Sydney Roth, Lina Rivetti, Annabel Kopell
Topic 1
The most vital asset in regulating what enters and
leaves the cell is the cell membrane. Both prokaryotic
and eukaryotic cells contain a cell membrane and the
membrane functions in the same way for all.
Necessary Functions:
o Separates internal metabolic reactions from external
surroundings
o Helps excrete the cell’s waste
o Responsible for the intake of substances needed for
cell functions
o Protective barrier against water from its
environment
• The proteins embedded in
• The cell membrane is
the bilayer are either
composed of a
phospholipid bilayer and
transport proteins, receptor
proteins.
proteins for odor, taste, and
• The phospholipids in the
hormones, or channels to
bilayer have hydrophilic
control the entry/exit of ions
heads and hydrophobic tails
and other substances that
allowing the membrane to
cannot travel through the
regulate water entry.
bilayer.
Cell membranes help organisms maintain
homeostasis by controlling what substances
enter/leave the cell.
Passive Transport- a process by which substances can
cross the cell membrane without any input of energy
by the cell.
• Facilitated diffusion- a process used for molecules
that cannot readily go through the cell membrane.
They are molecules that are not soluble in lipids or
are too large to pass through the membrane. Use
carrier proteins.
Active Transport- a process by which cells must use
energy to transport substances in/out of the cell
• Endocytosis- the process by
which cells ingest external fluid,
macromolecules, and large
particles, including other cells
• Exocytosis- the process by which
a substance is released from the
cell through a vesicle that
transport the substance to the
cell surface and then fuses with
the membrane to let the
substance out of the cell
• The golgi body is responsible for
packaging the cell secretions in
secretory vesicles for transport
out of the cell through the
membrane.
http://www.pbslearningmedia.org/asset/t
dc02_int_membraneweb/
http://www2.estrellamountain.edu/faculty/farabee/biobk/en
docytosis.gif
http://www.cytochemistry.net/cell-biology/Gol8.jpg
Introduction
In order for a cell to function properly, it must have a
particular structure. The cell also must be mobile if necessary
and be able to move materials over the surface of stationary
cell. The cytoskeleton forms the structure of the cell.
The cytoskeleton is a network of thin tubes and
filaments that crisscrosses the cytosol
• Maintains cell shape
• Anchors organelles and enzymes to specific regions
of the cell
• Contractility and movement (amoeboid movement)
• Intra cellular transport tracks for vesicle and
organelle movement by motor proteins
PowerPoint made by Andrew Zheng, Emmaline Stoddard, and Meghan Sardis
Parts of Eukaryotic Cytoskeleton
• Microfilaments- long
threads of actin
– Contribute to cell
movement
• Microtubules- hollow
tubes of tubulin
– Maintain cell shape,
anchor organelles,
contribute to cell
movement, track for
motor proteins
• Intermediate Filamentsrope-like fibrous proteins
– Provide structural
reinforcement, anchor
organelles, keep nucleus
in place
Parts of Prokaryotic Cytoskeleton
The cytoskeleton structures in
prokaryotes and eukaryotes are
different, though the functions
of these structures are similar
• FtsZ
– Forms filaments
• Mreb and ParM
– Maintenance of cell shape
• Crescentin
– Maintaining cell shape
Cellular Movement
• Flagella- long threadlike
• Cilia- short, hair-like
appendages on the
appendages extending
surface of a living cell
from the surface of a
– Whip back and forth in a
living cell
jerky fashion to propel
– “row” the protists like
thousands of oars
– Short
– Found in eukaryotic
cells
cell
– Longer than cilia
– Found typically in
prokaryotic cells,
sometimes in eukaryotic
cells
Citations and Links
• www.diffen.com
• http://www.stolaf.edu/people/giannini/flashani
mat/cellstructures/Motor%20protein.swf
• http://www.stolaf.edu/people/giannini/flashani
mat/cellstructures/micro%20slide.swf
• http://www.stolaf.edu/people/giannini/flashani
mat/cellstructures/microtubuletransport.swf
• http://learn.genetics.uutah.edu/content/begin/
cells/
The Purpose of Nutrients in a Cell
Obtaining and metabolizing nutrients is necessary in
order for a cell to complete several life processes. Cells
acquire nutrients and convert it to energy to move,
divide, produce secretory vesicles, contract, and
reproduce. Without energy, a cell wouldn’t be able to
“fuel” its internal organelles and perform any of the
essential functions of life.
Cell Comparisons
Prokaryotes/Eukaryotes
- Eukaryotes contain
internal organelles that
are not present in
prokaryotes, such as the
mitochondria, that assist
in obtaining and
metabolizing nutrients.
Animal Cells/Plant Cells
- Plants cells contain
chloroplasts that are not
present in animal cells.
- Both contain the
mitochondria that are
essential in producing ATP
the cell’s primary energy
source.
- Plant cells: Photosynthesis
- Animal cells: Diffusion
Emily Carrieri, Stella Hung & Sandro Conte
Structures Involved
• Cell Membrane
- Allows specific nutrients to enter the cell from outside
surroundings
- Protects internal metabolism from harmful conditions
outside the cell
• Mitochondria
- Takes food (in form of sugar) and combines with
oxygen to produce ATP.
- ATP is the primary energy source for the cell.
Structures Involved (cont.)
Chloroplast (plant cells only)
- The chloroplasts contain a green pigment Chlorophyll,
which absorbs energy from sunlight.
