Human Anatomy & Physiology PDF

6. REPRODUCTION: refers to the formation of new life; ANATOMY & PHYSIOLOGY formation of new cells for replacement and repair of old HUMAN BODY AND ORIENTATION...

6. REPRODUCTION: refers to the formation of new life; ANATOMY & PHYSIOLOGY formation of new cells for replacement and repair of old HUMAN BODY AND ORIENTATION cells as well as for growth. This is cellular reproduction. OTHER FUNCTIONS MUST PERFROM TO MAINTAIN LIFE: ANATOMY: study of the structure and shape of the body. From the Greek word to cut (tomy)& apart (ana). anatomy RESPIRATION: processes involved in the exchange of means to dissect, or cut apart and separate, the parts of oxygen and carbon dioxide between cells and external the body for study. environment. LEVELS OF STUDY DIGESTION: process of breaking down complex ingested foods into simple molecules that can be absorbed into the 1. GROSS ANATOMY: large structures that are visible to blood and utilized by the body. naked eye. Also called macroscopic anatomy. 2. MICROSCOPIC ANATOMY: too small; can only be NUTRITION: helps fuel your body. The foods you eat supply viewed through microscope. the nutrients your body needs to maintain the body. 3. SURFACE ANATOMY: uses superficial structures to locate deeper structures EXCRETION: is the process that removes the waste 4. ANATOMICAL IMAGING: non-invasive method for products of digestion and metabolism from the body. examining deep structures HOMEOSTASIS TWO BASIC APPROACHES: HOMEOSTASIS: maintenance of stable internal environment = dynamic state of equilibrium. Must be - SYSTEMIC ANATOMY: the study of the body by systems, maintained for normal body functioning and sustain life. such as the cardiovascular and nervous system. Ancient Greek ὅμοιος (hómoios, meaning “similar”), and - REGIONAL ANATOMY: the study of the organization of the stasis, from στάσις (stásis, meaning “standing”). body by areas (region) such as the head & abdomen HOMEOSTATIC IMBALANCE: a disturbance in homeostasis resulting in disease. PHYSIOLOGY: study of how the body and its part works or - Moderate Imbalance: (disease & disorder) functions. - Severe Imbalance: (death) LEVELS OF STRUCTURAL ORGANIZATION: RECEPTOR: responds to changes in environment. Sends 1. Chemical 4. Organ information to control center 2. Cell 5. Organ System CONTROL CENTER: determines set point; analyzes 3. Tissue 6. Organism information; determines appropriate response EFFECTOR: provides a means for response to stimulus. BASIC LIFE PROCESSES: FEEDBACK MECHANISM: 1. METABOLISM: sum of total chemical processes that occur in living organisms, resulting in growth, production of NEGATIVE FEEDBACK: shut off the original stimulus or energy, elimination of waste materials, etc. reduces; responds in an opposite direction; reduce an - ANABOLISM: build up complex molecules excessive response and keep variable within normal range. (ex. body temp. regulation & blood glucose) - CATABOLISM: breakdown of complex molecules POSITIVE FEEDBACK: increase original stimulus; 2. RESPONSIVENESS: or Irritability detects & adopt to maintains the direction of the stimulus. It tends to changes in internal or external environments and reacting accelerate or promote the effect of the stimulus. (ex. to that change. labor contraction) 3. MOVEMENT: locomotion. Each component has its own ORGAN SYSTEMS OF THE BODY job to perform in cooperation with others. 4. GROWTH: increase in size either through number of cells INTEGUMENTARY SYSTEM: external body covering; or through the size of each individual cell. In order for protects deeper tissue from injury; synthesizes vitamin growth to occur, anabolic processes must occur at a D; location of cutaneous nerve receptors. faster rate than catabolic processes. SKELETAL SYSTEM: protects & supports body organs; provides muscle attachment for movement; site of 5. DIFFERENTIATION: or development is a developmental blood cell formation; stores mineral; bone is life & process by which unspecialized cells change into functional tissue specialized cells. MUSCULAR SYSTEM: allows locomotion; maintains posture; produces heat  NERVOUS SYSTEM: fast-acting control system; responds 4. POSTERIOR (DORSAL): toward or at the backside of the to internal & external change; activates