bolus)
Reconstituted into TAGs at smooth ER; first stop for most digested fat is liver
4. therefore - How does plasma leave capillary at the renal corpuscle
5. How does reabsorption force nutrients across apical membrane of proximal tubule
Sorts - modifies - concentrates proteins from the ER
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
Alpha cells; stims gluconeogenesis in liver; acts via cAMP second messenger
Via secondary active transport proteins (COSTS E TO FILTER BLOOD - ESTABLISH FLUID/ION BALANCE)
6. How does the body mobilize fat stores
Formed in kidney (nephron) - sent thru renal pelvis - down ureter to bladder - drained by urethra'
Gonadotropin releasing hormone - GnRH
***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
Increases solute conc and osmotic pressure of the ***medulla
7. 90% digestion - absorption occurs in...
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
Gastrulation occurs: formation of three primary germ layers = differentiation
TAGS--->FFAs; remember that FFAs are broken down for energy in mito matrix by beta - oxidation
Neurons may perform one of three functions....
8. 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
Small amounts of hydrolyzed phospholipids and cholesterol: like other fat mols these can diffuse thru enterocyte membrane
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
Fallopian tubes
9. components of interstitial fluid
Cancer; apop can be programmed cell death; mitochon can play important role in apop
Regulated by gastrointestinal horms
Glycosaminoglycans - prots - AAs - lipids
Lots of water - minerals (electrolyte balance) - vitamins (aided by gut bacteria)
10. When 'coumadin targets liver enzymes to act as anticoagulant'...
Somatic nervous sys - autonomic nervous sys
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
It targets liver conc of prothrombin - fibrinogen etc
Lysosome
11. from thoracic duct - chylomicrons stick to capillary walls...
Increases surface area of food ball (bolus)
Spinal cord ventral horns; somatic motor neurons use acetylcholine for NTs (voluntary)
Where lipoprotein lipase hydrolyzes TAGs; products diffuse into target tiss (mostly liver - adipose tissue)
Peptide; responsible for luteal surge (driven in part by LH-->testosterone -->estradiol -->LH positive feedback); results in ovulation (follicle bursting) - releasing egg into fallopian tube/oviduct
12. Posterior eye
'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
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
vitreous humor - retina - fovea
Polysaccharides w/proteoglycans attached = glycosaminoglycans; often give pliability
13. pancreas secretes enzymes via
Facilitated diffusion: no symport w/ secondary transport
Pancreatic duct (made of acinar cells?)
Two perpendicular semicircular canals involved in balance - equilibrium
***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
14. smooth ER main function
Glucocorticoid (cortisol); mineralocorticoid (aldosterone)
PH 6.0; this accomplished by pancreatic secretion of bicarbonate which ups pH
The crypts of Lieberkuhn: sm intestine pH is not right; brush border enzs won't work right
Synthesizes lipids (including steroids); detoxifies drugs; is continuous with lumen
15. micelles vs liposomes
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
Know that 90% digestion - absorption occurs in sm intestine --> fine breakdown of carbs - fat - prots
Moves down thru esophageal sphincter
Liposome has phospholipid bilayer
16. exocrine types
sucrose (gluc+fruc) - lactose (gluc+galactose) - starch (gluc+gluc)
Trypsinogen is activated by enterokinase in the brush border; in turn - it activates other enzymes
Protein digestion begins in stomach; low pH denatures proteins - kills bacteria; mixes - stores food and destroys it to chyme (BOLUS-->CHYME)
Sudiferous (sweat) - sebaceous - digestive (bile - pancreatic enzs) - mucosal
17. What is gastric acid?
pericardial cavity - pleural cavity (contains lungs) - peritoneal cavity (abdominal)
HCl; secreted by parietal cells under stim by gastrin
Has memb - bound organelles - etc...
Reconstituted into TAGs at smooth ER; first stop for most digested fat is liver
18. Examples of GPCRs in sensory systems/signal transduction: What is the ligand or messenger in each case? ...SIGHT - SMELL - MOOD - FIGHT/FLIGHT etc
Salivary amylase; both hydrolyze glycosidic linkages
Pancreatic duct (made of acinar cells?)
