ANATOMY & PHYSIOLOGY Chapter 03 PDF

BSNR TERM ANATOMY & PHYSIOLOGY 118 01 CHAPTER 3: CELL BIOLOGY...

BSNR TERM ANATOMY & PHYSIOLOGY 118 01 CHAPTER 3: CELL BIOLOGY FANTON VAN USED A MICROSCOPE TO OBSERVE LEEUWENHOEK LIVING CELLS (CELLS HAVE ORGANELLES) 3.1. FUNCTIONS OF THE CELL -COULD SEE GREATER DETAIL DUE TO BETTER LENSES MATTHIAS PROPOSED THAT PLANTS ARE MADE UP CELL BASIC PRINCIPLE SCHLEIDEN OF CELLS THEODOR CONCLUDED THAT ALL LIVING THINGS KINDS OF CELL SCHWANN ARE MADE UP OF CELLS ▪ THERE ARE 2 KINDS OF CELLS: EUKARYOTIC CELL AND RUDOLPH VIRCHOW PROPOSED THAT CELLS CAME FROM PROKARYOTIC CELL OTHER LIVING CELLS BY DIVISION ▪ ALL LIVING ORGANISMS IN THE KINGDOM OF LIFE ARE COMPOSED OF AND DEPEND ON CELLS TO FUNCTION CHARACTERISTICS OF CELL NORMALLY ▪ CONTAINS ORGANELLS TO CARRY OUT SPECIFIC FOUR COMMON COMPONENTS OF CELLS FUNCTION’CONTAINS DNA AND RNA A PLASMA MEMBRANE – AN OUTER COVERING THAT SEPARATES THE CELL’S INTERIOR FROM ITS SURROUNDING ENVIRONMENT KINGDOMS OF LIFFE CYTOPLASM – CONSISTING OF JELLY-LIKE REGION WITHIN THE KINGDOM ANIMALIA MULTICELLULAR EUKARYOTE CELL IN WHICH OTHER CELLULAR COMPONENTS ARE FOUND KINGDOM PLANTAE MULTICELLULAR EUKARYOTE DNA- THE GENETIC MATERIAL OF THE CELL KINGDOM FUNGI MOSTLY EUKARYOTE RIBOSOMES - PARTICLES THAT SYNTHESIZE PROTEINS MULTICELLULAR KINGDOM PROTISTA MOSTLY EUKARYOTE GENERAL PARTS OF THE CELL UNICELLULAR KINGDOM ARCHAEA UNICELLULAR PROKARYOTE PLASMA MEMBRANE KINGDOM BADTERIA UNICELLULAR PROKARYOTE LOCATION: ▪ FORMS OUTER BOUNDARY OF EUKARYOTIC CELL PROKARYOTIC CELL THE CELL. INCLUDES ANIMAL CELLS, INCLUDES BACTERIA AND ▪ SURROUNDS PLANT CELLS, AND FUNGAL ARCHAEA CYTOPLASM. CELLS. ▪ SEPARATES THE HAVE TRUE NUCLEUS HAVE NO TRUE NUCLEUS CELL FROM THE CONTAINING DNA ENVIRONMENT. CELL THEORY STRUCTURE: ▪ LIPID BILAYER COMPOSED OF PHOSPHOLIPIDS AND ▪ THE WORD CELL WAS FIRST USED BY ROBERT HOOKE (1635 – CHOLESTEROL 1703) WHEN HE LOOKED AT CORK WITH A SIMPLE ▪ PROTEINS EXTEND ACROSS OR ARE EMBEDDED IN EITHER MICROSCOPE AND FOUND WHAT APPEARS TO BE BLOCKS OF SURFACE OF THE LIPID BILAYER MATERIALS UP THE CORK ▪ THE PROTEINS FORM TINY OPENINGS OR PASSAGEWAYS ▪ THE TERM CELL TODAY DESCRIBE THE UNIT OF LIFE THAT IN THE MEMBRANE CALLED PORES. SEPARATES ITSLEF FROM ITS SURROUNDING BY A THIN FUNCTION: PARTITION, THE CELL MEMBRANE ▪ FUNCTIONS AS THE OUTER BOUNDARY OF THE CELL. ▪ CELL THEORY IS ONE OF THE BASIC PRINCIPLES OF BIOLOGY – ▪ CONTROLS THE ENTRY AND EXIT OF SUBSTANCES. GERMAN SCIENTISTS (THEODOR SCHWAN, MATTHIAS ▪ RECEPTOR PROTEINS FUNCTION IN INTERCELLULAR SCHLEIDEN, AND RUDOPLH VIRCHOW) COMMUNICATION. CELL THEORY STATES: MODERN CELL THEORY ▪ MARKER MOLECULES ENABLE CELLS TO RECOGNIZE ONE ALL LIVING ORGANISMS ARE ENERGY FLOW OCCURS ANOTHER COMPOSED OF CELLS. THEY WITHIN CELLS. NUCLEUS MAY BE UNICELLULAR OR MULTICELLULAR LOCATION: ▪ FOUND WITHIN THE CYTOPLASM THE CELL IS THE BASIC UNIT OF ALL CELLS HAVE THE SAME STRUCTURE AND FUNCTION BASIC CHEMICAL AND SEPARATED FROM THE OF LIFE. COMPOSITION CYTOPLASM BY THE NUCLEAR OFMOLECULES). MEMBRANE. HEREDITY INFORMATION STRUCTURE: LARGEST ORGANELLE MADE UP (DNA) IS PASSED ON FROM OF 3 PARTS CELL TO CELL. ▪ NUCLEAR ENVELOPE: A DOUBLE MEMBRANE THAT SURROUNDS THE CELLS ARISE FROM PRE- ALL CELLS HAVE THE SAME BAS NUCLEUS; CONTAINS PORES TO LET EXISTING CELLS. (THEY ARE C CHEMICAL COMPOSITION OF MATERIALS IN AND OUT. NOT DERIVED FROM MOLECULES). ▪ CHROMATIN: THIN THREAD-LIKE STRUCTURES MADE UP SPONTANEOUS GENERATION.) OF DNA (CONTROL CELLS ACTIVITIES & PROVIDES INFORMATION THE RIBOSOMES NEED TO MAKE PROTEINS) SCIENTIST DISCOVERY ▪ NUCLEOLUS: DENSE BODIES CONSISTING OF RIBOSOMAL ROBERT HOOKE OBSERVED SLICES OF CORK (EMPTY RNA AND PROTEINS. COMPARTMENTS) -IDENTIFIED AND NAMED CELLS FUNCTION: ▪ CONTROLS ALL THE CELL’S ACTIVITIES ▪ CONTROLS WHICH PROTEIN ARE MADE  BSNR 118 | ANATOMY AND PHYSIOLOGY | TERM 01 ▪ SYNTHESIS AND CHEMICAL REACTION OF THE CELL ▪ MEMBRANOUS TUBULES AND FLATTENED SACS WITH NO CYTOPLASMIC ORGANELLES ATTACHED RIBOSOMES RIBOSOME FUNCTION: LOCATION: ▪ SYNTHESIZES LIPIDS ▪ ATTACHED TO ▪ METABOLIZES CARBOHYDRATES THE ER (MAKING ▪ DETOXIFIES POISON ROUGH ER); ▪ STORES CALCIUM SOME FLOAT FREELY IN THE GOLGI APPARATUS CYTOPLASM. STRUCTURE: LOCATION: ▪ SMALL GRAIN ▪ FOUND IN CYTOPLASM LIKE BODIES; NOT COVERED IN A MEMBRANE STRUCTURE: FUNCTION: ▪ STACKS OF FLAT, ▪ TO MAKE PROTEIN; GET INSTRUCTION FOR PROTEIN MEMBRANE-COVERE SACS; PRODUCTION FROM THE DNA IN NUCLEUS; THE DNA LOOKS A LOT LIKE SMOOTH GIVES THE RIBOSOMES THE CODES FOR WHICH AMINO ER ACIDS TO PUT TOGETHER TO MAKE A SPECIFIC KIND OF FUNCTION: PROTEIN ▪ SORT AND MODIFY PROTEINS FROM THE ER TO DO ▪ RIBOSOMES DROP PROTEINS DIRECTLY INTO THE ER FOR DIFFERENT JOBS; THESE ARE THEN PACKAGED IN SACS TRANSPORT; FREE-FLOATING ONES MAKE PROTEIN FOR (CALLED VESICLES) THAT BREAK OFF THE END OF THE THAT PARTICULAR SPOT IN THE CELL STACK; VESICLES GO TO EITHER THE CELL MEMBRANE FOR EXPORT OUTSIDE THE CELL (TO BE EXCRETED OR ‘GIVE ENDOPLASTIC RETICULUM OFF’ BY THE CELL OR TO THE OTHER PLACES WITHIN THE LOCATION: CELL ▪ EXTENDS FROM THE NUCLEAR MEMBRANE TO LYSOSOME THE CELL MEMBRANE STRUCTURE: ▪ FOUND THROUGHOUT THE ▪ SMALL, ROUND CYTOPLASM STRUCTURES FILLED WITH ▪ ROUGH ER IS USUALLY FOUND NEAR THE NUCLEUS DIGESTIVE CHEMICALS STRUCTURE: CALLED ENZYMES ▪ FOLDED FUNCTION: ▪ TUBE-LIKE MEMBRANE ▪ ROUGH ER HAS RIBOSOMES ON IT ▪ BREAKDOWN LARGE FOOD (SUGAR) MOLECULES INTO ▪ SMOOTH ER LACKS RIBOSOMES SMALL ONES SO THEY CAN ENTER THE MITOCHONDRIA FUNCTION: ▪ DIGEST WATSE PRODUCT, WORNOUT ORGANELLES, AND ▪ MOVES MATERIALS (ESPECIALLY PROTEINS) AROUND THE DEAD OR INJURED CELLES TO MAKE ROOM FOR NEW CELL CELLS (THE CELL’S MATERIALS CAN BE REUSED BY OTHER ▪ ACTS LIKE A CONVEYOR BELT OR PASSAGEWAY CELLS) ▪ CELL’S TRANSPORTATION SYSTEM ▪ PROTECT THE CELL FROM FOREIGN INVADERS ▪ SOMETIME ACT LIKE A “SEL-DESTRUCT” DEVICE FOR THE ROUGH ENDOPLASTIC RETICULUM CELL STRUCTURE: ▪ HAS BOUND PEROXISOME RIBOSOMES, WHICH SECRETE STRUCTURE: GLYCOPROTEINS ▪ MEMBRANE-BOUND (PROTEINS COVALENTLY VESICLE BONDED TO FUNCTION: CARBOHYDRATES) ▪ SERVES AS ONE SITE OF ▪ MEMBRANOUS LIPID AND AMINO ACID TUBULES AND DEGRADATION FLATTENED SACS WITH ▪ BREAKS DOWN HYDROGEN PEROXIDE ATTACHED RIBOSOMES FUNCTION: ▪ MEMBRANE FACTORY PROTEASOMES FOR THE CELL STRUCTURE: ▪ SYNTHESIZES PROTEINS AND TRANSPORTS ▪ TUBE-LIKE PROTEIN COMPLEXED IN THE CYTOPLASM THEM TO GOLGI FUNCTION: ▪ BREAK DOWN PROTEIN IN THE CYTOPLASM APPARATUS SMOOTH ENDOPLASTIC RETICULUM STRUCTURE: pg. 2  BSNR 118 | ANATOMY AND PHYSIOLOGY | TERM 01 MITOCHONDRIA MICROVILLI LOCATION: STRUCTURE: ▪ SCATTERED ▪ EXTENSIONS OF THROUGHOUT THE PLASMA CYTOPLASM MEMBRANE CONTAINING STRUCTURE: MICOFILAMENTS ▪ ROD-SHAPED FUNCTION: STRUCTURE THAT HAVE A FOLDED INNER MEMBRANE WITHIN AN OUTER ▪ INCREASE MEMBRANE (DOUBLE MEMBRANE) INNER MEMBRANE SURFACE AREA OF THE PLASMA MEMBRANE FOR FORMS PROJECTIONS CALLED CRISTAE ABSORPTION AND SECREATION ▪ THE POWERHOUSE OF THE CELL; THAT ARE MORE ACTIVE ▪ MODIFIED TO FORM SENSORY RECEPTORS WILL HAVE MORE MITOCHONDRIA – MUSCLE CELLS FUNCTION: CHARACTERISTIC FUNCTION OF THE CELL ▪ MAJOR SITES OF ATP SYNTHESIS WHEN OXYGEN IS AVAILABLE CELL METABOLISM AND ENERGY USE ▪ CELL