- 1.
- Chapter 4 Cell Structure (Sections 4.8 - 4.13)
2.
- 4.8 The Endomembrane System
- Theendomembrane systemincludes rough and smoothendoplasmic
reticulum( ER ),vesicles , andGolgi bodies
3. This system makes and modifies lipids and proteins; it also
recycles and disposes of molecules and particles
-
- Series of interacting organelles (endoplasmic reticulum, Golgi
bodies, vesicles) between nucleus and plasma membrane; produces
lipids, proteins
4.
5.
- Makes lipids, breaks down carbohydrates and fats, inactivates
toxins
- Finishes, sorts, ships lipids, enzymes, and proteins
- Modifies proteins made by ribosomes attached to it
- Digests, recycles materials
6.
- endoplasmic reticulum (ER)
-
- Organelle that is a continuous system of sacs and tubes
- 7. An extension of the nuclear envelope
8. Site where many new polypeptide chains are modified 9. Rough
ER is studded with ribosomes thatmake polypeptides thatenter the ER
as they are assembled 10. Smooth ER has no ribosomes: Enzymes
assemble lipids that form cell membranes, and break down substances
11.
- Small, membrane-enclosed, saclikevesicles form in a variety of
types, either on their own or by budding
12. Many vesicles transport substances from one organelle to
another, including endocytic vesicles and exocytic vesicles 13.
Other vesicles includeperoxisomes ,lysosomes , andvacuoles
(includingcentral vacuoles ) 14.
-
- Small, membrane-enclosed, saclike organelle; different kinds
store, transport, or degrade their contents
-
- Enzyme-filled vesicle that functions in intracellular
digestion
-
- Enzyme-filled vesicle that breaks down amino acids, fatty
acids, and toxic substances
15.
-
- A fluid-filled organelle that isolates or disposes of waste,
debris, or toxic materials
-
- Fluid-filled vesicle in many plant cells
16.
- Enzymes in aGolgi bodyfinish proteins and lipids that are
delivered by vesicles from the ER
-
- Modifies polypeptides and lipids; a ttaches phosphate groups or
oligosaccharides, and cuts certain polypeptides
- 17. Sorts and packages the finished products into vesiclesthat
carry them to lysosomes or to the plasma membrane
18.
- Functions ofthe Endomembrane System
- Vesicles Vesicles that bud from the rough ER carry some of the
new proteins to Golgi bodies. Other proteins migrate through the
interior of the rough ER, and end up in the smooth ER.
- Rough ER Some of the RNAin the cytoplasmis translated into
polypeptide chains by ribosomes attached to the rough ER. The
chains enter the rough ER, where they are modified into final
form.
19.
- Functions ofthe Endomembrane System (cont.)
- Smooth ERSome proteins from the rough ER are packaged into new
vesicles and shipped to Golgi bodies. Others become enzymes of the
smooth ER. These enzymes assemble lipids and inactivate
toxins.
- Golgi bodyProteins arriving in vesicles from the ER are
modified into final form and sorted. New vesicles carry them to the
plasma membrane or to lysosomes.
- Plasma membraneA vesicles membrane fuses with the plasma
membrane, so the contents of the vesicle are released to the
exterior of the cell.
20.
- Animation: The Endomembrane System
21.
- 4.9 Mitochondria and Plastids
- Mitochondriamake ATP by breaking down organic compounds in the
oxygen-requiring pathway of aerobic respiration
- Chloroplastsareplastids that produce sugars by
photosynthesis
22.
-
- Double-membraned organelle that produces ATP by aerobic
respiration in eukaryotes
- During aerobic respiration, hydrogen ions accumulate between
the two membranes
23. The buildup causes the ions to flow across the inner
mitochondrial membrane, through membrane transport proteins that
drive the formation of ATP 24.
25.
26.
- Energy powerhouse; produces many ATP by aerobic
respiration
27.
- Animation: Structure of a Mitochondrion
28.
- Theory of endosymbiosis: Mitochondria evolved from aerobic
bacteria that took up permanent residence inside a host cell
-
- Resemble bacteria in size, form, and biochemistry
- 29. Have their own DNA, which is similar to bacterial DNA
30. Divide independently of the cell, and have their own
ribosomes 31.
- Chloroplasts and Other Plastids
-
- An organelle that functions in photosynthesis or
storage,e.g.chloroplast, amyloplast
-
- Organelle of photosynthesis in the cells of plants and many
protists
32.
- Two outer membranes enclose a semifluid interior (stroma) that
contains enzymes and chloroplast DNA
33. In the stroma, a highly folded stack of membrane
(grana/granum ) forms a single, continuous compartment 34.
Photosynthesis takes place at the thylakoid membrane, which
incorporates pigments such as chlorophylls, which are green 35.