muscle & body; BEHIND glands 5. MEDIAL: toward or at the midline of the body; INNER SIDE ENDOCRINE SYSTEM: secretes regulatory hormones (growth, reproduction, and metabolism) 6. LATERAL: away from the midline of the body; OUTER SIDE CARDIOVASCULAR SYSTEM: transports materials in 7. INTERMEDIATE: between a more medial and a more body via blood pumped by heart (oxygen, carbon lateral structure dioxide, nutrients, wastes) LYMPHATIC SYSTEM: returns fluids to blood vessels; 8. PROXIMAL: close to the origin of the body or at the point of attachment of a limb to the body trunk. (point of disposes of debris, involved in immunity attachment: shoulders & pelvis) RESPIRATORY SYSTEM: keeps blood supplied with oxygen, removes carbon dioxide DIGESTIVE SYSTEM: breaks down food; allows for nutrients absorption into blood; eliminates indigestive material as feces URINARY SYSTEM: eliminates nitrogenous waste; maintains acid- base balance; regulates water and electrolytes REPRODUCTIVE SYSTEM: production of offspring ANATOMICAL TERMINOLOGIES Special terminology is used to prevent misunderstanding. Exact terms are used for: - Position - Regions - Directions - Structures STANDARD ANATOMICAL POSITION: The body standing upright, with feet shoulder width apart and parallel, palms facing forward. ANATOMICAL PLANES: a hypothetical plane used to transect the body, in order to describe the location of structures or direction of movements. ANATOMICAL PLANES: 1. SAGITTAL PLANE left and right portions; vertical cut; lengthwise cut - MIDSAGITTAL equal left and right - PARASAGITTAL unequal left and right 2. OBLIQUE PLANE divides the body at an angle 3. FRONTAL PLANE separates front and back 4. TRANSVERSE PLANE separates top and bottom DIRECTIONAL TERMS: 1. SUPERIOR (CRANIAL): towards the head end or upper FOUR ABDOMINAL QUADRANTS part of a structure; ABOVE RIGHT UPPER Right lobe of liver, gallbladder, right kidney, 2. INFERIOR (CAUDAL): away from the head end or toward QUADRANT portions of stomach, small & large intestine the lower part of a structure; BELOW LEFT UPPER Left lobe of liver, stomach, pancreas, left QUADRANT kidney, spleen, portions of large int. 3. ANTERIOR (VENTRAL): toward or at the front of the body: RIGHT LOWER Cecum, vermiform appendix, portions of IN FRONT OF QUADRANT small int, reproductive organs, right ureter LEFT LOWER Most of small intestines, portions of large int, QUADRANT left ureter, reproductive organs  NINE ABDOMINOPELVIC REGIONS: - Medial Rotation: Movement where the Anterior RIGHT HYPOCHONDRIAC Right Lobe of Liver, Gall Bladder surface is facing medially REGION - Lateral Rotation: Movement where the Anterior EPIGASTRIC REGION Left Lobe of Liver and Stomach surface is facing laterally LEFT HYPOCHONDRIAC Spleen and Diaphragm - Circumduction: Successive performances of Flexion, REGION Extension, Abduction, and Adduction. RIGHT LUMBAR REGION Ascending Colon of Large - Forearm Pronation: Medial Rotation of forearm where Intestine the palm of the hand faces in a posterior position. UMBILICAL REGION Small Intestine and Transverse - Forearm Supination: Lateral rotation of the forearm Colon of Large Intestine from the pronated position, where the palm of the LEFT LUMBAR REGION Descending Colon of Large hand faces in an anterior position. Intestine and Small portion of Small Intestine MEDICAL HISTORY RIGHT ILIAC REGION Cecum and Appendix HYPOGASTRIC REGION Small Portion of Small Intestine ANCIENT GREECE and Urinary Bladder LEFT ILIAC REGION Initial part of Sigmoid Colon 1. HIPPOCRATES (460-370 B.C.): Greek physician, diseases have natural causes, rejected the view that disease is BODY CAVITIES caused by evil spirits. Believed that brain was area of higher thought and emotion, not heart. Program for good BODY CAVITY: spaces in the body that holds or locate the organs health: rest, good nutrition & exercise. Started western medicine. BODY CAVITIES DORSAL CAVITY CRANIAL CAVITY: or intracranial 2. GALEN (130-200 A.D.) anatomy & physio; disease space which contains brain, the resulted from an internal imbalance, mistakes in meninges of the brain, and understanding circulation. Research based on ape cerebrospinal fluid. dissection. Textbook used for 1,000 years. VERTEBRAL CAVITY: includes spinal cord, meninges of the spinal