MCAT Bio Charts.docx

Eyes Ear Muscle Skin Stomach Light sensitive cells of the retina: Photoreceptor cells Rodes: transmit info about contrast Cones: color Photosensitive retinal ganglion cells: pupillary reflex and circadian rhythm Myopia (Nearsightedness) Inability to focus on distant object Vestibulo-ocular reflex Al...

Eyes Ear Muscle Skin Stomach Light sensitive cells of the retina: Photoreceptor cells Rodes: transmit info about contrast Cones: color Photosensitive retinal ganglion cells: pupillary reflex and circadian rhythm Myopia (Nearsightedness) Inability to focus on distant object Vestibulo-ocular reflex Allows the body to stabilize images on the retina in moments of head movement Ex: Watching a tennis match Most active in situations in which one is moving their heads and attempting to usually view something simultaneously Lens and Ciliary Muscle Help focus light onto the retina Iris & Pupil Controls the amount of light that enters the eye Sclera & Cornea Outermost layer and transparent part of the eye Protect the inner structures of eye and help maintain shape Rodes & cones Are responsible for the transduction of visual stimuli in the eye Accommodation Lens of the eye must be able to change its shape in order to refocus the vision on near or far objects as the eye moves Mydriasis Dilation of the pupil Convergence Ability of the eye to move towards one another in order to focus an object that are very close up Contrast Quality of different in color or brightness of object Fovea Highest visual sharpness Have many cons Otolith Structure of the saccule of the inner ear that enhances sensitivity to changes in horizontal movement and vertical acceleration Saccule Small membranous sac in the vestibule of the inner ear that plays role in interpreting linear acceleration (upward and downward motion) Inferior colliculus Located in the midbrain Play role in sound localization, auditory freq determination, integration of auditory and nonauditory structures Medial geniculate nucleus Relay center b/w the inferior colliculus and auditory cortex In the thalamus Malleus Middle ear structure Plyas a role in transmitting sound waves from the tympanic membrane to inner ear Auditory Nerve Terminates in the cochlear nucleus of the brainstem Tympanic membrane (Ear drum) Middle ear Structure b/w the outer and middle ear that vibrates in response to sound waves Sound waves hit the TM, causing it to vibrate and these vibrations transfer to the ossicles in the middle ear Organ of Corti Plays role in the transduction of sound waves into electric impulses Vestibule Sends signal to the brain regarding the org. changes in position and velocity, contribute to postural equilibrium Auditory ossicles Middle ear Malleus: When sound hit the TM, it vibrates, causing the malleus, to vibrate Incus: Vibrates travel down the incus and stapes to the cochlea by the oval window which connects the stapes and cochlea Stapes How sound travels? Pass thought the tympanic membrane Through the auditory ossicles Through the oval window arriving at the inner ear Sound waves interact with the hair cells of cochlea before being converted to electrochemical signals that the brain can interpret Auditory Transduction Refers to the process in which the ear convert sound waves into electrical impulse that the brain can interpret Auditory Canal Part outer ear, help amplify sound Rhythm detection Occurs in the auditory cortex Vestibular nerve Innervates the vestibular system within the inner ear, contributes to balance and orientation Cochlear nerve Innervates the cochlear which plays a role in hearing Vestibular System Vestibular nerve and Cochlear nerve merge Cranial nerve 8 which travels to the brain Inner ear Saccule, utricle, semi circular canals Basilar membrane Pitch perception, is enabled by physical variation Tectorial membrane Role in the transduction of sound waves to electric impulses Semicircular canals Play role in maintaining balance and orientation Ossicles Transmit vibrates that will ultimately be perceived as sound 3 bones: malleus, incus, stapes Oval window Middle ear It is a membranous covering the entrance to the cochlea Pinna Visible part of outer ear Organ of Corti The main sensory organ for hearing with the cochlea Sound waves Sound waves moves the outer ear causing the tympane mem to vibrate to the ossicles then to the inner ear Dichotic listening task Involves presenting different auditory stimuli to each ear Smooth Muscle Lines the walls of most blood vessels Spindle- shape cells, centrally located nucleus Non- striated Uninucleate Skeletal muscle Striated multi-nucleated Cardiac Muscle Striated Uninucleate Function of Ca2+ Binds to troponin causing tropomyosin to exit the myosin binding site of actin Increase Muscle