METABOLISM INVOLVES ALL CHEMICAL REACTIONS CENTRIOLES THAT OCCUR WITHIN A CELL. ▪ THESE METABOLIC REACTIONS OFTEN INVOLVE ENERGY LOCATION: TRANSFERS, MEANING THE ENERGY RELEASED BY ONE ▪ LOCATED IN THE REACTION IS THEN USED IN ANOTHER REACTION. CENTROSOME – A ▪ FOR EXAMPLE, THE ENERGY RELEASED FROM THE SPECIALIZED AREA OF DIGESTION OF LARGE NUTRIENT MOLECULES FUELS THE CYTOPLASM CELLULAR ACTIVITIES, SUCH AS THE SYNTHESIS OF OTHER WHERE MICROTUBULE MOLECULES AND MUSCLE CELL CONTRACTION. FORMATION OCCURS ▪ DURING SOME METABOLIC REACTIONS, ENERGY IS ALSO STRUCTURE: RELEASED AS HEAT, WHICH HELPS MAINTAIN BODY ▪ PAIR OF CYLINDRICAL ORGANELLES CONSISTING OF TEMPERATURE. TRIPLETS PARALLEL MICROTUBULES FUNTION: SYNTHESIS OF MOLECULES ▪ SERVES AS CENTERS FOR MICROTUBULE FORMATION ▪ DETERMINE CELL POLARITY DURING CELL DIIVSION ▪ THE DIFFERENT CELLS OF THE BODY SYNTHESIZE, OR ▪ FORM BASAL BODIES OF CILIA AND FLAGELLA PRODUCE, VARIOUS TYPES OF MOLECULES, INCLUDING PROTEINS, NUCLEIC ACIDS, AND LIPIDS. ▪ THE STRUCTURAL AND FUNCTIONAL CHARACTERISTICS CILIA OF CELLS ARE DETERMINED BY THE TYPES OF MOLECULES STRUCTURE: THEY PRODUCE. ▪ EXTENSIONS OF THE PLASMA COMMUNICATION MEMBRANE CONTAINING DOUBLETS OF PARALLEL ▪ CELLS COMMUNICATE WITH EACH OTHER BY USING MICROTUBULES; 10𝜇𝑚 IN LENGTH CHEMICAL AND ELECTRICAL SIGNALS. ▪ FOR EXAMPLE, NERVE CELLS PRODUCE CHEMICAL FUNCTION: SIGNALS BY WHICH THEY COMMUNICATE WITH MUSCLE ▪ MOVE MATERIALS OVER THE SURFACE OF THE CELLS CELLS. THEN, MUSCLE CELLS RESPOND TO THE CHEMICAL SIGNALS BY CONTRACTING OR RELAXING FLAGELLUM REPRODUCTION AND INHERITANCE STRUCTURE: ▪ MOST CELLS CONTAIN A COMPLETE COPY OF ALL THE ▪ EXTENSION OF THE PLASMA GENETIC INFORMATION OF THE INDIVIDUAL. MEMBRANE CONTAINING DOUBLETS OF ▪ THIS GENETIC INFORMATION ULTIMATELY DETERMINES PARALLEL MICROTUBULES; 55𝜇𝑚 IN LENGTH THE STRUCTURAL AND FUNCTIONAL CHARACTERISTICS OF THE CELL. FUNCTION: ▪ AS A PERSON GROWS, CELLS DIVIDE TO PRODUCE NEW CELLS, EACH CONTAINING THE SAME GENETIC ▪ IN HUMANS, PROPELS SPERMATOZOA INFORMATION. ▪ SPECIALIZED CELLS CALLED GAMETES ARE RESPONSIBLE FOR TRANSMITTING GENETIC INFORMATION TO THE NEXT GENERATION. pg. 3  BSNR 118 | ANATOMY AND PHYSIOLOGY | TERM 01 PROTEINS 45% TO 50% OF THE VOLUME CARBOHYDRATES 4% TO 8% CHAPTER 3: CELL BIOLOGY GLYCOLAX - COLLECTION OF GLYCOLIPIDS, GLYCOPROTEINS, 3.2. HOW WE SEE CELLS AND CARBOHYDRATES ON THE OUTER SURFACE OF THE PLASMA MEMBRANE. ALSO CONTAINS MOLECULES ABSORBED FROM THE MAJOR TYPES OF MICROSCOPES EXTRACELLULAR ENVIRONMENT, SO THERE IS OFTEN NO PRECISE BOUNDARY BETWEEN THE PLASMA MEMBRANE AND THE LIGHT MICROSCOPE EXTRACELLULAR ENVIRONMENT. ▪ ALLOW US TO VISUALIZE THE GENERAL FEATURES OF GLYCOLIPIDS – CARBOHYDRATES + LIPIDS CELLS, SUCH AS THE NUCLEUS. ▪ THE MAGNIFICATION OF LIGHT MICROSCOPES IS LIMITED, GLYCOPROTEINS – CARBOHYDRATES + PROTEINS SO NOT ALL CELL STRUCTURES CAN BE THOROUGHLY INVESTIGATED. MEMBRANE POTENTIAL ELECTRON MICROSCOPE ▪ AN ELECTRICAL CHARGE DIFFERENCE ACROSS THE ▪ USED IN ORDER TO STUDY THE FINE STRUCTURES OF PLASMA MEMBRANE CELLS ▪ RESULT OF THE CELL’S REGULATION OF ION MOVEMENT INTO AND OUT OF THE CELL SCANNING ELECTRON MICROSCOPE (SEM) REASONING: ▪ CAN REVEAL FEATURES OF THE CELL SURFACE AND THE THERE ARE MORE POSITIVELY CHARGED IONS ON THE OUTSIDE OF SURFACES OF INTERNAL STRUCTURES THE CELL MEMBRANE THUS MAKING IT POSITIVELY CHARGE; ON THE OTHER HAND, THERE ARE MORE NEGATIVELY CHARGED IONS AND TRANSMISSION ELECTRON MICROSCOPE (TEM) PROTEIN ONTH E INSIDE OF THE MEMBRANE THUS IT IS NEGATIVELY CHARGED. ▪ ALLOWS US TO SEE “THROUGH” PARTS OF THE CELL AND THUS TO DISCOVER DETAILED ASPECTS OF CELL CHAPTER 3: CELL BIOLOGY STRUCTURE 3.4. MEMBRANE LIPIDS CHAPTER 3: CELL BIOLOGY 3.3. PLASMA MEMBRANE PHOSPHOLIPID ▪ READILY ASSEMBLE TO FORM A LIPID BILAYER PLASMA MEMBRANE / CELL MEMBRANE ▪ CONSIDERED AS AMPIPHATIC MOLECULE = CONSIST OF BOTH POLAR AND NONPOLAR MOLECULE CELL MEMBRANE HEAD HYDROPHILIC ATTRACTED TO WATER POLAR ▪ FORMS THE BOUNDARY OF OUR CELL TAIL HYDROPHOBIC WATER REPELLANT NON-POLAR IT SEPARATES THE INTRACELLULAR SUBSTANCES ▪ POLAR MOLECULES WHICH ARE CHEMICALLY (INSIDE THE CELL) FROM THE EXTRACELLULAR INCOMPATIBLE WITH THE CENTER OF THE MEMBRANE, SUBSTANCES (THOSE OUTSIDE) REQUIRE AN EXPENDITURE OF ENERGY FOR THEIR TRANSPORT. ▪ ENCLOSES AND SUPPORTS THE CELL CONTENTS. ▪ NON-CHARGED MOLECULES CAN FREELY CROSS THE ▪ CONSIDERED THE EDGE OF LIFE MEMBRANES SINCE THEY CAN EASILY PASS THROUGH ▪ CONTROLS ALL INBOUND AND OUTBOUND TRAFFIC THE HYDROPHOBIC TAILS OF THE MEMBRANE BECAUSE ▪ EXHIBITS SELECTIVE PERMEABILITYY: IT ALLOWS SOME THEY ARE ALSO NONPOLAR. EX. CARBON DIOXIDE, SUBSTANCES TO CROSS IT MORE EASILY THAN OTHERS OXYGEN, GLYCEROL, AND ALCOHOL AS A RESULT, THE INTRACELLULAR CONTENTS OF CELLS ARE DIFFERENT FROM THE EXTRACELLULAR FLUID MOSAIC MODEL ENVIRONMENT ▪ NEITHER RIGID NOR STATIC IN STRUCTURE ▪ DESCRIBES THE PLASMA MEMBRANE AS FLUID ▪ ABILITY OF THE CELL TO DISCRIMINATE IN ITS CHEMICAL COMBINATION OF PHOSPHOLIPIDS, CHOLESTEROL, AND EXCHANGES IS FUNDAMENTAL TO LIFE PROTEINS ▪ THE “MOSAIC” PART IS ATTRIBUTED TO THE MIXED FUNTION OF CELL MEMBRANE COMPOSITION OF THE CELL MEMBRANE, AND THE ▪ IT PROTECTS THE INTEGRITY OF THE INTERIOR OF THE CELL BY “FLUID” PART COME FROM THE ABILITY OF THE BILAYER ALLOWING CERTAIN SUBSTANCES INTO THE CELL WHILE TO DRIFT SIDEWAYS AND SPIN AROUND THEIR LONG KEEPING OTHER SUBSTANCES OUT. (HOMESTASIS) AXIS ▪ IT ALSO SERVES AS A BASE OF ATTACHMENT FOR THE CYTOSKELETON IN SOME ORGANISMS AND THE CELL WALL IN PHOSPHOLIPIDS ❖ MAIN FABRIC OF THE MEMBRANE OTHERS. THUS, THE CELL MEMBRANE ALSO SERVES TO HELP CHOLESTEROL ❖ TUCKED BETWEEN THE HYROPHOBIC TAILS SUPPORT THE CELL AND HELP MAINTAIN ITS SHAPE. OF THE MEMBRANE PHOSPHOLIPIDS ▪ ANOTHER FUNCTION OF THE MEMBRANE IS TO REGULATE CELL INTEGRAL PROTEINS ❖ EMBEDDED IN THE PHOSPHOLIPIDS BILAYER, GROWTH THROUGH THE BALANCE OF ENDOCYTOSIS AND ❖ MAY OR MAY NOT EXTEND THROUGH EXOCYTOSIS. BOTH LAYER PERIPHERAL ❖ ON THE INNER OR OUTER SURFACE OF THE MEMBRANE POTENTIAL PROTEINS PHOSPHOLIPID BILAYER, BUT NOT EMBEDDED IN ITS HYDROHOPHOBIC CORE COMPONENTS OF CELL MEMBRANE LIPIDS 45% TO 50% OF THE VOLUME pg. 4  BSNR 118 | ANATOMY AND PHYSIOLOGY | TERM 01 CARBOHYDRATES ❖ ATTACHED TO PROTEINS OR LIPIDS ON THE ▪ CONSIST OF REGIONS MADE UP OF AMINO ACIDS WITH EXTRACELLULAR SIDE OF THE MEMBRANE HYDROPHOBIC R GROUPS AND OTHER REGIONS OF (FORMING GLYCOPROTEINS AND AMINO ACIDS WITH HYDROPHILIC R GROUPS GLYCOLIPIDS) PERIPHERAL MEMBRANE PROTEINS FLUID NATURE: ▪ ATTACHED TO EITHER THE INNER OR THE OUTER ▪ DISTRIBUTION OF MOLECULES IN PLASMA MEMBRANE ▪ REPAIR: PHOSPHOLIPID TENDS TO REASSEMBLE AROUND SURFACES OF THE LIPID BILAYER. DAMAGED SITES AND CLOSE THEM MARKER MOLECULE ▪ ENABLES MEMBRANES TO FUSE TOGETHER ▪ CELL SURFACE MOLECULES THAT ALLOW CELLS TO CHOLESTEROL IDENTIFY OTHER CELLS OR OTHER MOLECULES ▪ MOSTLY GLYCOLIPID OR GLYCOPROTEIN ▪ ONLY FOUND IN AN ANIMAL CELL MEMBRANE ▪ THE PROTEIN PORTIONS OF GLYCOPROTEINS MAY BE ▪ REDUCES MEMBRANE FLUIDITY AT MODERATE TEMPERATURE, EITHER INTEGRAL OR PERIPHERAL MEMBRANE PROTEINS BUT AT LOW TEMPERATURE HINDERS SOLIDIFICATION ▪ INTERCELLULAR COMMUNICATION AND RECOGNITION o DUE TO