cord and DARK AGES (200-1200 A. D) the fluid-filled spaces between them. - sad time; little new knowledge; taboo against VENTRAL CAVITY Thoracic Cavity is composed of the dissecting human cadavers continued; avoided actual bilateral Pleural Cavity (Lungs), and involvement; authority prevails. the medial Mediastinum, which houses the Pericardial Cavity (Heart) RENAISSANCE ABDOMINAL bounded primarily by the abdominal CAVITY muscles and contains stomach, 1. DA VINCI (1452-1515): anatomy and physiology intestines, liver, spleen, pancreas, and 2. VESALIUS (1514-1564): anatomy & physiology; Followed kidney. Galen’s writings, but later found out he was wrong PELVIC CAVITY is a small space enclosed by the bones of the pelvis and contains 3. WILLIAM HARVEY (1578-1657) disproved Galen that urinary bladder, part of large blood is not made from liver; heart is a pump not a suction intestines, and the internal device; showed circuit circulation; showed existence of reproductive organs. valves in veins. THORACIC is separated by the Diaphragm from 1600s Medicine: Leeches & Maggots CAVITY the Abdominopelvic Cavity. - To treat the blood flow and to eat the human flesh TERMS RELATED TO MOVEMENT: MEDICAL IMAGING - Flexion: Creation of an angle by bending X-RAY 2D picture (radiation) - Extension: Straightening a body part ULTRASOUND through sound waves - Lateral Flexion: Lateral movement of a trunk in a CT SCAN 3D picture; series of x-ray detailed Coronal Plane structure - Abduction: Movement of a limb away from the MRI can see through soft tissues (radio waves) midline in a Coronal Plane PET SCAN detects active parts of organs - Adduction: Movement of a limb toward the body in a PILL CAM needs to swallow to see through Coronal Plane inside the body - Rotation: Movement of a body part around the long SMART PHONE APPS axis (Axis containing the Sagittal and Coronal Plane)  BASIC CHEMISTRY RADIOACTIVTY: process of spontaneous atomic decay - Cell tissues and organs are composed of chemicals RADIOISOTOPE: heavy isotope, tends to be unstable - Chemical reactions are important for function MOLECULE: particle formed when 2 or more atoms of the - Chemistry is the study of elements, compounds, same elements chemically combine. chemical reactions, and molecular structure COMPOUND: particle formed when 2 or more atoms of the MATTER: anything that occupies space and has mass. It different elements chemically combine. generally exists in 3 states: solid, liquid, and gas MOLECULAR FORMULAS: depict the elements present and ENERGY: capacity to do work or to move matter. Energy the number of each atom present in the molecule has kinetic (active) and potential (stored) energy capacities - atoms are united by chemical bonds - atoms dissociate from other atoms when chemical bonds are broken COMPOSITION OF MATTER: - chemical bonds: ionic, covalent, hydrogen bonds - ELEMENTS: fundamental unit of matter. 96% of the body is made from four elements. BONDING OF ATOMS - Oxygen – 65 % - Hydrogen – 10% Bonds form when atoms combine with other atoms - Carbon – 18% - Nitrogen – 3% Electrons of an atom occupy regions of space called ELECTRON SHELLS which circle nucleus - ATOMS: fundamental elements of matter; composed of For atoms with atomic numbers of 18 or less the following rules apply: (lower shells are filled first) 3 subatomic particles: proton, electron, and neutron. - 1st shell can hold up to 2 electrons COMPONENTS OF ATOM: - 2nd shell can hold up to 8 electrons - 3rd shell can hold up to 8 electrons PROTONS positive charge inside the nucleus NEUTRONS negative charge inside the nucleus ION: an atom that gains or loses electrons to become ELECTRONS negative charge outside the nucleus stable. An electrically charged atom. - CATION: positively charged ion; formed when an - Protons and Neutrons join together to form nucleus atom loses electrons - ANION: negatively charged ion; formed when an ATOMIC STRUCTURE: atom gains electrons. - NUCLEUS: protons and neutrons IONIC BONDS: an attraction between cation and anion. - OUTSIDE NUCLEUS: electrons Formed when electrons are transferred from one atom to another. IDENTIFYING ELEMENTS: COVALENT BONDS: formed when atoms share electrons ATOMIC NUMBER: equal to the number of protons that POLAR MOLECULES: molecule