contraction Decrease transport of Ca2+ to the extracellular environment. Increase availability of intracellular Ca2+ to bind to troponin. Increase overall Ca2+ stores in the sarcoplasmic reticulum. Z-lines (zig-zag lines) Define the Merkel Cells Skin cells involved in sense of touch and are found in the epidermis Chief cells Produce pepsinogen Parietal cells HCl, digestive E G cells Gastrin Thrombin Clotting Factor Mitosis and Meiosis Hormones Carbs Cell Signaling/ Communication Genetics Crossing over Take place b/w chromatids on separate chromosomes Genes that are link often cross over together Anaphase I Homologous chromosomes separate, during anaphase 2, sister chromatids separate Meiosis Contributes to genetic diversity through independent assortment, crossing over and random fertilization LH Directly inc. testosterone Ovulation in female Testosterone Aid in 2nd sexual characteristics Estrogen Dec. estrogen will cause the Pit. To release more LH and the LH will cause the ovary to release mote estrogen Progestogen Inc. progestogen will inhibit the Pit. Causing an dec. in LH and FSH Prolactin Milk Production Oxytocin Milk Ejection Contractions Parathyroid Hormone Inc. blood Ca2+ level Calcitonin Secreted from the thyroid gland Dec. blood Ca2+ levels Calcitriol is the most active from of Vit D and stimulates intestinal Ca2+ absorption Erythropoietin (EPO) Water- soluble horm. That stimulates RBC production in the bone marrow Syn. & secreted from the kidney Leptin Cause you to feel full Ghrelin Cause you to feel hungry ADH Cause upregulation of aquaporin channels within the collecting ducts Creating urine that low in volume but highly concentrated Somatostin D cells Inhibit the effects on the functioning of the digestive system Stress Cause Epi to inc. BP and glucose Suppress TSH Cause inc. in ACTH, cortisol Estradiol Responsible for 2nd sexual charactertics breast and bone maturation Steroid Horm Are syn. From cholesterol No 2nd messenger Peptide Horm Syn. From aa Bind form receptors on the extracellular side of plasma mem. induce a 2nd messenger cascade Tropic horm Solely released by the A Pit. And responsible for controlling the production of other horm in endocrine glands Glycosidic Bonds Joins carbs to other moles. O- glycosidic covalent link b/w carbs protein, joining OH and sugar N- glycosidic link joining amide and sugar Linkages Starch: a- 1,4 linkage Glycogen: a- 1, 6 linkage Cellulose: B- 1, 4 linkage Juxtracrine Involves direct contact b/w adjacent cells Paracrine Within short range of distance, interferons Endocrine Uses the bloodstream to transport signaling Autocrine Signaling b/w same cells Endocrine glands Release horm. Directly into the blood, has high level of specificity Exocrine glands Release substances into through ducts onto body surfaces Ex: salivary glands & sweat glands Bottleneck Genetic diversity of a pop change suddenly, dec. the number of reproducing individuals An even that reduce size of a pop, leading to dec. number of reproducing individuals Ex: natural disasters Genetic drift Random chance fluctuation due to explainable event Leads to fixation or loss of alleles contributing to genetic diff b/w pop Genetic selection Certain genes become more prevalent in species over time Group selection Refers to the idea that natural selection can act on grp of org rather than a single org. Fisherman selection Sexual selection in which females purposefully mate with males with more desirable appearances despite these traits not being inherently beneficial Incomplete Dominance Occurs when the presence of 2 alleles for a gene results in blended phenotype Ex: Gray fur Co-dominance White and black fur Epigenetics Reversible genetic changes that do not alter the DNA sequence Changes are largely carried out through methylation and deacetylation causing dec. transcription of a gene Demethylation and acetylation causes inc. transcription of a gene Convergent evolution The process whereby distantly related organism independently evolve similar traits to adapt to similar needs Sexual selection Favors traits that inc. an org. chances of attracting mate and reproducing Kin selection Focuses on the role of genetic relatedness in the evolution of social behaviors Ex: Org are more likely to help close relatives, inc. the chances of their shared genes being passed on to future generations Artificial selection Process by which humans selectively breed org with desirable traits to produce offsprings Specialization Development of unique adaptations in response to specific environmental conditions or resources Can lead to divergence of pop a they adapt to diff niches Differential reproduction Variation in reproductive success among indiduals w/in a pop due to diff traits that affect reproduction and survival