Studied by 6 people
Prokaryotic cell
NO ORGANELLES,SMALL,BACTERIA,NO NUCLEOUS
Eukaryotic cell
ORGANELLES,BIG,PLANTS,ANIMALS,FUNGI,NUCLEOUS,
ALL CELLS
cytoplasm, ribosomes, DNA , cell membrance
Robert Hooke
discovered cells through microscope/cell theory
Anton
Discovered microscope
Light Microscopes
Glass lenses,Light to magnify,1,000x bigger,LIVE specimen
Electron Microscopes
Magnifies up to 500,000x, magnets to aim a
beam of electrons at a cell to produce an image
Small Cells have…
a greater ratio of surface area to volume than a large cell of the same shape
Cell Membrane
separates a cell from its surroundings, regulates what enters and leaves the cell and helps protect and support the cell.
Cytoplasm
The cytoplasm is the fluid-filled region of the cell that contains the organelles(cellular metabolism)
Nucleus (the control center)
is the cell’s control center. directs protein synthesis and contains the cell’s (DNA).
Ribosomes
(little protein makers)
Proteins are assembled on ribosomes, using the instructions in DNA. Found throughout the cytoplasm and on the rough ER.
Endoplasmic Reticulum
Proteins and other materials move throughout the cell by way of the endoplasmic reticulum.
Smooth Endoplasmic Reticulum
Does not have ribosomes attached to its surface
Contains enzymes that perform specialized tasks,
such as making membrane lipids and detoxification of drugs.
Help move materials throughout the cell.
Rough Endoplasmic Reticulum
Has ribosomes attached to its surface
Helps with making proteins
Help move materials throughout the cell.
Golgi Body
(the shipping warehouse)
receive proteins and other formed materials from the endoplasmic reticulum, package them, and distribute them to other parts of the cell or out of the cell.
Mitochondrion
(the powerhouse of the cell)
convert energy in food molecules, such as sugars, to energy the cell can use (called ATP) to carry out its functions, also known as cellular respiration
Cytoskeleton
The cytoskeleton is network of protein fibers that provide structural support
and are involved in various types of cell movement:
Microtubules
Hollow tubes of globular proteins that form a rigid skeleton or the cell and act as tracks for organelle movement and also act as anchors for organelles.
Microfilaments
: Thin threads of protein called actin that enable cells to
change shape and move. (Ex: actin filaments interact with other thicker
filaments to make muscle cells contract)
Intermediate Filaments:
Reinforce cell shape and help anchor certain
organelles (Ex: the nucleus is held in place by them)
Cilia
Short, hair-like structures
made of microtubules that
help cells move
Flagella
Are longer and move with a
whip-like motion and are
made of microtubules
Centrioles
(cell division)
a type of microtubule that
help cells divide and are located in the cytoplasm
near the nucleus
Lysosomes
(the little garbage disposals)
small organelles filled with enzymes that break
down lipids, carbohydrates, proteins and damaged organelles into
small molecules that can be used by the rest of the cell.
Peroxisomes
similar to lysosomes, but are found in all types of eukaryotic cells
Cell Wall
Plants, fungi, and some protists and bacteria have cell walls
outside of the cell membrane to protect the cell
Vacuoles
(the plant storage warehouse and support
system)
store materials such as water, salts, proteins, and
carbohydrates as well as help support heavy
structures (plants) and help cells move
Chloroplasts
(plant’s little sunshine food makers)
found only in plant cells and they convert energy from the sun into glucose using the chemical reactions of photosynthesis.
Animal Cells
Centrioles
Lysosomes
Plant Cells
Cell Wall
Large Central Vacuole
Chloroplasts
Selective Permeability
The plasma membrane allows some substances to pass through while keeping others out
Non-polar, hydrophobic molecules
are soluble in lipids and
can easily pass through the plasma membrane
Polar molecules and ions
are not soluble in lipids and
cannot pass through
Lipids, mainly phospholipids,
are the main structures of the plasma
membrane
a phosphate group
(head)
2 fatty acids
(tail)
The fatty acid tails are nonpolar,
therefore hate water and are
hydrophobic
Phospholipids have
hydrophillic heads & hydrophobic tails
The hydrophilic heads
face the liquid inside/outside the cell
The hydrophobic face
each other, away from the liquidy cytoplasm
and the watery environment outside the cell
Proteins can form channels (tunnels) for
polar substances to easily
pass through.