with a slightly negative end the atoms contain & a slightly positive end. Results when electrons are not ATOMIC MASS NUMBER: sum of protons and neutrons shared equally on covalent bonds. (water is important PM) ATOMIC WEIGHT: mass number of all isotopes of an element. Isotopes & atomic weight. HYDROGEN BONDS: a weak attraction between the positive end of one polar molecule and negative end of ATOMS WANT STABILITY: The defining characteristics of another polar molecule. Formed between water stable elements is the maximum number of electrons in its molecules. Important for protein and nucleic acid valence (outer) shell structure ISOTOPES: have the same number of protons vary in CHEMICAL REACTION: number of neutrons. (oxygen often forms isotopes) - REACTANTS: starting materials of the reaction. The - RADIOACTIVE ISOTOPES: are unstable releasing atoms, ions, or molecules energy or pieces of themselves (atomic - PRODUCTS: substances formed at the end of the radiation). Release of protons and neutrons called chemical reaction ATOMIC DECAY - RADIATION: forms the energy when there is an atomic decay TYPES OF CHEMICAL REACTION SYNTHESIS more complex chemical structure is - For an element, atomic weight is often considered the REACTION formed (ex. A + B -> AB) average of the atomic weight of its isotopes.  DECOMPOSITION chemical bonds are broken to form - ADENOSINE TRIPHOSPHATE (ATP): chemical energy REACTION a simpler chemical structure (ex. AB used by all cells. Energy is released by breaking high -> A+B) energy phosphate bond. ATP is replenished by EXCHANGE chemical bonds are broken and oxidation of food fuels. REACTION new bonds are formed (ex. AB + CD -> AD + CB) INORGANIC COMPOUND: lack carbon; tends to be simpler REVERSIBLE the products can change back to compounds (water, salts, acid bases) ex. water REACTION the reactants (ex. A + B -> AB) IMPORTANT INORGANIC COMPOUND: BIOCHEMISTRY: ESSENTIAL FOR LIFE 1. WATER: most abundant compounds ORGANIC COMPOUND: contains compound; most are covalently bonded (carbohydrates, proteins, fats, sugars VITAL PROPERTIES: & starches) ex. glucose - HIGH HEAT CAPACITY: prevent sudden changes in IMPORTANT ORGANIC COMPOUND: body temperature - POLARITY/ SOLVENT PROPERTIES: dissolve/ suspend 1. CARBOHYDRATES: contain carbon, hydrogen, and - CHEMICAL REACTIVTY: uses water as a reactant, oxygen. Include sugars, and starches. (hydrolysis) to digest food CLASSIFIED ACCORDING TO SIZE WATER AND LIVING THINGS MONOSACCHARIDES: simple sugars CHARACTERISTICS OF WATER POLARITY DISACCHARIDES: 2 simple sugars joined by LIQUID remains liquid in our bodies dehydration UNIVERSAL SOLVENT facilitate chemical reactions in POLYSACCHARIDES: long branching chains of and out of the bodies linked simple sugars COHESIVE helps water base solutions fill PROPERTIES blood vessels (without hydrogen 2. LIPIDS: contains carbon, hydrogen, oxygen, insoluble in bonding between water water, neutral fats. Found in fat deposits, solid, animal fat, molecules, body fluids would be composed of fatty acids, and glycerol, source of stored gaseous form) ABILITY TO CHANGE prevents drastic changes energy. TEMPERATURE COMMON LIPIDS IN THE HUMAN BODY (OTHER FORMS) VAPORIZATION keeping body temperature from overheating (liquid to gas) PHOSPHOLIPIDS: form cell membranes- cell wall, ABILITY TO FREEZE becomes less dense in weight electrical charge which allows selective permeability 2. SALTS: easily dissociate into ions in the presence of of cell wall. water; vital to many body functions; include electrolytes STEROIDS: include cholesterol, bile salts, vitamin D, and when conduct electrical currents (Na, K, Cl, Ca, Phos.) in some hormones (corticosteroids, sexual hormones) the body 3. PROTEINS: made up of amino acids. Contains carbon, 3. ACID AND GASES: another form of electrolytes; they are oxygen, hydrogen, nitrogen, and something sulfur. ionized and dissociate in water causing electrical - Account for over half of the body’s organic conduction. matter - ACIDS: release hydrogen ions. Sour or sharp taste, - Provides for construction materials for body tissues tomato juice, coffee, and vinegar - Plays a vital role in cell function - BASES: protein acceptors- gain hydrogen ions bitter 4. ENZYMES: acts as a biological catalyst. Increase