- The energy converts water and carbon dioxide into
sugars (like glucose) that the mitochondria can convert
into ATP.
Prokaryotes
- Prokaryotes obtain and metabolize nutrients
differently due to the fact that they lack the internal
organelles that eukaryotes have.
- Prokaryotes obtain their nutrients through the
process of diffusion.
- Storage Granules: After the nutrients are
metabolized through a series of chemical reactions
in the cytoplasm, they are stored in storage granules
in some form of energy (glycogen, lipids, etc.) and
are used as needed.
Cells must Grow, Develop, and
Reproduce Overview
• By Jackie Romankow, Emma Williams, Brian Zeng,
and Vineet Parikh.
• This is the cell cycle- the repeating
of set events in the life of a cell
• First interphase happens
• Then cell division
• Why?
– This cycle happens to replace dead
or dying cells, and/or to produce a new
organism.
http://www.cellsalive.com/cell_cycle.htm
Centrosomes and Cytoplasm
• http://cellsalive.com/mitosis.htm
• A centrosome only functions during mitosis
• Cytokinesis is the division of cytoplasm of cells
Nucleus
• This is arguably the most important organelle
involved in cell reproduction and growth.
• Mitosis is
the cycle in
which the
Nucleus
divides
Differences in the Cycle
Plant vs. Animal
Eukaryotes vs. Prokaryotes
Proteins Synthesis
• The process by which
cells synthesize, modify,
and ship proteins to
their respective
destinations.
• Group Members: Nicki Wang,
Ethan Goldring, Amelia Fruda,
and Gavin Van Skiver.
http://www.proteinsynthesis.org/wpcontent/uploads/2013/02/protein-synthesis-ribosome.jpg
Process of Protein Synthesis
1. Proteins are assembled in The process is broken into 2
steps: Transcription,
the ribosomes by RNA,
then Translation.
which act on instructions
from the DNA.
2. Vesicles transport proteins
to the Golgi Apparatus.
3. The Golgi Apparatus
modifies proteins and ‘relabels’ them into new
vesicles.
4. Vesicles release proteins
that have destinations
http://4.bp.blogspot.com/k0yymaOn57o/T59yTtItXYI/AAAAAAAAERY/Xc_dZTuFYrQ/s1600/MJ+2
outside the cell.
012+howproteinsynthesisworks.jpg
Organelles Involved
• Nucleus: where the process
begins (with DNA and RNA)
• Rough Endoplasmic Reticulum:
place where Ribosomes are
attached in cytoplasm.
• Ribosomes: where the
proteins are synthesized.
• Golgi Apparatus: where the
proteins are modified and
packaged into different
vesicles, so they can be moved
to different regions of the cell.
• Vesicles: the organelles that
release the proteins.
http://www.enchantedlearning.com/subjects/animals
/cell/anatomy.GIF
Why it is Important?
• Protein synthesis allows new proteins to be
created, replacing dying or diseased proteins.
– Proteins are important to cell function!
• Protein synthesis also allows DNA to have a
hand in the daily function of a cell.
A Helpful Animation:
http://www.stolaf.edu/people/giannini/flashanimat/cellstructures/en
domembrane%20protein%20synthesis.swf
Any Differences?
• In a eukaryotic cell the process
of transcription occurs in the
nucleus, while translation
occurs in the cytoplasm. In
prokaryotic cells, both stages
occur in the cytoplasm
• When protein synthesis occurs
in a ribosome not located
http://www.odec.ca/projects/2004/mcgo4s0/p
ublic_html/t3/antisense1.gif
inside the Rough ER, the
proteins produced never leave
the cell.
Storing and Digesting Nutrients in Cells
Haley Frey, Jonathan Rich, Sarah Rosa
Why is storing and digesting nutrients so
important for cell function?
• Cells need nutrients for energy (ATP), cellular
functions, and to create new tissues and cells.
• A cell can’t use food until it has been digested.
• Cells also need to neutralize dangerous
substances.
Lysosomes
• vesicles that bud from the Golgi apparatus
• contain hydrolytic enzymes to break down
substances into useful material
– carbs, lipids, proteins, nucleic acids
• Autophagy: they digest worn out organelles
• Autolysis: lysosomes in a cell breaking down
that cell
http://highered.mcgrawhill.com/sites/9834092339/student_view0/chapter4/lysosomes.html
Peroxisomes
• found in the kidney and liver cells
• deal with harmful substances
– free radicals (oxygen ions) which are harmful
• detoxify alcohol and other drugs
• digests hydrogen peroxide (H2O2)
• break down fatty acids for energy
Digestion Process
PLANT CELLS
Organelles involved:
- Large vacuole: stores digested
material, act as lysosomes for the
plants
- Peroxisomes: convert fatty acids
to sugar and assist chloroplasts
What happens: material enters the
cell and the peroxisomes begin to
digest them. The digested material is
then stored in the
vacuole.
Decaying organelles
are broken down
and reused in other
places.
ANIMAL CELLS
Organelles involved:
- Lysosomes: contain enzymes to
digest bacteria and other
substances
- Peroxisomes: digest harmful H2O2
What happens: material enters the
cell and the lysosomes and
peroxisomes begin to digest it. The
useful material is transferred to the
mitochondria to be
used for energy.
Decaying
organelles are broken down
and reused in other placed.