Sympatric speciation Formation of new species w/out geographic isolation Usually due to reproductive isolation Allopatric speciation Occurs when pop becomes geographically isolated from on another Gene pool Total collection of alleles in a pop Genetic diversity Variety of alleles w/in a pop gene pool. Contribute to pop ability to adapt to changes in environment Random mutation Changes in genetic, material that can introduce new alleles into a pop, inc. genetic diversity Emigration Movement of indivulas out a pop, dec. genetic diversity by removing individuals and their unique genetic material Outbreeding Mating of unrelated ir distantly related indivudlas which help maintain and inc. genetic diversity by producing offsprings with higher hetero genotypes Mendel’s Law of segregation Alleles are randomly sep. to the sex cells so that sex cells contains only one gene of the pair Law of dominance Org with alternate forms of gene will express the dominant gene Law of indenpent assortment The inheritance of one trait is not dependent on the inheritance of another Occurs in Metaphase I Mendelian inheritance Idealized form of inheritance which assume that each trait is controlled Male Reproduction System Female Reproduction System Post- translational Modification Membrane Functions Types of Receptors Seminiferous tube Produce sperm and store it Epipdymis Transport sperm and sperm matures Vas deferens Transport mature sperm to urethra Ejaculatory duct Delivers the sperm Nothing Urethra Penis Seminal vesicles Produce fluid part of the semen Spermatogenesis Form mature sperm Testes Sperm is produce here Ureter Directly connect to renal pelvis Uterus Protects and nourishes developing embryo and fetus Layers: Endometrium: inner lining Myometrium: layer of smooth muscle Cervix: connect to vagina Ovary Produces oocytes and secretes hormones Uterine (fallopian) tube Location of fertilization Phosphorylation When a phosphate grp of covalently attached to a protein Glycosylation (Carb) When carbs grp covalently attached to the protein Liquidation Addition of lipid grp Proteins that undergo this process get anchored to the membrane Ubiquitination When a ubiquitin is covalently attached to the amine grp of Lys This makes the protein for degradation by the proteasome DNA Methylation The addition of methyl grp to a DNA molecule, leading to repression of transcription Glycoproteins Mole. In plasma mem. that play role in maintaining the mem. integrity and generating immune response Sulfolipids Play role in photosynthesis and are only present in mem. of plants Vertical diffusion The movement of mole. From on leaflet to another in cell membrane Less common Lateral diffusion Movement of mole. Within a single leaflet of lipid bilayer of cell mem. Energetically favorable, does not require energy Fippases & Floppases Move of phsoplipids in only a single direction and are ATP dependent Flip: movement from outer to inner mem Flop: movement from inner to outer Scramblases Are ATP- independent E that moves phospholipids from the inner leaflet of cell mem to the outer leaflet of the mem. while moving phospholipids from the outer to inner leaflet Aquaporins Open channels that allow water to move passively across the mem. Cell resting membrane potential is negative Interceptors Detect stimuli coming from the internal organs and blood vessels Gustatory chemoreceptors Located in taste buds of the tongue and response for sense of taste Baroreceptors Responds in changes to blood pressure and blood pressure Proprioceptors Involved in the perception of body position and movement Nociceptor Responsible for detching harmful stimuli high temp, sharp objects, tissue damage Osmoreceptors Sensitive to changes in con. Of ions in body fluids such as blood Regulating thirst and the secretion of ADH Photoreceptors Responds to light and are found in retia if eye Chemoreceptors Changes in the con. Of ions or molecules Mechanoreceptors Sensory receptors that responds to mechanical forces, vibrations and pressure changes Types of Scans Cell to Cell Junctions Reflexes DNA, RNA Immune System MRI Reveal images of anatomy EEG Electrical activity in the brain CT scans Anatomy PET scans Reval info about metabolic activity Desmosomes Serve to strengthen cell- cell connections by binding the cytoskeleton of adjacent cells Cadherins Ca2+ dependent transmembrane glycoproteins that medicate cell- cell adhesion by binding to cadherins on other cells Gap junctions Are incerecellar junctions that allow for rapid exchange of ions and small mole. b/w adjacent cells Ex: Cardiac Cells Tight junctions Prevent the leakage of small mole and ions b/w adjacent epithelial cells Prevent paracellular transport Hemidesmosomes Junction that attach cells to the extracellular matrix