Copyright (c) 2008, 2005 by Mosby, Inc., an affiliate of Elsevier Inc. All rights reserved.

Copyright © 2005, Elsevier, Inc. All rights reserved. Slide 1 1 Copyright (c) 2008, 2005 by Mosby, Inc., an affiliate of Elsevier Inc. All rights reserved. Chapter 3 Cells and Tissues

2 Copyright (c) 2008, 2005 by Mosby, Inc., an affiliate of Elsevier Inc. All rights reserved. Identify and discuss the basic structure and function of the three major components of a cell List and briefly discuss the functions of the primary cellular organelles Compare the major passive and active transport processes that function to move substances through cell membranes Learning Objectives

3 Copyright (c) 2008, 2005 by Mosby, Inc., an affiliate of Elsevier Inc. All rights reserved. Compare and discuss DNA and RNA and their functions in protein synthesis Discuss the stages of mitosis and explain the importance of cellular reproduction Learning Objectives (cont’d.)

4 Copyright (c) 2008, 2005 by Mosby, Inc., an affiliate of Elsevier Inc. All rights reserved. Explain how epithelial tissue is grouped according to shape and arrangement of cells List and briefly discuss the major types of connective and muscle tissue List the three structural components of a neuron Learning Objectives (cont’d.)

Copyright © 2005, Elsevier, Inc. All rights reserved. Slide 5 5 Copyright (c) 2008, 2005 by Mosby, Inc., an affiliate of Elsevier Inc. All rights reserved. Chapter 3 Lesson 3.1

6 Copyright (c) 2008, 2005 by Mosby, Inc., an affiliate of Elsevier Inc. All rights reserved. Size and Shape Human cells vary considerably in size All are microscopic Cells differ notably in shape Cytoplasm contains specialized organelles surrounded by a plasma membrane

7 Copyright (c) 2008, 2005 by Mosby, Inc., an affiliate of Elsevier Inc. All rights reserved. Composition Cytoplasm contains specialized organelles A plasma membrane surrounds each cell Organization of cytoplasmic substances is important for life The small, circular body called the nucleus is inside the cell

8 Copyright (c) 2008, 2005 by Mosby, Inc., an affiliate of Elsevier Inc. All rights reserved. Composition (cont’d.) General Characteristics of the Cell

9 Copyright (c) 2008, 2005 by Mosby, Inc., an affiliate of Elsevier Inc. All rights reserved. Plasma membrane  Forms outer boundary of cell  Only 7 nm (3/10,000,000 of an inch) thick  Thin, two-layered membrane of phospholipids containing proteins form the framework of the plasma membrane  Is selectively permeable Parts of a Cell

10 Copyright (c) 2008, 2005 by Mosby, Inc., an affiliate of Elsevier Inc. All rights reserved. Parts of a Cell (cont’d.) Cytoplasm  Internal living material of cells  Organelles: Small structures that make up most of the cytoplasm Ribosomes: May attach to rough endoplasmic reticulum (ER) or lie free in cytoplasm

11 Copyright (c) 2008, 2005 by Mosby, Inc., an affiliate of Elsevier Inc. All rights reserved. Parts of a Cell (cont’d.) Endoplasmic Reticulum (ER)  Network of connecting sacs and canals  Carries substances through cytoplasm

12 Copyright (c) 2008, 2005 by Mosby, Inc., an affiliate of Elsevier Inc. All rights reserved. Parts of a Cell (cont’d.) Golgi apparatus  Group of flattened sacs stacked on one another near nucleus Mitochondria  Composed of inner and outer membranes  Each contains one DNA molecule

13 Copyright (c) 2008, 2005 by Mosby, Inc., an affiliate of Elsevier Inc. All rights reserved. Parts of a Cell (cont’d.) Lysosomes  Membranous-walled organelles  Contain digestive enzymes Centrioles  Paired organelles  Fine tubules that lie at right angles to each other near the nucleus

14 Copyright (c) 2008, 2005 by Mosby, Inc., an affiliate of Elsevier Inc. All rights reserved. Parts of a Cell (cont’d.) Cilia  Fine hairlike extensions found on free or exposed surfaces of some cells Flagellum  Single projection extending from cell surfaces  Much larger than cilia

15 Copyright (c) 2008, 2005 by Mosby, Inc., an affiliate of Elsevier Inc. All rights reserved. Parts of a Cell (cont’d.) Nucleus  Controls every organelle in the cytoplasm  Controls cell reproduction  Contains the genetic code  Component structures include nuclear envelope, nucleoplasm, and chromatin granules

16 Copyright (c) 2008, 2005 by Mosby, Inc., an affiliate of Elsevier Inc. All rights reserved. Relationship Between Cell Structure and Function Regulation of life processes Survival of species through reproduction of the individual Relationship of structure to function is apparent in number and type of organelles seen in different cells

17 Copyright (c) 2008, 2005 by Mosby, Inc., an affiliate of Elsevier Inc. All rights reserved. Movement of Substances Through Cell Membranes Passive transport processes  Do not require added energy and result in movement “down a concentration gradient”  Types of passive transport include  Diffusion o Osmosis o Dialysis  Filtration

18 Copyright (c) 2008, 2005 by Mosby, Inc., an affiliate of Elsevier Inc. All rights reserved. Movement of Substances Through Cell Membranes (cont’d.) Passive Transport Processes

19 Copyright (c) 2008, 2005 by Mosby, Inc., an affiliate of Elsevier Inc. All rights reserved. Passive transport processes  Diffusion  Substances scatter themselves evenly throughout an available space  It is unnecessary to add energy to the system  Movement is from high to low concentration  Osmosis and dialysis are specialized examples of diffusion Movement of Substances Through Cell Membranes (cont’d.)

