Transcript Parts of the Cell

Parts of the Cell
4.4 Eukaryotic cells are partitioned into functional
compartments
• There are four life processes in eukaryotic cells
that depend upon structures and organelles
–
–
–
–
Manufacturing
Breakdown of molecules
Energy processing
Structural support, movement, and communication
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4.4 Eukaryotic cells are partitioned into functional
compartments
• Manufacturing involves the nucleus, ribosomes,
endoplasmic reticulum, and Golgi apparatus
Copyright © 2009 Pearson Education, Inc.
4.4 Eukaryotic cells are partitioned into functional
compartments
• Breakdown of molecules involves lysosomes,
vacuoles, and peroxisomes
– Breakdown of an internalized bacterium by a
phagocytic cell would involve all of these
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4.4 Eukaryotic cells are partitioned into functional
compartments
• Energy processing involves mitochondria in
animal cells and chloroplasts in plant cells
Copyright © 2009 Pearson Education, Inc.
4.4 Eukaryotic cells are partitioned into functional
compartments
• Structural support, movement, and
communication involve the cytoskeleton,
plasma membrane, and cell wall
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Pili
Nucleoid
Ribosomes
Plasma membrane
Bacterial
chromosome
Cell wall
Capsule
Flagella
NUCLEUS:
Nuclear envelope
Smooth endoplasmic
reticulum
Chromosomes
Nucleolus
Rough
endoplasmic
reticulum
Lysosome
Centriole
Ribosomes
Peroxisome
CYTOSKELETON:
Microtubule
Intermediate
filament
Microfilament
Golgi
apparatus
Plasma membrane
Mitochondrion
NUCLEUS:
Rough endoplasmic
reticulum
Nuclear envelope
Chromosome
Ribosomes
Nucleolus
Smooth
endoplasmic
reticulum
Golgi
apparatus
CYTOSKELETON:
Central vacuole
Microtubule
Chloroplast
Cell wall
Intermediate
filament
Plasmodesmata
Microfilament
Mitochondrion
Peroxisome
Plasma membrane
Cell wall of
adjacent cell
Hydrophilic head
Phosphate
group
Symbol
Hydrophobic tails
Outside cell
Hydrophilic
heads
Hydrophobic
region of
protein
Hydrophobic
tails
Inside cell
Proteins
Hydrophilic
region of
protein
Nucleus
Double-layer membrane with pores. Connected
to ER.
Ribosomes made in a part called the nucleolus.
Two membranes of
nuclear envelope
Nucleus
Nucleolus
Chromatin
Pore
Endoplasmic
reticulum
Ribosomes
4.9 The endoplasmic reticulum is a biosynthetic factory
• There are two kinds of endoplasmic reticulum—
smooth and rough
• Smooth ER lacks attached ribosomes
• Rough ER lines the outer surface of membranes
– They differ in structure and function
– However, they are connected
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Nuclear
envelope
Ribosomes
Smooth ER
Rough ER
4.9 The endoplasmic reticulum is a biosynthetic factory
• Smooth ER is involved in a variety of diverse
metabolic processes (ex: synthesis of many
types of lipids)
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4.9 The endoplasmic reticulum is a biosynthetic factory
• Rough ER makes additional membrane for itself
and proteins destined for secretion (these
proteins are transported in vesicles)
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Transport vesicle
buds off
4
Ribosome
Secretory
protein
inside transport vesicle
3
Sugar
chain
1
2 Glycoprotein
Polypeptide
Rough ER
Golgi
Receives proteins in vesicles from the ER.
Modifies proteins- adds sugar chains to “mark”
them for a certain destination.
Puts the proteins back into vesicles and sends
them out.
4.11 Lysosomes are digestive compartments within a
cell
• A lysosome is a membranous sac containing
digestive enzymes
– The enzymes and membrane are produced by the ER
and transferred to the Golgi apparatus for processing
– The membrane serves to safely isolate these potent
enzymes from the rest of the cell
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4.11 Lysosomes are digestive compartments within a
cell
• One of the several functions of lysosomes is to
remove or recycle damaged parts of a cell
– The damaged organelle is first enclosed in a
membrane vesicle
– Then a lysosome fuses with the vesicle, breaking
down the damaged organelle
Animation: Lysosome Formation
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Vacuoles
• Functions: storage, maintaining water
balance, holding pigments, etc.
• Membrane-bound.
Chloroplast
Nucleus
Central
vacuole
Nucleus
Contractile
vacuoles
Mitochondria
• Convert sugar (glucose) into ATP (adenosine
triphosphate)- small energy packets. This is
called cellular respiration.
• Have two membranes (inner and outer)
Mitochondrion
Outer
membrane
Intermembrane
space
Inner
membrane
Cristae
Matrix
Chloroplasts
• Use the sun’s energy to create glucose from
carbon dioxide and water (photosynthesis)
Chloroplast
Stroma
Inner and outer
membranes
Granum
Intermembrane
space
Mitochondrion
Engulfing of
photosynthetic
prokaryote
Some
cells
Engulfing
of aerobic
prokaryote
Chloroplast
Host cell
Mitochondrion
Host cell
4.17 The cell’s internal skeleton helps organize its
structure and activities
• The cytoskeleton is composed of three kinds of
fibers
– Microfilaments (actin filaments) support the cell’s
shape and are involved in motility
– Intermediate filaments reinforce cell shape and
anchor organelles
– Microtubules (made of tubulin) shape the cell and
act as tracks for motor protein
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ATP
Vesicle
Receptor for
motor protein
Motor protein
(ATP powered)
Microtubule
of cytoskeleton
(a)
Microtubule
(b)
Vesicles
0.25 µm