HIGH TEMPERATURE MOLECULE MOVES ARE IMPORTANT BECAUSE CELLS ARE NOT ISOLATED AGGRESSIVELY ENTITIES; THEY MUST WORK TOGETHER TO ENSURE ▪ WITHOUT CHOLESTEROL, NORMAL BODY FUNCTION. PHOSPHOLIPIDS WILL BE TOO FLUID AND ▪ A SPERM CELL’S RECOGNITION OF AN OOCYTE AND THE IT WON’T HOLD ITS SHAPE IMMUNE SYSTEM’S ABILITY TO DISTINGUISH BETWEEN o DUE TO LOW TEMPERATURE THE TENDENCY OF SELF-CELLS AND FOREIGN CELLS FATTY ACIDS IS TO SOLIDIFY ▪ WITHOUT CHOLESTEROL, ATTACHMENT PROTEIN PHOSPHOLIPIDS WILL BE RIGID, NOT AS ▪ INTEGRAL PROTEINS THAT ALLOW CELLS TO ATTACH TO FLEXIBLE, AND IT MAY BREAK OTHER CELLS OR TO EXTRACELLULAR MOLECULES ▪ CHOLESTEROL MOLECULES ARE SELECTIVELY DISPERSED ▪ MOSTLY ARE ATTACH TO INTRACELLULAR MOLECULES BETWEEN MEMBRANE PHOSPHOLIPIDS. THIS HELPS TO KEEP CELL MEMBRANES FROM BECOMING STIFF BY PREVENTING CADHERINS PHOSPHOLIPIDS FROM BEING TOO CLOSELY PACKED TOGETHER. ▪ PROTEINS THAT ATTACH CELLS TO OTHER CELLS ▪ CHOLESTEROL IS NOT FOUND IN THE MEMBRANES OF PLANT CELLS. INTEGRINS FATTY ACIDS: ▪ PROTEINS THAT ATTACH CELLS TO EXTRACELLULAR SATURATED – STRAIGHT TAIL MOLECULES UNSATURATED - BENT TAIL / KINKS ▪ FUNCTION IN PAIRS OF INTEGRAL MEMBRANE PROTEINS, WHICH INTERACT WITH BOTH INTRACELLULAR AND IMPORTANCE: EXTRACELLULAR MOLECULES ▪ THE NUMBER OF SATURATED AND UNSATURATED ACIDS IS ▪ FUNCTION IN CELLULAR COMMUNICATION. IMPORTANT TO MAINTAIN THE FLUIDITY OF THE CELL TRANSPORT PROTEIN MEMBRANE ▪ INTEGRAL PROTEINS THAT ALLOW IONS OR MOLECULES ▪ TOO MUCH UNSATURATED FATTY ACIDS PREVENTS THE TAIL TO MOVE FROM ONE SIDE OF THE PLASMA MEMBRANE FROM STICKING TOGETHER, TOO FLUID THAT THE MATERIALS TO THE OTHER EASILY PASS AND LEAVE CHARACTERISTICS OF TRANSPORT PROTEINS ▪ TOO MUCH SATURATED FATTY ACIDS ALLOWS THE TAILS TO SPECIFICITY STICK TOGETHER, TOO VISCOUS THAT MATERIALS CANNOT PASS THROUGH ▪ EACH TRANSPORT PROTEIN BINDS TO AND TRANSPORTS CHAPTER 3: CELL BIOLOGY ONLY A CERTAIN TYPE OF 3.5. MEMBRANE PROTEINS MOLECULE OR ION ▪ THE CHEMICAL STRUCTURE OF FUNCTIONS OF MEMBRANE PROTEINS THE BINDING SITE DETERMINES ▪ BASED ON THEIR LOCATION AMONG OR ATTACHED TO THE SPECIFICITY OF THE THE PHOSPHOLIPID MOLECULES, MEMBRANE PROTEINS TRANSPORT PROTEIN BECAUSE CAN BE CLASSIFIED AS INTEGRAL OR PERIPHERAL. ONLY SUBSTANCES THAT ARE ▪ MEMBRANE PROTEINS CAN FUNCTION AS MARKER THE RIGHT SHAPE CAN BIND TO MOLECULES, ATTACHMENT PROTEINS, TRANSPORT THE PROTEIN PROTEINS, RECEPTOR PROTEINS, OR ENZYMES ▪ THE ABILITY OF MEMBRANE PROTEINS TO FUNCTION DEPENDS ON THEIR THREE-DIMENSIONAL SHAPES AND THEIR CHEMICAL CHARACTERISTICS. INTEGRAL MEMBRANE PROTEINS ▪ PENETRATE DEEPLY INTO THE LIPID BILAYER, IN MANY CASES EXTENDING FROM ONE SURFACE TO THE OTHER pg. 5  BSNR 118 | ANATOMY AND PHYSIOLOGY | TERM 01 COMPETITION ▪ OPEN OR CLOSE WHEN THERE IS A CHANGE IN THE MEMBRANE POTENTIAL. ▪ RESULT OF MOLECULES WITH SIMILAR SHAPE BINDING TO THE TRANSPORT PROTEIN IMPORTANCE: FUNCTIONING MEMBRANE ION CHANNEL IS ▪ CLOSELY RELATED IMPORTANT FOR MAINTAINING HOMEOSTASIS SUBSTANCES THAT HAVE THE SAME SHAPE MAY CYSTIC FIBROSIS: BIND TO THE SAME ▪ GENETIC DISORDER THAT AFFECTS CHLORIDE ION BINDING SITE. CHANNELS. THE FAILURE OF THESE ION CHANNELS TO ▪ THE SUBSTANCE IN THE FUNCTION CAUSES THE AFFECTED CELLS TO PRODUCE GREATER THICK, VISCOUS SECRETIONS. CONCENTRATION OR THE ▪ COMMONLY AFFECTS THE LUNGS AND PANCREAS SUBSTANCE THAT BINDS ▪ IN PANCREAS, THE THICK SECRETIONS BLOCK THE TO THE BINDING SITE RELEASE OF DIGESTIVE ENZYMES, RESULTING IN AN MORE READILY IS MOVED ACROSS THE PLASMA INABILITY TO DIGEST CERTAIN TYPES OF FOOD AND MEMBRANE AT THE GREATER RATE. SOMETIMES LEADING TO SERIOUS CASES OF SATURATION PANCREATITIS (INFLAMMATION OF THE PANCREAS) ▪ IN LUNGS, THE THICK SECRETIONS BLOCK AIRWAYS AND ▪ RATE OF MOVEMENT OF MOLECULES ACROSS THE MAKE BREATHING DIFFICULT. MEMBRANE IS LIMITED BY THE NUMBER OF AVAILABLE TRANSPORT PROTEINS ▪ AS THE CONCENTRATION OF A TRANSPORTED CARRIER PROTEINS SUBSTANCE INCREASES, MORE TRANSPORT PROTEINS HAVE THEIR BINDING SITES OCCUPIED, SO THE RATE AT ▪ INTEGRAL MEMBRANE PROTEINS THAT MOVE IONS OR WHICH THE SUBSTANCE IS MOVED ACROSS THE PLASMA MOLECULES FROM ONE SIDE OF THE PLASMA MEMBRANE INCREASES MEMBRANE TO THE OTHER. ▪ THE RATE OF MOVEMENT REMAINS CONSTANT EVEN THE ▪ SPECIFIC IONS OR MOLECULES ATTACH TO BINDING SITES CONCENTRATION OF SUBSTANCES INCREASE FURTHER WITHIN THE CARRIER PROTEIN. ▪ THE BINDING OF THE SPECIFIC ION OR MOLECULE CAUSES THREE MAJOR CLASSES OF TRANSPORT PROTEINS THE CARRIER PROTEINS TO CHANGE SHAPE AND RELEASE THE BOUND ION OR MOLECULE TO THE OTHER SIDE OF CHANNEL PROTEINS THE PLASMA MEMBRANE. ▪ ONE OR MORE INTEGRAL MEMBRANE PROTEINS ▪ THE CARRIER PROTEIN THEN RESUMES ITS ORIGINAL ARRANGED SO THAT THEY FORM A TINY CHANNEL SHAPE AND IS AVAILABLE TO TRANSPORT MORE IONS OR THROUGH THE PLASMA MEMBRANE MOLECULES ▪ IONS OR SMALL MOLECULES OF THE RIGHT SIZE, CHARGE, UNIPORT AND SHAPE CAN PASS THROUGH THE CHANNEL. THE CHARGES IN THE HYDROPHILIC PART OF THE CHANNEL ▪ MOVEMENT OF ONE SPECIFIC ION OR MOLECULE ACROSS PROTEINS DETERMINE WHICH TYPES OF IONS CAN PASS THE MEMBRANE THROUGH THE CHANNEL. ▪ CARRIER PROTEIN: UNIPORTER ▪ IONS BRIEFLY BIND TO SPECIFIC SITES INSIDE CHANNELS AND THAT THE SHAPES OF THOSE CHANNELS CHANGE AS SYMPORT | COTRANSPORT IONS ARE TRANSPORTED THROUGH THEM. ▪ SIZE AND CHARGE WITHIN A CHANNEL DETERMINE THE ▪ IS THE MOVEMENT OF TWO DIFFERENT IONS OR CHANNEL’S SPECIFICITY. MOLECULES IN THE SAME DIRECTION ACROSS THE ▪ SIMILAR IONS MOVING INTO AND BINDING WITHIN A PLASMA MEMBRANE CHANNEL PROTEIN ARE IN COMPETITION WITH EACH ▪ CARRIER PROTEIN: SYMPORTER OTHER ANTIPORT | COUNTERTRANSPORT ▪ NUMBER OF IONS MOVING INTO A CHANNEL PROTEIN CAN EXCEED THE CAPACITY OF THE CHANNEL, THUS ▪ MOVEMENT OF TWO DIFFERENT IONS OR MOLECULES IN SATURATING THE CHANNEL. OPPOSITE DIRECTIONS ACROSS THE PLASMA MEMBRANE ▪ CARRIER PROTEIN: ANTIPORTER LEAK ION CHANNELS | NON-GATED ION CHANNEL ATP-POWERED PUMPS ▪ ALWAYS OPEN AND ARE RESPONSIBLE FOR THE PLASMA MEMBRANE’S PERMEABILITY TO IONS WHEN THE ▪ TRANSPORT PROTEINS THAT REQUIRE CELLULAR ENERGY PLASMA MEMBRANE IS AT REST TO MOVE SPECIFIC IONS OR MOLECULES FROM ONE SIDE OF THE PLASMA MEMBRANE TO THE OTHER. GATED ION CHANNEL ▪ FUELED BY THE BREAKDOWN OF ADENOSINE ▪ OPEN AND CLOSE DEPENDING ON CERTAIN CONDITIONS TRIPHOSPHATE (ATP OF THE CELL. ▪ HAVE BINDING SITES, TO WHICH SPECIFIC IONS OR MOLECULES CAN BIND, AS WELL AS A BINDING SITE FOR LIGAND-GATED ION CHANNEL ATP. ▪ THE BREAKDOWN OF ATP TO ADENOSINE DIPHOSPHATE ▪ ION CHANNELS THAT RESPOND TO LIGANDS (ADP) RELEASES ENERGY, CHANGING THE SHAPE OF THE ▪ LIGAND: GENERIC TERM FOR ANY CHEMICAL SIGNAL PROTEIN, WHICH MOVES THE ION OR MOLECULE ACROSS MOLECULE USED BY CELLS TO COMMUNICATE WITH THE MEMBRANE EACH OTHER VOLTAGE-GATED ION CHANNEL pg. 6  BSNR 118 | ANATOMY AND PHYSIOLOGY | TERM 01 RECEPTOR PROTEIN ▪ SOME MEMBRANE ASSOCIATED ENZYMES ARE ALWAYS ACTIVE; OTHERS ARE ACTIVATED BY MEMBRANE-BOUND ▪ MEMBRANE PROTEINS OR GLYCOPROTEINS THAT HAVE RECEPTORS OR G PROTEIN COMPLEXES. AN EXPOSED RECEPTOR SITE ON THE OUTER CELL SURFACE. SPECIFIC SUBSTANCES, SUCH AS CHEMICAL SIGNALS, CAN ATTACH TO THE RECEPTOR SITE CHAPTER 3: CELL BIOLOGY ▪ INTERCELLULAR COMMUNICATION 