- Chlorophylls and other molecules in the thylakoid membrane use
the energy in sunlight to synthesize ATP
36. ATP is used in the stroma to build carbohydrates from carbon
dioxide and water 37.
- ChloroplastSpecializes in photosynthesis
38.
- ChloroplastSpecializes in photosynthesis
39.
40.
- thylakoids(inner membrane system folded into flattened
disks)
41.
- Chromoplasts are plastids that make and store pigments other
than chlorophylls
-
- Red, orange, and yellow pigments color many flowers, leaves,
fruits, and roots
- Amyloplasts store starch grains
-
- Abundant in starch-storing cells of stems, tubers (underground
stems), and seeds
42.
- 4.10 The Dynamic Cytoskeleton
- Acytoskeleton includesmicrotubules ,microfilaments ,
andintermediate filaments
-
- Dynamic framework of protein filaments that support, organize,
and move eukaryotic cells and their internal structures
43.
-
- Cytoskeletal element involved in cellular movement; hollow
filament of tubulin subunits
-
- Reinforcing cytoskeletal element; a fiber of actin
subunits
-
- Cytoskeletal element that locks cells and tissues together
44.
- Microtubules assemble, separate the cells duplicated
chromosomes, then disassemble
45.
- Microtubules (yellow) support and guide the growing ends of
young nerve cells
46.
- Examples of Microfilaments
- Myosin and actin microfilaments interact in contraction of
muscle cells
-
- Reinforcing mesh of microfilaments under a plasma membrane
47.
- Examples of Intermediate Filaments
- The nuclear envelope is supported by an inner layer of
intermediate filaments called lamins
48. Intermediate filaments connect to structures that lock cell
membranes together in tissues 49.
50.
- Animation: Cytoskeletal Components
51.
- Motor proteinsmove cell parts when energized by a
phosphate-group transfer from ATP
-
- Energy-using protein that interacts with cytoskeletal elements
to move the cells parts or the whole cell
52.
- Kinesin ( tan)drags a pink vesicle along a microtubule
53.
- Animation: Motor Proteins
54.
- Dynein interacts with arrays of microtubules to bring about
movement of eukaryotic flagella and cilia
55.
- A 9+2 array of microtubules extends lengthwise through a
flagellum orcilium
56. The microtubules grow from a barrel-shapedcentriole , which
remains below the finished array as abasal body 57.
-
- Short, movable structure that projects from the plasma membrane
of some eukaryotic cells
-
- Barrel-shaped organelle from which microtubules grow
-
- Organelle that develops from a centriole
58.
- 9+2 array: a ring of nine pairs of microtubules plus one pair
at its core
59.
- pair of microtubules in a central sheath
- ASketch and micrograph of one eukaryotic flagellum,
cross-section. Like a cilium, it contains a 9+2 array: a ring of
nine pairs of microtubules plus one pair at its core. Stabilizing
spokes and linking elements that connect to the microtubules keep
them aligned in this radial pattern.
60.
- BProjecting from each pair of microtubules in the outer ring
are arms of dynein, a motor protein that has ATPase activity.
Phosphate-group
- transfers from ATP cause the dynein arms to repeatedly bind the
adjacent pair of microtubules, bend, and then disengage. The dynein
arms walk along the microtubules. Their motion causes adjacent
microtubule pairs to slide past one another
- CShort, sliding strokes occur in a coordinated sequence around
the ring, down the length of each microtubule
- pair. The flagellum bends as the array inside bends:
- basal body, a microtubule organizing center that gives rise to
the 9+2 array and then remains beneath it, inside the
cytoplasm
61.
- Animation: Flagella Structure
62.
- Pseudopods move the cell and engulf prey
63. Motor proteins attached to microfilaments drag the plasma
membrane 64.
- 4.11 Cell Surface Specializations
- Most cells of multicelled organisms are surrounded by a complex
mixture of fibrous proteins and polysaccharides calledextracellular
matrix,orECM
- extracellular matrix (ECM)
-
- Complex mixture of cell secretions
- 65. Supports cells and tissues
66. Has roles in cell signaling 67.
-
- Secreted covering at a body surface
- 68. Chitin covering protects arthropods
69. Waxy coat protects plants exposed surfaces 70.
- photosynthetic cell inside leaf
- thick, waxy cuticle atleaf surface
71.
- ECM in animals consists of various carbohydrates and proteins;
it is the basis of tissue organization, and provides structural
support
72. Example:Bone is mostly extracellular matrix composed of
collagen, a fibrous protein, hardened by mineral deposits 73.
- Plant cell wall is a type of ECM:Pliableprimary
wallsenclosesecondary wallsstrengthened withlignin
-
- The first cell wall of young plant cells
-
- Lignin-reinforced wall inside the primary wall of a plant
cell
-
- Material that stiffens cell walls of vascular plants
74.
