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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. from thoracic duct - chylomicrons stick to capillary walls...
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)
Prophase II: no crossing over b/c there are no homologous chromosomes; nuclear envelope dissolves Metaphase II: chromosomes line up at metaphase plate Anaphase II: sister chromatids separate - migrate to opp poles Telophase II: nuclear envelope reap
Somatic nervous sys - autonomic nervous sys

2. parathyroid hormone
cornea (1.4 refractory index; bends light) - pupil (size of pupil is determined by contraction state of the iris) - aqueous humor
Glands w/ducts: Exocrine glands
Di - tri - peptides; inside enterocytes are hydrolyzed to amino acids
Increases blood Calcium

3. Bile salts and lipase
Reconstituted into TAGs at smooth ER; first stop for most digested fat is liver
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
Meiosis creates germ cells
Oxidizes macromolecules; breaks down very long - chain FAs by beta - oxidation; products (acetyl - CoA) are shuttled to mitochondrion for citric acid cycle

4. What is feces composed of...
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
Meiosis creates germ cells
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
Gonadotropin releasing hormone - GnRH

5. Determination is different than differentiation
Determination is a pre - programmed fate - differentiation is the actual materialization of that fate
Prophase I: crossing over occurs; nuclear envelope is absorbed into ER; chromosomes condense)
On to the distal tubule where sodium - calcium are reabsorbed - protons - bicarbonate - potassium are secreted via membrane transport proteins
Estradiol (estrogen - steroid horm); prepares uterine wall for pregnancy; just before ovulation - release of estradiol stims LH in pos feedback

6. FLAT PG: prolactin
Peptide; prolactin promotes milk production; prolactin release is stimulated by act of suckling - which in turn inhibits menstrual cycle
Renal pyramids --->renal calyx-->renal pelvis -->ureter -->urethra
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
Membrane - bound - endocytosed bodies

7. hypothalamus - AP - ACTH - cortisol release from adrenal cortex
Result: stress reaction; increase glycogenolysis - gluconeogenesis; fat/prot breakdown; increase blood glucose
Number of centromeres - Not number of chromatids eg - two sister chromatids connected by one centromere = one chromosome
Carry signals to musc OR Gland
Alpha cells; stims gluconeogenesis in liver; acts via cAMP second messenger

8. Fructose relates how structurally to glucose
From lumenal (apical) to enterocyte to basolateral side of epithelial tissue
An endogenous morphine
Carry signals to musc OR Gland
Fructose is a structural isomer of glucose

9. lysosome pH
Sympathetic: dilates pupil (for night hunting)
5
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
Trypsinogen is activated by enterokinase in the brush border; in turn - it activates other enzymes

10. Local vs long - distance mediators
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
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
Peripheral nervous sys
Paracrine (local) - endocrine (longer distance)

11. Thus inhibiting parietal cells could do What to blood pH
Liposome has phospholipid bilayer
Small amounts of hydrolyzed phospholipids and cholesterol: like other fat mols these can diffuse thru enterocyte membrane
Lumen (ie continuous w/body cavity) and cytosol
Lower blood pH

12. Chewing does what?
Increases surface area of food ball (bolus)
Increases solute conc and osmotic pressure of the ***medulla
Where lipoprotein lipase hydrolyzes TAGs; products diffuse into target tiss (mostly liver - adipose tissue)
Contain capillary network - lymph vessels (lacteals)

13. 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
HCl; secreted by parietal cells under stim by gastrin
Glucocorticoid (cortisol); mineralocorticoid (aldosterone)
Oxidizes macromolecules; breaks down very long - chain FAs by beta - oxidation; products (acetyl - CoA) are shuttled to mitochondrion for citric acid cycle

14. Creating gradients requires what?
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
Can be saturated; conc of a solute is called the transport maximum --->excess goes into urine
Secreted by delta cells of Islets of langerhans; inhibits insulin and glucagon; slows digestion
Glands w/ducts: Exocrine glands

15. FLAT PG: TSH aka thyrotropin
Night vision
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
Lysosome
Liposome has phospholipid bilayer

16. fat digestion is time - intensive
Primitive streak - which consists of cells of the MESODERM ****
Know that 90% digestion - absorption occurs in sm intestine --> fine breakdown of carbs - fat - prots
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
Needs time for bile - lipase - micelle migration - enterocyte uptake

17. Liver Functions
Lower blood 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
Thru tight junctions by favorable osmotic gradient
Facilitated diffusion: no symport w/ secondary transport

18. signal transduction occurs by 2 paths
1) by integral ion channels 2) transmitted by second messenger system
Below hypothalamus
Alpha cells; stims gluconeogenesis in liver; acts via cAMP second messenger
Alpha 1-4 and 1-6 (branching) glycosidic linkages

