Download Cells

EOC Thursday
March 28
Cells
Organelles
Cell Theory
Characteristics of living things
Movement across the cell membrane
Cell Theory
• All life forms are made from one or more cells.
• Cells only arise from pre-existing cells.
• The cell is the smallest form of life.
Characteristics of Living Things
Characteristics of Living Things
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Made of Cells
Has a metabolism (homeostasis)
Grow and Develop
Reproduce
Adapt and Respond to the environment
Use and Need Energy
• Sometimes you see these:
– Has DNA as Genetic code
– Has capacity to evolve
– Complex and organized
Two Cell Types:
Eukaryote vs. Prokaryote
Prokaryote
Eukaryote
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Cytoplasm
Cell membrane
DNA
Single-celled
– All are bacteria
Cytoplasm
Cell membrane
DNA
Some are single-celled
Membrane bound
organelles
• Some are multi-cellular
Plant Cell
Notice
this
Animal Cell
Notice
this
What are the differences between
plant and Animal Cells?
Plant Cells
Animal Cells
• Cell Wall
• Chloroplast
• Large Central Vacuole
• Centriole
• Lysosomes
All other organelles are found in
BOTH plants and animal cells
Nucleus
• Double Membrane with
pores
• Nucleolus in center
• Function: stores DNA
Endoplasmic Reticulum
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Folded membrane
Interior is called lumen
Rough ER has ribosomes
Smooth ER no ribosomes
• Function:
– Rough: Protein making
– Smooth: Lipid making
and de-toxing drugs and
alcohol
Golgi Apparatus
• Stacked layers of
membrane-enclosed
spaces
• Function: Processes,
sorts, prepares and
delivers proteins. (UPS
of the cell!)
Vesicles
• Sacs within cytoplasm
• Function: to transport
materials around the
cell keeping the
material away from the
cytoplasm.
? Why do you think some
things need to be
isolated from the
cytoplasm???
Mitochondria
• Bean shaped
• Have own ribosomes and
DNA
• Double Membrane
– Inner and outer
• Function: produce energy
from the food you eat
Note: food and energy are
NOT the same thing!
Vacuole
• Fluid filled sac
• Animals have many tiny
ones
• Plants have a large central
vacuole, unique to them
• Function: storage of
materials. The large central
vacuole in plants stores
water and helps the plant
maintain its shape.
? Why do plants look shriveled
when they need water??
Lysosomes
• Another sac like structure
• Contains enzymes
• May or may not be
present in plant cells?
• Function: To digest or
destroy garbage in the
cell: old cell parts,
bacteria or other
invaders.
Centrosomes and
Centrioles
• The centrosome is a
region of cytoplasm
where microtubules are
produced in the cell.
• Centrioles are
microtubules arranged
in a circle. In animal
cells, they seem to play
a role in cell division. In
addition, centrioles help
to organize other
microtubules into cilia
and flagella.
Chloroplasts
• Inner and outer
membrane (like mitochondria)
• Have own ribosomes
and DNA (like mitochondria)
• Stacks of disc shaped
sacs in the inner
membrane, called
thylakoids
• Contain chlorophyll
Function: convert the sun’s
energy into food for the plant
Similarities between
mitochondria and chloroplasts
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Own DNA
Own Ribosome's
Double membrane
Similar shape
Scientists believe both were at one time freeliving prokaryotes that were engulfed by other
cells and incorporated into their structure
Cell wall
• Rigid layer outside of
the cell membrane
• Found in plants, algae,
fungi and some
prokaryotes (bacteria)
• Function: protection
and support
Cell membrane
Function: to regulate
what enters and exits
the cell.
Charged
head
Add this to your study guide
Diffusion and osmosis
• Refers to the movement of stuff across a
membrane
• Rely on a concentration gradient
• Require NO energy
• The difference?
– Diffusion is the movement of particles or
molecules
– Osmosis is the movement of water
Which way will the particles move
(A to B or B to A)
and why?
A
B
Which way will the particles move
(A to B or B to A)
and why?
A
B
The particles move from side
A to side B, BECAUSE there
are more particles on side A…
Particles move with the
concentration gradient.
Remember this saying
High to Low is the way to GO!
Active transport
• Requires energy (ATP)
• Moves materials AGAINST the concentration
gradient
• Transport proteins or vesicles are used
Vesicles can be formed
inside or outside of the cell
What about the rest of the study
guide?
• The rest is review from prior weeks. See what
you remember. This is good practice!!
Fun Links
• Cell Membrane Tutorial
– http://www.biology.arizona.edu/cell_bio/problem
_sets/membranes/index.html
• Interactive tour of the cell
– http://cellsalive.com/cells/cell_model.htm