NAME____________________________ DATE______________CLASS_________
Homework/Test
Objectives:
Discuss the function of the Golgi apparatus and ER
Standard:
Structure,
function, and purpose of organelles
Sub-objectives:
function of secretory proteins
Researchers at Yale have
discovered that, contrary to previous beliefs, the GOLGI APPARATUS is an ORGANELLE
that exists independently of the larger ENDOPLASMIC RETICULUM and is a
crucial component of cell division.
Published
in a recent issue of Nature, the discovery gives researchers a better
understanding of the cell division process and of the processes present in the
uncontrolled cell division that marks cancer.
In
normal cell division, a mother cell divides into two daughters and the division
is regulated until it stops. In a skin melanoma, for example, the cell division inexplicably
starts up again and continues unregulated. This study could help cancer
researchers understand why the regulation stops.
"Researchers
once thought that the Golgi apparatus was no more than an outgrowth of an
organelle called the endoplasmic reticulum," said Graham Warren, professor
of cell biology at Yale and a leading expert in the field. "We’ve shown
that it is an organelle within a cell that has its own autonomy and so
must grow and divide to keep pace with the growth and division of the cell it
inhabits."
The
Golgi apparatus sorts and modifies cell products such as HORMONES, growth
factors and digestive enzymes, and sends them to their final destinations within
the cell. For example, the Golgi decides whether a given protein will leave the
cell or be delivered to the cell surface or another destination. As with all
other cellular organelles, the Golgi has to grow and divide and has to be
inherited.
The
Golgi apparatus is normally thought of as a stack of membrane compartments
through which the SECRETORY PROTEINS pass, but Warren and colleagues have
been able to show that the Golgi has an existence even when these membranes are
removed from the apparatus.
"We
found that there are proteins, which we term matrix proteins, that form a
scaffold to organize the membranes," said Warren. "We think this
scaffold might be the Golgi apparatus proper, responsible for its growth,
division and partitioning between the two daughter cells."
In
past research, Warren and his team have shown that the regrowth of a mother
Golgi in the newly formed daughter cells requires a number of matrix proteins
that are involved in putting the new Golgi complex together.
The
significance of this new finding, Warren said, is at the basic cell biological
level. "People have tended to think of organelles such as the Golgi in
terms of the membranes, in part because this is the structure you see by
electron microscopy," said Warren. "You don't see the matrix proteins.
What we have done is to focus attention on these underlying structures, which
might actually be more relevant to people interested in studying the
biogenesis of these organelles."
"Now
that we know that the Golgi is an independent organelle that has its own
identity, we can start looking at it from a basic cell biology perspective that
has medical implications for diseases like cancer, " said Warren.
Instructions:
Please number
the lines in the article, highlight concepts and terms, and place notes along
the margins. (5 pts.)
Please
write answers all questions, except the multiple choice, on a sheet of paper
incorporating the question in your answers.
1.
Define and
write in a sentence all underlined words. (10 pts)
2.
Create a divided
page graphic organizer study guide using the CAPITALIZED bold type
words. (15 pts.)
3.
The
regrowth of a mother Golgi in a new
daughter cell is contingent upon
what? Circle the best
answer. Cite the sentence in the
article, page in the text, or other source.
(5 pts)
A.
Cytoplasm
B.
DNA
C.
Proteins
D.
Matrix
proteins
4.
According
to the article what is the function of the Golgi apparatus? (5 pts)
A.
Store
toxins and other waste materials
B.
Sorts and
modifies cell products such as hormones and digestive hormones
C.
Reproduce
DAN and RNA
D.
Produce
ribosomes
5.
What is
the discovery that is so important in the article? (5 pts)
A.
That the
Golgi apparatus produces DNA
B.
That the
Golgi apparatus is an independent organelle
C.
That the
Golgi apparatus is useless
D.
None of
these
6.
Define an
organelle. (10 pts)
7.
Ribosomes
are found on __________________ER. (5 pts)
A.
rough
B.
smooth
C.
both a and
b
D.
simple
E.
None of
these
8.
What is
the function of the endoplasmic reticulum? (10 pts)
9. If a
cell didn’t have ribosomes, it would be unable to __________________________
(10 pts)
A.
extract
energy from glucose
B.
synthesize
sugars
C.
store food
in the form of fat
D.
form
proteins
E.
utilize
oxygen
9.
The
organelle that pinches off portions of its membrane to form vesicles used for
storage or transport is the
(5 pts)
A.
mitochondria
B.
chloroplast
C.
nucleolus
D.
Golgi body
11. An organelle found
in the nucleus is a ______________ (5 pts)
A.
pastid
B.
vacuole
C.
nucleolus
D.
mitochondria
12. Which of the
following contain enzymes and are the main organelles of intracellular
digestion? (5 pts)
A.
Golgi
bodies
B.
Ribosomes
C.
Mitochondria
D.
Lysosomes
E.
Endoplasmic
reticulum
13. Which of the
following cell organelles is responsible for disposal of hydrogen peroxides? (5
pts.)
A.
Golgi
bodies
B.
Ribosomes
C.
Mitochondria
D.
Lysosomes
E.
Peroxisomes