490 likes | 796 Views
Cytology. Study of cells ~70 trillion = human body. Cells. Cells vary greatly in SIZE and STRUCTURE two main parts - NUCLEUS & CYTOPLASM, Enclosed in a CELL MEMBRANE (also called PLASMA MEMBRANE). Cell Membrane. Extremely thin Outpouchings and infoldings Porous
E N D
Cytology Study of cells ~70 trillion = human body
Cells • Cells vary greatly in SIZE and STRUCTURE • two main parts - NUCLEUS & CYTOPLASM,Enclosed in a CELL MEMBRANE (also called PLASMA MEMBRANE)
Cell Membrane • Extremely thin • Outpouchings and infoldings • Porous • Selectively Permeable = controls what enters and leaves the cell, it allows some things to pass but not others
Membrane Structure • Lipids, proteins, carbs • Phospholipidbilayer
CYTOPLASM - area b/w the plasma membrane and nucleus. • metabolic reactions/activities take place. • Filled with a clear fluid called CYTOSOL. • Contains ORGANELLES
Cytoskeleton- • protein rods/ tubules
Microfilaments- tiny rods of the protein actin • Various cell movements • Microtubules- long slender tubes of globular protein tubulin. • Maintain shape of cell • move organelles in cell
Organelles • Ribosome- • Protein/RNA • Structural support • Link amino acids together to form proteins
Endoplasmic Reticulum- • Smooth ER- • contains enzymes that synthesize lipids, absorb fats from digestive tract, break down drugs. • Rough ER- Contains Ribosome • Site of Protein Synthesis • Send to Golgi Apparatus
Golgi Apparatus- • proteins arrive in vesicles from ER • Modifies proteins chemically • Send proteins in vesicles out of cell (vesicle trafficking)
Mitochondria- 2 layers of membranes • Cristae- folded inner membrane • Matrix- fluid inside membranes • Captures/Transfers energy in the form of ATP
Lysosome- • acts as garbage disposal • Break down proteins, carbs, nucleic acids • Destroy worn cell parts
Peroxisomes- contain enzymes • Catalyze chemical reactions • Synthesis of bile acids • Breakdown of lipids • Degradation of rare biochemicals • Detoxification of alcohol
Centrosome- two hollow cylinders (centrioles) • Made of microtubules • From spindle fibers to move chromosomes during mitosis
Cilia/Flagella- • motile extensions of certain cells
Nucleus • Spherical structure • Contains DNA
Nuclear Envelop- double layered membrane • Nuclear pores- allow substances in and out • Nucleoplasm- fluid inside • Nucleolus- Site of ribosome production • Ribosomes move out nuclear pores • Chromatin- DNA fibers • Form chromosomes in mitosis
MEMBRANES • phospholipidbilayer • 2 Tails- Hydrophobic • Head- Hydrophilic • Controls movement of substances in and out of cell
Peripheral proteins • Integral proteins • Function • Help communicate with other cells • Transport substances across membrane
Passive Transport • Diffusion- movement of particles from a concentrated area to a less concentrated area • Equilibrium Diffusion Example
Passive Transport • Osmosis - transport of water across membrane from a high concentration to a lower concentration • Hypertonic • Hypotonic • Isotonic
Passive Transport Facilitated Diffusion - Transport proteins = pathway for molecules to pass through membrane
Active Transport • Uses Energy • Moves against concentration gradient • Some Carrier proteins act as pumps
Sodium Potassium Pump • Na+ binds to carrier protein inside cell • Carrier protein splits Phosphate group from molecule of ATP and phosphate group binds • ATP supplies energy needed to reshape protein • With new shape moves Na+ outside cell, and the shape is perfect to bind for K+ • Repeats
Active Transport • Exocytosis- vesicles exports product from cells • Endocytosis- vesicle takes material into cell • Pinocytosis- transports of solutes or fluids • Phagocytosis-movement of large particles or whole cells
Cell Life Cycle • Mitosis = nuclear division • followed by cytokinesis • The steps of mitosis ensure that each new cell has the exact same number of chromosomes as the original
Interphase • 90% of cells life • G1 – growth phase • S phase (synthesis) – genetic material replicates • G2 – synthesize structures
Prophase • 1. chromosomes visible (chromatids) • 2. centrioles migrate to the poles • 3. nuclear membrane disappears • 4. nucleolus disappears • 5. spindle forms
Metaphase • chromosomes line up on the equator, spindle attaches
Anaphase • chromatids separate and move to opposite poles
Telophase • 1. chromosomes disappear • chromatin • 2. nuclear membrane reforms • 3. nucleoli reappears • 4. spindle disappears • 5. centrioles duplicate
Cytokinesis • division of the cytoplasm to form 2 new daughter cells • - organelles are divided • - daughter cells are genetically identical
Homework • Draw and label the phases of mitosis • Label : Centromere, centrioles, spindle fibers, and sister chromatids