Babinski reflex Spreading of a baby toes and lifting of it big toe when the baby sole is stimulated Rooting reflex Baby head movement toward an object that stimulate it mouth and cheeks Palmar grasp reflex Grasping response that occurs when a baby palm is stimulated Moro reflex Exhibited by startled babies Extension and drawing in of the baby arm and legs, throwing back of the head, loud crying Ribosomes Large 60 40 80s Small 50 30 70s Ligases E that binds two DNA fragments, by phosphodiester bonds Primase Makes an RNA primer, to match a fragment of DNA at the beginning of DNA replication Helicase Separates the parent DNA double helix at the replication fork Topoisomerase Relieves the overwinding of DNA strands ahead of the DNA replication fork by breaking, swiveling and rejoining DNA strands Adaptative Immunity Dendric cell Immature B cells Langerhans cells Dendritic cells that are specialized immune cells in the skin and mucous mem. Capture antigens in skin and presents to T cells to initiate 6immune response Erythrocytes RBC Live for 120 days Megakaryocytes Large cell found in red bone marrow that fragment to create platelets Hematopoiesis The body process of making RBC, WBC, platelets Erythropoiesis: RBC Leukopoiesis: WBC Thrombopoiesis: Platelets Plasma Contains clotting factors Kidney Nervous System Heart/ Lungs H+ Is absorbed in the distal tubules and collecting duct Regulating urine pH Nephrons Proximal tubules (PCT) Where Bicarbonate absorption occurs (h3CO+) Reabsorbs ions, H2O and nutrients Remove toxins Adjust filtrate pH Part of the renal cortex Distal tubules (DCT) Secretes and absorbs ions to maintain blood pH and electrolyte balance Aldosterone binds and act on Part of the renal cortex Glomerulus Filter small solutes from the blood Part of the Renal Cortex Descending Loop of Henle Aquaporins allow for water to pass from filtrate into the interstitial fluid Ascending Loop of Henle Reabsorbs Na+ and Cl- from filtrate into interstitial fluid Collecting duct Reabsorb solutes and water ADH act on Urine will be max concentrated Loop of Henle In the Medulla Renal Medulla Renal pyramids Renal afferent arteriole Towards the glomerulus Renal efferent arteriole Away from the glomerulus Function ADH Upregulation of aquaporins in the collecting ducts Inc. permeability of CD by upregulating aquaporins which leads to an inc. in reabsorption of water back into bloodstream Dec. urine volume and blood osmolarity Inc. blood volume and BP If ADH is deficient the body would not be retaining adequate amount of water, leading to excessive thirst Aldosterone Low levels would lead to Na+ reabsorption Notes Inc Pressure & Inc. force which Inc. Filtration & Inc. Reabsorption Hyponatremia Blood Na+ levels are too low Hypokalemia K+ Levels are low Hypervolemia Blood plasma has to much fluid Enteric NS Responsible for the involuntary control of gastrointestinal functioning Somatic NS Associated with voluntary control of body movements through stimulation of the skeletal muscle Parasympathetic NS Has long preganglionic fibers that synapse close to the effector organ, short postganglionic fibers Sympathetic NS Part of the automatic response to danger Inc. HR and BP Dilates blood vessels in muscle Constrict blood vessels in gut Autonomic NS Controls the secretion of both the endocrine and exocrine glands Ex: Lung, heart, pancreas Pulmonary Veins Undergo gas exchange in the lungs, resulting in the removal of CO2 and O2 to the blood Carry O2 from the lungs to LA Pulmonary Artery Carries dO2 blood from the RV to the lungs for oxygenation Lowest blood pressure Carotid artery Carry O2 blood from the aorta to head and neck Renal artery Carry O2 blood from aorta to kidney PCO2 Higher in the veins than in the arteries b/c the veins carry blood that has already circulated through the tissue and picked up CO2 LV Receives blood from the LA and Pumps blood into the aorta RA Receives blood from the superior vena cava ( deoxygenated) LA Receives oxygenated blood from the pulmonary vein (lungs) and pumps to LV RV Receives blood from the RA Aorta Carries O2 blood from the LV to rest of body Arteries Carry O2 blood away from the heart and distribute in to the body and tissue and organs Can with stand high pressure Capillaries Which are the smallest blood vessels where exchange of O2, nutrients and waste product occurs b/w blood and tissue Veins Carry blood back to the heart and have thinner walls and lower pressure that arteries Venules Small veins that collect blood from capillaries and transport it to larger veins Arterioles Smallest branches of arteries that help regulate blood flow and pressure by dilating and constricting Inhalation Diaphragm contracts to inc. the lung volume, generating a pressure gradient that draws in air from