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C h a p t e r
2
The Cell
PowerPoint® Lecture Slides
prepared by Jason LaPres
North Harris College
Houston, Texas
Copyright © 2009 Pearson Education, Inc.,
publishing as Pearson Benjamin Cummings
Introduction
Cells are the structural “building blocks” of all plants and animals.
Cells are produced by the division of pre-
existing cells.
Cells are the smallest structural units that
perform all vital functions.
Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Introduction
Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Cells fall into two categories:
Sex cells (germ cells or reproductive cells),
which are the sperm in males and oocyte in
females.
Somatic cells are all of the other cells in the
body that are not sex cells.
The Study of Cells
Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
The study of cells is cytology.
Most common methods of study:
Light microscopy
Transmission electron microscopy
Scanning electron microscopy
The Study of Cells
Figure 2.1 Different Techniques, Different Perspectives
Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
The Study of Cells
Figure 2.2 The Diversity of Cells in the Body
Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Cellular Anatomy
Figure 2.3 Anatomy of a Typical CellCopyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Cellular Anatomy
Figure 2.4 A Flow Chart for the Study of Cell Structure
Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Cellular Anatomy
Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Cellular Anatomy
Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Cellular Anatomy
Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
The Plasmalemma
Four major functions of the cell membrane
can be described:
Physical isolation
Regulation of exchange with the environment
Sensitivity
Structural support
Cellular Anatomy
Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Cellular Anatomy
Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
The Plasmalemma
Membrane permeability: passive processes
Diffusion
Osmosis
Facilitated diffusion
Cellular Anatomy
Figure 2.6 Diffusion across Plasmalemmae
Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Cellular Anatomy
Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
The Plasmalemma
Membrane permeability: active processes:
Active transport uses enzymes and carrier
proteins.
Ion pumps are carrier proteins for charged particles.
Ions moved regularly by active transport include:
Na+
Ca2+
Mg2+
K+
An ion pump that moves two ions simultaneously in
opposite directions is called an exchange pump.
Cellular Anatomy
Figure 2.7 Pinocytosis and PhagocytosisCopyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Cellular Anatomy
Figure 2.8 Receptor-Mediated EndocytosisCopyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Cellular Anatomy
Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Cellular Anatomy
Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Figure 2.9 The Cytoskeleton
Cellular Anatomy
Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Figure 2.9a The Cytoskeleton
Cellular Anatomy
Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
The cytoplasm is the general term for the material inside the cell.
Cytoplasm is a fluid that is very high in protein.
The cytosol is the intracellular fluid.
The cytosol is high in potassium ions.
Cytosol contains an overall negative charge.
Transmembrane potential
The cytosol contains high concentrations of proteins.
Organelles are structures within the cytoplasm that have a particular function and very distinct structure.
Cellular Anatomy
Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Nonmembranous Organelles
The Cytoskeleton:
Microfilaments
Intermediate filaments
Thick filaments
Microtubules
Cellular Anatomy
Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Nonmembranous Organelles:
Centrioles
Cilia
Flagella
Cellular Anatomy
Figure 2.10 Centrioles and Cilia
Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Cellular Anatomy
Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Cellular Anatomy
Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Nonmembranous Organelles
Ribosomes:
60% RNA and 40% protein
Free ribosomes:
Float in the cytoplasm
Fixed ribosomes:
Attached to the endoplasmic reticulum
Cellular Anatomy
Figure 2.11 Ribosomes
Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Cellular Anatomy
Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Membranous Organelles
Mitochondria are double-membraned
organelles:
Cristae are the folds of the inner membrane.
The inner fluid is the matrix.
They produce ATP.
Cellular Anatomy
Figure 2.12 Mitochondria
Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Cellular Anatomy
Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Membranous Organelles
The Nucleus is the control center of the cell.
Nucleoplasm
Nuclear envelope
Perinuclear space
Nuclear pores
Nuclear matrix
Cellular Anatomy
Figure 2.13 The Nucleus
Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Cellular Anatomy
Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Membranous Organelles—The Nucleus
Chromosomes:
DNA wrapped around proteins called histones.
Nucleosomes
Chromatin
Cellular Anatomy
Figure 2.14 Chromosome Structure
Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Cellular Anatomy
Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Membranous Organelles
The endoplasmic reticulum (ER) has four major functions:
Synthesis of all classes of macromolecules
Storage of the manufactured molecules
Transport of substances from one area of the cell to another
Enzymes in the lumen of the ER provide detoxification.
Smooth and rough ER
Cellular Anatomy
Figure 2.15 The Endoplasmic Reticulum
Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Cellular Anatomy
Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Membranous Organelles
The Golgi apparatus has three main
functions:
Synthesis and packaging of secretions
Packaging of enzymes for use in the cytosol
Renewal and modification of the cell
plasmalemma
Cellular Anatomy
Figure 2.16 The Golgi Apparatus
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Cellular Anatomy
Figure 2.17 The Function of the Golgi Apparatus
Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Cellular Anatomy
Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Membranous Organelles
Lysosomes function in three manners:
Lysosomes fuse with phagosomes to digest
solid materials.
Lysosomes fuse with and recycle damaged
organelles.
Lysosomes sometimes rupture a process
resulting in autolysis.
Cellular Anatomy
Figure 2.18 Lysosomal Functions
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Cellular Anatomy
Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Membranous Organelles
Peroxisomes function as intracellular
digestive vesicles:
Are abundant in liver cells
Digest fats and toxins
Convert hydrogen peroxide to water
Cellular Anatomy
Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Membrane flow is the continual movement
and recycling of the plasmalemma.
The ER, Golgi apparatus, and vesicles constantly
recycle the lipids, protein channels, and enzymes
of the plasmalemma.
Intercellular Attachment
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There are three major types of cell junctions:
Tight junctions
Communicating junctions
Anchoring junctions
Intercellular Attachment
Figure 2.19 Cell AttachmentsCopyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
The Cell Life Cycle
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The Cell Life Cycle
Figure 2.21 DNA ReplicationCopyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
The Cell Life Cycle
Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Mitosis—the distribution process of
genetic information
Mitosis consists of four stages:
Prophase
Metaphase
Anaphase
Telophase
The Cell Life Cycle
Figure 2.22 Interphase and MitosisCopyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
The Cell Life Cycle
Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
The Cell Life Cycle
Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
The Cell Life Cycle
Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings