Cell Structures

•_______________ is the study of cells. There are 2 main types of microscopes to study cell

structures: the ______________ microscope and __________________ microscope. Light

microscopes are ________________ microscopes. This means they have _____ or more

lenses (the _______________________ + the _____________________ / eyepiece lens).

They work by allowing light to ______________________ a specimen, so the objects being

viewed must be _____________________. There are 2 main types of electron microscopes:

___________________ (TEM) and __________________ (SEM). Transmission electron

microscopes send electrons ________________ a specimen so the images are often

__________________________. While scanning electron microscopes “scan” the

_________________ of a specimen and offer a __________ image.

•The first person to make a microscope was _____________________ and it magnified

objects ______ X (today that would be considered a _______________________ lens). The

person who then improved upon the first microscope was _____________________.

_______________ viewed _____________ under a microscope. He said it reminded him of

the living quarters of _____________ called ________________. Therefore, he named what

he saw _____________. _______________________ was the first to view plant cells and

______________________ was the first to view animal cells.

•To determine how much an object is being magnified, you _______________ the ocular

lens by the objective lens. This tells you how much larger the object is than the real size / the

naked eye. The ______________________ is how ___________________ the object being

viewed is. It is the minimum distance ___________________ can be separated and still be

distinguished as 2 separate points.

Microscope Resolution Magnification Advantages Disadvantages

Light

TEM

SEM

*Note: 1 µm = ______ mm. 1 nm = ______ µm.

Q: Label the images either

SEM or TEM.

•So far we have seen how to view cell structures. To see how a cell _________________ a

process called cell ___________________________ is used. This involves taking the cells

_____________, separating the ___________________, and then studying the organelles’

____________________ / functions. To get the organelles out of cells it is necessary to:

A) Put them into a ______________________ to break open the cells.

B) _________________________ them so that the _______________ organelles

will form a pellet at the bottom and the smaller organelles will be in the liquid

floating on top called the _____________________.

C) Pour off the liquid and re-centrifuged again at a ______________ speed and

_____________ time.

D) Repeat.

•________________________ cells also known as __________________, do not have a

membrane-bound _________________. Instead, their main DNA is in a large loop called the

________________________. In addition to this main DNA, prokaryotes / bacteria also

have smaller circles of DNA called ____________________. Similar to plants, they also

have a cell _________, but it is not made of ___________________. It is made of a

substance called _____________________________. Bacteria have three layers to them

(starting from the outside): ______________ also called the _____________ layer, then the

________________, then the ____________ or _____________ membrane. They have tiny

hairs surrounding them called __________ that are used for __________________________.

*Note: Students often mistake pili for ______________. Be aware that bacteria do not have

cilia! Instead, bacteria use _________________ for locomotion.

•_________________________ are larger than prokaryotes. The prefix “eu” means

___________ in reference to the fact that they have a true __________________ and other

membrane-bound organelles that allow for ________________________________-different

compartments / areas that can carry out different reactions. This is important because it

allows for incompatible processes to occur _______________________ inside the same cell.

•There are both ____________ and ___________ limits to cell ___________. Most

prokaryotes / bacteria are between ______ to _______ µm. Most eukaryotes are between

_______ to ________ µm.

Fun Fact: Sturgeon (the largest fresh water fish in the world and whose eggs are used for caviar) recently were

found to have the largest bacteria in their gut (.2mm) which means they are visible with the naked eye!

•The limits on cell size are due to __________________ requirements (recall metabolism

means the ______ of all chemical reactions in the body). A cell can’t be too __________

because it needs enough room inside it for things like _________ and enzymes to sustain

itself and reproduce. Likewise, a cell can’t be too ______________ because metabolism

with the ___________________________ environment (outside of the cell) would then be

too _________ from the outer membrane. For example, if you had a cell the size of a

_________________, when that cell makes ______________ products that it needs to

______________ to another cell in the body, it would take too long to get the products to the

plasma membrane.

•The ____________________ is a ______________-bound organelle in eukaryotic cells. It

contains ____________ of the genes that control the entire cell.

Q: Where is DNA also found inside eukaryotic cells?

________________________________________________________________________

•The nucleus is surrounded by a nuclear ___________________ / __________________

which is a double membrane with ___________ that regulate _______________ and exit

from the nucleus. The nucleus contains ___________. When DNA is in the loose form it is

called ______________________ and when it condenses into ___-shaped structures during

cell division it is called _______________________________. Also inside the nucleus is the

______________________ which makes __________________. Protein _______________

Q: If you increase the surface area of a

1 mm cube to a 2 mm cube, what happens

to the volume?

