Download Matter in Ecosystems Part 2

More on Matter &
Energy in Ecosystems
Macromolecules to Organelles to Cells
IN
Where are cells on the biological scale?
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Sub-Atomic Particles
Atoms
Molecules
Macromolecules (proteins, lipids, nucleic acids, carbohydrates)
Organelles
Let’s scale up!
Cells
Tissue
Organs
Atom
Tissue
Population
Organ System
Molecule
Organ
Community
Organism
Macromolecule
System
Ecosystem
Population
Community
Organelle
Organism
Biome
Ecosystems
Cell
Biosphere
Biome
Biosphere
Solar System
Universe
A sense of scale
between living cells
and atoms. Each
diagram shows an
image magnified by a
factor of 10 in a
progression from a
thumb, to skin cells,
to a ribosome, to a
cluster of atoms
forming part of one
of the many protein
molecules in our
bodies.
HYPERLINK!!!
• http://learn.genetics.utah.edu/content/cells/scale/
I. Macromolecules Make up the Organelles of a Cell
A.
B.
C.
D.
Proteins
Carbohydrates
Lipids
Nucleic acids
Cell
Organelles
II. Cell Organelles
A.Nucleus
a. Has a nuclear envelope and a
nucleolus
b.Contains DNA
c. Controls all cell activities
B. Mitochondria
a. Double membrane; football shape
b. “Power House” of the cell
1. Food converted into ATP energy
(adenosine triphosphate=“gasoline of cells”)
2. Uses Oxygen, produces CO2
C. Endoplasmic Reticulum
a. Site where cell membrane and
proteins are made
b. Two types of ER membrane:
Rough (ribosomes attached)
and Smooth
c. “Highways” of the cell
D. Golgi Apparatus Receives and modifies
proteins
E. Lysosomes
a. Cellular digestion
b. Breakdown of waste
F. Cytoplasm (cytosol) -
Water based, gel-like
material where
chemical reactions
occur
G. Cytoskeleton Filaments move
organelles and the
cell
H. Vesicles Sacs of material from
the cell membrane,
ER, and Golgi
I. Chloroplast (plant cells only)
a. Bean-shaped; with numerous membranes
b. Contains chlorophyll
c. Where photosynthesis takes place
J. Ribosomes
a. tiny molecular machine made of two
subunits
b. the site of protein synthesis
K. Cell Membrane (plasma membrane)
a. Encloses cell and organelles
b. Membrane is fluid-like and is
constantly in motion
c. Made of a “phospholipid bilayer”
d. Phospholipids have non-polar,
hydrophobic (water hating) ends that
stick together and polar,
hydrophilic (water loving) ends
II. Importance of the Cell Membrane
A. Proteins on the surface and
embedded in the cell
membrane interact with “lipid
bilayer”
B. Membrane and proteins
control what goes in and out
of cell
C. Proteins act like pores,
channels, pumps and carriers
D. Many enzymes in the cell
membrane speed up chemical
reactions
E. Carbohydrate “antenna”
embedded in membrane
allows cells to communicate
carbohydrates
III. Crossing the Cell Membrane
A. The membrane is
selectively permeable
which means some
things can get through
and some cannot.
B. Small, polar molecules
pass through the
membrane with ease
Ex: Water, carbon dioxide,
and oxygen
C. Large, non-polar
molecules and ions do
not pass through
without help
Ex: glucose
OUT: Cell Membrane Model
• Use the contents in the baggy to build a model of the cell
membrane. Color and label the proteins, carbohydrates,
lipid bilayer, fatty acids, and phosphate group.
STOP
I. Cells Respond to their Environment
A. Homeostasis – cells maintain a constant internal
environment in response to environmental changes
B. Assures balance and equilibrium to keep cells healthy
II. Maintaining Cell Homeostasis with and
without Energy
A. Passive Transport
(Requires no Energy)
a. Diffusion – Molecules move
from an area of higher
concentration to an area of
lower concentration
b. Simple Diffusion –Molecules
move directly through the
membrane. Molecules move with
the concentration gradient (a
difference in the concentration of
molecules across a distance.)
Diagram what happens after
diffusion in your notes.
Draw arrows into your
notes to show molecule
movement.
c. Facilitated Diffusion – carrier proteins help
transport larger molecules and ions WITH their
concentration gradient (from HIGH to LOW concentration)
d. Osmosis – water molecules diffuse
• Solute – molecule
being dissolved
across a cell membrane
• Solvent – the
1. Water moves from an area of higher substance that
(water) concentration to an area of dissolves the solute;
usually water.
lower (water) concentration.
2. Water always moves in the directionAdd to your
notebook!
of high solute.
3. Osmosis affects cells.
Types of Solutions:
• Hypotonic – Solute concentration is
lower outside the cell compared to
inside the cell. (water moves in)
• Hypertonic – Solute concentration is
higher outside the cell compared to
inside the cell. (water moves out)
• Isotonic – Solute concentration is equal
inside and outside the cell.
B. Active Transport (Requires Energy)
a. Carrier proteins move
molecules against
concentration gradient
From LOW to HIGH
b. Movement in Vesicles - Some molecules are too
large to transport through carrier proteins.
1. Endocytosis – cell
membrane pinches in and
creates a vesicle enclosing
macromolecules and large
particles
Ex: food and bacteria
2. Exocytosis - membrane
vesicle fuses with cell
membrane and releases
material outside cell
Ex: proteins, waste, and
toxins
Need Energy