Transcript THE CELL - TeacherWeb

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 MEMBRANEBOUND
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
Complete the web with four
characteristics of cells.
All organisms
are made of
cells.
Cells
Cells do the
jobs that keep
organisms
alive.
Cells are the smallest
part of a living thing.
cells are like
tiny building blocks.
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/