1) by integral ion channels 2) transmitted by second messenger system
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
19. what happens to bile secretions
Zygote (morula) composed of eight or more cells; All cells at this stage are TOTipOTENT STEM Cells: do not grow - form by cleavage
Mostly reabsorbed to liver
vitreous humor - retina - fovea
5
20. when thinking of proteins - think
Focuses light thru the vitreous humor onto retina; acts as a converging lens (image is real - inverted)
sucrose (gluc+fruc) - lactose (gluc+galactose) - starch (gluc+gluc)
Nitrogen
Estradiol (estrogen - steroid horm); prepares uterine wall for pregnancy; just before ovulation - release of estradiol stims LH in pos feedback
21. Gland: ovaries
Estrogen: steroid; stims LH in luteal surge; causes growth of female sex organs progesterone: prepares/maintains uterus for pregnancy
Where lipoprotein lipase hydrolyzes TAGs; products diffuse into target tiss (mostly liver - adipose tissue)
Inactive: rhodopsin is activated by photons; activated rhodopsin hyperpolarizes rod cells - causes photobleaching
Digestion
22. gametes are haploid
**NO*** lipase digests fat; no bonds broken by bile; only opens up more SA for lipase
Oxytocin and ADH (aka vasopressin)
Zygotes are diploid
**only para effectors have muscarinic receptors; symp effectors are adrenergic (epi - norepi); **neuromuscular junction uses nicotinic receptors
23. What is endothelium?
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
Somatic sensory = dorsal root ganglia (outside spinal cord); somatic effector = ventral horns of spinal cord
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
Inner lining of blood vessels
24. Mucus - digestive enzymes released thru
Glands w/ducts: Exocrine glands
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
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
Focuses light thru the vitreous humor onto retina; acts as a converging lens (image is real - inverted)
25. What is the adventitia?
Increase surface area of sm intestine; this improves digestion (enzymes adsorbed to villi) and absorption
Liver is the control center for blood glucose; is fed by portal vein from sm intest
Outermost layer of blood vessel
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
26. lysosome pH
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
5
Inner lining of blood vessels
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
27. only monosaccharides are absorbed
Which is why lactase - maltase - dextrinase - sucrase are on brush border
HCl; secreted by parietal cells under stim by gastrin
Eg spinal nerve - cranial nerve; Not All Nervous Tissue In Brain - SC Is CNS Tissue
Hydrostatic pressure forces some plasma thru *fenestrations of the glomerular endothelium* and into Bowman's capsule; B.C. is continuous with lumen of nephron
28. Important aspect of crypt of Lieberkuhn - secreted intestinal juice
Contains lysozyme - which regulates bacteria within intestine; breaks down peptidoglycans (**bact wall); innate immunity
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
At metaphase II of meiosis II (halted during reductional division); if fertilized - process continues toward haploid gamete
Inner lining of circulatory system
29. 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)
Normally contracted
Zygote - morula (first four days) - blastocyst (4 day+; implants in uterine lining) - gastrula (2 week) - neurula (3 week)...
Lower blood pH
30. Sensory neuron cell bodies vs. somatic motor cell bodies
Peptides
Maintains hi estrogen levels; body does not recognize luteal surge - ovulation does not occur; hi progesterone can lessen shedding by thickening the uterine lining
Somatic sensory = dorsal root ganglia (outside spinal cord); somatic effector = ventral horns of spinal cord
Facilitated diffusion: no symport w/ secondary transport
31. Three stages of the menstrual cycle
'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
Follicular (proliferative)= 8d - Luteal (post - ovulation; corpus luteum secretions)= 13d - Menstruation (shed uterine lining if no implantation)= 5
90-140 mg/dl
Oxidizes macromolecules; breaks down very long - chain FAs by beta - oxidation; products (acetyl - CoA) are shuttled to mitochondrion for citric acid cycle
32. Where do pancreatic secretions take effect
Digestion
RBCs - large proteins; What does enter is called the filtrate
On the chyme exiting the stomach and entering duodenum thru the pyloric sphincter
Sorts - modifies - concentrates proteins from the ER
33. What testosterone released by secondary follicle by LH stim is converted to...
Pancreatic duct (made of acinar cells?)