the rate taste, become slippery when wet, ammonia, of chemical reactions household cleaners, and detergents. Neutralization reaction 5. NUCLEIC ACIDS: provides blueprints of life that makes DNA and RNA. Nucleotide bases include: A= Adenine, T= 3. pH: measures relative concentration of hydrogen ions. Thymine, G= Guanine, U= Uracil, C= Cytosine pH 7.0 = neutral - DEOXYRIBONUCLEIC ACID (DNA): organized by pH below 7.0 = acidic complimentary bases to form double helix. Replicates pH above 7.0 = basic before cell division. Provides instruction for every BUFFERS: chemicals that regulate pH change protein in the body. - pH needs to be maintained in humans in order to maintain homeostasis  THE CELLULAR LEVEL OF ORGANIZATION TRANSPORT ACROSS CELL MEMBRANE: CELL MEMBRANE AND ITS INVOLVEMENT IN TRANSPORT - cell membrane is selectively permeable; allows only small, non-polar molecules to pass freely STRUCTURE OF THE CELL MEMBRANE: - molecules able to pass will flow across the membrane - separates cell’s internal environment from the external if there is gradient environment - flow occur from high to low concentration unless - regulates movement of materials into & out of the cell prevented by resistance - composed of phospholipids, cholesterol, PASSIVE TRANSPORT: carbohydrates, and proteins - flexible, dynamic structure - movement does not require energy; requires concentration gradient PHOSPHOLIPIDS: major structural component of cell membrane. TWO FORMS SIMPLE molecules move from higher to lower AMPHIPATHIC MOLECULES DIFFUSION concentration without the use of HYDROPHILIC (water-loving) phosphate heads- membrane proteins phosphate group FACILITATED molecules move from higher to lower HYDROPHOBIC (water-fearing) fatty acids tails- DIFFUSION concentration through membrane non polar proteins - arranged into bilayer (2 layers) - ex. of diffusion: perfume diffuses across a room phosphate heads face internal and external SIMPLE DIFFUSION ACROSS CELL MEMBRANE: environment - Small, non-polar molecules can pass through the cell fatty acid tails create hydrophobic region with membrane. bilayer - Diffusion continues until a net equilibrium is reached - organized into bilayer to form biological membranes - Diffusion occurs faster at higher temperature CELL MEMBRANE STRUCTURE: FACILITATED DIFFUSION ACROSS CELL MEMBRANE: - selectively permeable barrier, composed mainly of - Requires assistance of transmembrane proteins phospholipid bilayer - Molecules still move down concentration gradient - INTRACELLULAR FLUID (ICF): inside of the cell, also - Used for molecules that cannot diffuse through cell called CYTOSOL membrane, such as polar or ionic molecules - EXTRACELLULAR FLUID (ECF): outside of the cell. - Protein is also associated with cell membrane OSMOSIS: MEMBRANE PROTEINS: - Movement of water across cell membrane - Water moves from areas of lower solute to higher - Proteins associated with cell membrane adds solute concentration functionality - HYPOTONIC SOLUTION: less solute outside of cell. - serves as channel protein, receptors, enzymes, and in Water enters cell when they are in hypotonic solution cell – cell recognition - HYPERTONIC SOLUTION: more solute outside of cell. - transmembrane or integral proteins span the entire Water will leave in hypertonic solution width of cell membrane - peripheral proteins WATER MOLECULE SOLUTION: do not span the membrane - Osmosis depends on the ratio of solute molecules to attached to the interior or exterior of the water membrane - Water will move from area of lower solute GLYCOPROTEINS: proteins that have carbohydrate concentration to areas of higher solute concentration molecules attached. (aid in cell recognition) OSMOSIS ACROSS A MEMBRANE: GLYCOCALYX: formed by numerous glycoproteins - water moves across a semipermeable membrane only present in some cells; can serve as toward the area with a higher solute concentration receptors for hormones and a means to bind to other cells; help break down nutrients  SOLUTION COMPARISON THE CYTOPLASM AND CELLULAR ORGANELLES ISOSMOTIC have equal concentrations of INTERNAL COMPONENTS OF CELLS SOLUTION solute CYTOPLASM fluid like interior of cells including its HYPEROSMOTIC contains more solute by compartments and organelles SOLUTION comparison