3.6. TRANSPORT MECHANISMS ▪ ONE CELL CAN RELEASE A CHEMICAL SIGNAL THAT DIFFUSES TO ANOTHER CELL AND BINDS TO ITS ▪ MOLECULES AND IONS CAN MOVE ACROSS THE PLASMA RECEPTOR. MEMBRANE IN DIFFERENT WAYS, DEPENDING ON THE ▪ ACTS AS A SIGNAL THAT TRIGGERS A RESPONSE CHEMICAL CHARACTERISTICS OF THE MOLECULES AND ▪ SIGNAL WOULD HAVE NO EFFECT ON OTHER CELLS THAT IONS AND THE STRUCTURE AND FUNCTION OF THE CELL. LACKED THE SPECIFIC RECEPTOR MOLECULE. ▪ MOLECULES THAT ARE SOLUBLE IN LIPIDS, SUCH AS OXYGEN, CARBON DIOXIDE, AND STEROIDS, PASS THROUGH THE PLASMA MEMBRANE READILY BY DISSOLVING IN THE LIPID BILAYER. RECEPTORS LINKED TO CHANNEL PROTEINS ▪ SOME SMALL, NON-LIPID-SOLUBLE MOLECULES, SUCH AS UREA, CAN DIFFUSE BETWEEN THE PHOSPHOLIPID ▪ HELP FORM LIGAND-GATED ION CHANNELS MOLECULES OF THE PLASMA MEMBRANE. ▪ FORM RECEPTORS ON THE CELL SURFACE ▪ LARGE, NON-LIPID-SOLUBLE MOLECULES AND IONS THAT ▪ COMBINATION OF LIGAND AND RECEPTORS CAUSED THE CANNOT DIFFUSE ACROSS THE PHOSPHOLIPID BILAYER ALTERATION IN 3D STRUCTURE OF THE PROTEINS OF ION MAY MOVE ACROSS THE PLASMA MEMBRANE WITH THE CHANNELS, CAUSING THE CHANNELS EITHER TO OPEN OR HELP OF TRANSPORT PROTEINS. TO CLOSE. THE RESULT IS A CHANGE IN THE PERMEABILITY ▪ FINALLY, LARGE, NON-LIPID-SOLUBLE MOLECULES, AS OF THE PLASMA MEMBRANE TO THE SPECIFIC IONS WELL AS SMALL PIECES OF MATTER AND EVEN WHOLE PASSING THROUGH THE ION CHANNELS CELLS, CAN BE TRANSPORTED ACROSS THE PLASMA MEMBRANE IN A VESICLE. RECEPTORS LINKED TO G PROTEIN COMPLEXES ▪ MEMBRANE TRANSPORT MECHANISMS ARE CLASSIFIED ▪ FUNCTION BY ALTERING THE ACTIVITY OF A G PROTEIN AS EITHER PASSIVE OR ACTIVE BASED ON WHETHER OR COMPLEX LOCATED ON THE INNER SURFACE NOT THE CELL EXPENDS METABOLIC ENERGY DURING THE ▪ G PROTEIN COMPLEX ACTS AS AN INTERMEDIARY TRANSPORT PROCESS BETWEEN A RECEPTOR AND OTHER CELLULAR PROTEINS PASSIVE MEMBRANE TRANSPORT ▪ INTERACTS WITH A RECEPTOR PROTEIN WHEN A CHEMICAL SIGNAL IS BOUND TO IT. ▪ A TRANSPORT PROTEIN MOVES SUBSTANCES FROM A PROCESS: REGION OF HIGHER CONCENTRATION TO ONE OF LOWER CONCENTRATION. THIS IS THE REASON WHY PASSIVE 1. WHEN THE G PROTEIN COMPLEX IS NOT INTERACTING TRANSPORT IS ALSO CALLED FACILITATED TRANSPORT. WITH A RECEPTOR PROTEIN, THE Α SUBUNIT OF THE G ▪ ENERGY – INDEPENDENT MECHANISM OF THE CELL, PROTEIN COMPLEX HAS GUANOSINE DIPHOSPHATE (GDP) ALLOWING SMALL MOLECULES TO ENTER INTO IT ATTACHED TO IT WITHOUT ENERGY CONSUMPTION 2. WHEN A CHEMICAL SIGNAL BINDS TO THE RECEPTOR, THE ▪ CELL DOES NOT EXPEND METABOLIC ENERGY RECEPTOR BECOMES ASSOCIATED WITH THE G PROTEIN COMPLEX. THE Α SUBUNIT RELEASES THE GDP AND DIFFUSION ATTACHES TO GUANOSINE TRIPHOSPHATE ▪ SOLUTION CONSISTS OF ONE OR MORE SUBSTANCES 3. WHEN A CHEMICAL SIGNAL BINDS TO THE RECEPTOR, THE DISSOLVED IN THE PREDOMINANT LIQUID OR GAS RECEPTOR BECOMES ASSOCIATED WITH THE G PROTEIN ▪ THE MOVEMENT OF SOLUTES FROM AN AREA OF HIGHER COMPLEX. THE Α SUBUNIT RELEASES THE GDP AND SOLUTE CONCENTRATION TO AN AREA OF LOWER ATTACHES TO GUANOSINE TRIPHOSPHATE SOLUTE CONCENTRATION ; PRODUCT OF THE CONSTANT 4. THE ACTIVATED Α SUBUNIT CAN STIMULATE A CELL RANDOM MOTION OF ALL ATOMS, MOLECULES, OR IONS RESPONSE IN AT LEAST THREE WAYS: (1) BY MEANS OF IN A SOLUTION INTRACELLULAR CHEMICAL SIGNALS, (2) BY THE OPENING ▪ HIGHER SOLUTE CONCENTRATION TO THAT OF LOWER OF ION CHANNELS IN THE PLASMA MEMBRANE, AND (3) SOLUTE CONCENTRATION; T AN EQUILIBRIUM WILL EXIST BY THE ACTIVATION OF ENZYMES ASSOCIATED WITH THE BECAUSE NO NET MOVEMENT OF SOLUTES WILL OCCUR PLASMA MEMBRANE CONCENTRATION GRADIENT APPLICATION: ▪ THE CONCENTRATION DIFFERENCE BETWEEN TWO ▪ DRUGS WITH STRUCTURES SIMILAR TO THOSE OF POINTS, DIVIDED BY THE DISTANCE BETWEEN THE TWO SPECIFIC CHEMICAL SIGNALS MAY COMPETE WITH THOSE POINTS CHEMICAL SIGNALS FOR THEIR RECEPTOR SITES. ▪ CONCENTRATION DIFFERENCE OCCURS WHEN THE ▪ DEPENDING ON THE EXACT CHARACTERISTICS OF A DRUG, SOLUTES ARE NOT EVENLY DISTRIBUTED IN A SOLVENT. IT BINDS TO A RECEPTOR SITE AND EITHER ACTIVATES OR ▪ GREATER THE CONCENTRATION GRADIENT, THE GREATER INHIBITS THE ACTION OF THE RECEPTOR. THE RATE OF DIFFUSION ENZYMES ▪ GREATER THE CONCENTRATION GRADIENT, THE GREATER THE RATE OF DIFFUSION ▪ CATALYZE CHEMICAL REACTIONS ON EITHER THE INNER ▪ INCREASING THE CONCENTRATION DIFFERENCE OR THE OUTER SURFACE OF THE PLASMA MEMBRANE. BETWEEN THE TWO POINTS OR DECREASING THE ▪ SOME ENZYMES ON THE SURFACE OF CELLS IN THE SMALL DISTANCE BETWEEN THE TWO POINTS CAUSES THE INTESTINE BREAK THE PEPTIDE BONDS OF DIPEPTIDES TO CONCENTRATION GRADIENT TO INCREASE, WHEREAS FORM TWO SINGLE AMINO ACIDS. DECREASING THE CONCENTRATION DIFFERENCE pg. 7  BSNR 118 | ANATOMY AND PHYSIOLOGY | TERM 01 BETWEEN THE TWO POINTS OR INCREASING THE DESCRIPTION OF OSMOTIC PRESSURE OF SOLUTION DISTANCE BETWEEN THE TWO POINTS CAUSES THE CONCENTRATION GRADIENT TO DECREASE. ISOSMOTIC: ▪ IMPORTANT MEANS BY WHICH SUBSTANCES MOVE ▪ SOLUTIONS WITH THE SAME CONCENTRATION OF BETWEEN THE EXTRACELLULAR AND INTRACELLULAR SOLUTE PARTICLES HAVE THE SAME OSMOTIC PRESSURE. FLUIDS IN THE BODY. ▪ THE SOLUTIONS ARE ISOSMOTIC EVEN IF THE TYPES OF ▪ SOME NUTRIENTS ENTER AND SOME WASTE PRODUCTS SOLUTE PARTICLES IN THE TWO SOLUTIONS DIFFER FROM LEAVE THE CELL BY DIFFUSION, AND MAINTENANCE OF EACH OTHER THE APPROPRIATE INTRACELLULAR CONCENTRATION OF THESE SUBSTANCES DEPENDS TO A LARGE DEGREE ON HYPEROSMOTIC DIFFUSION ▪ IF ONE SOLUTION HAS A GREATER CONCENTRATION OF FACTORS AFFECTING DIFFUSION SOLUTE PARTICLES, AND THEREFORE A GREATER OSMOTIC PRESSURE THAN ANOTHER SOLUTION, THE MAGNITUDE OF THE CONCENTRATION GRADIENT FIRST SOLUTION IS SAID TO BE HYPEROSMOTIC COMPARED WITH THE MORE DILUTE SOLUTION. ▪ THE RATE OF DIFFUSION INCREASES AS THE CONCENTRATION GRADIENT INCREASES. HYPOSMOTIC: ▪ THE GREATER THE CONCENTRATION GRADIENT, THE GREATER THE NUMBER OF SOLUTE PARTICLES MOVING ▪ THE MORE DILUTE SOLUTION, WITH THE LOWER FROM A HIGHER TO A LOWER SOLUTE CONCENTRATION. OSMOTIC PRESSURE, IS HYPOOSMOTIC COMPARED WITH THE MORE CONCENTRATED SOLUTION. TEMPERATURE TONICITY ▪ AS THE TEMPERATURE OF A SOLUTION INCREASES, THE SPEED AT WHICH ALL MOLECULES MOVE INCREASES, THE SHAPE OF THE CELL REMAINS CONSTANT, MAINTAINING ITS RESULTING IN A GREATER DIFFUSION RATE INTERNAL TENSION OR TONE SIZE IS0TONIC: ▪ SMALL MOLECULES DIFFUSE THROUGH A SOLUTION ▪ IF A CELL PLACED INTO A SOLUTION NEITHER SHRINKS MORE READILY THAN DO LARGE ONES, SO SMALLER NOR SWELLS MOLECULES DIFFUSE FASTER THAN LARGER MOLECULES. ▪ MAY BE ISOSMOTIC TO THE CYTOPLASM. ▪ NOT ALL ISOSMOTIC SOLUTIONS ARE ISOTONIC. VISCOSITY HYPERTONIC: ▪ A MEASURE OF A FLUID’S RESISTANCE TO FLOW. A FLUID WITH A LOW VISCOSITY FLOWS MORE EASILY, AND A ▪ IF A CELL IS PLACED INTO A SOLUTION AND WATER FLUID WITH A HIGH VISCOSITY FLOWS LESS EASILY MOVES OUT OF THE CELL BY OSMOSIS, CAUSING THE CELL TO SHRINK ▪ MAY BE HYPEROSMOTIC TO THE CYTOPLASM OSMOSIS ▪ CRENATION: E, WATER MOVES BY OSMOSIS FROM THE ▪ DIFFUSION OF WATER (SOLVENT) ACROSS A SELECTIVELY CELL INTO THE HYPERTONIC SOLUTION, CAUSING THE PERMEABLE MEMBRANE CELL TO SHRINK, A PROCESS CALLED CRENATION IN RED ▪ DIFFUSION OF WATER (SOLVENT) ACROSS A SELECTIVELY BLOOD CELLS PERMEABLE MEMBRANE ▪ KIDNEYS HAVE AQUAPORINS, OR WATER CHANNEL