(the making of proteins) begins in the nucleus. The nucleus sends out genetic messages from

____________ in a smaller form called _______________ that eventually becomes proteins.

•Ribosomes are where ___________ are linked together to form ___________________ /

polypeptides. They are small structures with _______ parts: a ____________ subunit

(_______) and a __________ subunit (_______). There are 2 types of ribosomes:

_____________ and ________________ / attached ribosomes. Free ribosomes are found in

the fluid of the cell called the _________________. They assemble proteins that will

_______________ in the cytosol. The bound / attached ribosomes are located on the

_______ (endoplasmic reticulum). They make the proteins that will be incorporated into

membranes or proteins that will _____________ the cell.

*Note: Cytosol is just the _____________ of the cell. Cytoplasm actually means

__________________ inside the cell (organelles + the fluid / cytosol) except the nucleus.

•The ________________________ system (endo = ______________ and membrane =

phospholipid bilayer). All these members are either: A) Related ________________ by

physical contact or B) Related ____________________ through _________________

vesicles.

•The endoplasmic reticulum (ER) is a large double membrane network of sacs called

_____________________ which means chests. The ER is connected to the nuclear

__________________. Within the sacs of the cisternae called the _____________________

space or __________________ (Note: Lumen is a general term in biology to mean any open

cavity) proteins are _________________ into their functional forms.

•There are 2 types of ER: the ___________________ ER and the _________________ ER.

The smooth ER lacks ___________________.

•The smooth E.R. is the site where:

A) ________________ are synthesized. This includes phospholipids as well as

________________.

B) _______________________ are metabolized. For instance, ______________ in

the liver and muscles.

C) Drugs and poisons are ___________________. To accomplish this, the liver adds

______ to drugs / alcohol to make them more ________________ and easier to

flush from the body. If a person drinks a lot of alcohol, their liver cells have lots

of __________________ ER.

D) ________________ cells pump _________ from the cytosol into the cisternal

space and is involved in muscle cell ______________________________.

•The rough ER has ribosomes and is the site where:

A) _______________________ proteins / proteins that get secreted from cells are

made. For example, the pancreas cells have rough ER that makes the protein

______________ that is secreted into the __________________________. Most

secretory proteins are ___________________________. “Glyco” = small

_________________________ are covalently bound to a protein.

What makes up the endomembrane

system?

1)

2)

3)

4)

5)

6)

7)

B) Proteins + ________________________ (in other words, cell membranes) are

put together that can be ______________________________ and used as

transport __________________ to other endomembrane components.

•The ___________________ apparatus / complex / body is where transport vesicles arrive

from the ER. The Golgi apparatus ___________________ and ____________ cell products.

The transport vesicle arrives on the ________ side of the flattened, membranous sacs /

_________________ of the Golgi apparatus. _________________ as well as phospholipids

get altered by ______________ in the Golgi. Altered can include adding a “glyco”(sugar) to

a protein or adding a __________ (fat) to a protein. The altered proteins are then given

molecular __________________ to be recognized at different “docking sites” once they

leave the Golgi. The newly modified products then leave the Golgi on the ______________

side. They either go to another location _________________ the cell or to the _________/

plasma membrane to be shipped _________________ of the cell.

•_________________ are membrane-enclosed sacs of hydrolytic ______________________.

They have a pH of ______ and ________________ the 4 macromolecules.

•_____________________________ (phago = ____________) is when an ______________

or a __________________ engulfs food / bacteria. The engulfed food particle then fuses

with a _________________ in order to digest it and then release the nutrients into the cell for

its own use. ___________________ (auto = ____________) is when a cell ______________

its _________ worn out cell parts.

•Some ___________________ diseases result from impaired lysosome function. If a cell

lacks an ____________ enzyme to break down substrates inside the lysosome the substrates

begin to ____________________. For example, with ________________________ disease

a person accumulates too many _____________________ in the brain.

•There are 3 types of _________________________-membrane-bound sacs, larger than

vesicles inside cells.

1) __________________ vacuoles we already discussed and arise when a cell

_________________ nutrients via phagocytosis.

2) ______________________ vacuoles are what ___________________ (like a

______________________) use to pump out excess _______ from a cell.

3) The _______________ vacuole is very large in ___________________ and is

bound by a membrane called a ____________________. This vacuole stores

mostly _________, but also _________________ products. It also gives

__________________ to flower petals and can contain ____________________

compounds. The central vacuole also gets ___________________ to help plant

cells grow.

•__________________________ and _________________________ are not part of the

endomembrane system (not formed from ER). They are formed from ________________

ribosomes and their _______ ribosomes. Mitochondria are the site of ________________

respiration.

