Download LIFE SCIENCE 1.2

LIFE SCIENCE
1.2
Microscopes allow us
to see inside the cell.
Because cells are
very small, in order
to measure them
we need a new
unit.
The micrometer (mm)is one
millionth of a meter.
Cells can range from 1 to 1000
micrometers.
It would take 17,000 bacterial
cells to line up across a dime.
Light Microscopes
bend light and
magnify cells up
1000 times.
Cells can be treated with
dyes to make more visible.
Cameras and computers
observe movement of cell
parts.
Can observe living cells.
Scanning Electron Microscope
and
Transmission Electron Microscope
SEM and TEM can view
objects as small as 0.002
micrometers.
Can see details inside the
cell.
Use particles called electrons
not light to produce an image.
Can magnify objects up to 1
million times.
Can not be used to study live
specimens.
SEM
THE CELL SAMPLE IS COATED
WITH A HEAVY METAL SUCH AS
GOLD.
A BEAM OF ELECTRONS IS RUN
BACK AND FORTH OVER THE
SURFACE.
THE ELECTRONS BOUNCE OFF
THE SURFACE AND ARE READ BY
A DETECTOR WHICH PRODUCES
A 3 D IMAGE OF THE SURFACE
SEM IMAGES
Butterfly Proboscis
Pollen
TEM
THE CELL SAMPLE IS SLICED
EXTREMELY THIN.
ELECTRONS PASS THROUGH A
SECTIO.
IMAGES PRODUCED ARE 2
DIMENSIONAL.
TEM
Golgi Bodies
Mitochondrian
CELLS ARE DIVERSE
EVERY CELL HAS:
Cell membrane- separates the
cell from its environment.
Cytoplasm – gelatin-like
material inside the cell, carries
on most of the work of the cell.
Two categories of Cells
Eukaryotic Cells
Prokaryotic Cells
Two categories of Cells
Eukaryote- eu: true;
kary: nucleus


Genetic material
contained in a
membrane bound
structure called a
nucleus. Contain other
membrane bound
structures called
organelles.
Usually multicellular
organisms.
Prokaryote- pro:
before; kary: nucleus
 Genetic
material
contained in the
cytoplasm does
not have
membrane bound
organelles.
 Usually unicellular
organisms
Eukaryotic Cells
are divided into 2 types
Plant Cells
Animal Cells
ORGANELLES: any part of the cell that is
enclosed by a membrane.
THESE ORGANELLES ARE ONLY FOUND IN PLANT CELLS.
Cell Wall



Plant cells have a
cell wall.
A tough outer
covering that lies just
outside the cell
membrane.
Supports and
protects the cell.
Chloroplast



All energy comes
from the sun.
Chloroplasts help the
plant capture and
use the sun’s energy.
Plants convert this
energy into sugar
and store the excess
as starch.
THESE ORGANELLES ARE ONLY
FOUND IN PLANT CELLS.
Cell Wall
Chloroplast
These organelles are found in all
eukaryotic cells…both Plant and
Animal
Endoplasmic
Reticulum
Mitochondria
 The
powerhouse of
the cell.
 Releases energy
from sugar for use
by the cell.



A system of twisting and
winding membranes,
some contain
Ribosomes which
manufacture proteins.
The ER manufactures
parts of the cell
membrane.
Part of the cellular
transportation system.
These organelles are found in all
eukaryotic cells…both Plant and
Animal
Mitochondria
Endoplasmic
Reticulum
These organelles are found in all
eukaryotic cells…both Plant and
Animal
Ribosomes
 Found
attached to
the endoplasmic
reticulum and
floating freely in
the cytoplasm.
 Manufacture
proteins.
Golgi Apparatus



ER breaks off and forms
Vesicles.
Inside the vesicles are
products the cell has
made for transport
outside of the cell.
The Golgi Apparatus
which looks like a stack
of pancakes finishes the
processing of the
products.
These organelles are found in all
eukaryotic cells…both Plant and
Animal
Ribosomes
Golgi Apparatus
Organelles for storage
recycling and waste
Vacuole





Enclosed in a
membrane
Found in plant and
fungus cells.
Can store water, waste
and other materials.
Plant cells have one
large central vacuole
that helps support the
plant.
Not found in animal
cells.
Lysosome


Vesicles that contain
chemicals to
breakdown materials
taken in by the cell
as well as old cell
parts.
Animals do not make
their own food like
plants do so must
digest or breakdown
the food.
Organelles for storage
recycling and waste
Vacuole
Lysosome