HYPOTONIC: PROTEINS, THAT OPEN AND CLOSE TO ADJUST ▪ IF A CELL IS PLACED INTO A SOLUTION AND WATER MEMBRANE PERMEABILITY TO WATER. MOVES INTO THE CELL BY OSMOSIS, CAUSING THE CELL ▪ WATER DIFFUSES FROM A SOLUTION WITH TO SWELL PROPORTIONATELY MORE WATER, ACROSS A ▪ MAY BE HYPOSMOTIC TO CYTOPLASM SELECTIVELY PERMEABLE MEMBRANE, AND INTO A ▪ LYSES: THEREFORE, WATER MOVES BY OSMOSIS INTO THE SOLUTION WITH PROPORTIONATELY LESS WATER CELL, CAUSING IT TO SWELL. IF THE CELL SWELLS ▪ SOLUTION CONCENTRATIONS ARE DEFINED IN TERMS OF ENOUGH, IT CAN RUPTURE, A PROCESS CALLED5 SOLUTE CONCENTRATIONS; LESS CONCENTRATED SOLUTION (FEWER SOLUTES, MORE WATER) INTO THE FACILITATED DIFFUSION MORE CONCENTRATED SOLUTION (MORE SOLUTES, LESS ▪ ESSENTIAL MOLECULES CANNOT ENTER OR EXIT THE CELL WATER) BY DIFFUSING DIRECTLY THROUGH THE PLASMA DUE TO ▪ E LARGE VOLUME CHANGES CAUSED BY WATER THEIR CHEMICAL STRUCTURE OR SIZE MOVEMENT DISRUPT NORMAL CELL FUNCTION ▪ MEDIATED TRANSPORT: MEMBRANE TRANSPORT OSMOTIC PRESSURE PROCESS BY WHICH MEMBRANE TRANSPORT PROTEINS MEDIATE, OR ASSIST, THE MOVEMENT OF LARGE, WATER- ▪ FORCE REQUIRED TO PREVENT WATER FROM MOVING BY SOLUBLE MOLECULES OR ELECTRICALLY CHARGED OSMOSIS ACROSS A SELECTIVELY PERMEABLE MOLECULES OR IONS ACROSS THE PLASMA MEMBRANE MEMBRANE ▪ FACILITATED DIFFUSION: MEDIATED TRANSPORT ▪ DETERMINED BY PLACING THE SOLUTION INTO A TUBE PROCESS THAT MOVES SUBSTANCES INTO OR OUT OF THAT IS CLOSED AT ONE END BY A SELECTIVELY CELLS FROM A HIGHER TO A LOWER CONCENTRATION PERMEABLE MEMBRANE ▪ CARRIER PROTEINS AND CHANNEL PROTEINS CARRY OUT ▪ PROVIDES INFORMATION ABOUT THE TENDENCY FOR FACILITATED DIFFUSION. FACILITATED DIFFUSION DOES WATER TO MOVE BY OSMOSIS ACROSS A SELECTIVELY NOT REQUIRE METABOLIC ENERGY TO TRANSPORT PERMEABLE MEMBRANE SUBSTANCES ACROSS THE PLASMA MEMBRANE. pg. 8  BSNR 118 | ANATOMY AND PHYSIOLOGY | TERM 01 ▪ THE RATE AT WHICH MOLECULES OR IONS ARE PHAGOCYTOSIS TRANSPORTED IS DIRECTLY PROPORTIONAL TO THEIR CONCENTRATION GRADIENT UP TO THE POINT OF ▪ “CELL-EATING,” SATURATION ▪ SOLID PARTICLES ARE INGESTED AND PHAGOCYTIC VESICLES ARE FORMED WHITE BLOOD CELLS AND SOME ACTIVE MEMBRANE TRANSPORT OTHER CELL TYPES PHAGOCYTIZE BACTERIA, CELL DEBRIS, AND FOREIGN PARTICLES. ACTIVE TRANSPORT ▪ PHAGOCYTOSIS IS THEREFORE IMPORTANT IN ELIMINATING HARMFUL SUBSTANCES FROM THE BODY ▪ A MEDIATED TRANSPORT PROCESS THAT REQUIRES ENERGY PROVIDED BY ATP PINOCYTOSIS ▪ TRANSPORTED SUBSTANCE TO THE OPPOSITE SIDE OF THE MEMBRANE AND ITS SUBSEQUENT RELEASE FROM ▪ “CELL-DRINKING,” THE ATP-POWERED PUMP ARE FUELED BY THE ▪ DISTINGUISHED FROM PHAGOCYTOSIS IN THAT SMALLER BREAKDOWN OF ATP. VESICLES FORM, AND THEY CONTAIN MOLECULES ▪ ACTIVE TRANSPORT IS IMPORTANT BECAUSE IT CAN DISSOLVED IN LIQUID RATHER THAN PARTICLES MOVE SUBSTANCES AGAINST THEIR CONCENTRATION ▪ PINOCYTOSIS OFTEN FORMS VESICLES NEAR THE TIPS OF GRADIENTS—THAT IS, FROM LOWER CONCENTRATIONS DEEP INVAGINATIONS OF THE PLASMA MEMBRANE TO HIGHER CONCENTRATIONS. ▪ COMMON TRANSPORT PHENOMENON IN A VARIETY OF CELL TYPES SECONDARY TRANSPORT HYPERCHOLESTEROLEMIA ▪ INVOLVES THE ACTIVE TRANSPORT OF AN ION, SUCH AS SODIUM, OUT OF A CELL, ESTABLISHING A ▪ COMMON GENETIC DISORDER CHARACTERIZED BY THE CONCENTRATION GRADIENT, WITH A HIGHER REDUCTION IN OR ABSENCE OF LOW-DENSITY CONCENTRATION OF THE IONS OUTSIDE THE CELL. LIPOPROTEIN (LDL) RECEPTORS ON CELL SURFACES, ▪ THE TENDENCY FOR THE IONS TO MOVE BACK INTO THE WHICH INTERFERES WITH THE RECEPTOR-MEDIATED CELL (DOWN THEIR CONCENTRATION GRADIENT) ENDOCYTOSIS OF LDL CHOLESTEROL PROVIDES THE ENERGY NECESSARY TO MOVE A ▪ AS A RESULT OF INADEQUATE CHOLESTEROL UPTAKE, DIFFERENT ION OR SOME OTHER MOLECULE INTO THE CHOLESTEROL SYNTHESIS WITHIN THESE CELLS IS NOT CELL. REGULATED, AND TOO MUCH CHOLESTEROL IS PRODUCED. THE EXCESS CHOLESTEROL ACCUMULATES IN BLOOD VESSELS, RESULTING IN ATHEROSCLEROSIS. VESICULAR TRANSPORT ATHEROSCLEROSIS CAN CAUSE HEART ATTACKS OR STROKES ▪ VESICULAR TRANSPORT IS THE MOVEMENT OF LARGER VOLUMES OF SUBSTANCES ACROSS THE PLASMA EXOCYTOSIS MEMBRANE THROUGH THE FORMATION OR RELEASE OF VESICLES, MEMBRANE-BOUND SACS, IN THE CYTOPLASM. ▪ SECRETIONS ACCUMULATE WITHIN VESICLES. VESICULAR TRANSPORT INCLUDES ENDOCYTOSIS AND ▪ THESE SECRETORY VESICLES THEN MOVE TO THE PLASMA EXOCYTOSIS MEMBRANE, WHERE THE VESICLE MEMBRANE FUSES ▪ REQUIRES ENERGY IN THE FORM OF ATP AND THEREFORE WITH THE PLASMA MEMBRANE AND THE VESICLE IS AN ACTIVE MEMBRANE TRANSPORT PROCESS. CONTENTS ARE EXPELLED FROM THE CELL ▪ INVOLVES THE BULK MOVEMENT OF MATERIAL INTO THE ▪ THE SECRETION OF DIGESTIVE ENZYMES BY THE CELL, VESICULAR TRANSPORT DOES NOT DEMONSTRATE PANCREAS AND THE SECRETION OF MUCUS BY THE THE DEGREE OF SPECIFICITY OR SATURATION THAT SALIVARY GLANDS ARE EXAMPLES OF EXOCYTOSIS OTHER FORMS OF ACTIVE MEMBRANE TRANSPORT PUTANGINA AYOKO NA EXHIBIT CHAPTER 3: CELL BIOLOGY TYPES OF VESICULAR TRANSPORT 3.7. CYTOPLASM ENDOCYTOSIS CYTOPLASM ▪ OCCURS WHEN MATERIAL MOVES THROUGH THE PLASMA MEMBRANE AND INTO THE CYTOPLASM BY THE ▪ THE CELLULAR MATERIAL OUTSIDE THE NUCLEUS BUT FORMATION OF A VESICLE. INSIDE THE PLASMA MEMBRANE, IS ABOUT HALF ▪ CAN EXHIBIT SPECIFICITY CYTOSOL AND HALF ORGANELLES ▪ THE PLASMA MEMBRANE MAY CONTAIN SPECIFIC CYTOSOL RECEPTOR MOLECULES THAT RECOGNIZE CERTAIN SUBSTANCES AND ALLOW THEM TO BE TRANSPORTED ▪ THE FLUID PORTION OF THE CYTOPLASM INTO THE CELL BY PHAGOCYTOSIS OR PINOCYTOSIS. THIS ▪ A COLLOID, A VISCOUS SOLUTION CONTAINING IS CALLED RECEPTOR-MEDIATED ENDOCYTOSIS DISSOLVED IONS AND MOLECULES AS WELL AS ▪ THIS MECHANISM INCREASES THE RATE AT WHICH THE SUSPENDED MOLECULES, ESPECIALLY PROTEINS. CELLS TAKE UP SPECIFIC SUBSTANCES. CHOLESTEROL AND o ENZYMES, FATTY ACIDS, NUCLEOTIDES, GROWTH FACTORS ARE EXAMPLES OF MOLECULES THAT AMINO ACIDS, AND OTHER MOLECULES CAN BE TAKEN INTO A CELL BY RECEPTOR-MEDIATED o OTHER PROTEINS IN THE CYTOSOL MAKE UP ENDOCYTOSIS THE CYTOSKELETON AND CYTOPLASMIC INCLUSIONS pg. 9  BSNR 118 | ANATOMY AND PHYSIOLOGY | TERM 01 CYTOSKELETON CHAPTER 3: CELL BIOLOGY ▪ SUPPORTS THE CELL AND HOLDS THE NUCLEUS AND 3.8. THE NUCLEUS AND CYTOPLASMIC ORGANELLES OTHER ORGANELLES IN PLACE. ▪ RESPONSIBLE FOR CHANGES IN CELL SHAPE AND THE ORGANELLES MOVEMENT OF CELL ORGANELLES ▪ STRUCTURES WITHIN CELLS THAT ARE SPECIALIZED FOR CONSIST OF THREE GROUPS OF PROTEIN PARTICULAR FUNCTIONS, SUCH AS MANUFACTURING PROTEINS OR PRODUCING ATP MICROTUBULES ▪ INDIVIDUAL WORKSTATIONS WITHIN THE CELL, EACH RESPONSIBLE FOR PERFORMING SPECIFIC TASKS. ▪ HOLLOW TUBES COMPOSED PRIMARILY OF PROTEIN ▪ ONE CLASS OF ORGANELLES HAS MEMBRANES THAT ARE UNITS CALLED TUBULIN. THE MICROTUBULES SIMILAR TO THE PLASMA MEMBRANE, WHEREAS OTHER ▪ BOUT 25 NANOMETERS (NM) IN DIAMETER, WITH WALLS ORGANELLES ARE CLUSTERS OF PROTEINS AND OTHER ABOUT 5 NM THICK, VARY IN LENGTH BUT NORMALLY MOLECULES NOT SURROUNDED BY A MEMBRANE SEVERAL MICROMETERS (ΜM) LONG (LENGTH CAN ▪ INTERIOR OF THE MEMBRANE-BOUND ORGANELLES IS CHANGE AS TUBULIN SUBUNITS ARE ADDED OR SEPARATED FROM THE CYTOPLASM, CREATING SUBCELLULAR REMOVED.) COMPARTMENTS HAVING THEIR OWN ENZYMES CAPABLE OF CARRYING OUT UNIQUE CHEMICAL REACTIONS ROLES: ▪ NUCLEUS IS THE LARGEST ORGANELLE OF THE CELL. ▪ HELP PROVIDE