- APlant cell secretions form the middle lamella, a layer that
cements adjoining cells together.
- BIn many plant tissues, cells also secrete materials that are
deposited in layers on the inner surface of their primary wall.
These layers strengthen the wall and maintain its shape. They
remain after the cells die, and become part of pipelines that carry
water through the plant.
- pipeline made of abutting cell walls
- secondary cell wall (added in layers)
75.
- Animation: Plant Cell Walls
76.
- In plants, open channels calledplasmodesmata
(plasmodesma)extend across cell walls, connecting the cytoplasm of
adjoining cells
-
- Cell junctions that connect the cytoplasm of adjacent plant
cells
- 77. Allowwater, nutrients, and signaling molecules to flow
quickly from cell to cell
78.
- CPlasmodesmata are channels across the cell walls and the
plasma membranes of living cells that are pressed against one
another in tissues.
79.
- Cell Junctions in Animals
- In animal tissues, cells are connected to their neighbors and
to ECM bycell junctions
-
- Structure that connects a cell to another cell or to
extracellular matrix
- 80. Cells send and receive ions, molecules, or signals through
some junctions
81. Other kinds help cells recognize and stick to each other and
to extracellular matrix 82.
-
- Arrays of fibrous proteins; join epithelial cells and
collectively prevent fluids from leaking between them
-
- Cell junction that anchors cells to each other or to
extracellular matrix
-
- Cell junction that forms a channel across the plasma membranes
of adjoining animal cells
83.
- free surface of epithelial tissue
- basement membrane (extracellular matrix)
84.
- Animation: Animal Cell Junctions
85.
- 4.12 Summary: Plant Cells
86.
- 4.12 Summary: Plant Cells
87.
- Energy powerhouse; produces many ATP by aerobic
respiration
- Lysosome-like Vesicle Digests, recycles materials
- Golgi BodyFinishes, sorts, ships lipids, enzymes, and
proteins
- Smooth ERMakes lipids, breaks down carbohydrates and fats,
inactivates toxins
- Rough ERModifies proteins made by ribosomes attached to it
- Ribosomes(attached to rough ER and free in cytoplasm) Sites of
protein synthesis
- NucleusKeeps DNA separated from cytoplasm; makes ribosome
subunits; controls access to DNA
- Central VacuoleIncreases cell surface area; stores metabolic
wastes
- ATypical plant cell components
- Cell WallProtects, structurally supports cell
- Chloroplast Specializes in photosynthesis
- Plasma Membrane Selectively controls the kinds and amounts of
substances moving into and out of cell; helps maintain cytoplasmic
volume, composition
- intermediate filaments(not shown)
- Plasmodesma Communication junction between adjoining cells
- CytoskeletonStructurally supports, imparts shape to cell; moves
cell and its components
88.
- Animation: Common Eukaryotic Organelles
89.
90.
- BTypical animal cell components.
- Plasma MembraneSelectively controls the kinds and amounts of
substances moving into and out of cell; helps maintain cytoplasmic
volume, composition
- CytoskeletonStructurally supports, imparts shape to cell; moves
cell and its components
- Energy powerhouse; produces many ATP by aerobic
respiration
- Special centers that produce and organize microtubules
- Golgi BodyFinishes, sorts, ships lipids, enzymes, and
proteins
- Smooth ERMakes lipids, breaks down carbohydrates and fats,
inactivates toxins
- Rough ERModifies proteins made by ribosomes attached to it
- Ribosomes(attached to rough ER and free in cytoplasm) Sites of
protein synthesis
- Lysosome Digests, recycles materials
- NucleusKeeps DNA separated from cytoplasm; makes ribosome
subunits; controls access to DNA
91.
92.
-
- Cells of protists, plants, fungi, and animals are
eukaryotic
- 93. They have a nucleus and other membrane-enclosed
compartments
94. Cells differ in internal parts and surface specializations
95.
- Life is a property that emerges from cellular components, but a
collection of those components in the right amounts and proportions
is not necessarily alive
96. Characteristics of life:
-
- A set of properties unique to living things
- 97. Collectively, these properties characterize living things
as different from nonliving things
98.
- Characteristics of Living Things
- They make and use organic molecules of life
99. They consist of one or more cells 100. They engage in
self-sustaining biological processes such as metabolism and
homeostasis 101. They change over their lifetime by growing,
maturing, and aging 102. They use DNA as hereditary material 103.
They have the collective capacity to change over successive
generations by adapting to environmental pressures 104.
- Food for Thought (revisited)
- Meat, poultry, milk, and fruits sterilized by exposure to
radiation are available in supermarkets
105. By law, irradiated foods must be marked with a special
symbol:
- Foodssterilized with chemicals are not currently required to
carry any disclosure
