CELLS Smallest unit of life that can carry out all the functions of an organism.

THE MICROSCOPE * The invention of the microscope was one of the most important breakthroughs in biology. * Invented-1600s.

* In 1665 Robert Hooke (scientist) observed cork thru the microscope and described what looked like “empty chambers” and called them “cells.” * In the 1670’s, Anton van Leeuwenhoek, observed pond water & blood (living cells).

More “Science Guys” Schleiden (Botanist)- all plants are made-up of cells (1838). Schwann (Zoologist)-all organisms including animals are made-up of cells(1839). Virchow (Doctor)-all cells arise only from existing cells -Biogenesis ( 1855).

CELL THEORY 1. Cells are the basic units of life 2. All organisms are made of cells 3. All cells come from existing cells (Biogenesis )

PROKARYOTIC CELLS * GENERALLY SMALLER THAN EUKARYOTIC CELLS * CONTAIN GENETIC INFORMATION * DO NOT HAVE A NUCLEUS EXAMPLE: BACTERIA

EUKARYOTIC CELLS * GENERALLY LARGER AND MORE COMPLEX THAN PROKARYOTIC CELLS * HAVE A NUCLEUS IN WHICH GENETIC MATERIAL IS SEPARATED FROM THE REST OF THE CELL EXAMPLE: PLANTS, ANIMALS, FUNGI AND PROTISTS.

Plant Cell Nuclear envelope Ribosome (attached) Ribosome (free) Smooth endoplasmic reticulum Nucleus Rough endoplasmic reticulum Nucleolus Golgi apparatus Mitochondrian Cell wall Cell Membrane Chloroplast Vacuole

Animal Cell Centrioles Nucleolus Nucleus Nuclear envelope Rough endoplasmic reticulum Golgi apparatus Smooth endoplasmic reticulum Mitochondrian Cell Membrane Ribosome (free) Ribosome (attached)

TYPES OF EUKARYOTIC CELLS Plant Cells: –Cell Wall –Chloroplasts –Central Vacuole Animal Cells: –Centrioles –Lysosomes

CELL STRUCTURE CYTOPLASM - the portion of the cell outside the nucleus that holds the organelles in place.

* Contains nearly all the cell’s DNA (genetic code) * Surrounded by a nuclear envelope * contains the nucleolus (where assembly of ribosomes begin) NUCLEUS - the “Control Center” of the cell.

CELL MEMBRANE: PHOSPHOLIPID BILAYER THAT REGULATES WHAT ENTERS AND LEAVES THE CELL. ALSO PROVIDES SUPPORT AND PROTECTION CELL WALL: LIES OUTSIDE THE CELL MEMBRANE AND ALSO PROVIDES SUPPORT AND PROTECTION TO THE CELL.

RIBOSOMES: Small particles of RNA and protein scattered throughout the cytoplasm. Where proteins are assembled. ribosomes

ENDOPLASMIC RETICULUM: The site where lipid components of the cell membrane are assembled, along with proteins and other materials. Can be rough or smooth

GOLGI APPARATUS: MODIFIES, SORTS AND PACKAGES PROTEINS AND OTHER MATERIALS TO BE SHIPPED TO OTHER PARTS OF THE CELL WHERE NEEDED.

MITOCHONDRIA: CONVERTS ENERGY STORED IN FOOD TO COMPOUNDS THAT CAN BE USED MORE EASILY BY THE CELL. “ENERGY SOURCE” “The Mighty Mitochondria”

CYTOSKELETON: PROVIDES SHAPE/STRUCTURE TO THE CELL. ALSO INVOLVED IN MOVEMENT.

Lysosomes: a bag of hydrolytic enzymes. Function 1.intracellular digestion 2.programmed destruction. Like a tiny stomach or garbage disposal.

Vacuoles: Sacs that are larger than vesicles having functions in digestion, pumping excess material, storage, cell stabilizer, and are found in many protists and plants. Plant Cells (First major difference between Plant and Animal Cells) have a large central Vacuole that holds water. Pressure against the cell wall causes the leaves to stand up and not droop. ( turgor pressure)

Plastids (3 types of plant organelles) : 1. Amyloplasts store starch 2. Chromoplasts contain pigments 3.Chloroplasts contain chlorophyll. Chloroplasts have double membrane. The inner membrane looks like stacks of coins called grana. The liquid-filled area between the thylakoid and outer membrane is called the stroma.

CENTRIOLES PAIRED STRUCTURES OUTSIDE THE NUCLEUS (ANIMAL CELLS ONLY) CREATE THE SPINDLE DURING MITOSIS(CELL DIVISION)

FLAGELLA AND CILIA FLAGELLA: LONG, WHIP-LIKE TAIL FOR MOVEMENT( ONE OR TWO) CILIA: TINY HAIR-LIKE, USED FOR MOVEMENT FOUND ON ONE-CELLED (UNICELLULAR) ORGANISMS