A receptor protein
has a shape that fits the shape of a specific
messenger, such as a hormone
signal transduction
Some proteins are receptors for chemical messengers from other cells
A receptor protein has a shape that fits the shape of a specific messenger, such as a hormone
The binding of the messenger to the receptor triggers a chain reaction
It relays the message to a chain of proteins, and then to a molecule
that performs a specific activity inside the cell
proteins have a carbohydrate chains attached to them,
glycoproteins
Glycoproteins act
like chemical identification cards that allow cells to
recognize and interact with each other
Cholesterol
helps to prevent the fatty-acid tails from sticking together
The concentration of a solution
is the amount of solute in a
liquid (solvent). HIGH concentration means LOTS of solute.
Passive Transport
Diffusion
Facilitated
Diffusion
Osmosis
Active Transport
Protein Pumps
Endocytosis
Exocytosis
diffusion,
molecules move from an area of higher concentration to
an area of lower concentration without using energy
3 factors affect how fast diffusion occurs:
Concentration: diffusion is faster at higher
concentrations
Temperature: diffusion is faster at higher
temperatures
Pressure: diffusion is faster at higher pressures
Facilitated Diffusion
When a protein facilitates the diffusion
of a molecule from high to low
concentration, it is called facilitated
diffusion
Each facilitator protein is specific to
each kind of molecule (for example,
glucose can only go through glucose
facilitator proteins).
Channel Proteins
open and close to allow
substances to diffuse
through the plasma
membrane
Carrier Proteins
change shape to help
move particles through
the membrane
Osmosis
In osmosis, water diffuses through a selectively permeable
membrane.
Water will always move from where there is MORE water (high
concentration of water) to where there is LESS water (lower
concentration of water).
Hypertonic-
when a solution has a higher
concentration of solutes (and less water) than the
cell(water moves OUT
of cell)
Hypotonic- when a solution has a lower
concentration of solutes (and more water) than the
cell.
Isotonic- when a solution has the same
concentration of solutes as the cell.(water
moves INTO cell)
active transport
when cells move materials in the opposite
direction from which the materials would normally
move—that is from LOW to HIGH concentration.
Cells use.. in active transport
energy (ATP) for active transport
two major types of active transport
1) When ONE molecule is transported at a time
using protein pumps
2) When MANY molecules are transported at a
time using endo and exocytosis.
Pumps are special transport proteins that allow molecules to
travel from low to high concentration USING ENERGY!!! NOT the same thing as facilitated diffusion
How Protein Pumps Work
Solute attaches to the protein
ATP phosphorylates the protein (attaches a phosphate group onto
the protein)
This causes the protein to change shape and the solute to be
released on the other side of the membrane
The phosphate group detaches, and the protein returns to its
original shape, for a new round
Sodium Potassium Pump
Active transport allows a cell to maintain concentrations of small
molecules that are different from the concentration of its
surroundings
An animal cell has a higher concentration of potassium ions (K+) and a
lower concentration of sodium ions (Na+) than the solution outside
the cell
Nerve signals depend on these concentration differences
The sodium-potassium pump helps cells maintain these steep
gradients by shuttling Na+ and K+ across the membrane
Endocytosis
Endocytosis is the process of taking material into the cell by
pockets (vesicles) created by the cell membrane.
pinocytosis
Cells use pinocytosis to take in liquid (cell drinking)
phagocytosis
Cells use phagocytosis to take in solids (cell eating)
Receptor-Mediated Endocytosis
It is the same as endocytosis except that it is highly specific to which molecule it brings in
hypercholesterolemia
They have fewer or no cholesterol receptors
Therefore, the cholesterol is not being taken up by their cells via
receptor-mediated endocytosis
The cholesterol remains in their blood and accumulate, causing reduced blood
flow, leading to heart disease
Cells take in cholesterol from the blood by receptor-mediated
endocytosis
Exocytosis
the membrane of the food or water vacuole (blob) binds with the cell’s membrane and then forces the waste contents out of the cell.
Endocytosis & Exocytosis Examples
Endocytosis and Exocytosis moves large molecules, like proteins,
across the plasma membrane
Example: When we weep, cells in our tear glands use exocytosis to
export a salty solution containing proteins
Example: Certain cells in the pancreas make the hormone insulin and
secrete it into the bloodstream by exocytosis
Note 
Flashcard (33)