20 Copyright (c) 2008, 2005 by Mosby, Inc., an affiliate of Elsevier Inc. All rights reserved. Passive transport processes  Filtration  Movement of water and solutes through a membrane because of a greater pushing force on one side of the membrane  This force is called hydrostatic pressure  Responsible for urine formation Movement of Substances Through Cell Membranes (cont’d.)

21 Copyright (c) 2008, 2005 by Mosby, Inc., an affiliate of Elsevier Inc. All rights reserved. Active transport processes  Occurs only in living cells  Movement of substances is “up the concentration gradient”  Requires energy from adenosine triphosphate (ATP) Movement of Substances Through Cell Membranes (cont’d.)

22 Copyright (c) 2008, 2005 by Mosby, Inc., an affiliate of Elsevier Inc. All rights reserved. Active Transport Processes Movement of Substances Through Cell Membranes (cont’d.)

23 Copyright (c) 2008, 2005 by Mosby, Inc., an affiliate of Elsevier Inc. All rights reserved. Active transport processes  Ion pumps  An ion pump is a protein complex in the cell membrane called a carrier  Ion pumps use energy from ATP to move substances across cell membranes against their concentration gradients Movement of Substances Through Cell Membranes (cont’d.)

24 Copyright (c) 2008, 2005 by Mosby, Inc., an affiliate of Elsevier Inc. All rights reserved. Active transport processes  Phagocytosis and Pinocytosis  Both are active transport mechanisms, because they require cell energy  Phagocytosis is a protective mechanism often used to destroy bacteria  Pinocytosis is used to incorporate fluids or dissolved substances into cells Movement of Substances Through Cell Membranes (cont’d.)

Copyright © 2005, Elsevier, Inc. All rights reserved. Slide Copyright (c) 2008, 2005 by Mosby, Inc., an affiliate of Elsevier Inc. All rights reserved. Chapter 3 Lesson 3.2

26 Copyright (c) 2008, 2005 by Mosby, Inc., an affiliate of Elsevier Inc. All rights reserved. Cell Reproduction Mitosis  The process of cell reproduction  During the process, one cell divides to become two cells  Tied closely to the production of proteins

27 Copyright (c) 2008, 2005 by Mosby, Inc., an affiliate of Elsevier Inc. All rights reserved. Cell Reproduction (cont’d.) DNA molecule and genetic information  Chromosomes are composed largely of DNA  DNA are shaped like a long, narrow spiral staircase  Each step in the DNA ladder consists of a pair of bases o Only two combinations of bases occur o This is called complementary base pairing

28 Copyright (c) 2008, 2005 by Mosby, Inc., an affiliate of Elsevier Inc. All rights reserved. Genetic Code DNA molecule and genetic information  Genes dictate formation of enzymes and other proteins by ribosomes  Although the types of base pairs in all chromosomes are the same, the sequence varies  Each gene directs the synthesis of a specific protein  Genetic code: The storage of information in each gene

29 Copyright (c) 2008, 2005 by Mosby, Inc., an affiliate of Elsevier Inc. All rights reserved. Genetic Code (cont’d.) RNA molecules and protein synthesis  Ribonucleic acid (RNA) transfers genetic information from the nucleus to the cytoplasm  RNA composition  Sugar: Ribose  Phosphate  Nitrogen bases: Cytosine, guanine, adenine, uracil

30 Copyright (c) 2008, 2005 by Mosby, Inc., an affiliate of Elsevier Inc. All rights reserved. Genetic Code (cont’d.) RNA molecules and protein synthesis  Transcription  Double-stranded DNA separates to form messenger RNA (mRNA  Each strand of mRNA duplicates a particular gene (base-pair sequence) from a segment of DNA  mRNA molecules pass from the nucleus to the cytoplasm, where they direct protein synthesis in ribosomes and ER

31 Copyright (c) 2008, 2005 by Mosby, Inc., an affiliate of Elsevier Inc. All rights reserved. Genetic Code (cont’d.) Translation  Involves synthesis of proteins in cytoplasm by ribosome  Requires use of information contained in mRNA to direct the choice and sequencing of the building blocks called amino acids  As blocks of amino acids are assembled into proper sequence, a protein strand forms

32 Copyright (c) 2008, 2005 by Mosby, Inc., an affiliate of Elsevier Inc. All rights reserved. Genetic Code (cont’d.) Protein Synthesis

