WU:
1. Classify YOUR cells and tell me 1 complex structure you would find in them.
2. Why is it important for cells to be
compartmentalized?
Exceptions to the cell theory-
1. Where did the first cell come from?
2. What about Viruses?
- not a cell, but can reproduce if inside another cell - on the bridge between living and nonliving
THE ORGANELLES!
Name
~ Structure
~ Function
~ A or P?
~ Pic or Analogy
• We will complete the first 3 details in class, you will make an
analogy or sketch a
picture at home
You may make a BIG Organelle Table as we go if desired.
Name Structure Function A or P? Picture Analogy
Plasma Membrane Cell Wall Nucleus Nucleolus Ribosomes Cytoplasm Endoplasmic Reticulum Golgi apparatus Vacuoles Lysosomes Chloroplast Mitochondria Cytoskeleton Flagella
Cilia
Cytoplasm
The jelly-like, liquid portion of the cell that holds the organelles in place (chem rxns take place here too!)
Cytoplasm
Cytoskeleton
• Made of microfilaments (tiny, solid fibers) and microtubules (thin, hollow cylinders)
• These are proteins!
The Nucleus
• “Brain” of the cell (controls cell activities)
• Has a membrane (nuclear envelope) w/pores
• Only Eukaryotes!
Reproduction & Growth
Regulation & Homeostasis
What’s inside the nucleus?
• Chromosomes
• DNA (deoxyribonucleic acid) – genetic code
Chromatin
• Chromatin = tangled masses of DNA inside the nucleus
This condenses into chromosomes right before cell division begins.
Nucleolus
• Contains protein and RNA (ribonucleic acid)…
• Synthesizes ribosomes
Ribosomes
• Made of protein & rRNA
• Site of protein synthesis
• Free floating in the cytoplasm or on the
endoplasmic reticulum (ER).
Endoplasmic Reticulum (ER)
• 2 Types - Rough and Smooth ER
• Used for transport in the cell
Rough – has ribosomes
Smooth – does not have ribosomes
The smooth ER helps detoxify!
Mitochondrion
• Powerhouse of the Cell!!!
This makes ________
(Energy Molecule)!!!!!
• Double membrane
– Cristae and matrix
• Folded inner membrane increases surface area!!!
Cellular Respiration
Golgi Apparatus
• Packaging center of the cell (UPS!)
• It makes vesicles to
help with transport
Golgi Body Secreting Vesicles
Transport
Lysosomes
• Contain digestive enzymes
• Digest old worn out parts and invaders
Vacuole
• Storage
• Holds food, oil, wastes
• HUGE in plant cells – they usually only have 1!
• Smaller in animal cells – usually have more than 1!!
Listen to Cell Rap!
Cell Wall
Cell
Wall
Cell wall - What is it?
• Only in plant cells, bacteria, and fungi - outside of the cell/plasma membrane
• Made of cellulose
• DEAD – everything passes straight through it!!
• Maintains structure
The cell wall contains cellulose!!
Turgor pressure
• Pressure against the cell wall in a plant from water in the vacuole
• When turgor pressure is present= plants are perky instead of wilted!!
Centrioles (Animal Cells only)
Used during cellular reproduction
Centrioles
Chloroplast (Plant cells only)
• Carry out
photosynthesis - take energy from the sun and make food.
• Contain chlorophyll, so they’re green!
Photosynthesis
FLAGELLA:
Long, whip-like projection used for movement
CILIA: Short, hair- like projections
used for movement
Finish All Microscope
Eukaryotic Cells: Cheek, Onion, and Elodea lab (make wet mounts & stain) HW: Finish Organelle Table, Online HW Structure and Function, Cell Project!
WU:
Cell Specialization Reading pg 32 in
the purple books on desk
Cell Membrane (Plasma Membrane)
Excretion
Structure Plasma Membrane
• Phospholipid subunits
• Each has a polar head and a non-polar tail
• They form a double layer, called lipid bilayer,
because polar water
inside/outside cell repeals the non-polar tails
Polar Head
Non-polar Tail
STOP!! BIG WORDS!!!!
• Hydrophobic: Hydro = Water ; Phobic = afraid The tail of the phospholipid is hydrophobic
• Hydrophilic: Hydro = Water ; Philic = loving The head of the phospholipid is hydrophilic
• Structure of the phospholipid bilayer – (the heads are toward the water of the cytoplasm and
extracellular fluid, the tails are not)
•Protein channels (or transport proteins)
allow the passage of polar molecules in / out of cell; also serve as receptors to detect
foreign invaders as well as accept hormones.
• Glycoproteins/lipids – aid in cell identification
Fluid Mosiac Model
Has a lipid bilayer
With embedded
proteins
The phospholipid
Function of Cell membrane
• Controls transport into/out of a cell
• Holds the cell together
• Semi-permeable
(Selectively permeable) Gateway: allows only
certain materials to pass through
Phospholipid
Head
Tail
A concentration gradient influences what moves in and out of the cell
Larger or non-polar molecules can not simply diffuse through the membrane
Cell Membrane
• Membrane looks big?
Picture this…….
• It would take 10,000 membranes to equal the thickness of one sheet of paper!!!
Cholesterol in the Cell Membrane
• Important in cell signaling
• Provides structure, cell membrane would be
too fluid without
DIFFUSION
• Diffusion: mvmt of materials from an area of high to low concentration without the use of energy.
• Materials move with the Concentration gradient
• A type of Passive transport
Osmosis
• Osmosis: the diffusion of water through a membrane
• A type of Passive Transport
• Solutions can be referred to as:
– Isotonic
– Hypertonic – Hypotonic
Hypertonic, Hypotonic, Isotonic
• Isotonic solution – cell remains the
same….equal concentrations of water in and out of the cell.
• Hypertonic solution – Cell shrinks…There is a higher water concentration inside the cell than outside, so water will move out of the cell.
• Hypotonic solution – Cell expands…The water
concentration is higher on the outside of the cell
than inside, so water flows into the cell.
Facilitated Diffusion
• Transport proteins are used to move materials in and out of the cell by way of diffusion –
there is still no energy used from the cell.
Baggie Lab Set Up
• Starch Solution goes INTO the baggie and tie closed
• 10 drops of iodine into a 100mL beaker of water
• What does iodine indicate the presence of?
• Complete Cell Transport WS while waiting for
a reaction to occur. You may sit at labs, but
only if you’re productive. I will tell you to
come back to your seat if needed.
Osmosis Animation
• http://www.nclark.net/osmosisPocus.gif
Osmosis
Tube
Think about this…….
• You have two identical pitchers side by side, one filled with exactly 2 quarts of water, the
other filled with 2 quarts of Kool-
aid……….which has more water??
• WHY???
Check on Baggie Lab
• Conclusion and Clean up
• What happened?
• Set up your group’s Overnight Mini-
Experiment!
• Hypothesis before
you leave! What do
you hypothesize will
happen – if … then
WU:
Complete Beaker WS at desk
(at least 5 Q’s)
Passive vs. Active Transport
Facilitated diffusion
Active Transport
1 - Active transport requires energy
• 2 - Active transport brings substances from a low to high concentration
• 3 – Materials move against the concentration
gradient
ENDOCYTOSIS AND EXOCYTOSIS
• Endocytosis – materials move INTO the cell
• Exocytosis – materials move OUT OF the cell
Active Transport vs. Diffusion
Active Vs. Passive Transport
• Active Transport
– Requires Energy – Low to High
Concentration – Against
Concentration Gradient
– Use Proteins
• Passive Transport
– No Energy – High to Low – With the
concentration gradient
– May or may not use proteins
White blood cell engulfing video