19. what cannot cross the fenestrations of the renal corpuscle
**only para effectors have muscarinic receptors; symp effectors are adrenergic (epi - norepi); **neuromuscular junction uses nicotinic receptors
Where lipoprotein lipase hydrolyzes TAGs; products diffuse into target tiss (mostly liver - adipose tissue)
RBCs - large proteins; What does enter is called the filtrate
Ketone bodies; thus excessive reliance on fat for energy (eg low carb diets) results in ketosis; blood acidity increases

20. duodenum must have receptors for fat content - protein because
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
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
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
Abdominal cavity - which is coated in serous fluid

21. Human chorionic gonadotropin...
Form barrier to extracellular fluid
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
Secreted by implanted egg; HCG prevents degeneration of the corpus luteum; HCG in blood/urine is first sign of pregnancy
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

22. remaining secondary follicle becomes
Corpus luteum; secretes estradiol - progesterone throughout pregnancy OR if no pregnancy - for about 2 weeks (till menstruation = shedding of uterine lining)
cornea (1.4 refractory index; bends light) - pupil (size of pupil is determined by contraction state of the iris) - aqueous humor
Membrane - bound - endocytosed bodies
Conjunction of cell body w/axon

23. in the dark is rhodopsin active or inactive?
Uncontracted: parasymp (eg opoid use)
Secreted by delta cells of Islets of langerhans; inhibits insulin and glucagon; slows digestion
Inactive: rhodopsin is activated by photons; activated rhodopsin hyperpolarizes rod cells - causes photobleaching
Monitors filtrate pressure in the distal tubule; has specialized cells (granular cells) that secrete an enzyme (**renin); renin initiates regulatory cascade that produces angiotensin I - II - III that stim adrenal cortex to secrete aldosterone... ...

24. serous membranes have a viscera - facing layer and a body wall - facing layer
Visceral layer= parietal layer; serous membrane is the container of the coelom/peritoneal cavity
Ganglion
Eg spinal nerve - cranial nerve; Not All Nervous Tissue In Brain - SC Is CNS Tissue
An endogenous morphine

25. 'Cell bodies of somatic motor neurons are located in....'
Spinal cord ventral horns; somatic motor neurons use acetylcholine for NTs (voluntary)
At the collecting duct: becomes more permeable to water which passively diffuses *into the medulla* concentrating the urine
Buildup of macromolecules in lysosome due to deficient lysosome enzymes
Interneurons working to integrate signals received from the peripheral nervous system (sense organs)

26. calcitonin

27. What is a nerve? (PNS)
Peptides
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
Form barrier to extracellular fluid
- 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

28. What is secreted into filtrate by cells of the proximal tubule?
Organs
Sorts - modifies - concentrates proteins from the ER
Drugs - toxins - bile pigments (color the urine) - uric acid - antibiotics
Protein digestion begins in stomach; low pH denatures proteins - kills bacteria; mixes - stores food and destroys it to chyme (BOLUS-->CHYME)

29. protein absorption at enterocyte
After morula - with blastocyst (+8 cell count)--->totipotent to embryonic stem cell and so on
Calcitonin (peptide; lowers blood Ca); T3/T4 (tyrosine - derived; increase basal metabolic rate); T4= thyroxine
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
Contain capillary network - lymph vessels (lacteals)

30. main point of fat transport...
Homologous chromosomes separate - migrate towards opposite poles/centrioles
Fat is insoluble in blood and requires a carrier like lipoproteins (vLDL...HDL) or albumins; ...vLDL has hi triglycerides - hi cholesterol
Fat synthesis; carbs stored as free fatty acids - esterified to TAGs (requires small amount of E)
Hydrostatic pressure forces some plasma thru *fenestrations of the glomerular endothelium* and into Bowman's capsule; B.C. is continuous with lumen of nephron

31. Mucus - digestive enzymes released thru
Normally contracted
The crypts of Lieberkuhn: sm intestine pH is not right; brush border enzs won't work right
FAT=9 cal per gram Carbs=4.5 cal per gram - Prot=4 cal per gram - these seem to be for anhydrous forms
Glands w/ducts: Exocrine glands

32. What are the memb - bound enzymes of the brush border?
CARB- Digesting: dextrinase (polysachs produced by hydrolysis of starch) - maltase (glucose - glucose) - sucrase (glucose - fructose) - lactase (galactose - glucose) - Protein- Digesting: peptidases - NUCLEOTIDE- Digesting: nucleosidases
Ectoderm: outer coverings - nervous system Mesoderm: between covering ie musc - bone - etc - endoderm: digestive tract - viscera
Renal pyramids --->renal calyx-->renal pelvis -->ureter -->urethra
Monitors filtrate pressure in the distal tubule; has specialized cells (granular cells) that secrete an enzyme (**renin); renin initiates regulatory cascade that produces angiotensin I - II - III that stim adrenal cortex to secrete aldosterone... ...

