Concept 6.5: Mitochondria and chloroplasts change energy from one form to another Mitochondria are the sites of cellular respiration, a metabolic process.

Concept 6.5: Mitochondria and chloroplasts change energy from one form to another
Mitochondria are the sites of cellular respiration, a metabolic process that uses oxygen to generate ATP Chloroplasts, found in plants and algae, are the sites of photosynthesis Peroxisomes are oxidative organelles For the Cell Biology Video ER and Mitochondria in Leaf Cells, go to Animation and Video Files. For the Cell Biology Video Mitochondria in 3D, go to Animation and Video Files. For the Cell Biology Video Chloroplast Movement, go to Animation and Video Files. © 2011 Pearson Education, Inc.

The Evolutionary Origins of Mitochondria and Chloroplasts
Mitochondria and chloroplasts have similarities with bacteria Enveloped by a double membrane Contain free ribosomes and circular DNA molecules Grow and reproduce somewhat independently in cells © 2011 Pearson Education, Inc.

Chloroplasts: Capture of Light Energy
Chloroplasts contain the green pigment chlorophyll, as well as enzymes and other molecules that function in photosynthesis Chloroplasts are found in leaves and other green organs of plants and in algae © 2011 Pearson Education, Inc.

Chloroplast structure includes
Thylakoids, membranous sacs, stacked to form a granum Stroma, the internal fluid The chloroplast is one of a group of plant organelles, called plastids © 2011 Pearson Education, Inc.

Figure 6.18 The chloroplast, site of photosynthesis.
Ribosomes 50 m Stroma Inner and outer membranes Granum Chloroplasts (red) DNA Thylakoid Intermembrane space 1 m Figure 6.18 The chloroplast, site of photosynthesis. (a) Diagram and TEM of chloroplast (b) Chloroplasts in an algal cell

(a) Diagram and TEM of chloroplast
Figure 6.18a Ribosomes Stroma Inner and outer membranes Granum DNA Figure 6.18 The chloroplast, site of photosynthesis. Thylakoid Intermembrane space 1 m (a) Diagram and TEM of chloroplast

Stroma Inner and outer membranes Granum 1 m Figure 6.18aa
Figure 6.18 The chloroplast, site of photosynthesis. 1 m

(b) Chloroplasts in an algal cell
Figure 6.18b 50 m Chloroplasts (red) Figure 6.18 The chloroplast, site of photosynthesis. (b) Chloroplasts in an algal cell

Peroxisomes: Oxidation
Peroxisomes are specialized metabolic compartments bounded by a single membrane Peroxisomes produce hydrogen peroxide and convert it to water Peroxisomes perform reactions with many different functions How peroxisomes are related to other organelles is still unknown © 2011 Pearson Education, Inc.

1 m Chloroplast Peroxisome Mitochondrion Figure 6.19
Figure 6.19 A peroxisome.

Concept 6.6: The cytoskeleton is a network of fibers that organizes structures and activities in the cell The cytoskeleton is a network of fibers extending throughout the cytoplasm It organizes the cell’s structures and activities, anchoring many organelles It is composed of three types of molecular structures Microtubules Microfilaments Intermediate filaments For the Cell Biology Video The Cytoskeleton in a Neuron Growth Cone, go to Animation and Video Files For the Cell Biology Video Cytoskeletal Protein Dynamics, go to Animation and Video Files. © 2011 Pearson Education, Inc.

Figure 6.20 Figure 6.20 The cytoskeleton. 10 m

Roles of the Cytoskeleton: Support and Motility
The cytoskeleton helps to support the cell and maintain its shape It interacts with motor proteins to produce motility Inside the cell, vesicles can travel along “monorails” provided by the cytoskeleton Recent evidence suggests that the cytoskeleton may help regulate biochemical activities © 2011 Pearson Education, Inc.

Receptor for motor protein
Figure 6.21 Vesicle ATP Receptor for motor protein Motor protein (ATP powered) Microtubule of cytoskeleton (a) Microtubule Vesicles 0.25 m Figure 6.21 Motor proteins and the cytoskeleton. (b)

Microtubule 0.25 m Vesicles (b) Figure 6.21a
Figure 6.21 Motor proteins and the cytoskeleton. (b)

Components of the Cytoskeleton
Three main types of fibers make up the cytoskeleton Microtubules are the thickest of the three components of the cytoskeleton Microfilaments, also called actin filaments, are the thinnest components Intermediate filaments are fibers with diameters in a middle range For the Cell Biology Video Actin Network in Crawling Cells, go to Animation and Video Files. For the Cell Biology Video Actin Visualization in Dendrites, go to Animation and Video Files. © 2011 Pearson Education, Inc.

