Chapter 6 A Tour of the Cell

10 m 1 m 0.1 m 1 cm 1 mm 100 µm 10 µm 1 µm 100 nm 10 nm 1 nm 0.1 nm Fig. 6-2 Which microscope would work best for looking at macromolecules? 10 m Human height 1 m Length of some nerve and muscle cells 0.1 m Unaided eye Chicken egg 1 cm Frog egg 1 mm 100 µm Most plant and animal cells Light microscope 10 µm Nucleus Most bacteria 1 µm Mitochondrion Figure 6.2 The size range of cells Smallest bacteria Electron microscope 100 nm Viruses Ribosomes 10 nm Proteins Lipids 1 nm Small molecules 0.1 nm Atoms

Carbohydrate side chain Fig. 6-7 Describe the components of a phospholipid (see figure 5.13) that allow it to function as the major element in the plasma membrane. Outside of cell (a) TEM of a plasma membrane Inside of cell 0.1 µm Carbohydrate side chain Hydrophilic region Figure 6.7 The plasma membrane Hydrophobic region Hydrophilic region Phospholipid Proteins (b) Structure of the plasma membrane

Surface area increases while total volume remains constant Fig. 6-8 Why is a high surface to volume ratio important for a cell? Surface area increases while total volume remains constant 5 1 1 Total surface area [Sum of the surface areas (height  width) of all boxes sides  number of boxes] 6 150 750 Total volume [height  width  length  number of boxes] Figure 6.8 Geometric relationships between surface area and volume 1 125 125 Surface-to-volume (S-to-V) ratio [surface area ÷ volume] 6 1.2 6

ENDOPLASMIC RETICULUM (ER) Nucleolus NUCLEUS Rough ER Smooth ER Fig. 6-9a Circle the items found in animals but not plant cells. Nuclear envelope ENDOPLASMIC RETICULUM (ER) Nucleolus NUCLEUS Rough ER Smooth ER Flagellum Chromatin Centrosome Plasma membrane CYTOSKELETON: Microfilaments Intermediate filaments Microtubules Ribosomes Figure 6.9 Animal and plant cells—animal cell Microvilli Golgi apparatus Peroxisome Mitochondrion Lysosome

Rough endoplasmic reticulum Fig. 6-9b Circle the items found in plant cells but not animal cells. Nuclear envelope Rough endoplasmic reticulum NUCLEUS Nucleolus Chromatin Smooth endoplasmic reticulum Ribosomes Central vacuole Golgi apparatus Microfilaments Intermediate filaments CYTO- SKELETON Microtubules Figure 6.9 Animal and plant cells—plant cell Mitochondrion Peroxisome Chloroplast Plasma membrane Cell wall Plasmodesmata Wall of adjacent cell

Endoplasmic reticulum (ER) Fig. 6-11 What is the role of ribosomes? Cytosol Endoplasmic reticulum (ER) Free ribosomes Bound ribosomes Large subunit Figure 6.11 Ribosomes Small subunit 0.5 µm TEM showing ER and ribosomes Diagram of a ribosome

Smooth ER Nuclear envelope Rough ER ER lumen Cisternae Transitional ER Fig. 6-12 How is the role of smooth ER different than rough ER? Smooth ER Nuclear envelope Rough ER ER lumen Cisternae Transitional ER Ribosomes Transport vesicle 200 nm Smooth ER Rough ER Figure 6.12 Endoplasmic reticulum (ER)

(“receiving” side of Golgi apparatus) 0.1 µm Fig. 6-13 True or False. ER products can be processed from the trans face first. cis face (“receiving” side of Golgi apparatus) 0.1 µm Cisternae Figure 6.13 The Golgi apparatus trans face (“shipping” side of Golgi apparatus) TEM of Golgi apparatus

Lysosomes: Digestive Compartments Animation: Lysosome Formation Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings

Nucleus 1 µm Lysosome Digestive enzymes Lysosome Plasma membrane Fig. 6-14a Break down the word phagocytosis using Greek components. Nucleus 1 µm Lysosome Digestive enzymes Lysosome Figure 6.14a Lysosome—phagocytosis Plasma membrane Digestion Food vacuole (a) Phagocytosis

two damaged organelles 1 µm Fig. 6-14b Research the term autophagy. What do the components mean? Vesicle containing two damaged organelles 1 µm Mitochondrion fragment Peroxisome fragment Lysosome Figure 6.14b Lysosomes—autophagy Peroxisome Mitochondrion Digestion Vesicle (b) Autophagy

Video: Paramecium Vacuole Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings

Central vacuole Cytosol Nucleus Central vacuole Cell wall Chloroplast Fig. 6-15 What does the vacuole absorb when the plant cell grows? Central vacuole Cytosol Nucleus Central vacuole Figure 6.15 The plant cell vacuole Cell wall Chloroplast 5 µm

Nucleus Rough ER Smooth ER cis Golgi Plasma membrane trans Golgi Fig. 6-16-3 Number the migration pathways for membranes of the endomembrane system. Nucleus Rough ER Smooth ER cis Golgi Figure 6.16 Review: relationships among organelles of the endomembrane system Plasma membrane trans Golgi

