Ultra-structure of animal cells

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Ultra-structure of animal cells
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An animal cell possesses many structures not seen
with the light microscope since it can only
magnify up to 1,500 times.
The organelles may be seen using an electron
microscope which can magnify up to 500,000 times.
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nucloeolus
nucleus
nuclear membrane
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The nucleolus produces ribosomes.
The nucleus contains DNA which determines what
type of proteins are produced at the ribosomes in
the cytoplasm.
The nuclear membrane has pores that allow the
exit of mRNA (a messenger) to the ribosomes in
the cytoplasm for protein synthesis.
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mitochondrion
nucloeolus
nucleus
nuclear membrane
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Mitochondria are needed for aerobic respiration
which produces energy.
The more active a cell, the more mitochondria are
present.
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Rough Endoplasmic Reticulum
mitochondrion
nucloeolus
nucleus
nuclear membrane
Smooth Endoplasmic Reticulum
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The smooth Endoplasmic Reticulum (smooth ER)
isolates and transports lipids.
The ribosomes which are attached to the rough ER
make the proteins. The rough ER isolates and
transports these proteins. Some ribosomes are not
attached to the rough ER and exists free within
the cytoplasm.
Both types of ER are continuous with the nuclear
membrane.
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Ribosomes
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Rough Endoplasmic Reticulum
mitochondrion
nucloeolus
nucleus
nuclear membrane
Golgi body
Smooth Endoplasmic Reticulum
Secretory vesicles
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Vesicles become pinched from the rough ER. These
join together to become the Golgi body
(apparatus).
The proteins become packaged and processed here.
Eg. A carbohydrate may be added to produce a
glycoprotein.
Part of the Golgi body containing the packaged
protein will be pinched off to form the secretory
vesicles.
These in turn merge with the plasma membrane and
the packaged protein will be secreted from the
cell.
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Rough Endoplasmic Reticulum
mitochondrion
nucloeolus
Plasma membrane
nucleus
lysosomes
nuclear membrane
Golgi body
Smooth Endoplasmic Reticulum
Secretory vesicles
centrioles
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The centriole is important in mitosis and meiosis.
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The lysosme contains powerful digestive enzymes
which are important in phagocytosis (see variety
of animal cells pp) or may even digest the cell
itself.
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The plasma membrane or cell membrane controls
entry and exit of materials. It is selectively
permeable.
All membranes in the cell have the same structure
as the plasma membrane.
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What to do
1. Collect handout and using class resources
label it.
2. Copy and complete the following table using
information from the PowerPoint presentation.