Unformatted text preview: ope is contineous with another
membranous structure called the Endoplasmic reticulum (ER). These
are a series of flaten sacs and tubes, it comes in 2 different types:
1) Rough ER : the walls of the ER are studded with ribosomes, this
serves as a major site for protein synthesis.
2) Smooth ER: This lacks riboaomes. Serves as a site for lipid
synthesis and detoxification. It is imporatnt in cells that break down
compounds Membrane bound organelles Nucleus
Nucleolus DNA and protein organized into
chromosomes (chromatin) Endoplasmic reticulum
Tubular membranes and
cisternae Rough – ribosomes, for
membrane protein and secreted
protein synthesis Smooth – for lipid and steroid
synthesis, detoxification BIO 1140 – SLIDE 14 Golgi complex See Fig. 2.8 Stack of flattened vesicles
Sorting, modification and packaging
of proteins Nucleus Vesicles Rough ER Transport among organelles and/or
to plasma membrane Lysosomes, peroxisomes Vacuole Contain hydrolases, catalases
complex Vesicles Temporary storage Turgor pressure in plant cells Lysosome BIO 1140 – SLIDE 15 Fig. 2.16 > Protein that are synthesisized in the rough ER typically than move
to another membrane structure the Golgi complex. They move from
one to another by means of small, membrane bound vesicles.
> Vesicles are small, single membrane bound organelles that suttle
things around in the cell. They can suttle proteins from rough ER to the
golgi complex, they can also suttle proteins from the golgi complex out
to the membrane of the cell, if those proteins are going to be secreated
from the cell.
> The Golgi complex itslef is another set of flaten sacs and it is an
importanst site of protein modification and sorting. Proteins that are
synthesisized in the rough ER are than sent to the Golgi complex for
further modification. This can involve taking a long protein and
breaking it into smaller sub sections. It can involve adding tags, so the
protein can be sent to the right place in the cell. This process of
modifing the proteins, sorting them and than sending them off to the
approperate location takes place in the Golgi complex.
> Lysosomes, peroxisomers these are small, single membrane
bounded organelles. They are involved in breaking down compounds.
They contain enzymes that break down different types of bonds.
Lysosomes contain hydrolases, and peroxisomers contain catalases,
and they serve a varity of functions interms of breakdown. > Vacuoles are similar to lysosomes, that take place in amimals.
They function as temporary storage. But vacuoles are more known
in plant cells. > The Vacuole is much better known in plant
cells. In plant cells you have a large central
vacuole and this plays a really important role in
the plant acheving Turgor pressure. When a plant
is short on water the central vacuole sezies to
exert pressure on the cell contents resulting in
limp or wilted plants. When u water the plant the
central vacuole fills up with water and it exertes
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