SUPPORT AND STRUCTURE TO THE CYTOPLASM OF THE CELL NUCLEUS ▪ INTERNAL SCAFFOLDING ▪ NVOLVED IN CELL DIVISION AND IN THE TRANSPORT OF ▪ A LARGE, MEMBRANE-BOUND STRUCTURE USUALLY LOCATED INTRACELLULAR MATERIALS. NEAR THE CENTER OF THE CELL ▪ FORM ESSENTIAL COMPONENTS OF CERTAIN CELL ▪ MAY BE SPHERICAL, ELONGATED, OR LOBED, DEPENDING ON ORGANELLES, SUCH AS CENTRIOLES, SPINDLE FIBERS, THE CELL TYPE. ALL BODY CELLS HAVE A NUCLEUS AT SOME CILIA, AND FLAGELLA. POINT IN THEIR LIFE CYCLE (SEE SECTION 3.10), ALTHOUGH SOME CELLS, SUCH AS RED BLOOD CELLS, LOSE THEIR NUCLEI ACTIN FILAMENTS AS THEY DEVELOP. ▪ NUCLEUS CONSISTS OF NUCLEOPLASM SURROUNDED BY A ▪ MICROFILAMENTS NUCLEAR ENVELOPE ▪ SMALL FIBRILS, ABOUT 8 NM IN DIAMETER, THAT FORM ▪ NUCLEAR ENVELOPE IS COMPOSED OF TWO MEMBRANES BUNDLES, SHEETS, OR NETWORKS IN THE CYTOPLASM. SEPARATED BY A SPACE ▪ MUSCLE CELLS CONTAIN A LARGE NUMBER OF HIGHLY ▪ DEOXYRIBONUCLEIC ACID (DNA) IS MOSTLY FOUND WITHIN ORGANIZED ACTIN FILAMENTS, WHICH ARE RESPONSIBLE THE NUCLEUS FOR THE MUSCLE’S CONTRACTILE CAPABILITIES ▪ THE DNA AND ASSOCIATED PROTEINS ORGANIZED INTO DISCRETE STRUCTURES ROLES: ▪ THE ASSOCIATED PROTEINS INCLUDE HISTONES WHICH ARE ▪ PROVIDE STRUCTURE TO THE CYTOPLASM AND IMPORTANT FOR THE STRUCTURAL ORGANIZATION OF DNA MECHANICAL SUPPORT FOR MICROVILLI. ▪ DURING MOST OF THE CELL’S LIFE CYCLE, THE CHROMOSOMES ▪ SUPPORT THE PLASMA MEMBRANE AND DEFINE THE ARE DISPERSED THROUGHOUT THE NUCLEUS AS DELICATE SHAPE OF THE CELL. FILAMENTS COLLECTIVELY REFERRED TO AS CHROMATIN ▪ DURING CELL DIVISION THE CHROMATIN FILAMENTS BECOME INTERMEDIATE FILAMENTS DENSELY COILED, FORMING COMPACT CHROMOSOMES. ▪ PROTEIN FIBERS ABOUT 10 NM IN DIAMETER THAT RIBOSOME PROVIDE MECHANICAL STRENGTH TO CELLS ▪ SITES OF PROTEIN SYNTHESIS ROLES: ▪ COMPOSED OF A LARGE SUBUNIT AND A SMALL SUBUNIT ▪ RIBOSOMAL SUBUNITS CONSIST OF RIBOSOMAL RNA (RRNA) ▪ SUPPORT THE EXTENSIONS OF NERVE CELLS, WHICH HAVE PRODUCED IN THE NUCLEOLUS OF THE NUCLEUS AND A VERY SMALL DIAMETER BUT CAN BE UP TO A METER IN PROTEINS PRODUCED IN THE CYTOPLASM LENGTH ▪ RIBOSOMAL SUBUNITS THEN MOVE THROUGH THE NUCLEAR CYTOPLASMIC INCLUSIONS PORES INTO THE CYTOPLASM, WHERE THE RIBOSOMAL SUBUNITS ASSEMBLE WITH MRNA TO FORM THE FUNCTIONAL ▪ ARE AGGREGATES OF CHEMICALS EITHER PRODUCED OR RIBOSOME DURING PROTEIN SYNTHESIS. TAKEN IN BY THE CELL. LIPID DROPLETS OR GLYCOGEN ▪ FOUND FREE IN THE CYTOPLASM OR ATTACHED TO AN GRANULES STORE ENERGY-RICH MOLECULES; INTRACELLULAR MEMBRANE COMPLEX CALLED THE HEMOGLOBIN IN RED BLOOD CELLS TRANSPORTS ENDOPLASMIC RETICULUM. OXYGEN; THE PIGMENT MELANIN COLORS THE SKIN, ▪ FREE RIBOSOMES PRIMARILY SYNTHESIZE PROTEINS USED HAIR, AND EYES; AND LIPOCHROMES ARE PIGMENTS INSIDE THE CELL, WHEREAS RIBOSOMES ATTACHED TO THE THAT INCREASE IN AMOUNT WITH AGE. ENDOPLASMIC RETICULUM PRODUCE INTEGRAL MEMBRANE ▪ DUST, MINERALS, AND DYES CAN ALSO ACCUMULATE IN PROTEINS AND PROTEINS THAT ARE SECRETED FROM THE CELL. THE CYTOPLASM. pg. 10  BSNR 118 | ANATOMY AND PHYSIOLOGY | TERM 01 ENDOPLASTIC RETICULUM GLYCOPROTEINS OR BY ATTACHING LIPIDS TO THE PROTEINS TO FORM LIPOPROTEINS. THE OUTER MEMBRANE OF THE NUCLEAR ENVELOPE IS ▪ PROTEINS ARE THEN PACKAGED INTO VESICLES THAT PINCH CONTINUOUS WITH A SERIES OF MEMBRANES DISTRIBUTED OFF FROM THE MARGINS OF THE GOLGI APPARATUS AND ARE THROUGHOUT THE CYTOPLASM OF THE CELL COLLECTIVELY DISTRIBUTED TO VARIOUS LOCATIONS. SOME VESICLES CARRY REFERRED TO AS THE ENDOPLASMIC PROTEINS TO THE PLASMA MEMBRANE, WHERE THE PROTEINS ARE SECRETED FROM THE CELL BY EXOCYTOSIS; OTHER CONSISTS OF BROAD, FLATTENED, INTERCONNECTING SACS AND VESICLES CONTAIN PROTEINS THAT BECOME PART OF THE TUBULES NETWORK INSIDE THE CYTOPLASM) ▪ PLASMA MEMBRANE: AND STILL OTHER VESICLES CONTAIN ENZYMES THAT ARE USED WITHIN THE CELL. THE GOLGI THE INTERIOR SPACES OF THOSE SACS AND TUBULES ARE CALLED APPARATUS IS MOST HIGHLY DEVELOPED IN CELLS THAT CISTERNAE AND ARE ISOLATED FROM THE REST OF THE CYTOPLASM. SECRETE LARGE AMOUNTS OF PROTEIN OR GLYCOPROTEINS, SUCH AS CELLS IN THE SALIVARY GLANDS AND THE PANCREAS. ROUGH ENDOPLASMIC RETICULUM ▪ “ROUGH” BECAUSE RIBOSOMES ARE ATTACHED TO IT SECRETORY VESICLE ▪ SITES WHERE PROTEINS ARE PRODUCED AND MODIFIED FOR ▪ THE MEMBRANE-BOUND SECRETORY VESICLES THAT PINCH USE AS INTEGRAL MEMBRANE PROTEINS AND FOR SECRETION OFF FROM THE GOLGI APPARATUS MOVE TO THE SURFACE OF INTO THE EXTRACELLULAR SPACE. THE CELL, THEIR MEMBRANES FUSE WITH THE PLASMA ▪ THE AMOUNT AND CONFIGURATION OF THE ENDOPLASMIC MEMBRANE, AND THE CONTENTS OF THE VESICLES ARE RETICULUM WITHIN THE CYTOPLASM DEPEND ON THE TYPE RELEASED TO THE EXTERIOR BY EXOCYTOSIS. AND FUNCTION OF THE PARTICULAR CELL. ▪ THE MEMBRANES OF THE VESICLES ARE THEN INCORPORATED ▪ CELLS WITH ABUNDANT ROUGH ENDOPLASMIC RETICULUM INTO THE PLASMA MEMBRANE. SYNTHESIZE LARGE AMOUNTS OF PROTEIN, WHICH ARE ▪ SECRETORY VESICLES ACCUMULATE IN SOME CELLS, BUT THEIR SECRETED FOR USE OUTSIDE THE CELL. CONTENTS FREQUENTLY ARE NOT RELEASED TO THE EXTERIOR UNTIL THE CELL RECEIVES A SIGNAL. ▪ FOR EXAMPLE, SECRETORY VESICLES THAT CONTAIN THE SMOOTH ENDOPLASMIC RETICULUM HORMONE INSULIN DO NOT RELEASE IT UNTIL THE CONCENTRATION OF GLUCOSE IN THE BLOOD INCREASES AND ▪ ENDOPLASMIC RETICULUM WITHOUT ATTACHED RIBOSOMES, ACTS AS A SIGNAL FOR THE SECRETION OF INSULIN FROM THE MANUFACTURES LIPIDS, SUCH AS PHOSPHOLIPIDS, CELLS CHOLESTEROL, AND STEROID HORMONES, AS WELL AS CARBOHYDRATES. LYSOSOME ▪ ENZYMES REQUIRED FOR LIPID SYNTHESIS ARE ASSOCIATED WITH THE MEMBRANES OF THE SMOOTH ENDOPLASMIC ▪ ARE MEMBRANE-BOUND VESICLES THAT FORM AT THE GOLGI RETICULUM, AND CELLS THAT SYNTHESIZE LARGE AMOUNTS APPARATUS OF LIPIDS CONTAIN DENSE ACCUMULATIONS OF SMOOTH ▪ CONTAIN A VARIETY OF HYDROLYTIC ENZYMES THAT ENDOPLASMIC RETICULUM. FUNCTION AS INTRACELLULAR DIGESTIVE SYSTEMS. VESICLES ▪ MANY PHOSPHOLIPIDS PRODUCED IN THE SMOOTH TAKEN INTO THE CELL FUSE WITH THE LYSOSOMES TO FORM ENDOPLASMIC RETICULUM HELP FORM VESICLES WITHIN THE ONE VESICLE AND TO EXPOSE THE ENDOCYTIZED MATERIALS CELL AND CONTRIBUTE TO THE PLASMA MEMBRANE. TO HYDROLYTIC ENZYMES ▪ SMOOTH ENDOPLASMIC RETICULUM ALSO PARTICIPATES IN ▪ VARIOUS ENZYMES WITHIN LYSOSOMES DIGEST NUCLEIC DETOXIFICATION, THE PROCESSES BY WHICH ENZYMES ACT ON ACIDS, PROTEINS, POLYSACCHARIDES, AND LIPIDS. CHEMICALS AND DRUGS TO CHANGE THEIR STRUCTURE AND ▪ CERTAIN WHITE BLOOD CELLS HAVE LARGE NUMBERS OF REDUCE THEIR TOXICITY. LYSOSOMES THAT CONTAIN ENZYMES TO DIGEST ▪ THE SMOOTH ENDOPLASMIC RETICULUM OF SKELETAL PHAGOCYTIZED BACTERIA. LYSOSOMES ALSO DIGEST THE MUSCLE STORES THE CALCIUM IONS THAT FUNCTION IN ORGANELLES OF THE CELL THAT ARE NO LONGER FUNCTIONAL, MUSCLE CONTRACTION. A PROCESS CALLED AUTOPHAGY (SELF-EATING). ▪ IN OTHER CELLS, THE LYSOSOMES MOVE TO THE PLASMA MEMBRANE, AND THE ENZYMES ARE SECRETED BY EXOCYTOSIS. GOLGI APPARATUS ▪ FOR EXAMPLE, THE NORMAL PROCESS OF BONE REMODELING INVOLVES THE BREAKDOWN OF BONE TISSUE BY SPECIALIZED ▪ COMPOSED OF FLATTENED, MEMBRANOUS SACS, CONTAINING BONE CELLS. LYSOSOMES PRODUCED BY THOSE CELLS RELEASE CISTERNAE, STACKED ON EACH OTHER LIKE DINNER PLATES THE ENZYMES RESPONSIBLE FOR THAT DEGRADATION INTO ▪ CAN BE THOUGHT OF AS A PACKAGING AND