Transcript Cell Organization

CHAPTER 2
cells P. 38 - 44
EARLY DISCOVERIES
Anton
Van Leeuwenhoek
- made microscopes.
- saw “critters” in a
drop of water.
- never seen before.
Robert Hooke
- first to see cells in
slices of cork
- ‘named’ cells.
Led to others studying cells.
Matthias Schleiden
- studied every part of
plants.
- concluded all parts
were made of cells.
Theodor Schwann
- studied animals.
- concluded that all
animals were made of
cells.
Rudolph Virchow
- new cells come
from other living
cells.
These scientists’ work led to the
Cell Theory.
Cell theory
1.
2.
3.
All organisms are made of
cells.
Cells are the basic unit of
structure and function in all
organisms.
All cells come from other
cells.
Read p. 38 - middle p. 42.
STRUCTURE OF CELLS (p.
38)
Scientists discovered there
were parts inside the cell.
A) Cell Membrane
Like the protective skin of the cell
- the outer covering.
- controls what goes in and out.
 Food , water, oxygen enter - Wastes
leave.
 Selectively permeable: controls what
enters and leaves

CELL MEMBRANE
B) Nucleus
the ‘control center.
B1) nuclear membrane
-controls what
goes in and out of
the nucleus.
-
Contains chromosomes:
- structures that hold
hereditary material to
determines what you look
like.
- made of DNA.
C) Cytoplasm
Found inside the cell membrane outside
the nucleus.
 Gel - like substance: mostly water.
 Contains small structures called organelles
-all have a “job” inside the cell.

CYTOPLASM
Cell Organelles


Cells work 24 hours a day, 7 days a week
Cell Organelle: working parts of the cell.
Cell Organelles
1. Mitochondria
 Powerhouse of cell
 Food broken down and
energy is released.
 Which cells might have
lots of mitochondria?
2. Endoplasmic Reticulum (E.R.)
 Folded membrane
 Like conveyer belts in the factory.
(or a highway)

Transports materials throughout
the cell.
3. Ribosomes
 Most numerous organelle in the cell
 Some attached to E.R.
 Produces protein (food) for the cell
- releases energy from food.
 Which cells might have the most ribosomes?
4. Lysosomes
- contains chemicals (enzymes) to digest
wastes and ‘worn out’ parts of the cell.
- called ‘suicide sacs’
- break open and digest the cell when
it dies.
5. Vacuole
 Storage sacs
 Hold food, water, and wastes
 Larger in plant cells
ASSIGNMENT:
WORKSHEET
“CELL STRUCTURE”.
COLORED PENCILS NEEDED TOMORROW!
PLANT CELLS
-have two different parts than animal
cells.
1.
Cell Wall
- found outside the
cell membrane.
- for support and
protection.
- non-living
2. Chloroplasts
- where photosynthesis
takes place (turns
sunlight into food).
- contains chlorophyll.
(green)
Two basic types of cells
1) Prokaryotic cells
no membranes around internal
structures (no nucleus)
- simplest type of cell:
-
 Bacteria
ex. Pond Scum
Two basic types of cells
2) Eukaryotic cells
-
-
Nucleus surrounded a membrane.
most complex type of cell:
all plants and
animals.
TRANSPORT IN CELLS
how materials move
from cell to cell.
Diffusion
- the movement of
particles from high
concentration areas
to low concentration
areas.
Ex. dye in water
-
(CH. 3 p. 74)
Equilibrium
- when the particles
are spaced evenly.
In cells, water carries
food, wastes, etc.
- must enter/leave
the cell through
diffusion.
- it must go thru the
cell membrane.
(it is selectively
permeable)
Diffusion is a type of
passive transport.
- no energy is used
to move the particles.
Active Transport
-
uses energy.
- moves particles from low
concentrations to high concentrations.
DRAWING ON BOARD.
ASSIGNMENT:
SECTION REVIEW
QUESTIONS.
P. 45 1
P. 51 1+2
P. 78 1+2
Osmosis
- another method of cell transport of water
but it must move thru a cell membrane.
- high concentration to low concentration.
Osmosis Examples
- a wilting plant “straightens up” after
being watered.
Reverse osmosis can kill plants
- water is taken away from the roots by
the drier soil.
Example 2:
Salt on leeches
draws out their
moisture.
ASSIGNMENT:
WORKSHEET
“CELL TRANSPORT”
CELL RESPIRATION
-
-
-
the process that creates
energy from food and
oxygen.
The cell gives off carbon
dioxide (CO2) and water
(H2O) as wastes.
It takes place in the
mitochondria.
(P. 83)
Respiration gives you energy to run,
breathe, talk, etc.
- you take in food and oxygen.
- you give off H2O and CO2
Fermentation
-
(P.84)
a process which creates energy without
using oxygen.
ex. yeast
- uses nutrients and gives off CO2 and
alcohol.
- used to make bread and wine/beer.
You only use fermentation only during
heavy exercise.
During exercise, you don’t get enough
oxygen.
- your cells release energy thru
fermentation.
- wastes created H2O, CO2, and lactic
acid.
- causes ‘burning’ feeling.
- sore muscles.
-releases 18x less energy than respiration.
ASSIGNMENT:
WORKSHEET
“RESPIRATION”
PHOTOSYNTHESIS
(light)
p. 82
(to make)
- the process used by plants to make food.
-needs light, CO2, H2O, and chlorophyll
- it traps energy and uses it to break
down water into hydrogen and oxygen.
Where does it
takes place in
the cell?
Oxygen is given off as a waste.
Hydrogen combines with carbon to make
a sugar (glucose).
Glucose is stored/used as food or used
to build new structures (ex. stems)
- animals eat the plants and receive
energy from the stored sugars.
- the energy is passed on.
All living things depend upon sunlight. *
(except….)
Respiration and Photosynthesis are
linked.