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)
Interstitial fluid (eg prostaglandins - cytokines)
Estradiol (estrogen - steroid horm); prepares uterine wall for pregnancy; just before ovulation - release of estradiol stims LH in pos feedback
34. How does blood sugar move into tissues?
Formed in kidney (nephron) - sent thru renal pelvis - down ureter to bladder - drained by urethra'
CARB- Digesting: dextrinase (polysachs produced by hydrolysis of starch) - maltase (glucose - glucose) - sucrase (glucose - fructose) - lactase (galactose - glucose) - Protein- Digesting: peptidases - NUCLEOTIDE- Digesting: nucleosidases
Facilitated diffusion from hi to lo conc
- 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
35. How does water cross the apical membrane
Liposome has phospholipid bilayer
Thru tight junctions by favorable osmotic gradient
Normally contracted
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
36. What are the major carbohydrates
Gonadotropin releasing hormone - GnRH
sucrose (gluc+fruc) - lactose (gluc+galactose) - starch (gluc+gluc)
Paracrine (local) - endocrine (longer distance)
Number of centromeres - Not number of chromatids eg - two sister chromatids connected by one centromere = one chromosome
37. Where does fertilization occur
Fallopian tubes
Reconstituted into TAGs at smooth ER; first stop for most digested fat is liver
ER
Moves thru lymph sys; emptied into large veins (thus into bloodstream) of the neck at Thoracic duct
38. fructose enters enterocyte by
Salivary amylase; both hydrolyze glycosidic linkages
It is the animal counterpart of starch; it is more highly- branched - thus releases more glucose monomers upon repeated hydrolysis than starch
Facilitated diffusion: no symport w/ secondary transport
After morula - with blastocyst (+8 cell count)--->totipotent to embryonic stem cell and so on
39. Beta - oxidation in liver produces...
Ketone bodies; thus excessive reliance on fat for energy (eg low carb diets) results in ketosis; blood acidity increases
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
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
Nervous - muscle - epithelial (defines inner/outer) - connective (extensive matrices)
40. week three: neurulation; mesoderm induces ectoderm; thus - NEURULATION INVOLVES SC Development - at week three
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
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
Notochord (mesoderm) induces ectoderm to thicken into neural plate --->neural tube --->spinal cord
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
41. PNS nerve signal
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
Glucose = aldose fructose = ketose
Ups bicarbonate secretion by pancreas; raises pH to 6.0
Reconstituted into TAGs at smooth ER; first stop for most digested fat is liver
42. What force is acting upon chyme to move it forward down sm intestine
To the organelle w/ lumen: smooth ER; they are resynthesized into TAGs
Alpha cells; stims gluconeogenesis in liver; acts via cAMP second messenger
Peristalsis (esophagus) and segmentation (bi - directional=mixing)
PNS- Somatic - afferent (dorsal root ganglion) + efferent (ventral horns) PNS- ANS- afferent (sensors on viscera) + SYMP - PARA pre - post - ganglionic neurons
43. mucus cells line the stomach...
Posterior pituitary hormone; acts on uterus - mammary glands; causes uterine contractions - milk ejection
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
Sudiferous (sweat) - sebaceous - digestive (bile - pancreatic enzs) - mucosal
Conjunction of cell body w/axon
44. What hormones affect the stomach?
5
Fructose is a structural isomer of glucose
Micelles; micelles (made of bile) go back and forth between brush border and chyme
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
45. Alpha - amylase found where
Fallopian tubes
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
In mouth - breakdown of starch into polysaccharides
Meiosis creates germ cells
46. Human chorionic gonadotropin...
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
Secreted by implanted egg; HCG prevents degeneration of the corpus luteum; HCG in blood/urine is first sign of pregnancy
Eukaryotes
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
47. what else is located in the inner ear (not directly related to auditory)
Two perpendicular semicircular canals involved in balance - equilibrium
Mostly reabsorbed to liver
Membrane - bound - endocytosed bodies
Liver is the control center for blood glucose; is fed by portal vein from sm intest
48. Think of spinal cord injury
Nervous - muscle - epithelial (defines inner/outer) - connective (extensive matrices)
Systems (eg digestive system consists of many organs)
Injury that does not sever SC (causes deep lesion from back - front) might cause loss of feeling without full loss of motion
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
49. At post - two weeks ovulation
Secondary follicle: Theca cells differentiate from interstitial tissue - surround follicle - secrete testosterone when stimd by LH (compare to Leydig cells)
Sorts - modifies - concentrates proteins from the ER
Corpus luteum degrades into corpus albicans
Below hypothalamus
50. Gastrulation: ectoderm/mesoderm/endoderm
Ectoderm: outer coverings - nervous system Mesoderm: between covering ie musc - bone - etc - endoderm: digestive tract - viscera
Glucose and ketone bodies (not from glycogen stores)
At metaphase II of meiosis II (halted during reductional division); if fertilized - process continues toward haploid gamete
Has memb - bound organelles - etc...