ORGANELLES membrane bound structures that HYPOOSMOTIC contains less solute by perform specific function SOLUTION comparison CYTOSOL gel-like substance within the cytoplasm. Contains organelles and molecules - TONICITY: describes the osmolarity of the ECF compared needed by cell to the cytosol of the cell. ENDOPLASMIC RETICULUM (ER): EFFECT OF TONICITY ON CELLS ISOTONIC has equal water concentration across - Series of channels continuous with the nuclear SOLUTION the cell membrane (cell functions membrane; provides passage for synthesis; normally) transportation and storage HYPERTONIC contains more solute in the ROUGH ER: contains ribosomes; involved in protein SOLUTION environment (cell shrinks) synthesis HYPOTONIC contains fewer solute in the SOLUTION environment (cell swells and may burst) SMOOTH ER: lacks ribosomes; involved in lipid synthesis ACTIVE TRANSPORT GOLGI APPARATUS: series of flattened sacs; sort and - Requires energy to move molecules against their modifies products from rough ER for transport concentration gradient. From areas of lower - CIS-FACE: receives products for modification concentration to areas of higher concentration - TRANS-FACE: releases products after modification - PRIMARY ACTIVE TRANSPORT: uses ATP as energy source MEMBRANEOUS ORGANELLES FOR DETOXIFICATION - SECONDARY ACTIVE TRANSPORT: uses AND ENERGY PRODUCTION electrochemical gradient as energy source LYSOSOMES membrane bound vesicles that SYMPORTERS: move 2 molecules in same direction contain digestive enzymes; used to ANTIPORTERS: move 2 molecules in opposite breakdown wastes within cell direction PEROXISOMES contain enzymes used to produce hydrogen peroxide. Used for SODIUM – POTASSIUM PUMP: detoxification and lipid metabolism - Common examples of primary active transport MITOCHONDRIA site of aerobic respiration; - Uses ATP to move 3 sodium ions out of cell and 2 responsible for nutrient breakdown potassium ions into the cell against their concentration and ATP production gradients MITOCHONDRIA: ENDOCYTOSIS: a form of active transport; uses cell membrane to engulf materials; cell membrane pinches off - energy transformer of the cell to form a vesicle and material enters cell. - lined by 2 layers (outer membrane and inner membrane which is folded into cristae) 3 FORMS OF ENDOCYTOSIS - more numerous in muscle and nerves PHAGOCYTOSIS extends the cell membrane to bring in large molecules CYTOSKELETON: helps maintain structure of the cell; PINOCYTOSIS membrane invagination brings organizes cytoplasm; aids in separation during cellular in small amount of fluid division; composed of protein filaments that provide containing dissolved support substances 1. MICROTUBULES: made of tubulin RECEPTOR-MEDIATED more selective; LIGAND BINDS 2. INTERMEDIATE FILAMENTS: made of keratin ENDOCYTOSIS to membrane receptor for 3. MICROFILAMENTS: made of actin cellular entry DYNAMIC OF CYTOSKELETON: EXOCYTOSIS: process of a cell exporting material, or cell secretion; vesicle fuses with cell membrane; contents are - Cytoskeleton is not fixed. Cytoskeletal components released from cell; hormones & digestive enzymes form and can move depending on needs of the cells secreted this way - Helps move molecules & structures around interior of cell CELL SURFACE SPECIALIZATION: MAKING PROTEINS FROM DNA: - MICROVILLI: helps increase surface area of cell - Proteome is a cell’s full complement of proteins - CILIA: aid in movement or across the surface cell - Genes contain information necessary to make protein - FLAGELLA: long appendages used for movements - DNA is transcribed to mRNA - mRNA is then translated to protein THE NUCLEUS AND DNA TRANSCRIPTION: ORGANIZATION OF THE NUCLEUS: - process of creating a strand of messenger RNA from a - Nucleus houses the DNA of the cell DNA template - Most human cells have a single nucleus - occurs within the nucleus of the cell - Nucleus is surrounded by nuclear envelope - complementary mRNA is made from a gene of one - Nuclear pores allow small molecules to move into and strand of DNA out of cells - mRNA will leave the nucleus for translation - Nucleolus within nucleus is involved in ribosome production THE PROCESS OF TRANSCRIPTION NUCLEIC ACIDS FOUND IN HUMAN CELLS: 3 STAGES OF TRANSCRIPTION: - Nucleic acids found in