Table 6.1 The Structure and Function of the Cytoskeleton
10 m 10 m 5 m Table 6.1 The Structure and Function of the Cytoskeleton Column of tubulin dimers Keratin proteins Actin subunit Fibrous subunit (keratins coiled together) 25 nm 7 nm 812 nm   Tubulin dimer

Column of tubulin dimers
Table 6.1a 10 m Table 6.1 The Structure and Function of the Cytoskeleton Column of tubulin dimers 25 nm   Tubulin dimer

Table 6.1aa 10 m Table 6.1 The Structure and Function of the Cytoskeleton

10 m Actin subunit 7 nm Table 6.1b
Table 6.1 The Structure and Function of the Cytoskeleton Actin subunit 7 nm

Table 6.1bb 10 m Table 6.1 The Structure and Function of the Cytoskeleton

5 m Keratin proteins Fibrous subunit (keratins coiled together)
Table 6.1c 5 m Table 6.1 The Structure and Function of the Cytoskeleton Keratin proteins Fibrous subunit (keratins coiled together) 812 nm

Table 6.1cc 5 m Table 6.1 The Structure and Function of the Cytoskeleton

Microtubules Microtubules are hollow rods about 25 nm in diameter and about 200 nm to 25 microns long Functions of microtubules Shaping the cell Guiding movement of organelles Separating chromosomes during cell division For the Cell Biology Video Transport Along Microtubules, go to Animation and Video Files. For the Cell Biology Video Movement of Organelles in Vivo, go to Animation and Video Files. For the Cell Biology Video Movement of Organelles in Vitro, go to Animation and Video Files. © 2011 Pearson Education, Inc.

Centrosomes and Centrioles
In many cells, microtubules grow out from a centrosome near the nucleus The centrosome is a “microtubule-organizing center” In animal cells, the centrosome has a pair of centrioles, each with nine triplets of microtubules arranged in a ring © 2011 Pearson Education, Inc.

Longitudinal section of one centriole
Figure 6.22 Centrosome Microtubule Centrioles 0.25 m Longitudinal section of one centriole Figure 6.22 Centrosome containing a pair of centrioles. Microtubules Cross section of the other centriole

Longitudinal section of one centriole
Figure 6.22a 0.25 m Longitudinal section of one centriole Figure 6.22 Centrosome containing a pair of centrioles. Microtubules Cross section of the other centriole

Cilia and Flagella Microtubules control the beating of cilia and flagella, locomotor appendages of some cells Cilia and flagella differ in their beating patterns Video: Chlamydomonas Video: Paramecium Cilia © 2011 Pearson Education, Inc.

Power stroke Recovery stroke
Figure 6.23 Direction of swimming (a) Motion of flagella 5 m Direction of organism’s movement Figure 6.23 A comparison of the beating of flagella and motile cilia. Power stroke Recovery stroke (b) Motion of cilia 15 m

Figure 6.23a Figure 6.23 A comparison of the beating of flagella and motile cilia. 5 m

Figure 6.23b Figure 6.23 A comparison of the beating of flagella and motile cilia. 15 m

Cilia and flagella share a common structure
A core of microtubules sheathed by the plasma membrane A basal body that anchors the cilium or flagellum A motor protein called dynein, which drives the bending movements of a cilium or flagellum Animation: Cilia and Flagella © 2011 Pearson Education, Inc.

Outer microtubule doublet Plasma membrane
Figure 6.24 0.1 m Outer microtubule doublet Plasma membrane Dynein proteins Central microtubule Radial spoke Microtubules Cross-linking proteins between outer doublets (b) Cross section of motile cilium Plasma membrane Basal body 0.5 m 0.1 m (a) Longitudinal section of motile cilium Triplet Figure 6.24 Structure of a flagellum or motile cilium. (c) Cross section of basal body

Longitudinal section of motile cilium
Figure 6.24a Microtubules Plasma membrane Basal body Figure 6.24 Structure of a flagellum or motile cilium. 0.5 m (a) Longitudinal section of motile cilium

Outer microtubule doublet Plasma membrane
Figure 6.24b 0.1 m Outer microtubule doublet Plasma membrane Dynein proteins Central microtubule Radial spoke Cross-linking proteins between outer doublets (b) Cross section of motile cilium Figure 6.24 Structure of a flagellum or motile cilium.

