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MCAT Prep Biology

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. The energy in a system that can be used to drive chemical reactions. If the change in free energy of a reaction (Delta G - the free energy of the products minus the free energy of the energy of the reactants) is negative - the reaction will occur spo






2. The liquid portion of blood; plasma contains water - ions - buffers - sugars - proteins - etc. Anything that dissolves in blood dissolves in the plasma portion.






3. A protein that is associated with the plasma membrane of a cell - but that is not embedded in the lipid bilayer. Peripheral proteins typically associate with embedded proteins through hydrogen bonding or electrostatic interactions.






4. Active transport that releies on an established concentration gradient - typically set up by a primary active transporter. Secondary active transport relies on ATP indirectly.






5. A genotype in which two identical alleles are possessed for a given gene. The allelles can both be dominant (homozygous dominant) or both be recessive (homozygous recessive)






6. A carrier protein that transports two molecules across the plasma membrane in the same direction. For example - the Na+- glucose cotransporter in intestinal cells is a symporter.






7. The period of time following an action potential when it is possible - but difficult - for the neuron to fire a second action potential due to the fact that membrane is further from theshold potential (hyperpolarized).






8. A type of synapse at which a chemical (a neurotransmitter) is released from teh axon of a neuron into the ysnaptic cleft where it binds to receptors on the next structure in sequence - either another neuron or an organ.






9. Something that works together with another thing to augment the the second thing's activity. For example - a uscle that assists another muslce is said to be a syngergist. An enzyme that helps another enzyme is a synergist.






10. A stack of membranes found near the rough ER in eukaryotic cells that is involved in the secretory pathway. The Golgi is involved in protein glycosylation (and other protein modification) and sorting and packagin proteins.






11. The bond formed between the carboxyl group of one amino acid and the amino group of another.






12. A type of syanpse in which the cells are connected by gap junctions - allowing ions (and therefore an action potential) to spread easily from cell to cell - usually in smooth and cardiac muscle. - compared to chemical synapse.






13. The portion of the ear consisting of the pinna and the external auditory canal. The outer ear is separated from the middle ear by the tympanic membrane (the eardrum).






14. In skeleta and cardiac muscle tissue - a filament composed of actin - tropomyosin - and troponin. Thin filaments are attached to teh Z lines of the sarcomers and slide over thick filaments during muscle contraction.






15. The membrane surrounding the DNA in eukaryotic cells made of two lipid bilayers.






16. The connection of a mosin head group to an actin filament during muscle contraction (the sliding filament theory).






17. A green fluid made from cholesterol and secreted by teh liver. It is stored and concentrated in the gallbladder. Bile isn an amphipathic molecule that is secreted itno the small intestine when fats are present - adn serves to emulsify the fats for be






18. Aso called a subcutaneous layer - this is a layer of *fat located under the dermis of the skin. The hypodermis helps to insulate the body and protects underlying muscles and other structures.






19. The most common class of bone in the body - long bones have a well - defined shaft (the diaphysis) and two well - defined ends (the epiphyses).






20. Very small air tubes int eh respiratory system (diameter 0.5 - 1.0 mm). The walls of the bronchioles are made of smooth muscle (thus involunatry) to help regulate air flow.






21. The newly forming daughter strand of DNA that is replicated in a continuous fasion; the daughter strand that is replicated in thes aem direction that parental DNA is unwinding.






22. A bacterial extrachromosal elent that allows the bacterium to initati conjugation. Bacteria that possess teh F factor are known as F+ 'males'.






23. Paired masses of lymphatic tissue near the back of the throat that help trap inhaled or swallowed pathogens.






24. The perio dof tim ein a woman's life when ovulation and menstruation cease. Menopause typically begins in the late 40s.






25. A blood pressure cuff






26. Also called falopian tubes - these tubes extend laterally from their side of the uterus and serve as a passageway for the ocyte to travel from the ovary to the uterus. This is also the normal site of fertilization. Severing of the uterine tubes (tuba






27. A nucleotide sequence that intervenes between protein - coding sequences. In DNA - these intervening sequences typically contain **regulatory sequences - however - in RNA they are simply spliced out to form the mature (translated) transcript.






28. Chemoreceptors in the upper nasal cavity that respond to odo chemicals.






29. A gene that has effects on several different characteristics.






30. Paired glands found on the posterior external wall of the bladder in males. Their secretions contain an alkaline mucus and fructose - among other things - and make up approximately 60% of the ejaculate volume.






31. Cranial nerve pair X. The vagus nerves are very large mixed nerves (They carry both sensory input and motor input) that innervate virtually every visceral organ. They are especially important in transmitting parasympathetic input to the heart and dig






32. An enzyme secreted by the juxtaglomerular cells when blood pressure decreases. Renin onverts angiotensinogen to angiotensin I.






33. A non - protein - but organic - molecule (such as vitamin) that is covalently bound to an enzyme as part of the active site.






34. The regino of the digestive tract where virtually al digestion and absorption occur. It is subdivided into three regions: the duodenum - the jejunum - and the ileum.






35. A portion of DNA that codes for some product - usually a protein - including all regulatory sequences. Some genes code for rRNA and tRNA - which are not translated.






36. A dense - hard type of bone constructed from osteons (at the microscopic level). Compact bone forms the diaphysis of the the long bones - and the outer shell of the epiphyses and all other bones.






37. An immune organ located near the heart. THe thymus is the site of T cell maturation and is larger in children and adolescents.






38. The second major node of the cardiac conduction system (after the SA node). The cardiac impulse is delayed slightly at teh AV node - allowing the ventricles to contract just after the atria contract.






39. The tubes that carry urine from the kindeys to the bladder.






40. The formatino of the nervous system during weeks 5-8 of gestation. Neuralation begins when a section of the ectoderm invaginates and pinches off to form the neural groove - which ultimately forms the neural tube - From which the brain and spinal cord






41. A hormone released by teh G cells of the stomach in the presence of food. Gastrin promotes muscular activity of the stomach as well as secretion of hydrochloric acid - pepsinogen - and mucus.






42. The membrane that separate the outer ear from the middle ear. The tympanic membrane is also known as the eardrum.






43. (1) In the GI tract - organs that play a role in digestion but not directly part of the alimentary canal. These include the liver - the gallbladder - the pancreas - adn the salivary glands.






44. Also called simply - 'islet cells' these are the endocrine cells of the pancreas. Different cell types wihtin the inslets secrete insulin - glucagon - and somatostatin






45. A peptide hormone produced and secreted by the alpha cells - of the pancreas. It tartes primarily the liver - stimulating the breakdown of glycogen - thus increasing blood gluocse level.s






46. Oil - forming glands found all over the body - especially on the face and neck. The product (sebum) is released to the skin surface through hair follicles.






47. Aromatic bases found in DNA and RNA that are derived from purine. They have a double rightn structure and include adenine and guanine.






48. The third phase of the ovarian cycle - during which a corpus luteum is formed from the remnants of the follicle that has ovulated its oocyte. The corpus luteum secretes progestrone and estrogen during this time period - which typically lasts from day






49. A hormone produced from vitamin D that acts in essentially the same manner as parathyroid hormone.






50. To attach oxygen - to remove hydrogen - or to remove electrons from a molecule.