the environment Dec. pressure in chest cavity Exhalation Diaphragm relax Lung volume dec. Inc. pressure within the lungs to the point to where air id forced out Elastic recoil of lungs O2 Inc. temp results in an dec. binding affinity of Hb for O2 Responses to body temp Inc body temp includes sweating and vasodilation of surface capillaries Dec. body temp includes shivering and vasoconstriction of surface capillaries Hematocrit The volume % of RBC in the blood Replication, Transcription, and Translation Prokaryes, Virus Receptors Feedback Loops Action Potential Stop Codons UAG UAA UGA Anticodons AUC AUU ACU DNA Polymerase Responsible for proofreading the DNA seq during replication Recombinase Catalyases genetic recombination Translation Initiation factors: grp of protein that align mRNA, tRNA, and ribosomes for translation Sites of Translation A site Aa-bound tRNA enters the site a very beginning of translation P site Where tRNA remain attached to the elongating peptide chain E site Exit site The site where tRNA enters after aa has been added to peptide chain Types of Bacteria Bacilli: rod shaped Spirilla: spiral shaped Cocci- spherical shaped Structure of virus Nucleic acid and capsid: protein Nucleic acid generic material Capsid surrounds material Enveloped viruses Have lipid membrane Notes Receptor shape is Responsible for specificity G-protein linked receptors Have cAMP as 2nd messenger Transmembrane protein (7) Ligand + GPCR-> exchange of GDP for GTP -> dissociate from the heterometric G- protein a subunit hydrolyzes a subunit will then activate adenylate cyclase-> ATP to CAMP -> inc. cAMP levels cAMP will activate protein Kinase A PKA phosphorylates other protein After signal have been successfully transduced, phosphodiesterase catalyzes the cleavage of cAMP to AMP, restore baseline of cAMP Positive feedback Loop Occurs when a later part of the pathway stimulates an earlier part of the same pathway Encourage deviation from the mean value Less common in the human body Ex: Release of oxytocin Ex: Transcription of gene causes the production od transcription factors for that gene Negative Feedback Loop A later part of pathway inhibits an earlier part of pathway Help maintain homeostasis Ex: Assume that Ex is activated by cAMP, Ex inhibits the production of cAMP Resting Membrane Potential -70mV Voltage- gated Na+ open -55mV Voltage- gated K+ open +30mV Hyperpolarized -90mV All or None Phenomenon A threshold and a suprathreshold stimulation produce the same magnitude of the AP Suprathreshold- above threshold Stimulus produces the same magnitude AP as the threshold b/c the AP is all or nothing Subthreshold- below threshold Summation of impulse Occurs when excitatory impulses add together to reach the threshold to fire a neuron Temporal summation The effects of impulse received at the same place can add up if the impulse are received in close temporal succession Spatial summation Adding up the impulses received at different locations on one neuron Myelin Sheaths Allo the AP to take on a salatery conduction NMDA receptors glutamate-responsive ion channels that promote action potential formation upon activation increased expression of NMDA receptors in the hippocampus will increase the likelihood of action potential formation, increasing excitability. Cell Types Mutations Neurons/Neurotransmitter Goblet cells are specialized epithelial cells that produce mucus in the respiratory tract Pneumocytes II are another type of specialized epithelial cells that produce surfactant in the lungs. Frameshift mutation insertion or deletion of bases that result in shifting the reading frame Inversion Mutation involves flipping a chromosomal segment Translocation movement of a chromosomal segment to another chromosomes Beneficial mutation tend to accumulate in species during the course of evotion by natural selection Deleterious mutation tend to get eliminated over period of time Neutral mutation don’t causes any change in a species Somatic Mutations not carried forward from on generation is another Transition Mutation a point mutation that changes a purine nucleotide to another purine or a pyrimidine nucleotide to another pyrimidines Transversion Mutation change a purine to a pyrimidine Dendrites function is to receive AP from other neurons, direct impulse Axons Extends from the axon hillock Conducts impulse away from the cell body Have many branches, have 1 or more side branches called axon collaterals Are wrapped in myelin sheaths, insulating fats Myelin Sheath Prevent signals loss by insulation Nodes of Ranvier Allow AP to travel quickly through the axon Neurotransmitter The release of NT occurs from the presynaptic mem There is a diffusion of NY into synaptic cleft NT binds to the receptors present on postsynaptic mem