THE CELL

INTRO TO CELLS

• CELLS ARE BASIC UNITS OF ORGANISMS

• CELLS CAN ONLY BE OBSERVED UNDER A MICROSCOPE

• BASIC TYPES OF CELLS

• ANIMAL PLANT BACTERIAL

Microscopes and Cells

• 1600’s.–Anton van Leeuwenhoek first described living cells as seen through a simple microscope.

ANTOINE VAN LEEUWENHOEK

Using his handcrafted microscopes he was the first to observe and describe single celled organisms, which he originally referred to as animalcules, and which we now refer to as microorganisms. He was also the first to record microscopic observations of

muscle fibers, bacteria, spermatozoa and blood flow in capillaries (small blood vessels).

Microscopes and Cells–Robert Hooke – 1600’s used the first compound microscope to view thinly sliced cork cells.

•Compound scopes use a series of lenses to magnify in steps.• first to use the term “cell”.

Microscopes and Cells• 1830’s.

–Mathias Schleiden identified the first plant cells and concluded that all plants

made of cells.

- Thomas Schwann made the same conclusion about animal cells.

Twenty years later in 1855 Rudolf Virchow proposed an important extension of cell theory that "All living cells arise from pre-existing cells". ("Omnis cellula e celula") This statement has become what is known as the "Biogenic law".

This idea flew in the face of current doctrine. It implied that there was no spontaneous creation of cells from non-living matter.

CELL THEORY

• PROPOSED BY SCHLEIDEN, SCHWANN AND VIRCHOW

• ALL LIVING THINGS ARE COMPOSED OF CELLS

• CELLS ARE THE BASIC UNIT OF STRUCTURE AND FUNCTION IN LIVING THINGS

• ALL CELLS ARE PRODUCED FROM OTHER CELLS

NUMBER OF CELLS• ORGANISMS MAY BE:

–UNICELLULAR• COMPOSED OF ONE CELL ex. bacteria

–MULTICELLULAR– COMPOSED OF MANY CELLS THAT MAY

ORGANIZE ex. humans

PROKARYOTE EUKARYOTE• NO TRUE NUCLEUS

• NO MEMBRANE-BOUND ORGANELLES

• CIRCULAR DNA

• EX. BACTERIA

• PROBABLY FIRST CELL TYPE ON EARTH

• NUCLEUS

• MEMBRANE –BOUND ORGANELLES

• LINEAR DNA

• ALL OTHER CELLS

• EX. YEAST (UNICELLULAR; PLANTS & ANIMALS MULTI

Cells

Complete the web with fourcharacteristics of cells.

All organismsare made of cells.

cells are liketiny building blocks.

Cells do thejobs that keeporganismsalive.

Cells are the smallestpart of a living thing.

CELL SIMILARITIES

• CELLS COME IN ALL SHAPES AND SIZES AND PERFORM A VARIETY OF FUNCTIONS, BUT THEY ALL HAVE THE FOLLOWING THINGS IN COMMON

• CELL MEMBRANE

• DNA

• CYTOPLASM AND ORGANELLES

Intro to Parts of Cells

• YouTube - Anatomy of a Cell

• Click on Link to view video

CELL MEMBRANE

CELL MEMBRANE

• Protective layer around cell• Regulates interactions

between cell and it’s environment

• Controls what enters and exits

CYTOPLASM

CYTOPLASM

• Gelatin-like substance; constantly flowing

• Many important chemical reactions occur in it and most of life’s processes occur in it

• Contains a framework called cytoskeleton; helps maintain shape

CELL WALL

CELL WALL

• CELLS OF PLANTS, ALGAE, FUNGUS, AND SOME BACTERIA HAVE HARD CELL WALL

• PROVIDES STRENGTH AND SUPPORT TO CELL MEMBRANE

• CELLS OF MUSHROOMS, MOLD AND YEAST HAVE CELL WALL MADE OF CHEMICAL SIMILAR TO COVERING OF INSECTS

NUCLEUS

NUCLEUS

• LARGEST AND MOST VISIBLE ORGANELLE IN EUKARYOTES

• NUCLEUS MEANS KERNEL OR NUT• COVERED BY MEMBRANE• CONTROL CENTER OF CELL(DIRECTS ALL

CELL ACTIVITIES)• STORES DNA (LONG THREADLIKE

MATERIAL THAT CONTAINS CODE FOR CELL ACTIVITIES)

• HAS INFO ON HOW TO MAKE PROTEINS

RIBOSOMES

RIBOSOMES

• MAKES THE PROTEINS WHICH ARE MADE UP OF AMINO ACIDS USED BY THE BODY FOR GROWTH AND REPLACEMENT AND REPAIR OF BODY CELLS

• NOT MEMBRANE BOUND

• SOME FLOAT FREELY; OTHERS ARE ATTACHED TO THE ER

ENDOPLASMIC RETICULUM

ENDOPLASMIC RETICULUM(ER)

• MAKES LIPIDS AND OTHER MATERIALS FOR USE INSIDE AND OUTSIDE OF CELL

• BREAKS DOWN DRUGS AND OTHER CHEMICALS THAT COULD DAMAGE A CELL

• INTERNAL DELIVERY SYSTEM OF CELL; MOVES SUBSTANCES FROM ONE PART OF CELL TO ANOTHER

• SMOOTH ER (NO ATTACHED RIBOSOMES); ROUGH ER (RIBOSOMES ATTACHED)

MITOCHONDRIA

• ENERGY FOR THE CELL (ATP) IS PRODUCED AT THE MITOCHONDRIA (BREAKS DOWN FOOD INTO CO2 AND WATER)

• WE BREATHE AIR TO MAKE SURE OUR MITOCHONDRIA HAVE OXYGEN THEY NEED TO MAKE ATP

• HIGHLY ACTIVE CELLS LIKE THE HEART AND LIVER HAVE THOUSANDS

• OTHERS HAVE ONLY A FEW

CHLOROPLASTS

• CONTAINS CHLOROPHYLL ( ONLY IN PLANTS AND BACTERIA)

• MAKES FOOD IN PLANTS; CONVERTS SUNLIGHT, CARBON DIOXIDE AND WATER INTO SUGAR

GOLGI BODIES

• STACKED, FLATTENED MEMBRANES

• SORT PROTEINS, PACKAGE THEM, AND DELIVER THEM AROUND THE CELL

VACUOLES

• STORE WATER AND OTHER LIQUIDS

• SOME PLANTS WILT WHEN THEIR CELL VACUOLES LOSE WATER

• VACUOLES ARE USUALLY THE LARGEST ORGANELLE IN A PLANT CELL

LYSOSOMES

• CONTAIN ENZYMES

• DESTROY WORN OUT OR DAMAGED ORGANELLES

• GET RID OF WASTE MATERIALS

• PROTECT CELL FROM FOREIGN INVADERS

Challenge #1

Do you know the organelles?

T. Trimpe 2008 http://sciencespot.net/

Label the parts of the cell.

A. Cytoplasm

B. Cell membrane

C. Golgi Body

D. Lysosome

E. Endoplasmic Reticulum

F. Nucleus

G. Mitochondria

H. RibosomeImage: http://web.jjay.cuny.edu/~acarpi/NSC/13-cells.htm