Chapter Seven A View of the Cell
Chapter Seven A View of the Cell
Cellular Organization
• Cell • Tissue – group of cells functioning
together. • Organ – group of tissues
functioning together. • Organ System – group of organs
functioning together. • Organism – group of organ
systems functioning together.
The History of the Cell
• The Cell – The basic unit of an _______ – Discovery made possible by the invention of the _______
Microscopes and Cells
• 1600’s. – _____________________________ first described living cells as seen through a simple microscope.
Microscopes and Cells
– ____________used the first compound microscope to view thinly sliced cork cells.
• _____________ use a series of lenses to magnify in steps. • Hooke was the first to use the term “_______”.
Microscopes and Cells • 1830’s.
– _______________identified the first plant cells and concluded that all plants
made of cells. - __________________ made the same conclusion about animal cells.
Cell Theory:
• All organisms are made up______________________.
• The cell is the ____________________of all organisms.
• All cells come from ______________________.
_____ Basic Cell Types
1) _________ – Lacks internal compartments.
– No true _________. – Most are single-celled (unicellular) organisms.
– Examples: ________
Two Basic Cell Types 2) Eukaryote
– Has several internal structures (organelles).
– True nucleus. – Either unicellular or multicellular.
unicellular example: yeast multicellular examples: plants and animals
Cell size comparison
Bacterial cell
Animal cell
micron = micrometer = 1/1,000,000 meter diameter of human hair = ~20 microns
most bacteria 1-10 microns
eukaryotic cells 10-100 microns
The Parts of The Eukaryotic Cell 1) Boundaries
A) ____________________ -- Serves as a boundary between the cell and its external environment.
-- Allows materials to ________________________________________________
1) Boundaries
B) __________________ -- Surrounds the ____________________ of the cells of plants, bacteria, and fungi. -- Plant cell walls contain _________ while fungi cell walls contain _______.
The Parts of The Eukaryotic Cell: 2) Controls
A) __________ • Regulates cell function. • Surrounded by a double-layered membrane (_______________________) with large pores that allow materials to pass in and out of the nucleus.
• Contains _______ – long tangles of ______.
2) Controls
B) _____________ • Found in the __________ and responsible for ribosome production. Ribosomes are the sites of _________________.
The Parts of The Eukaryotic Cell: 3) Assembly
– ___________ • The ____________ material that surrounds the organelles.
The Parts of The Eukaryotic Cell: 4) Transport
A) ________________________ • Folded membrane that acts as the cell’s delivery system.
• __________________ contains enzymes for lipid synthesis.
• __________________ is studded with ribosomes for ________________.
4) Transport B) ___________________ (or Golgi body)
• A series of flattened sacs where newly made lipids and proteins from the E.R. are repackaged and shipped to the plasma membrane.
The Parts of The Eukaryotic Cell: 5) Storage
A) ___________
• A sac of fluid surrounded by a membrane used to _______ food, fluid, or waste products.
5) Storage B) ___________________
• Contain ______________. • Can fuse with vacuoles to____________, or can digest worn cell parts.
• Also known as “suicide sacs” because they can also destroy the whole cell.
The Parts of The Eukaryotic Cell: 6) Energy Transformers
A)_______________ Produce the ________
for the cell. Also known as the
“powerhouse of the cell”.
Has a highly folded inner membrane
(cristae).
6) Energy Transformers B) ______________
-- Found in _________ cells and some protists. -- Transforms light energy into chemical energy which is stored in food molecules. -- Contain _______________ – a green pigment that traps light energy and gives plants their green color.
The Parts of The Eukaryotic Cell: 7) Support
– _________________ • A network of thin, fibrous materials that act as a scaffold and support the organelles.
• _____________ – hollow filaments of protein.
• _____________ – solid filaments of protein.
The Parts of The Eukaryotic Cell: 8) Locomotion
1) __________ • Short, numerous, ______________________________________________from the plasma membrane.
• Move with a coordinated beating action.
8) Locomotion
B) ____________
• Longer, less numerous projections from the plasma membrane.
• Move with a ___________ action.
The Parts of The Eukaryotic Cell: 9) Cell Division
___________ – made of protein. – play a role in the splitting of
the cell into two cells. – found in animal and fungi cells.
Composite Animal Cell
bacteria cells
Types of cells
animal cells plant cells
Prokaryote - no organelles
Eukaryotes - organelles
Movement Across the Membrane
• Establishes Homeostasis • Occurs through channel proteins • Can be active or passive
– ____________transport does not require energy – ____________transport does require energy
Passive Transport - Diffusion • Particles in a solution move constantly • Particles tend to move from an area of
________concentration to _______ concentration
• When concentration is equal everywhere, it has reached equilibrium
• Substances diffuse across membranes without requiring the cell to use energy (___________________)
Diffusion
Diffusion- movement from _____ concentration _____concentration
Passive Transport-Osmosis
• If a substance can diffuse across a membrane, the membrane is said to be _____________ to it and ________________ if it can't diffuse across it
• Water diffuses easily
• ______________ is the diffusion of water across a _______________________________ membrane from an area of high concentration to low concentration
Osmosis • The direction of osmosis is determined by
comparing total solute concentrations – ________________-more solute, less water – ISOTONIC- equal solute, equal water – ________________- less solute, more water
hypotonic hypertonic
freshwater balanced saltwater
Managing water balance • Cell survival depends on balancing water
uptake & loss
Diffusion through phospholipid bilayer • What molecules can get through directly?
– _____ & other lipids
inside cell
outside cell
lipid salt
aa H2O sugar
NH3
What molecules can NOT get through directly? _______
molecules H2O
ions (charged) salts, ammonia
large molecules starches, proteins Semipermeable
Passive Transport-Facilitated Diffusion Cell membranes have ___________that act
like carriers, making it easier for certain molecules to cross. They "facilitate" the diffusion of molecules.
There are hundreds of different channels that only allow certain molecules to come through.
It will only occur if there is a higher concentration on one side of the membrane. It doesn't require energy. It's passive transport.
Channel protein
Active Transport
• Cells may need to move molecules ___________ concentration gradient – protein “pump” – “costs” energy = __________
How about large molecules? • Moving large molecules into & out of cell
– through vesicles & vacuoles – ____________
• phagocytosis = “cellular eating” • pinocytosis = “_____________”
– exocytosis
exocytosis
Endocytosis
phagocytosis
pinocytosis
receptor-mediated endocytosis
fuse with lysosome for digestion
non-specific process
triggered by molecular signal
Getting through cell membrane • Passive Transport
– _______________ • diffusion of nonpolar, hydrophobic molecules
– lipids – _________________ concentration gradient
– Facilitated transport • diffusion of polar, hydrophilic molecules • through a _________________
– HIGH → LOW concentration gradient
• Active transport – diffusion ___________________________________
• LOW → HIGH – uses a ________________ – requires _______________
ATP
Cell Membrane • Cell membrane establishes
___________________for the cell by controlling what passes in and out of the cell.
• HOW? 1. ______________________________creates a
barrier 2. ___________________ that allow polar
substances through 3. Glyco-proteins are name tags
Phospholipid Bilayer
Glycoprotein
Integral Proteins
Peripheral Proteins