Chapter 4: Cell Structure and Function Notes
I. Scientists and Discoveries
 Early 1600’s (Holland): first ___________________________________ was constructed
 __________________________________________ (1600’s): used a single lens as a microscope to study and very
carefully draw tiny living organisms
 (1655) English physicist _________________________________________ used light microscope to study thin
slices of plants—cork had many tiny chambers he called “________________” like monastery cells
 __________________= the basic units for all forms of life
 (1838) ____________________________________: concluded all plants are made of ________________
 (1839) ____________________________________: all animals made of cells
 (1855) _____________________________________ : studied cell reproduction; 5yrs research concluded with:
“Where a cell exists, there must have been a preexisting cell…
II. Cell Theory
 Consists of three parts:
1.
2.
3.
III. Basic Cell Strucutres
• Cells usually ___________________ micrometers
• Smallest: _______________ micrometers
• Largest: (amoeba Chaos chaos) 1000 micrometers
• All cells have a ________________________________ and ______________________________
• ______________________________________________: thin flexible barrier around a cell
• ______________________________________________: material inside the cell membrane
• Many cells also have __________________________________ (strong layer around cell membrane)
• Cell membranes & cell walls support & protect cells while allowing them to interact with their
environment
• Some cells also have a ___________________________ (a large structure that stores the cells genetic
information & controls the cells activities)
IV. Prokaryotes vs. Eukaryotes
 Cells are divided into two categories:
1. Prokaryotes
2. Eukaryotes
**divided into these two categories to separate cells that contain a ________________________ and
______________________________ (eukaryotes) to those that do not (prokaryotes)
V. Prokaryotes
• Usually ___________________________________ & _________________________________ than eukaryotes
• Contain cell membranes & _______________________________________
• DO NOT have ___________________________________
• All ___________________________________ are prokaryotes
o Examples: Escherichia coli (intestines), Staphylococcus aureus (skin infections)
• Carry out all activities that define life (grow, reproduce, respond to their environment, and some
even move)
VI. Eukaryotes
• CONTAIN nuclei, cell membrane, cytoplasm, and dozens of other specialized structures that perform
special function (_________________________________________)
• Some are single celled organisms, but most make up multicellular organisms
• All plants, animals, fungi, and many microorganisms are eukaryotes
VII. Cell Structures
A. __________________________________- refers to the region outside the nucleus but inside the cell membrane
 Also called the plasma membrane
 Bi-Layer phospholipids that regulates what enters and leaves the cell
B. Cell Wall
 Main function= provide ____________________________ and _______________________ for the cell
 Located _________________________ cell membrane
 Made of _________________________________ (a carbohydrate fiber) and ______________________ found in plants,
algae, fungi, and nearly all eukaryotes (not animal cells
C. Nucleus
 Controls most of the cell processes and contains _______________________ information of DNA
 ____________________________-granular material in the nucleus that consists of DNA bound to protein
 ____________________________- condensed chromatin that consists of genetic information that is to be
passed on during cell division
 ___________________________- small, dense region where assembly of ribosomes begins
 ____________________________- double-membrane layer that surrounds the nucleus. It contains many
nuclear ______________________________ that allow material to move in/out of the nucleus
D. Cytoskeleton
 Network of protein filaments that help the cell to maintain its shape, also involved in cell movement
 _____________________________________________-hollow tubes of protein, can serve as “tracks” along which
organelles move
 ________________________________-long, thin fibers that function in the movement & support of cells
E. Organelles in the Cytoplasm
 _______________________________- small particles made of RNA and protein
o produce proteins following coded instructions in the nucleus
 _________________________________________- organelle in which components of the cell membrane are
assembled and some proteins are modified (rough E.R.-have ribosomes attached to the surface)
 __________________________- enzymes in the Golgi Apparatus attach carbohydrates and lipids to proteins
 __________________________- small organelles filled with enzymes that break down lipids, carbohydrates,
and proteins from food into particles that can be used by the rest of the cell (also break down
organelles)
 ________________________- sac-like structures that store materials like water, salts, proteins, and
carbohydrates
 ________________________- found in plants
o Use energy from __________________ to make energy rich molecules in a process known as
____________________________
o Have a double ______________________
 _____________________________- use energy from food to make high energy compounds that the cell can use
to power _________________, ___________________, and ___________________
o Have a double _____________________
o Found in nearly all _________________________ cells
F. Organelle DNA
• _____________________ and _________________________ contain some of their own ______________________
information in the form of DNA
• These small DNA molecules contain information that is ___________________ for them to function
• _________________________ and ______________________ could have once been prokaryotic cells that were
__________________ by eukaryotic cells & formed a _____________________ relationship
V. Movement through the Membrane
 The cell membrane regulates what enters & leaves the cell & also provides
protection & support (figure 7-15)
o ___________________________–a double layered membrane formed when certain
kinds of ______________ are dissolved in water
o ___________________________-forms ___________________ & _____________ that help move
materials across the membrane
o _______________________________-attach to ___________________ & aids in
_________________ identification to allow cells to ID one another
 3 Types of Movement through the Membrane
1. ________________________: tendency of molecules to move from an area of _________
concentration to an area of lower concentration to reach __________________________
o causes many substances to move across the cell ________________ but __________
________ require the cell to use ______________
o concentration=
2. ____________________: diffusion of ___________ through a selectively ___________________
membrane
o _____________________ permeable= some substances can pass through but others
cannot
o Isotonic:
o Hypertonic:
o Hyptotonic:
o Osmosis exerts pressure known as ___________________ _________________ on the
hypertonic side of the selectively permeable membrane
o Osmotic pressure can cause a cell to _______________ or ________________
3. ______________________________: the process of protein channels allowing a
pathway for certain molecules to cross the membrane (figure 7-19)
o 100’s of different protein channels have been found that allow ions,
sugars & salts to cross the membrane
4. ______________________________: requires _____________ to move molecules across a cell
membrane ___________________ a concentration difference.
o The materials move from an area of ___________________ concentration to an
area of _______________ concentration (figure 7-20)-often compared to a
pump
5. __________________________: the process of taking large particles into the cell by means
of infoldings or pockets of the cell membrane that form _________________
6. __________________________: process of taking large particles into the cell by
endocytosis. Extensions of the ____________________ surround & __________________ the
large particles.
7. __________________________: membrane of the _________________ surrounding material
fuses with the cell membrane, forcing the contents ________ of the cell