CELLS

Scientist Involved in Cell Theory Hooke-coined the word “cell” von Leeuwenhoek- lens grinder; made microscopes; discovered microscopic organisms in pond water (animacules) Schleiden-botanist (all plants made of cells) Schwann-zoologist (all animals made of cells) Virchow-all cells produce more cells

Cell Theory Proposed 200 years AFTER Hooke coined the term cell All living things made of cells Cells are the basic unit of structure and function in living things All cells come from other cells

Microscopes Used to View Cells Compound light microscope- magnifies UP TO 1500 X Electron Microscopes- magnify up to 1,000,000 X

Images differ Greatly Image of RBCs from Compound Light Microscope (40x) 3-D image of RBCs (Scanning Electron Microscope (SEM) 2-D image of RBCs in blood vessel (Transmission Electron Microscope (TEM)

Cork

Lung Cancer SEM image

Deer Tick SEM image

Types of Cells PROKARYOTES EUKARYOTES No nucleus, no membrane bound organelles Archaebacteria & Eubacteria EUKARYOTES Nucleus, membrane-bound organelles Protists, fungi, plants, animals Humans have 200 types of cells (60 BILLION)

Bacillus Streptococcus

Features Common to Both cell membrane-semi-permeable Ribosomes-sites for protein making DNA Cytoplasm

Organelles Organelles Common to Eukaryotes Cell membrane, nucleus, nucleolus Cytoplasm, Ribosomes, Golgi apparatus Endoplasmic Reticulum, Lysosome mitochondria Plastids- (CHLOROPLASTS & LEUCOPLASTS) PLANTS ONLY Cell wall- PLANTS (cellulose), FUNGI (chitin), & SOME PROTISTS ONLY CENTRIOLES-ANIMALS ONLY Cilia=hair-like structures; Flagella = tail-like structures

Energy Use in Cells NRG in sugar molecules (glucose) is RELEASED (cellular respiration) by mitochondria as ATP Active cells, like muscles cells, have many mitochondria ATP is the “gasoline” for the cell

Cell Membrane Fluid Mosaic model Has 2 major molecular components 1. lipids (mostly phospholipids) 2. proteins          

Cell Transport PASSIVE-substances move from high concentration to low concentration (down a concentration gradient). NO ENERGY REQUIRED Diffusion- passive transport involving molecules OTHER THAN water through semi-permeable membrane

Facilitated Diffusion Type of passive transport Transport that is "facilitated" by proteins that span the membrane and provide an alternative route or bypass. Facilitated = helps

Osmosis- passive transport of water through semi-permeable membrane Plasmolysis-loss of water

Osmosis-Hypertonic, Isotonic, Hypotonic solutions Hypertonic-Contain a high concentration of solute (salt) relative to another solution (e.g. the cell's cytoplasm). When a cell is placed in a hypertonic solution, the water diffuses out of the cell, causing the cell to shrivel.

Osmosis-Hypertonic, Isotonic, Hypotonic solutions Isotonic-Contains the same concentration of solute (salt) relative to another solution (e.g. the cell's cytoplasm). When a cell is placed in an isotonic solution, the water diffuses into and out of the cell The cell’s shape will not change.

Osmosis-Hypertonic, Isotonic, Hypotonic solutions Hypotonic-Contain a low concentration of solute (salt) relative to another solution (e.g. the cell's cytoplasm). When a cell is placed in a hypotonic solution, the water diffuses into the cell, causing the cell to swell.

Hemolysis

Osmosis-Hypertonic, Isotonic, Hypotonic solutions

ACTIVE TRANSPORT- substance move from low concentration to high concentration (against the concentration gradient) REQUIRES ENERGY (ATP) In some cases, requires carrier protein Examples- -Endocytosis (2 types) -Exocytosis

ENDOCYTOSIS-moving large molecules across the cell membrane by engulfing them Phagocytosis-”to eat”

Pinocytosis-”to drink” Dissolved solutes carried into cell via vesicles

Exocytosis Requires NRG Substances moving out of the cell via vesicle