healthy human cells include - INITIATION: DNA strands are separated and RNA DNA, mRNA, tRNA, and rRNA polymerase begins to synthesize complementary RNA - DNA is storage form of genome molecule - mRNA is used in translation of proteins - ELONGATION: RNA polymerase continues to add - tRNA moves amino acids during translation nucleotides to growing strand - rRNA is structural component of ribosomes - TERMINATION: RNA polymerase reaches end of gene and mRNA transcript is released NUCLEOTIDE BASES OF DNA: TRANSLATION: - DNA has a double helix structure formed by hydrogen bonds between nucleotide bases - Process of creating a protein from mRNA template - The 4 nucleotide bases of DNA are Adenine, Thymine, - Occurs in the cytoplasm of the cell Cytosine, & Guanine - Carried out by ribosomes - Adenine forms a double bond with thymine - RIBOSOMAL RNA (rRNA): components of - Cytosine forms a triple bond with Guanine ribosomes - Each 3 nucleotides sequence of mRNA is a codon ORGANIZATION OF DNA: - Ribosomes read codons - DNA strands are wrapped around histone proteins for - Transfer RNA (tRNA) brings amino acids to ribosomes organization - tRNA contains anticodons that match specific mRNA - Chromatin is the loose form of DNA codons - Chromatin is packed during replication to form - amino acids are linked by peptide bonds to form chromosome proteins PROTEIN SYNTHESIS PROCESS OF TRANSLATION: - INITIATION: ribosome subunits attach to start codon of PROTEIN SYNTHESIS WITHIN THE CELL: mRNA transcript - DNA contains the genetic code of cell - ELONGATION: tRNA molecules are attracted to the - Genetic code provides the instruction to produce ribosome and deliver corresponding amino acids to cellular proteins the growing polypeptide - Protein production begins in the nucleus and ends in - TERMINATION: translation continues until ribosome the cytoplasm reaches a “stop” codon that ends the process - Genes are transcribed into messenger RNA. Gene is a CELL REPLICATION segment of DNA that codes for a protein - mRNA is then translated into proteins THE CELL CYCLE: - gene segment/ template strand - DNA -> mRNA = transcription - Three phases: interphase, mitosis, cytokinesis. - mRNA -> protein = translation - The cell spends most of its time in interphase.  INTERPHASE IS SPLIT INTO STEM CELLS: G1 PHASE cell grows, makes proteins, & carries out - can differentiate into specific cell types cellular functions - specific genes are turned on during differentiation S PHASE cell replicates its DNA transcription factors turn on necessary genes G2 PHASE cell prepares for mitosis turning specific genes on in stem cells CELLULAR REPLICATION: occurs as the parent cell divides produces certain proteins needed for the to form 2 daughter cells; mitosis occurs in somatic cells differentiated cell’s functions Daughter cells are identical to parent cell Cell contains 46 chromosomes (diploid number) - Meiosis occurs for reproductive cells resulting cells have half the amount of genetic material from parent and half from the other parent cell contains 23 chromosomes (haploid number) DNA REPLICATION: the process of copying DNA; occurs during the S phase of the cell cycle 3 PHASES INITIATION: DNA strands are separated by helicase ELONGATION: DNA polymerase synthesizes new strand TERMINATION: DNA replication stops - CHROMATIN: linear form of DNA - Condensed into chromosomes during replication - Replicated copy is called SISTER CHROMATID - Sister chromatids are attached at a CENTROMERE - Chromatids separates during mitosis. Makes sure each daughter cell has a complete copy of DNA MITOSIS: Cell replication consist of 4 major phases by cytokinesis 4 MAJOR PHASES PROPHASE chromatin condenses into chromosomes and centrioles migrate to opposite sides of the cell METAPHASE chromatids align in the middle of cell ANAPHASE chromatids separate and move toward the opposite side of the cell TELOPHASE nucleoli and nuclear membrane start to form and chromosomes return to chromatin form - CYTOKINESIS: cleavage furrow divide cell into two distinct cells CELLULAR DIFFERENTIATION: - the cells of the human body develop from a single cell - cell becomes specialized for a specific function through differentiation - stem cells are undifferentiated yet can become required cell types