Outer microtubule doublet
Figure 6.24ba 0.1 m Outer microtubule doublet Dynein proteins Central microtubule Radial spoke Cross-linking proteins between outer doublets Figure 6.24 Structure of a flagellum or motile cilium. (b) Cross section of motile cilium

Cross section of basal body
Figure 6.24c 0.1 m Triplet Figure 6.24 Structure of a flagellum or motile cilium. (c) Cross section of basal body

Cross section of basal body
Figure 6.24ca 0.1 m Triplet Figure 6.24 Structure of a flagellum or motile cilium. (c) Cross section of basal body

How dynein “walking” moves flagella and cilia
Dynein arms alternately grab, move, and release the outer microtubules Protein cross-links limit sliding Forces exerted by dynein arms cause doublets to curve, bending the cilium or flagellum For the Cell Biology Video Motion of Isolated Flagellum, go to Animation and Video Files. For the Cell Biology Video Flagellum Movement in Swimming Sperm, go to Animation and Video Files. © 2011 Pearson Education, Inc.

Figure 6.25 How dynein “walking” moves flagella and cilia.
Microtubule doublets ATP Dynein protein (a) Effect of unrestrained dynein movement Cross-linking proteins between outer doublets ATP Anchorage in cell Figure 6.25 How dynein “walking” moves flagella and cilia. (b) Effect of cross-linking proteins 1 3 2 (c) Wavelike motion

(a) Effect of unrestrained dynein movement
Figure 6.25a Microtubule doublets ATP Figure 6.25 How dynein “walking” moves flagella and cilia. Dynein protein (a) Effect of unrestrained dynein movement

Anchorage in cell Cross-linking proteins between outer doublets ATP 1
Figure 6.25b Cross-linking proteins between outer doublets ATP 1 3 2 Anchorage in cell Figure 6.25 How dynein “walking” moves flagella and cilia. (b) Effect of cross-linking proteins (c) Wavelike motion

Microfilaments (Actin Filaments)
Microfilaments are solid rods about 7 nm in diameter, built as a twisted double chain of actin subunits The structural role of microfilaments is to bear tension, resisting pulling forces within the cell They form a 3-D network called the cortex just inside the plasma membrane to help support the cell’s shape Bundles of microfilaments make up the core of microvilli of intestinal cells © 2011 Pearson Education, Inc.

Microfilaments (actin filaments)
Figure 6.26 Microvillus Plasma membrane Microfilaments (actin filaments) Figure 6.26 A structural role of microfilaments. Intermediate filaments 0.25 m

Microfilaments that function in cellular motility contain the protein myosin in addition to actin
In muscle cells, thousands of actin filaments are arranged parallel to one another Thicker filaments composed of myosin interdigitate with the thinner actin fibers © 2011 Pearson Education, Inc.

Figure 6.27 Microfilaments and motility.
Muscle cell 0.5 m Actin filament Myosin filament Myosin head (a) Myosin motors in muscle cell contraction Cortex (outer cytoplasm): gel with actin network 100 m Inner cytoplasm: sol with actin subunits Extending pseudopodium Figure 6.27 Microfilaments and motility. (b) Amoeboid movement Chloroplast 30 m (c) Cytoplasmic streaming in plant cells

Muscle cell 0.5 m Actin filament Myosin filament Myosin head
Figure 6.27a Muscle cell 0.5 m Actin filament Myosin filament Myosin Figure 6.27 Microfilaments and motility. head (a) Myosin motors in muscle cell contraction

Figure 6.27aa 0.5 m Figure 6.27 Microfilaments and motility.

Cortex (outer cytoplasm): gel with actin network
Figure 6.27b Cortex (outer cytoplasm): gel with actin network 100 m Inner cytoplasm: sol with actin subunits Figure 6.27 Microfilaments and motility. Extending pseudopodium (b) Amoeboid movement

Chloroplast 30 m (c) Cytoplasmic streaming in plant cells
Figure 6.27c Chloroplast 30 m Figure 6.27 Microfilaments and motility. (c) Cytoplasmic streaming in plant cells

Localized contraction brought about by actin and myosin also drives amoeboid movement
Pseudopodia (cellular extensions) extend and contract through the reversible assembly and contraction of actin subunits into microfilaments © 2011 Pearson Education, Inc.