____________ ribosomes in the mitochondrial matrix Fig. 6-17 Fill in the missing information. Intermembrane space Outer membrane ____________ ribosomes in the mitochondrial matrix Inner membrane ______ Figure 6.17 The mitochondrion, site of cellular respiration ______ 0.1 µm

Inner and outer membranes Fig. 6-18 Fill in the missing information. Ribosomes _______ Inner and outer membranes _______ 1 µm _________ Figure 6.18 The chloroplast, site of photosynthesis

Receptor for motor protein Fig. 6-21 What do vesicles use to get from point A to point B in a cell? Vesicle ATP Receptor for motor protein Motor protein (ATP powered) Microtubule of cytoskeleton (a) Microtubule Vesicles 0.25 µm Figure 6.21 Motor proteins and the cytoskeleton (b)

10 µm Column of tubulin dimers Tubulin dimer   25 nm Table 6-1a Highlight/underline the main functions of microtubules. 10 µm Table 6-1a Column of tubulin dimers 25 nm   Tubulin dimer

Table 6-1b Highlight/underline the main functions of microfilaments. Actin subunit 7 nm

Fibrous subunit (keratins coiled together) Table 6-1c Highlight/underline the main functions of intermediate filaments. 5 µm Table 6-1c Keratin proteins Fibrous subunit (keratins coiled together) 8–12 nm

Longitudinal section of one centriole Microtubules Cross section Fig. 6-22 How many microtubules are in a centrosome? In the drawing, circle and label one microtubule and describe its structure. Centrosome Microtubule Centrioles 0.25 µm Figure 6.22 Centrosome containing a pair of centrioles Longitudinal section of one centriole Microtubules Cross section of the other centriole

Video: Paramecium Cilia Video: Chlamydomonas Video: Paramecium Cilia Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings

Direction of organism’s movement Fig. 6-23 How are flagella and cilia similar? Direction of swimming (a) Motion of flagella 5 µm Direction of organism’s movement Figure 6.23a A comparison of the beating of flagella and cilia—motion of flagella Power stroke Recovery stroke (b) Motion of cilia 15 µm

Animation: Cilia and Flagella Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings

Cross section of cilium Fig. 6-24 What happens to the basal body of the sperm’s flagellum? Outer microtubule doublet Plasma membrane 0.1 µm Dynein proteins Central microtubule Radial spoke Protein cross-linking outer doublets Microtubules (b) Cross section of cilium Plasma membrane Basal body 0.5 µm (a) Longitudinal section of cilium 0.1 µm Figure 6.24 Ultrastructure of a eukaryotic flagellum or motile cilium Triplet (c) Cross section of basal body

Cross-linking proteins inside outer doublets Fig. 6-25b What energy molecule must be utilized to move flagella? ATP Cross-linking proteins inside outer doublets Anchorage in cell (b) Effect of cross-linking proteins 1 3 Figure 6.25b, c How dynein “walking” moves flagella and cilia 2 (c) Wavelike motion

Microfilaments (actin filaments) Fig. 6-26 Why increase the surface area of a nutrient absorbing cell? Microvillus Plasma membrane Microfilaments (actin filaments) Figure 6.26 A structural role of microfilaments Intermediate filaments 0.25 µm

Muscle cell Actin filament Myosin filament Myosin arm Fig, 6-27a True or False. The length of the actin and myosin filaments remain the same during muscle contraction. Muscle cell Actin filament Myosin filament Myosin arm Figure 6.27a Microfilaments and motility (a) Myosin motors in muscle cell contraction

Cortex (outer cytoplasm): gel with actin network Fig. 6-27bc True or False. Actin subunits are arranged in a permanent structure during amoeboid movement. Cortex (outer cytoplasm): gel with actin network Inner cytoplasm: sol with actin subunits Extending pseudopodium (b) Amoeboid movement Nonmoving cortical cytoplasm (gel) Chloroplast Streaming cytoplasm (sol) Figure 6.27b,c Microfilaments and motility Vacuole Parallel actin filaments Cell wall (c) Cytoplasmic streaming in plant cells

Video: Cytoplasmic Streaming Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings

Figure 6.30 Extracellular matrix (ECM) of an animal cell, part 1 Fig. 6-30 The ECM is the animal equivalent to the _______________________ in a plant cell. Collagen Proteoglycan complex Polysaccharide molecule EXTRACELLULAR FLUID Carbo- hydrates Fibronectin Core protein Integrins Proteoglycan molecule Plasma membrane Proteoglycan complex Figure 6.30 Extracellular matrix (ECM) of an animal cell, part 1 Micro- filaments CYTOPLASM

Tight Junctions, Desmosomes, and Gap Junctions in Animal Cells Which one is the animal equivalent of a plasmodesmata? Animation: Tight Junctions Animation: Desmosomes Animation: Gap Junctions Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings

Tight junctions prevent fluid from moving across a layer of cells Fig. 6-32a Watertight skin is due to what junction? Tight junctions prevent fluid from moving across a layer of cells Tight junction Intermediate filaments Desmosome Gap junctions Figure 6.32 Intercellular junctions in animal tissues—tight junctions Extracellular matrix Space between cells Plasma membranes of adjacent cells

5 µm Fig. 6-33 What components of a cell function in phagocytosis? Figure 6.33 The emergence of cellular functions