DISTRIBUTION THE EXTRACELLULAR FLUID. CENTER BECAUSE IT MODIFIES, PACKAGES, AND DISTRIBUTES PROTEINS AND LIPIDS MANUFACTURED BY THE ROUGH AND PERIXOSOME SMOOTH ENDOPLASMIC RETICULA ▪ PROTEINS PRODUCED AT THE RIBOSOMES ATTACHED TO THE ▪ ARE MEMBRANE-BOUND VESICLES THAT ARE SMALLER THAN ROUGH ENDOPLASMIC RETICULUM MOVE INTO THE LYSOSOMES. PEROXISOMES CONTAIN ENZYMES THAT BREAK ENDOPLASMIC RETICULUM DOWN FATTY ACIDS AND AMINO ACIDS. ▪ PROTEINS ARE LATER PACKAGED INTO TRANSPORT VESICLES ▪ THE BREAKDOWN OF THESE MOLECULES CAN PRODUCE THAT THEN MOVE TO THE GOLGI APPARATUS. HYDROGEN PEROXIDE (H2O2) AS A TOXIC BY-PRODUCT. ▪ TRANSPORT VESICLES FUSE WITH THE GOLGI APPARATUS PEROXISOMES ALSO CONTAIN THE ENZYME CATALASE, WHICH MEMBRANE AND RELEASE THE PROTEINS INTO THE GOLGI BREAKS DOWN HYDROGEN PEROXIDE TO WATER AND OXYGEN APPARATUS CISTERNA. THEREBY ELIMINATING THE TOXIC SUBSTANCE. ▪ CONCENTRATES AND, IN SOME CASES, CHEMICALLY MODIFIES ▪ CELLS THAT ARE ACTIVE IN DETOXIFICATION, SUCH AS LIVER THE PROTEINS BY SYNTHESIZING AND ATTACHING AND KIDNEY CELLS, HAVE MANY PEROXISOMES. CARBOHYDRATE MOLECULES TO THE PROTEINS TO FORM pg. 11  BSNR 118 | ANATOMY AND PHYSIOLOGY | TERM 01 ▪ MICROTUBULES APPEAR TO INFLUENCE THE DISTRIBUTION OF ACTIN AND INTERMEDIATE FILAMENTS. PROTEASOME ▪ THROUGH ITS CONTROL OF MICROTUBULE FORMATION, THE CENTROSOME IS CLOSELY INVOLVED IN DETERMINING CELL ▪ ARE LARGE PROTEIN COMPLEXES CONTAINING ENZYMES THAT SHAPE AND MOVEMENT. BREAK DOWN AND RECYCLE OTHER PROTEINS WITHIN THE ▪ THE MICROTUBULES EXTENDING FROM THE CENTROSOMES CELL. ARE VERY DYNAMIC—CONSTANTLY GROWING AND ▪ PROTEASOMES ARE NOT SURROUNDED BY MEMBRANES BUT SHRINKING. INSTEAD ARE A COLLECTION OF SPECIFIC PROTEINS FORMING ▪ BEFORE CELL DIVISION, THE TWO CENTRIOLES DOUBLE IN BARREL-LIKE STRUCTURES. NUMBER; THE CENTROSOME DIVIDES INTO TWO; AND ONE ▪ THE INNER SURFACES OF THE BARREL HAVE ENZYMATIC CENTROSOME, CONTAINING TWO CENTRIOLES, MOVES TO REGIONS THAT BREAK DOWN THE PROTEINS. EACH END OF THE CELL. ▪ OTHER PROTEINS AT THE ENDS OF THE BARREL REGULATE ▪ MICROTUBULES CALLED SPINDLE FIBERS EXTEND OUT IN ALL WHICH PROTEINS ARE TAKEN IN FOR BREAKDOWN AND DIRECTIONS FROM THE CENTROSOME. RECYCLING ▪ THESE MICROTUBULES GROW AND SHRINK EVEN MORE RAPIDLY THAN THOSE OF NON-DIVIDING CELLS. MITOCHONDRIA ▪ IF THE EXTENDED END OF A SPINDLE FIBER COMES IN CONTACT WITH A CHROMOSOME, THE SPINDLE FIBER ATTACHES TO THE ▪ ORGANELLES THAT PROVIDE THE MAJORITY OF THE ENERGY CHROMOSOME AND STOPS GROWING OR SHRINKING. FOR THE CELL. CONSEQUENTLY, THEY ARE OFTEN CALLED THE ▪ EVENTUALLY, SPINDLE FIBERS FROM EACH CENTROSOME BIND CELL’S POWER PLANTS. TO ALL THE CHROMOSOMES. DURING CELL DIVISION, THE ▪ SMALL, ROD-SHAPED STRUCTURES SPINDLE MICROTUBULES FACILITATE THE MOVEMENT OF ▪ VERY DYNAMIC AND CONSTANTLY CHANGE SHAPE AND CHROMOSOMES TOWARD THE TWO CENTROSOMES NUMBER AS THEY SPLIT AND FUSE WITH EACH OTHER. ▪ MAJOR SITES FOR THE PRODUCTION OF ATP, WHICH IS THE CILIA AND FLAGELLA PRIMARY ENERGY SOURCE FOR MOST ENERGY-REQUIRING CHEMICAL REACTIONS WITHIN THE CELL CILIA ▪ MITOCHONDRION HAS AN INNER AND AN OUTER MEMBRANE, SEPARATED BY AN INTERMEMBRANE SPACE. THE OUTER ▪ STRUCTURES THAT PROJECT FROM THE SURFACE OF CELLS AND MEMBRANE HAS A SMOOTH CONTOUR, BUT THE INNER ARE CAPABLE OF MOVEMENT MEMBRANE HAS NUMEROUS INFOLDINGS CALLED CRISTAE ▪ CYLINDRICAL IN SHAPE, MEASURING ABOUT 10 ΜM IN LENGTH THAT PROJECT LIKE SHELVES INTO THE INTERIOR OF THE AND 0.2 ΜM IN DIAMETER. MITOCHONDRION. THE MATERIAL LOCATED INSIDE THE INNER ▪ MOVEMENT OF THE CILIUM RESULTS WHEN THE MEMBRANE IS CALLED THE MATRIX. MICROTUBULES MOVE PAST EACH OTHER, A PROCESS THAT ▪ MITOCHONDRION HAS AN INNER AND AN OUTER MEMBRANE, REQUIRES ENERGY FROM ATP SEPARATED BY AN INTERMEMBRANE SPACE. THE OUTER ▪ DYNEIN ARMS, PROTEINS CONNECTING ADJACENT PAIRS OF MEMBRANE HAS A SMOOTH CONTOUR, BUT THE INNER MICROTUBULES, PUSH THE MICROTUBULES PAST EACH OTHER. MEMBRANE HAS NUMEROUS INFOLDINGS CALLED CRISTAE A BASAL BODY (A MODIFIED CENTRIOLE) IS LOCATED IN THE (KRIS′TEˉ; SING. CRISTA) THAT PROJECT LIKE SHELVES INTO THE CYTOPLASM AT THE BASE OF THE CILIUM INTERIOR OF THE MITOCHONDRION. THE MATERIAL LOCATED ▪ NUMEROUS ON SURFACE CELLS THAT LINE THE RESPIRATORY INSIDE THE INNER MEMBRANE IS CALLED THE MATRIX. TRACT AND THE FEMALE REPRODUCTIVE TRACT. IN THESE ▪ MITOCHONDRION HAS AN INNER AND AN OUTER MEMBRANE, REGIONS, CILIA MOVE IN A COORDINATED FASHION, WITH A SEPARATED BY AN INTERMEMBRANE SPACE. THE OUTER POWER STROKE IN ONE DIRECTION AND A RECOVERY STROKE MEMBRANE HAS A SMOOTH CONTOUR, BUT THE INNER IN THE OPPOSITE DIRECTION MEMBRANE HAS NUMEROUS INFOLDINGS CALLED CRISTAE ▪ THEIR MOTION MOVES MATERIALS OVER THE SURFACE OF THE (KRIS′TEˉ; SING. CRISTA) THAT PROJECT LIKE SHELVES INTO THE CELLS. FOR EXAMPLE, CILIA IN THE TRACHEA MOVE MUCUS INTERIOR OF THE MITOCHONDRION. THE MATERIAL LOCATED CONTAINING TRAPPED DUST PARTICLES UPWARD AND AWAY INSIDE THE INNER MEMBRANE IS CALLED THE MATRIX. FROM THE LUNGS, THUS HELPING KEEP THE LUNGS CLEAR OF ▪ EXERCISE, THE NUMBER OF MITOCHONDRIA WITHIN THE DEBRIS. MUSCLE CELLS INCREASES TO PROVIDE THE ADDITIONAL ATP REQUIRED FOR MUSCLE CONTRACTION ▪ CONTAIN DNA AND RIBOSOME – INFORMATION FOR MAKING SOME MITOCHONDRIAL PROTEINS IS STORED IN MITOCHONDRIAL DNA, ▪ PROTEINS ARE SYNTHESIZED ON MITOCHONDRIAL RIBOSOMES ▪ STRUCTURE OF MOST MITOCHONDRIAL PROTEINS IS DETERMINED BY NUCLEAR DNA, AND THESE PROTEINS ARE SYNTHESIZED ON RIBOSOMES WITHIN THE CYTOPLASM AND THEN TRANSPORTED INTO THE MITOCHONDRIA. CENTRIOLE AND SPINDLE FIBERS ▪ THE CENTROSOME, A SPECIALIZED ZONE OF CYTOPLASM CLOSE TO THE NUCLEUS, IS THE CENTER OF MICROTUBULE FLAGELLA FORMATION IN THE CELL. ▪ WITHIN THE CENTROSOME ARE TWO CENTRIOLES EACH ▪ HAVE A STRUCTURE SIMILAR TO THAT OF CILIA, BUT THEY ARE CENTRIOLE IS A SMALL, CYLINDRICAL ORGANELLE ABOUT 0.3– LONGER (45 ΜM). SPERM CELLS ARE THE ONLY HUMAN CELLS 0.5 ΜM IN LENGTH AND 0.15 ΜM IN DIAMETER, AND THE TWO THAT POSSESS FLAGELLA, AND USUALLY ONLY ONE FLAGELLUM CENTRIOLES ARE NORMALLY ORIENTED PERPENDICULAR TO EXISTS PER CELL. EACH OTHER WITHIN THE CENTROSOME ▪ FURTHERMORE, WHEREAS CILIA MOVE SMALL PARTICLES ACROSS THE CELL SURFACE, FLAGELLA MOVE THE ENTIRE CELL. pg. 12  BSNR 118 | ANATOMY AND PHYSIOLOGY | TERM 01 FOR EXAMPLE, EACH SPERM CELL IS PROPELLED BY A SINGLE GENETIC CODE FLAGELLUM. ▪ IN CONTRAST TO CILIA, WHICH HAVE A POWER STROKE AND A ▪ THE INFORMATION CONTAINED IN MRNA AND IT RELATES THE RECOVERY STROKE, FLAGELLA MOVE IN A WAVELIKE FASHION NUCLEOTIDE SEQUENCE OF MRNA TO THE AMINO ACID SEQUENCE OF A PROTEIN. THE MRNA IS ORGANIZED INTO MICROVILLI CODONS, THREE NUCLEOTIDE SEQUENCES, EACH OF WHICH SPECIFIES AN AMINO ACID DURING TRANSLATION. ▪ CYLINDRICALLY SHAPED EXTENSIONS OF THE PLASMA ▪ FURTHERMORE, SOME CODONS ACT AS SIGNALS DURING MEMBRANE ABOUT 0.5–1.0 ΜM IN LENGTH AND 90 NM IN TRANSLATION. AUG, WHICH SPECIFIES METHIONINE, ALSO DIAMETER ACTS AS A START CODON, WHICH SIGNALS THE BEGINNING OF ▪ PRESENCE OF MICROVILLI INCREASES THE CELL SURFACE TRANSLATION. UAA, UGA, AND UAG ACT AS STOP CODONS, AREA. WHICH SIGNAL THE END OF TRANSLATION. UNLIKE THE START ▪ INDIVIDUAL MICROVILLI CAN USUALLY BE SEEN ONLY WITH AN CODON, STOP CODONS