Download Monkemeier - Madison Public Schools

Monkemeier
Honors Biology
December 8, 2014 – December 12, 2014
Unit 4: Microscopes, Structure and Function of Cells
Endomembrane Systems within Eukaryotes!
Eukaryotic cells are far more complex than prokaryotic cells. The hallmark of the
eukaryotic cell is compartmentalization, which is achieved by an extensive
endomembrane system that weaves through the cell interior and by numerous
organelles. The organelles of a eukaryote are surrounded by their own membranes –
with one exception being ribosomes since ribosomes do not have a membrane.
The interior of a eukaryotic cell is packed with membranes so thin that they are
invisible under the low-resolving power of light microscopes. The endomembrane system
fills the cell, dividing it into compartments, channeling the passage of molecules through
the interior of the cell, and providing surfaces for the synthesis of lipids and some
proteins. The largest of the internal membranes is called the endoplasmic reticulum (ER).
Endoplasmic means within the cytoplasm and reticulum means “a little net”. It is a
phospholipid bilayer with embedded proteins. The inner region of the endoplasmic
reticulum is cisternal space or lumen, and the exterior region is the cytostol.
NOTE: These pictures are in color on the Monkemeier Teacher Web Page.
Directions: Complete the sentences below with the word bank that follows
1. Proteins syhesized on the _____________________________ are transported
by vesicles to the ____________________________ where they are modified,
packaged and distributed to their final location.
2. ________________________ are vesicles that contain digestive enzymes.
These can fuse with vesicles containing extracellular material or old organelles,
causing the contents to be digested, broken down or degraded.
3. ______________________________ are a subclass of microbodies that carry
out oxidative metabolism that generates peroxides. The isolation of these
enzymes in vesicles protects the rest of the cell from the very reactive chemistry
occurring inside.
4. __________________________________ are membrane-bound structures
that have a variety of roles ranging from storage to cell growth in plants. These
are also found in some fungi and protists.
5. The ____________________________________ is involved in synthesizing
lipids . Cells in the testes, intestine and brain have abundant amounts of SER.
Word Bank
Chloroplasts
Golgi Apparatus
Lysosomes
Mitochondria
Peroxisomes
rough endoplasmic reticulum
smooth endoplasmic reticulum
Vacuoles