Cell Biology Essential Question Cell Name those who

Cell Biology

Essential Question Cell Name those who added to the cell theory; what did each contribute? 10. 29. 2007

Cell Theory • Robert Hooke (1665) – first discovered and named “cells” – looked at dead cells of a cork plant Cell

Cell Theory • Anton van Leeuwenhoek (1674) – built microscopes to study ‘animalcules’ known today as microorganisms – first to see living cells Cell

Cell Theory • Matthias Schleiden (1838) – stated all plants are made of cells Cell

Cell Theory • Theodore Schwann (1839) – studied human notochord – concluded all animals are made of cells

Cell Theory • Rudolph Virchow (1858) – every cell comes from another cell like it.

Cell Theory • modern Cell Theory – All living things are composed of cells. – Cells are the units of structure and function in living things. – New cells are produced from pre-existing cells.

Cell Structure • Cells can come in 3 shapes 1. Sphere 2. Brick 3. Cube Cell

Cell Structure The smallest are bacteria cells The largest is the human egg Cell

Cell Structure Cell • Two types of organisms 1. Unicellular- ex. Bacteria, yeasts, Amoeba 2. Multicellular- some cells are specialized; evolved from unicellular cells

Cell Structure • Levels of organization cell tissue organ system organism Cell

Organelles cell membrane Cell

Organelles Cell (transparent layer between cells) cell wall

Organelles nucleus Cell

Cell Organelles (stained green) microtubules

Cell Organelles microfilaments

Cell Organelles (red) ribosome

Cell Organelles (yellow) endoplasmic reticulum

Cell Organelles (purple) golgi apparatus

Cell Organelles lysosome

Cell Organelles vacuole

Cell Organelles mitochondria

Cell Organelles flagella

Cell Organelles cilia

Cell Organelles (green) chloroplast

Cell Organelles (green) cell wall

Cell Organelles centriole

Cell Organelles (white) cytoplasm

Organelles What is a plastid? A storage cell Which 3 organelles are plastids? Cell

Essential Question What are the different states of concentration across a membrane? 11. 5. 2007 Cell

Cell Types of cells • cells classifications – prokaryote • no membrane bound organelles (no nucleus) ex: bacteria – eukaryote • cells with membrane bound organelles ex: plants, fungi, animals, protists

Cell Transport • cell membrane – fluid mosaic model • membrane constantly moving – 3 main molecules • proteins • carbohydrates • lipids – hydrophilic (water loving) heads – hydrophobic (water fearing) tails

Transport Cell

Cell Transport • cell membrane – allows for transport of materials into and out of cell

Cell Transport • diffusion – movement of molecules from higher to lower concentration

Cell Transport • equilibrium – state in which concentration is equal in all areas

Transport • osmosis – movement of water from higher to lower concentration. Cell

Cell Transport • osmosis – hypertonic • concentration of solute is greater outside cell – hypotonic • concentration of solute is less outside cell – isotonic • concentration of solute is equal on both sides of membrane

Transport • osmosis Cell

Transport • osmosis Cell

Cell Transport • osmosis Which is isotonic, hypertonic, hypotonic? Isotonic hypertonic hypotonic

Transport • osmosis Cell meaning concentration percent water moves of name of solute of water into/out of cell (compared to cell) hyper hypo iso (compared to cell)

Transport • osmosis Cell meaning concentration percent water moves of name of solute of water into/out of cell hyper more hypo iso (compared to cell) higher lower out of cell

Transport • osmosis Cell meaning concentration percent water moves of name of solute of water into/out of cell hyper more hypo less iso (compared to cell) higher lower higher out of cell into cell

Transport • osmosis Cell meaning concentration percent water moves of name of solute of water into/out of cell hyper more hypo less iso same (compared to cell) higher lower same lower higher same out of cell into cell both directions

Essential Question Be able to differentiate between the types of cell transport. 11. 7. 2007 Cell

Cell Transport • facilitated diffusion – molecules move across membrane with help of transport proteins

Cell Transport • active transport – uses energy to transport molecules against concentration gradient

Cell Transport • active transport – uses energy to transport molecules against concentration gradient

Cell Transport • endocytosis – engulfing solid particles using the cell membrane

Cell Transport • endocytosis – engulfing solid particles using the cell membrane 1. phagocytosis • endocytosis of solid material 2. Pinocytosis • Endocytosis of liquid material

Transport • exocytosis – cell secretes large particles via membrane bound sacs Cell

Transport Cell Tugor: the pressure within cells derived from osmotic pressure differences between the inside and outside of the cell causing rigidity.

Evolution of eukaryotic cells Prokaryotes were the 1 st to evolve, then eukaryotes Why? ? Cell

Evolution of eukaryotic cells Cell Symbiotic Theory: prokaryotes were once engulfed by other cells, giving rise to eukaryotes. 1. Ex. Mitochondria and Chloroplasts have their own DNA and RNA

Evolution of eukaryotic cells Cell mitochondria are the result of endocytosis of aerobic bacteria chloroplasts are the result of endocytosis of photosynthetic bacteria