GENERAL-BIOLOGY-WPS-Office.docx

**GENERAL BIOLOGY 1 REVIEWER** **Cell -- building blocks of life** **-comes from various shapes and sizes** POSTULATES OF CELL THEORY **Robert Hooke** --- he discovered the cells **Anton Van Leeuwenhoek** --- observed red blood cells, sperms **Robert Brown** --- discovered the nucleus **Matth...

**GENERAL BIOLOGY 1 REVIEWER** **Cell -- building blocks of life** **-comes from various shapes and sizes** POSTULATES OF CELL THEORY **Robert Hooke** --- he discovered the cells **Anton Van Leeuwenhoek** --- observed red blood cells, sperms **Robert Brown** --- discovered the nucleus **Matthias Schleiden** --- botanist **Theodore Schwann** --- zoologist **Rudolf Virchow** --- all living cells comes from pre-existing cells CELL STRUCTURES AND FUNCTIONS **Organelles** --- cell structures that perform specific functions **MANUFACTURING** **Nucleus (principal)---** DNA and RNA synthesis ; assembly of ribosomes **Ribosomes (teachers)---** protein synthesis **Rough ER (hallways and corridor)**--- synthesis of membrane lipids and proteins; formation of transport vesicles **Smooth ER (hallways and corridor) ---** lipid synthesis **Golgi Apparatus** --- modification and transport of macromolecules **BREAKDOWN** **Lysosomes (janitor)---** digestion of ingested food **Vacuoles** (**cabinets)**--- storage of chemicals **Peroxisomes** --- diverse metabolic processes \\ **ENERGY PROCESSING** **Mitochondria ---** chemical energy of food to chemical energy of ATP **Chloroplast ---** light energy to chemical energy of sugars **STRUCTURAL SUPPORT, MOVEMENT AND COMMUNICATION** **Cytoplasm** Jelly(**school perimeter)**--- jelly-like substance that hold the cell organelles in place **Cytoskeleton** --- structural support, movement and road for transportation **Centrioles** --- helpers in cell division **Cell** **Membrane** ( **security** **guard** )--- separates cell from outside and controls what enters and leaves the cell **Cell** **Wall** --- encloses and supports the cell **CELL CYCLE** occurrence of physical and metabolic of the cell in a regular and repetitive manner **Consist of Two Periods** **Interphase (resting phase) ---** longest period of the cell cycle **M-Phase (mitotic or meiosis phase)** **3 Phases** **Gap 1 Phase (G1 Phase) ---** increases the volume of the cell **Synthesis Phase (S-Phase) ---** DNA activation synthesis and histones **Gap 2 Phase (G2 Phase) ---** RNA activation synthesis and proteins vital for chromosome formation **CELL CYCLE CHECKPOINTS** **G1 checkpoint ---** nutrients, DNA damage and growth factors **Metaphase checkpoint ---** chromosome spindle attachment **G2 checkpoint ---** cell size and DNA replication **MITOSIS AND MEIOSIS** **MITOSIS (also called somatic cell division)** **--- process of nuclear division in which replicated chromosomes separate and form new daughter nuclei** **STAGES OF MITOSIS** **Prophase (pro means 'before') ---** mitosis begins chromosomes condense and become visible **Metaphase (meta means 'after')** spindle fibers attach to the centromeres of each chromosomes **Anaphase ('up' or 'back')** centromeres split and microtubules pull sister chromatids apart **Telophase (telo means 'end')** two daughter chromatids arrive at each pole and begin to uncoil, becoming less condensed **REGULATION OF CELL CYCLE** **External Factors** from outside the cell that are in the form of messages from nearby cells **Internal Factors** kinase is an enzyme that transfer a phosphate from one moleule to a target molecule **APOPTOSIS** --- orderly programmed cell death or suicide **MEIOSIS** --- division of germ cell involving two fissions of the nucleus giving rise to four gametes --- occurs only in gonads (testes or ovaries) --- sex cells produce gametes (sperms or egg) **Male : spermatogenesis** **Female : oogenesis** **Two Divisions** ** Meiosis l** ** Meiosis ll** **STAGES OF MEIOSIS I** **Prophase l ---** chromosomes condensed **Synapsis occurs : homologous chromosomes come** together to form **a tetrad** **Tetrad ---** two **chromosomes or** four **chromatids** **Metaphase l ---** pairs of homologous chromosomes moves to the equator of the cell (metaphase plate) **Anaphase l ---** homologous chromosomes moves to the opposite pole of the cell **STAGES OF MEIOSIS II** **Telophase l and Cytokinesis ---** chromosomes gather at the poles of the cell **Prophase ll ---** a new spindle fiber forms around the chromosomes **Metaphase ll ---** chromosomes lined up the equator **Anaphase ll ---** centromeres divide **Telophase ll and Cytokinesis ---** nuclear envelope forms around each set of chromosomes **GAMETOGENESIS ---** production of sex cells **Importance of Meiosis** --- independent assortment --- crossing over and fertilization **GENETIC DISORDERS** **1. Turner Syndrome (45, Xn)---** female individuals **2. Trisomy 21 (down syndrome) ---** mongoloid, passed through genes **3. Klinefelter Syndrome (XXY, 47) ---** prostate gland, bulbourethral gland, testicles **4. Trisomy X (47, XXX) ---** learning disability **Cell Modification** Cilia- for locomotion, humans help removing contaminants Flagella- movement present in motile bacteria fungi, spermcells Pseudopodia- for locomotion and ingestion of particles - Arm like projections -prevents leakage of gastric juices Gap Junctions- found in animal cell -cell to cell communication specially during embryonic development Cancer- group of diseases characterized by uncontrolled and abnormal cell division -tumor is formed when cancerous cells divide continuously until it is in disorganized mass -categorized as benign or malignant Benign- "kind" Malignant- "wicked" **TYPES OF CANCER** **1. Carcinomas- carcin-cancer omas tumors** **- epithelial cells** **2. Melanomas- melan- black** **- melanocytes (pigment called melancocytes; found in skin)** **Sarcoma** --- flesh --- muscles cells, connective tissues **Leukemia** --- "leuk" --- white --- "emia"--- white --- rapid growth of abnormal leukocytes Lymphoma --- "oma"--- tumor --- lymphatic tissues **Causes** --- environmental agents --- cancer causing genes **Proto-oncogenes** --- encourages cell division Tumor Suppressor Genes --- inhibits cell division **Cell Membrane Transport** **1. Diffusion- the passive movement of molecules from a higher to a lower concentration until equilibrium is reached** **2. Osmosis- the diffusion of water across a differentially permeable membrane due to concentration differences** **3. Tonicity- concentration of solutes** **3.1 Hypertonic Solution- greater solute concentration** **than the \> shriveled other** **ex: Red Blood Cell Solution** **3% NaCl 5% NaCl** **3.2 Hypotonic Solution** **- solute with a lower concentration compared to another solution -\> swell** **3% Na; 97% H2O** **Solution** **1%; 99% H2O** **3.3 Isotonic -\> balance** **Exocytosis- cellular secretion** **Endocytosis** - **Phagocytosis- "cell eating"** - **Pinocytosis- "cell drinking"**