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Health Occupations. The Cell. Definitions. Anatomy Study of form & structure of organism Physiology Study of processes of living organisms, why & how they work Pathophysiology Study of how disease occurs & responses of living organisms to disease processes. Protoplasm.
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Health Occupations The Cell
Definitions Anatomy Study of form & structure of organism Physiology Study of processes of living organisms, why & how they work Pathophysiology Study of how disease occurs & responses of living organisms to disease processes
Protoplasm • Basic substance of life • Makes up all living things • Carbon, oxygen, hydrogen, sulfur, nitrogen, phosphorus • Unique combo we call life • Forms the basic unit of structure in all living things – the cell
The Cell • Microscopic • Carries on all functions of life • Building block of the body • Functions • Takes in food and oxygen • Produces heat & energy • Moves & adapts to the environment • Eliminates wastes • Performs special functions • Reproduces to create new, identical cells
Cell Parts • Cell Membrane – • Outer protective covering • Semi permeable • Allows certain substances in & out • Prevents other substances from leaving or entering
Cell Parts • Cytoplasm • Jelly like fluid inside cell that surrounds cell parts • Water, proteins, lipids, CHO, minerals, salts • Site for all chemical reactions in cell • Contains organelles • Cell structures that help cell function • nucleus, mitochrondria, ribosomes, liposomes, centrioles, Golgi apparatus, endoplasmic reticulum
Cell Membrane Cytoplasm
Cell Parts - Organelles • Nucleus • Brains of the cell • Controls cell activities • Directs reproduction
Nucleus Cell Membrane Cytoplasm
Cell Parts - Organelles • Nucleolus • Inside nucleus • Important for reproduction • Manufactures ribosomes • RNA – ribonucleic acid & protein • Move from nucleus to cytoplams • Aids in protein synthesis (production) • Can exist freely or as attached to endoplasmic reticulum
Ribosomes Nucleolus Nucleus Cell Membrane Cytoplasm
Cell Parts - Organelles • Chromatin • Inside nucleus • Make up of DNA • Deoxynucleic acid & protein • During reproduction • Chromatin condenses & forms chromosomes • Human has 46 or 23 pairs • Chromosomes • 100,000 genes with inherited characteristics • Gene • Specific & unique code of about 1,000 DNA pairs that carry coding for exact cell duplication • Can be used for identification because each sequence is unique
Ribosomes Nucleolus Chromatin Nucleus Cell Membrane Cytoplasm
Cell Parts - Organelles • Centrosome • Located in cytoplasm near nucleus • Contains 2 centrioles • During mitosis (cell division), centrioles separate • Cytoplasmic spindle fibers form between centrioles & attach to chromosomes • Creates an even division of chromosomes in the 2 new cells
Ribosomes Nucleolus Chromatin Nucleus Centrosome Cell Membrane Cytoplasm
Cell Parts – Organelles • Mitochondria • Rod-shaped • Furnaces or power houses of cells • Break down CHO, proteins, fats • Produce ATP • Adenosine triphosphate • Cell’s major energy source
Ribosomes Nucleolus Mitochondria Chromatin Nucleus Centrosome Cell Membrane Cytoplasm
Cell Parts - Organelles • Golgi Apparatus • Stack of membrane layers • Produces, stores, packages secretions for discharge from cell • Salivary, gastric, pancreatic cells have many golgi apparatus
Golgi apparatus Ribosomes Nucleolus Mitochondria Chromatin Nucleus Centrosome Cell Membrane Cytoplasm
Cell Parts - Organelles • Endoplasmic reticulum (ER) • Fine network of tubular structures • Allows for transport of materials in & out of nucleus • Aids in synthesis & storage of proteins • Rough Endoplasmic reticulum • Has ribosomes, sites for protein production • Smooth Endoplasmic reticulum • No ribosomes, not present in every cell • Assists with cholesterol synthesis, fat metabolism, & drug detoxification
Golgi apparatus Ribosomes Nucleolus Mitochondria Chromatin Nucleus Centrosome Cell Membrane Cytoplasm Rough ER Smooth ER
Cell Parts - Organelles • Lysosomes • Oval or round bodies in cytoplasm • Contain digestive enzymes that digest and destroy • Old cells • Bacteria • Foreign materials • Important function of immune system
Golgi apparatus Ribosomes Nucleolus Mitochondria Chromatin Nucleus Centrosome Cell Membrane Lysosome Cytoplasm Rough ER Smooth ER
Cell Parts – Organelles • Pinocytic vessels • Pocket like folds in cell membrane • Allow large molecules like fats & proteins to enter cell • When molecules are inside, folds close to form vacuoles or bubbles in cytoplasm
Golgi apparatus Ribosomes Nucleolus Mitochondria Chromatin Nucleus Pinocytic vessel Centrosome Cell Membrane Lysosome Cytoplasm Rough ER Smooth ER
Cell Parts - Organelles • Vacuole • Closet or storage place of cell • May be empty or full • Looks like bubble in cytoplasm
Golgi apparatus Ribosomes Nucleolus Vacuole Mitochondria Chromatin Nucleus Pinocytic vessel Centrosome Cell Membrane Lysosome Cytoplasm Rough ER Smooth ER
Homeostasis • Tendency of a cell to maintain a state of balance • Molecules pass in & out of cell to do this • Cells constantly adjust these to maintain balance • Fluids • Temperature • Oxygen • Electrolytes • Nutrients
Electrolytes • Compounds made of charged particles or ions • Conduct electrical current in water or cytoplasm • + charge = cation (acid) Na++, K+, Mg++, H+ • - charge = anion (base) HCO3, HPO4, C, SO4) • pH measures how much acid/base is present • Each tissue has own normal pH • If pH is not maintained, cell doesn’t function right
Cellular reproduction • Mitosis • Most cells • Divides into 2 identical cells • Asexual • Continuous reproduction • Skin, blood, intestines • Every few years • Muscle • Never • Spinal cord, nervous cells, brain cells
Mitosis • DNA molecules duplicate themselve • Centrioles separate & a spindle forms between them • Duplicated chromosomes line up along center of spindle • Chromosomes separate • Two nuclei form as cell separates • Each new cell has the full number of chromosomes
Meiosis • Process by which sex cells divide • Uses 2 separate cell divisions to produce 4 new cells • Ova – female cells • Spermatozoa – male cells • Chromosome number decreases to 23 (1/2 of mitosis) before division
Meiosis • When ova & sperm join, form a zygote (new cell) with 46 chromosomes (23 from ova & 23 from sperm) • After zygote forms, rapid mitosis occurs • 4-5 days, becomes blastocyst which contains embryonic stem cells • Stem cells have ability to transform into any specialized cell & perform functions • Controversy – can stem cells cure diseases like DM, Parkinson’s disease, osteoporosis, arthritis, heart disease?
Heredity • Passing on of genetic information that determines individual characteristics • Determines physical appearance, blood type, gender • Genes • Contain heredity info in cell • Made up of DNA forming chromosomes • 50-100,000 genes on each chromosome determining general human & individual traits • Dominant gene – characteristic appears when only 1 gene is inherited • Recessive gene – trait only appears when gene is present on both chromosomes
Abnormal genes • Cause many inherited, hereditary, or genetic disorders • Described as CONGENITAL or CONDITION rather than contagious or disease • Some disorders affect only 1 body part, others affect entire systems • Disorders include – clubfoot, cleft lip/palate, cystic fibrosis, Down’s syndrome, Huntington’s chorea, Klinefelter’s syndrome, Neural tube defect, Neurofibromatosis, PKU, Sickle cell anemia, Tay-Sachs disease