Q: What is the equation for cellular respiration?

___________________________________________________________________________

•Cells can have anywhere between _____ to ____________ of mitochondria in a cell.

Q: What type of cell has the most mitochondria? __________________________________

•Mitochondria have their own ______________ and their own _________ (can reproduce on

their own!). The mitochondria itself has a smooth _________________ membrane made of a

__________________________ bilayer and proteins. There is then a ______________, then

another ____________ membrane also made up of a phospholipid bilayer and proteins. This

2nd

membrane is ______________________ or has infoldings called _________________.

Reactions in the mitochondria occur at 2 locations: the ________________________ space

(found between the outer and inner membrane) and the mitochondrial _______________ (the

area inside the inner membrane). Each of these compartments contains different

___________. For example, the intermembrane space has enzymes for making __________.

•Chloroplasts contain the green pigment _______________________ and they make food for

plants. ______________________ are ________________ or yellow in color and give some

fruits and flowers their color (i.e. tomatoes). ______________________ are colorless and

store __________________________ (i.e. potatoes). Amylo-, chromo-, and chloroplasts are

therefore all found in _________________ and all are called _________________________.

•Chloroplasts have _____ compartments that allow for compartmentalization during

photosynthesis. 1) The _____________ membrane space is between the inner and outer

membranes. 2) The area inside the inner membrane where the _________________ fluid is

located. 3) The area inside a ___________________ (a stack of thylakoids = ___________

or plural ________________ that are connected by tubules).

•The ___________________________ is a network of fibers throughout the cytoplasm. Its

function is to provide _____________ or support to the cell. It attaches to organelles and

moves them using _______________________________.

•1) ____________________________ are large, ______________, coiled and made of a

protein called _______________________. They provide shape to the cell, form cilia /

flagella, form ________________ that are used in cell division, and ________ organelles.

•2) __________________________ are _____________, thin, coiled and made of the protein

________________. They allow for ______________ cell contractions (actin and myosin),

cleave a cell in two, ____________________ movement with _________________ or “false

feet” (i.e. in _______________), cytoplasmic ___________________ (circular flow of

cytoplasm distributes materials in cells).

•3) ____________________ filaments are solid, intermediate ______________________,

“rope-like”, and made of the protein ____________________. They provide cell shape and

_________ the position of organelles in place like the nucleus.

•The ultrastructure of cilia and flagella work due to the ____________ protein called ____________.

Dynein arms move the microtubules that make up cilia and flagella by ____________________ and

_______________ the microtubules. This allows for “walking”. ____________ are then able to

move a cell in strokes like a _____________________. __________________ propel a cell in a

____________________ motion.

•Cell walls are found in ___________________, ____________________, _________________ and

some protists. Recall that plant cell walls are made up of ___________________. The function of

cell walls in plants is to hold the plant up. The development of plant cell walls begins when a young

plant cell secretes the thin, flexible _____ cell wall. Next, the cell adds the middle _______________

which is made of a ______________ substance called ______________ that holds one cell to another

cell. Lastly, older plants strengthen cell walls with a strong ______ cell wall. If the plant is a

_____________ plant like a tree, it will have ______________ secondary cell walls.

•The _________________________________ (ECM) in animal cells is attached to the outside of the

cell. The main components to the ECM are __________________________________. The ECM is

important to the cell because it can transmit ______________________ from the outside of the cell to

the inside of the cell allowing for cellular _________________________________.

•Both plant and animal cells have intercellular ____________________ between their cells. Plants

have only one kind of junction called _______________________________. These are openings /

___________________ for cytoplasm to pass through from one plant cell to the next.

•Animal cells have 3 kinds of junctions: _________________, ____________________ / anchoring,

and ____________ / communicating.

1) Tight junctions are _____________ tight / leak proof like a ________________ between

animal cells.

2) Desmosomes or ___________________ junctions are also fused tight/ leak proof, but their

clamp has ____________________ which are actually _____________________ filaments.

3) Gap or ___________________ junctions allow for _____________________ between cells.

They allow salts, sugars, amino acids, and small molecules to ______________ between

animal cells.

Q: Which animal cell junction is most like a plant cell’s plasmodesmata?

_________________________________________________________________________________

•________________ are organelles that contain enzymes that produce _________________________

(H2O2) as a by-product. They have many roles including detoxifying ________________ in the liver

by transferring ______________ from the poisons to ____________ to form __________. However,

because _____________ is also toxic, different enzymes convert it into ____________.

Q: Which organelles and/or structures are only found in plant cells?

_________________________________________________________________________________

Q: Which organelles and/or structures are only found in animal cells?

_________________________________________________________________________________