PDQ’s Eukaryotic Cells
4.3-4.5
1. Nuclear Envelope/Pores
• Double Phospholipid membrane around
nucleus
• Contains pores to allow RNA and protein out
of the nucleus.
• Function is to separate transcription from
translation
2. Nucleolus vs. rRNA vs. ribosomes
• Nucleolus - makes ribosomes, inside nucleus
• rRNA – ribosomal RNA, made inside nucleolus
• Ribosomes
– consists of 2 units;
– protein synthesis,
– can be found free in cytoplasm or attached to the
RER;
– do not have a membrane around them; are not
considered to be organelles;
3. Free ribosomes vs. RER ribosomes
• If the ribosome made protein that is destined
to be modified, then those ribosomes go and
attach to the RER.
4. Endomembrane System
• RER- chemically modifies proteins and tags them
for delivery and sends them out in vesicles
• SER – lipid & steroid synthesis; chemical
breakdown of drugs; break down glycogen in
animal cells
• Golgi Apparatus – packages and sorts proteins;
adds carbohydrates to some proteins; makes
polysaccharides in plant cells
• Lysosomes – originate from Golgi Body; contain
digestive enzymes to break down
macromolecules
5. Endomembrane System Function
• The endomembrane system is a series of
compartments that work together to package,
label, and ship proteins and molecules
6. Path of protein
• Part 1
– RER, vesicle, CIS region of Golgi Body, Vesicle – out
from Trans Region of Golgi, plasma membrane
• Part 2
– Primary lysosome comes from Golgi, phagosome
comes from membrane with food, join together to
form the secondary lysosome, digestion of small
molecules into cytoplasm, undigested molecules
gets released out of plasma membrane
7. Lysosomal storage disorder
• Lysosomes fail to digest stuff
• They can be detected in cells where an
accumulation occurs due to the lack of it
breaking down
8. Chloroplasts and mitochondria
• No, they are not a part of the endomembrane
system, though they contain membranes
around them.
9. Functions of chloroplasts and
mitochondria
Chloroplasts
• photosynthesis
Mitochondria
• Breakdown of glucose into
ATP
10. Plastids
• Big category of many organelles which store
pigments, carbohydrates, lipids or protein
• Chloroplast is an example
11. Chloroplasts, Chromoplasts,
Leucoplasts
• Chloroplasts – contains chlorophyll (green)
• Chromoplasts – yellow and red pigments
• Leucoplasts - colorless
12. Peroxisomes and Vacuoles
• They are not a part of the endomembrane
system
13. Peroxisomes
• Small organelles that accumulate toxins such
as H2O2.
• Break down this H2O2 into water and oxygen
14. Vacuole Functions
• Storage of food, water, waste, pigments and
enzymes
• Structure – take up 90% of cell volume
• Reproduction – storing pigments attracts
animals which assists in pollination
• Catabolism – enzymes break down proteins
etc.
15. Plants waste
• Central Vacuole contains digestive enzymes to
help break down things
16. Mitochondria and chloroplast
16 continued… endosymbiotic theory
• Chloroplast and mitochondria both have their
own DNA
17. Cytoskeleton
•
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•
•
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Supports cell
Maintains cell shape
Controls organelles and their movement
Involved with cytoplasmic streaming
Interacts with extracellular structures
Helps to anchor cell in place
18. Microfilaments
• Bundles 7 nm in
diameter
• Made up of the
protein actin
• Help cell to move
• Determine and
stabilize cell shape
18. Intermediate filaments
• Tough ropelike
protein
assemblages, 812 nm
• Anchor cell
structures in
place
• Resist tension
18. Microtubules
• Largest diameter, long
and hollow
• Form a rigid skeleton
• Act as framework along
which motor proteins
can move structures in
cell
19. Cilia and Flagella
• Made of a 9+2
pattern of
microtubules
• These microtubules
slide past each
other driven by a
motor protein
called dynein
powered by ATP
20. Centriole
• Same as cilia