Cytoplasmic streaming is a circular flow of cytoplasm within cells
This streaming speeds distribution of materials within the cell In plant cells, actin-myosin interactions and sol-gel transformations drive cytoplasmic streaming Video: Cytoplasmic Streaming © 2011 Pearson Education, Inc.

Intermediate Filaments
Intermediate filaments range in diameter from 8–12 nanometers, larger than microfilaments but smaller than microtubules They support cell shape and fix organelles in place Intermediate filaments are more permanent cytoskeleton fixtures than the other two classes For the Cell Biology Video Interphase Microtubule Dynamics, go to Animation and Video Files. For the Cell Biology Video Microtubule Sliding in Flagellum Movement, go to Animation and Video Files. For the Cell Biology Video Microtubule Dynamics, go to Animation and Video Files. © 2011 Pearson Education, Inc.

Concept 6.7: Extracellular components and connections between cells help coordinate cellular activities Most cells synthesize and secrete materials that are external to the plasma membrane These extracellular structures include Cell walls of plants The extracellular matrix (ECM) of animal cells Intercellular junctions For the Cell Biology Video Ciliary Motion, go to Animation and Video Files. © 2011 Pearson Education, Inc.

Cell Walls of Plants The cell wall is an extracellular structure that distinguishes plant cells from animal cells Prokaryotes, fungi, and some protists also have cell walls The cell wall protects the plant cell, maintains its shape, and prevents excessive uptake of water Plant cell walls are made of cellulose fibers embedded in other polysaccharides and protein © 2011 Pearson Education, Inc.

Plant cell walls may have multiple layers
Primary cell wall: relatively thin and flexible Middle lamella: thin layer between primary walls of adjacent cells Secondary cell wall (in some cells): added between the plasma membrane and the primary cell wall Plasmodesmata are channels between adjacent plant cells For the Cell Biology Video E-cadherin Expression, go to Animation and Video Files. © 2011 Pearson Education, Inc.

Secondary cell wall Primary cell wall Middle lamella 1 m
Figure 6.28 Secondary cell wall Primary cell wall Middle lamella 1 m Central vacuole Cytosol Figure 6.28 Plant cell walls. Plasma membrane Plant cell walls Plasmodesmata

Secondary cell wall Primary cell wall Middle lamella 1 m Figure 6.28a
Figure 6.28 Plant cell walls. 1 m

10 m RESULTS Distribution of cellulose synthase over time
Figure 6.29 RESULTS 10 m Figure 6.29 Inquiry: What role do microtubules play in orienting deposition of cellulose in cell walls? Distribution of cellulose synthase over time Distribution of microtubules over time

10 m Distribution of cellulose synthase over time Figure 6.29a
Figure 6.29 Inquiry: What role do microtubules play in orienting deposition of cellulose in cell walls? Distribution of cellulose synthase over time

10 m Distribution of microtubules over time Figure 6.29b
Figure 6.29 Inquiry: What role do microtubules play in orienting deposition of cellulose in cell walls? Distribution of microtubules over time

The Extracellular Matrix (ECM) of Animal Cells
Animal cells lack cell walls but are covered by an elaborate extracellular matrix (ECM) The ECM is made up of glycoproteins such as collagen, proteoglycans, and fibronectin ECM proteins bind to receptor proteins in the plasma membrane called integrins For the Cell Biology Video Cartoon Model of a Collagen Triple Helix, go to Animation and Video Files. For the Cell Biology Video Staining of the Extracellular Matrix, go to Animation and Video Files. For the Cell Biology Video Fibronectin Fibrils, go to Animation and Video Files. © 2011 Pearson Education, Inc.

Figure 6.30 Extracellular matrix (ECM) of an animal cell.
Collagen EXTRACELLULAR FLUID Polysaccharide molecule Proteoglycan complex Carbo- hydrates Fibronectin Core protein Integrins Proteoglycan molecule Plasma membrane Proteoglycan complex Figure 6.30 Extracellular matrix (ECM) of an animal cell. Micro- filaments CYTOPLASM

Collagen EXTRACELLULAR FLUID Proteoglycan complex Fibronectin
Figure 6.30a Collagen EXTRACELLULAR FLUID Proteoglycan complex Fibronectin Integrins Plasma membrane Figure 6.30 Extracellular matrix (ECM) of an animal cell. CYTOPLASM Micro- filaments

Polysaccharide molecule
Figure 6.30b Polysaccharide molecule Carbohydrates Core protein Figure 6.30 Extracellular matrix (ECM) of an animal cell. Proteoglycan molecule Proteoglycan complex

Cell Junctions Neighboring cells in tissues, organs, or organ systems often adhere, interact, and communicate through direct physical contact Intercellular junctions facilitate this contact There are several types of intercellular junctions Plasmodesmata Tight junctions Desmosomes Gap junctions © 2011 Pearson Education, Inc.

