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 Membrane

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