DO NOT SPECIFY AMINO ACIDS. ELECTRON MICROSCOPE ▪ THEREFORE, THE PROTEIN-CODING REGION OF AN MRNA ▪ MICROVILLI DO NOT MOVE, AND THEY ARE SUPPORTED WITH BEGINS AT THE START CODON AND ENDS AT A STOP CODON ACTIN FILAMENTS, NOT MICROTUBULES. ▪ FOUND ON THE CELLS OF THE INTESTINE, KIDNEY, AND OTHER TRANSLATION AREAS WHERE ABSORPTION IS AN IMPORTANT FUNCTION ▪ IN CERTAIN LOCATIONS OF THE BODY, MICROVILLI ARE HIGHLY ▪ TRANSLATION IS THE SYNTHESIS OF A PROTEIN AT THE MODIFIED TO FUNCTION AS SENSORY RECEPTORS. FOR RIBOSOME BASED ON THE SEQUENCE OF THE CODONS OF EXAMPLE, ELONGATED MICROVILLI IN HAIR CELLS OF THE MRNA INNER EAR RESPOND TO SOUND ▪ TRANSLATION REQUIRES RIBOSOMES AND TRNA. RIBOSOMES CONSIST OF RIBOSOMAL RNA (RRNA) AND PROTEINS. LIKE CHAPTER 3: CELL BIOLOGY MRNA, TRNA AND RRNA ARE PRODUCED IN THE NUCLEUS BY 3.9. GENE EXPRESSION TRANSCRIPTION ▪ THE FUNCTION OF TRNA IS TO MATCH A SPECIFIC AMINO ACID ▪ GENES ARE THE FUNCTIONAL UNITS OF HEREDITY. TO A SPECIFIC CODON OF MRNA. ▪ HEREDITY IS THE TRANSMISSION OF GENETIC TRAITS FROM ▪ THERE ARE MULTIPLE TYPES OF TRNA, EACH SPECIFIC TO ONE PARENT TO OFFSPRING. AMINO ACID. THE AMINO ACID BINDS TO ONE END OF ITS ▪ EACH GENE IS A SEGMENT OF A DNA MOLECULE THAT SPECIFIC TRNA MOLECULE. SPECIFIES THE STRUCTURE OF AN RNA MOLECULE. ▪ ANOTHER PART OF THE TRNA, CALLED THE ANTICODON, ▪ THIS RNA CAN BE FUNCTIONAL ON ITS OWN, OR IT CAN CONSISTS OF THREE NUCLEOTIDES AND IS COMPLEMENTARY PRODUCE A PROTEIN. TO A PARTICULAR CODON OF MRNA. ▪ THE PRODUCTION OF RNA AND/OR PROTEINS FROM THE ▪ POLYRIBOSOME : THE RESULTING CLUSTER OF RIBOSOMES INFORMATION STORED IN DNA IS CALLED GENE EXPRESSION ATTACHED TO THE SAME MRNA ▪ PROPROTEIN: MANY PROTEINS ARE LONGER WHEN THEY ARE TRANSCRIPTION FIRST MADE THAN IN THEIR FINAL, FUNCTIONAL STATE ▪ PROENZYMES: MANY PROTEINS ARE ENZYMES, AND THE ▪ TRANSCRIPTION IS THE SYNTHESIS OF MRNA, TRNA, AND RRNA PROPROTEINS OF THOSE ENZYMES ARE CALLED PROENZYMES. MOLECULES BASED ON THE NUCLEOTIDE SEQUENCE IN DNA ▪ MANY PROTEINS ARE ENZYMES, AND THE PROPROTEINS OF TRANSCRIPTION OCCURS WHEN A SECTION OF A DNA THOSE ENZYMES ARE CALLED PROENZYMES. MOLECULE UNWINDS AND ITS COMPLEMENTARY STRANDS SEPARATE. ONE OF THE DNA STRANDS SERVES AS THE REGULATION OF GENE EXPRESSION TEMPLATE STRAND FOR THE PROCESS OF TRANSCRIPTION ▪ RNA POLYMERASE IS AN ENZYME THAT SYNTHESIZES THE ▪ MOST OF THE CELLS IN THE BODY HAVE THE SAME DNA. COMPLEMENTARY RNA MOLECULE FROM DNA. RNA HOWEVER, THE TRANSCRIPTION OF MRNA IN CELLS IS POLYMERASE MUST ATTACH TO THE DNA MOLECULE NEAR THE REGULATED SO THAT ONLY THE NECESSARY GENES ARE BEGINNING OF THE GENE A DNA NUCLEOTIDE SEQUENCE TRANSCRIBED. CALLED A PROMOTER SIGNALS THE BEGINNING OF THE GENE ▪ THE PROTEINS ASSOCIATED WITH DNA IN THE NUCLEUS PLAY A AND IS THE SITE FOR INITIAL RNA POLYMERASE BINDING ROLE IN REGULATING TRANSCRIPTION. AS CELLS ▪ RNA POLYMERASE IS AN ENZYME THAT SYNTHESIZES THE DIFFERENTIATE AND ACQUIRE SPECIALIZED FUNCTIONS COMPLEMENTARY RNA MOLECULE FROM DNA. RNA DURING DEVELOPMENT, PART OF THE DNA IS NO LONGER POLYMERASE MUST ATTACH TO THE DNA MOLECULE NEAR THE TRANSCRIBED, WHEREAS OTHER SEGMENTS OF DNA BECOME BEGINNING OF THE GENE MORE ACTIVE. ▪ REGIONS OF THE MRNA THAT DO CODE FOR PROTEINS ARE ▪ GENE EXPRESSION IN A SINGLE CELL IS NOT NORMALLY CALLED EXONS, WHEREAS THE REGIONS THAT DO NOT CODE CONSTANT BUT FLUCTUATES IN RESPONSE TO CHANGES IN FOR A PROTEIN ARE CALLED INTRONS. AN MRNA THAT SIGNALS FROM WITHIN AND OUTSIDE THE CELL. CONTAINS INTRONS IS CALLED A PRE-MRNA ▪ CHAPTER 3: CELL BIOLOGY ▪ IN A PROCESS CALLED ALTERNATIVE SPLICING, VARIOUS 3.10. CELL CYCLE COMBINATIONS OF EXONS ARE INCORPORATED INTO MRNA. WHICH EXONS—AND HOW MANY—ARE USED TO MAKE MRNA INTERPHASE CAN VARY BETWEEN CELLS OF DIFFERENT TISSUES, RESULTING IN DIFFERENT MRNAS TRANSCRIBED FROM THE SAME GENE. ▪ PHASE BETWEEN CELL DIVISIONS; NEARLY ALL OF THE LIFE ALTERNATIVE SPLICING ALLOWS A SINGLE GENE TO PRODUCE CYCLE OF A TYPICAL CELL IS SPENT IN INTERPHASE MORE THAN ONE SPECIFIC PROTEIN; HOWEVER, THE VARIOUS ▪ CELL CARRIES OUT THE METABOLIC ACTIVITIES NECESSARY FOR PROTEINS USUALLY HAVE SIMILAR FUNCTIONS IN DIFFERENT LIFE AND PERFORMS ITS SPECIALIZED FUNCTIONS TISSUES. IN HUMANS, NEARLY ALL MRNAS UNDERGO ▪ INCREASE IN CELL SIZE AS MANY CELL COMPONENTS DOUBLE ALTERNATIVE RNA SPLICING IN QUANTITY AND A DOUBLING OF THE DNA CONTENT DURING DNA REPLICATION. pg. 13  BSNR 118 | ANATOMY AND PHYSIOLOGY | TERM 01 ▪ CENTRIOLES WITHIN THE CENTROSOME ARE ALSO ▪ DURING MITOSIS, THE CHROMATIN BECOMES VERY DENSELY DUPLICATED. COILED TO FORM COMPACT CHROMOSOMES CALLED MITOTIC ▪ INTERPHASE CAN BE DIVIDED INTO THREE SUBPHASES, CALLED CHROMOSOMES. G1, S, AND G2 ▪ MITOTIC CHROMOSOMES ARE DISCRETE BODIES THAT CAN BE STAINED AND EASILY SEEN WITH A LIGHT MICROSCOPE. DURING G1 (THE FIRST GAP PHASE) ▪ AS A RESULT, EACH MITOTIC CHROMOSOME CONSISTS OF TWO COPIES OF THE ORIGINAL CHROMOSOME. EACH COPY IS THE CELL CARRIES OUT ROUTINE METABOLIC ACTIVITIES. CALLED A CHROMATID ▪ CHROMATIDS ARE ATTACHED AT THE CENTROMERE DURING THE S PHASE (THE SYNTHESIS PHASE) ▪ THE KINETOCHORE IS A PROTEIN STRUCTURE THAT BINDS THE THE DNA IS REPLICATED (NEW DNA IS SYNTHESIZED). CENTROMERE AND PROVIDES A POINT OF ATTACHMENT FOR MICROTUBULES THAT WILL SEPARATE AND MOVE THE DURING THE G2 PHASE (THE SECOND GAP PHASE) CHROMATIDS DURING MITOSIS ▪ AFTER THE CHROMATIDS HAVE SEPARATED, EACH IS THE CELL PREPARES FOR CELL DIVISION. CONSIDERED A CHROMOSOME. EACH DAUGHTER CELL RECEIVES ▪ MANY BODY CELLS DO NOT DIVIDE FOR DAYS, MONTHS, OR ▪ MITOSIS IS DIVIDED INTO FOUR PHASES: PROPHASE, EVEN YEARS. THESE “RESTING” CELLS DO NOT FOLLOW THE METAPHASE, ANAPHASE, AND TELOPHASE NORMAL PATTERN OF THE CELL CYCLE BUT INSTEAD ENTER WHAT IS CALLED THE G0 PHASE, IN WHICH THEY REMAIN DURING PROPHASE UNLESS STIMULATED TO DIVIDE. ▪ THE CHROMATIN CONDENSES TO FORM MITOTIC DNA REPLICATION CHROMOSOMES. THE CHROMOSOMES ARE VISIBLE WITH ▪ PROCESS IN WHICH THE TWO STRANDS OF A DNA MOLECULE A LIGHT MICROSCOPE, AND IT IS EVIDENT THAT EACH HAS EACH SERVE AS THE TEMPLATE FOR MAKING REPLICATED. COMPLEMENTARY NEW STRANDS OF NUCLEOTIDES. THE TWO ▪ ALSO, THE CENTRIOLES IN THE CYTOPLASM DIVIDE AND OLD STRANDS COMBINE WITH THEIR RESPECTIVE MIGRATE TO EACH POLE OF THE CELL. COMPLEMENTARY NEW STRAND, THEREBY PRODUCING TWO ▪ MICROTUBULES CALLED SPINDLE FIBERS EXTEND FROM MOLECULES OF DNA THE CENTRIOLES TO THE CENTROMERES OF THE ▪ DURING INTERPHASE, DNA AND ITS ASSOCIATED PROTEINS CHROMOSOMES. APPEAR AS DISPERSED CHROMATIN THREADS WITHIN THE ▪ IN LATE PROPHASE, THE NUCLEOLUS AND NUCLEAR NUCLEUS. WHEN DNA REPLICATION BEGINS, THE TWO ENVELOPE DISAPPEAR. STRANDS OF EACH DNA MOLECULE SEPARATE FROM EACH IN METAPHASE OTHER FOR SOME DISTANCE ▪ THE PRODUCTION OF THE NEW NUCLEOTIDE STRANDS IS ▪ THE CHROMOSOMES ALIGN NEAR THE CENTER OF THE CELL. CATALYZED BY DNA POLYMERASE, AN ENZYME THAT ADDS NEW NUCLEOTIDES TO THE 3′ END OF THE GROWING STRANDS. AT THE BEGINNING OF ANAPHASE ▪ ONE STRAND, CALLED THE LEADING STRAND, FORMS AS A CONTINUOUS STRAND, WHEREAS THE OTHER STRAND, CALLED ▪ THE CHROMATIDS SEPARATE. THE LAGGING STRAND, FORMS IN SHORT SEGMENTS CALLED ▪ AT THIS POINT, ONE OF THE TWO IDENTICAL SETS OF OKAZA