Plasmodesmata in Plant Cells
Plasmodesmata are channels that perforate plant cell walls Through plasmodesmata, water and small solutes (and sometimes proteins and RNA) can pass from cell to cell © 2011 Pearson Education, Inc.

Cell walls Interior of cell Interior of cell Plasmodesmata
Figure 6.31 Cell walls Interior of cell Interior of cell Figure 6.31 Plasmodesmata between plant cells. Plasma membranes 0.5 m Plasmodesmata

Tight Junctions, Desmosomes, and Gap Junctions in Animal Cells
At tight junctions, membranes of neighboring cells are pressed together, preventing leakage of extracellular fluid Desmosomes (anchoring junctions) fasten cells together into strong sheets Gap junctions (communicating junctions) provide cytoplasmic channels between adjacent cells © 2011 Pearson Education, Inc.

Figure 6.32 Exploring: Cell Junctions in Animal Tissues
Tight junctions prevent fluid from moving across a layer of cells Tight junction TEM 0.5 m Tight junction Intermediate filaments Desmosome TEM 1 m Figure 6.32 Exploring: Cell Junctions in Animal Tissues Gap junction Ions or small molecules Space between cells TEM Extracellular matrix Plasma membranes of adjacent cells 0.1 m

Tight junctions prevent fluid from moving across a layer of cells
Figure 6.32a Tight junctions prevent fluid from moving across a layer of cells Tight junction Intermediate filaments Desmosome Gap junction Figure 6.32 Exploring: Cell Junctions in Animal Tissues Ions or small molecules Plasma membranes of adjacent cells Space between cells Extracellular matrix

Tight junction TEM 0.5 m Figure 6.32b
Figure 6.32 Exploring: Cell Junctions in Animal Tissues TEM 0.5 m

Figure 6.32c Figure 6.32 Exploring: Cell Junctions in Animal Tissues TEM 1 m

Figure 6.32d Figure 6.32 Exploring: Cell Junctions in Animal Tissues TEM 0.1 m

The Cell: A Living Unit Greater Than the Sum of Its Parts
Cells rely on the integration of structures and organelles in order to function For example, a macrophage’s ability to destroy bacteria involves the whole cell, coordinating components such as the cytoskeleton, lysosomes, and plasma membrane © 2011 Pearson Education, Inc.

Figure 6.33 Figure 6.33 The emergence of cellular functions. 5 m

Figure 6.UN01 Summary table, Concepts 6.3–6.5
Nucleus (ER) (Nuclear envelope) Figure 6.UN01 Summary table, Concepts 6.3–6.5

Figure 6.UN01a Summary table, Concept 6.3
Nucleus (ER) Figure 6.UN01a Summary table, Concept 6.3

Figure 6.UN01b Summary table, Concept 6.4
(Nuclear envelope) Figure 6.UN01b Summary table, Concept 6.4

Figure 6.UN01c Figure 6.UN01c Summary table, Concept 6.5

Figure 6.UN02 Figure 6.UN02 Appendix A: answer to Figure 6.22 legend question

Figure 6.UN03 Figure 6.UN03 Appendix A: answer to Figure 6.24 legend question

Figure 6.UN04 Figure 6.UN04 Appendix A: answer to Concept Check 6.2, question 2

Concept 6.5: Mitochondria and chloroplasts change energy from one form to another Mitochondria are the sites of cellular respiration, a metabolic process.

Similar presentations

Presentation on theme: "Concept 6.5: Mitochondria and chloroplasts change energy from one form to another Mitochondria are the sites of cellular respiration, a metabolic process."— Presentation transcript:

Similar presentations

About project

Feedback

Log in

Auth with social network:

Concept 6.5: Mitochondria and chloroplasts change energy from one form to another Mitochondria are the sites of cellular respiration, a metabolic process.

Similar presentations

Presentation on theme: "Concept 6.5: Mitochondria and chloroplasts change energy from one form to another Mitochondria are the sites of cellular respiration, a metabolic process."— Presentation transcript:

Similar presentations

About project

Feedback