33. peroxisome is derived from this
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
Prophase I: crossing over occurs; nuclear envelope is absorbed into ER; chromosomes condense)
ER
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

34. How does the body mobilize fat stores
Vitamin K - b12 - thiamin - riboflavin
sucrose (gluc+fruc) - lactose (gluc+galactose) - starch (gluc+gluc)
***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
Meiosis creates germ cells

35. In general - parietal=
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
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
Homologous chromosomes separate - migrate towards opposite poles/centrioles
The wall of the body or of a body cavity or hollow structure

36. What is a toxic byproduct of gluconeogenesis from proteins
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
TAGS--->FFAs; remember that FFAs are broken down for energy in mito matrix by beta - oxidation
Ammonia; must be converted to urea by liver and excreted in urine by kidney
Adrenal gland -- AC: steroids (cortisol - aldosterone); AM: catecholamines (epi - norepi); Islets of langerhans: peptides (insulin/glucagon) ANTAGONISTS: calcitonin (thyroid - peptide lowers Ca in blood); parathyroid hormone - peptide - vitamin D pat

37. food in duod stims release of gastrointestinal hormones
Gall bladder - pancreatic secretions increase - arrive via ampulla of vater (duct glands); insulin secretion increases (fed state; ductless glands)
Cancer; apop can be programmed cell death; mitochon can play important role in apop
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
(haploid organism) many fungi and protozoa; individuals are typically haploid; fertilization may occur with immediate meiosis back to haploid state

38. After meiosis II - Female

39. Where does fertilization occur
Pancreatic duct (made of acinar cells?)
Fallopian tubes
Fovea (highest amount of cones)
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

40. Spinal cord horns (thick knobs) point
Mouth - esophagus - stomach - duodenum - jejunum - ileum - ascending colon - transverse colon - descending colon - sigmoid colon - rectum - anus
At the first capillary bed of the nephron called the glomerulus which is encased by ***Bowman's capsule
Visceral layer= parietal layer; serous membrane is the container of the coelom/peritoneal cavity
Ventrally (picture skeletal vertebrae)

41. Different organs working together
Systems (eg digestive system consists of many organs)
Serous membrane (slick - reducing friction) that forms lining of the coelom --> secretes lubricating fluid
Note: enteric= small intestine - double layer of peritoneum that suspends jejunum/ileum from posterior abdominal wall = connective tissue
Duodenum (wraps around pancreas; most digestion occurs here) - jejunum (pH 7-9; 2m) - ileum

42. What is the net effect of the distal tubule
Testosterone upon stim by LH
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
(haploid organism) many fungi and protozoa; individuals are typically haploid; fertilization may occur with immediate meiosis back to haploid state

43. After meiosis II - Male

44. When 'coumadin targets liver enzymes to act as anticoagulant'...
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
Ventrally (picture skeletal vertebrae)
It targets liver conc of prothrombin - fibrinogen etc
Diarrhea: excess water loss in feces; poor absorption of vitamins - minerals

45. Alpha - amylase found where
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
Can be saturated; conc of a solute is called the transport maximum --->excess goes into urine
ER
In mouth - breakdown of starch into polysaccharides

46. A pinpoint iris is contracted or uncontracted
At the first capillary bed of the nephron called the glomerulus which is encased by ***Bowman's capsule
Lysosome
Uncontracted: parasymp (eg opoid use)
Membrane - bound - endocytosed bodies

47. Cell bodies of SYMP postganglionic neurons lie far from effector...
Parathyroid hormone (peptide; increases blood Ca); thus - might increase osteoclast/decrease osteoblast activity
Sudiferous (sweat) - sebaceous - digestive (bile - pancreatic enzs) - mucosal
Glands w/ducts: Exocrine glands
Within the paravertebral ganglion - running parallel to spinal cord

48. oxytocin
Posterior pituitary hormone; acts on uterus - mammary glands; causes uterine contractions - milk ejection
Mouth - esophagus - stomach - duodenum - jejunum - ileum - ascending colon - transverse colon - descending colon - sigmoid colon - rectum - anus
Changes: volume of filtrate does not change: osmolarity of filtrate --->reabsorbed ions like sodium carry water across membrane
Testosterone upon stim by LH

49. Stomach has no lacteals
Hypothalamus --->AP--->target tissues eg TSH - thyroid - T3/T4 release - increase basal metabolic rate
Most absorption occurs in sm intestine
Within the paravertebral ganglion - running parallel to spinal cord
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

50. What is the endothelium?
Number of centromeres - Not number of chromatids eg - two sister chromatids connected by one centromere = one chromosome
CARB- Digesting: dextrinase (polysachs produced by hydrolysis of starch) - maltase (glucose - glucose) - sucrase (glucose - fructose) - lactase (galactose - glucose) - Protein- Digesting: peptidases - NUCLEOTIDE- Digesting: nucleosidases
'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
Inner lining of circulatory system