33 Copyright (c) 2008, 2005 by Mosby, Inc., an affiliate of Elsevier Inc. All rights reserved. Cell Division Reproduction of cell by division of the nucleus (mitosis) and the cytoplasm DNA replication  Process by which each half of a DNA molecule becomes a whole molecule identical to the original DNA molecule  Precedes mitosis

34 Copyright (c) 2008, 2005 by Mosby, Inc., an affiliate of Elsevier Inc. All rights reserved. Cell Division (cont’d.) Mitosis  Process in cell division in which identical chromosomes (DNA molecules) to each new cell are formed when the original cell divides  Enables cells to reproduce their own kind

35 Copyright (c) 2008, 2005 by Mosby, Inc., an affiliate of Elsevier Inc. All rights reserved. Cell Division (cont’d.) Mitosis

36 Copyright (c) 2008, 2005 by Mosby, Inc., an affiliate of Elsevier Inc. All rights reserved. Stages of Mitosis Prophase—first stage  Chromatin granules become organized  Chromosomes (pairs of linked chromatids) appear  Chromatids are held together by a beadlike structure called a centromere  Centrioles move away from each other  Spindle fibers form between centrioles  The nuclear envelope disappears, freeing genetic material

37 Copyright (c) 2008, 2005 by Mosby, Inc., an affiliate of Elsevier Inc. All rights reserved. Stages of Mitosis (cont’d.) Metaphase—second stage  The nuclear envelope and nucleolus have disappeared  Chromosomes align across the center of each cell  Spindle fibers attach themselves to each chromatid

38 Copyright (c) 2008, 2005 by Mosby, Inc., an affiliate of Elsevier Inc. All rights reserved. Stages of Mitosis (cont’d.) Anaphase—third phase  Centromeres break apart  Separated chromatids are now called chromosomes once again  Chromosomes are pulled to opposite ends of the cell  A cleavage furrow develops at end of anaphase  Beginning to divide cell into two daughter cells

39 Copyright (c) 2008, 2005 by Mosby, Inc., an affiliate of Elsevier Inc. All rights reserved. Stages of Mitosis (cont’d.) Telophase—fourth stage  Cell division is completed  Nuclei appear in daughter cells  Nuclear envelope and nucleoli appear  Cytoplasm and organelles divide equally  Daughter cells become fully functional

Copyright © 2005, Elsevier, Inc. All rights reserved. Slide Copyright (c) 2008, 2005 by Mosby, Inc., an affiliate of Elsevier Inc. All rights reserved. Chapter 3 Lesson 3.3

41 Copyright (c) 2008, 2005 by Mosby, Inc., an affiliate of Elsevier Inc. All rights reserved. Tissues Epithelial tissue  Covers body and lines body cavities  Cells packed closely together with little matrix  Classified by shape and arrangement of cells

42 Copyright (c) 2008, 2005 by Mosby, Inc., an affiliate of Elsevier Inc. All rights reserved. Tissues (cont’d.) Epithelial tissue  Simple squamous epithelium  Single layer of very thin, irregularly shaped cells  Transport is function (such as absorption of oxygen into blood)  Located in alveoli of lungs, lining of blood and lymphatic vessels  Stratified squamous epithelium  Several layers of closely packed cells  Protection is primary function

43 Copyright (c) 2008, 2005 by Mosby, Inc., an affiliate of Elsevier Inc. All rights reserved. Tissues (cont’d.) Epithelial tissue  Simple columnar epithelium  Single layer of tall, narrow cells  Contain mucus-producing goblet cells  Stratified transitional epithelium  Up to 10 layers of roughly cuboidal-shaped cells that distort to squamous shape when stretched  Functions as protection  Found in body areas subject to stress and that stretch, such as urinary bladder

44 Copyright (c) 2008, 2005 by Mosby, Inc., an affiliate of Elsevier Inc. All rights reserved. Tissues (cont’d.) Epithelial tissue  Pseudostratified epithelium  Single layer of tall cells that wedge together to appear as if there are two or more layers  Simple cuboidal epithelium  Form tubules specialized for secretory activity  Usually form clusters called glands

45 Copyright (c) 2008, 2005 by Mosby, Inc., an affiliate of Elsevier Inc. All rights reserved. Tissues (cont’d.) Classification of Epithelial Tissues

46 Copyright (c) 2008, 2005 by Mosby, Inc., an affiliate of Elsevier Inc. All rights reserved. Tissues (cont’d.) Connective tissue  Most abundant tissue in body  Most widely distributed tissue in body  Multiple types, appearances, and functions  Relatively few cells in intercellular matrix

47 Copyright (c) 2008, 2005 by Mosby, Inc., an affiliate of Elsevier Inc. All rights reserved. Tissues (cont’d.) Connective tissue  Types  Areolar: Glue that holds organs together  Adipose (fat): Lipid storage is primary function  Fibrous: Consists of strong, white collagen fibers

48 Copyright (c) 2008, 2005 by Mosby, Inc., an affiliate of Elsevier Inc. All rights reserved. Tissues (cont’d.) Connective tissue types  Bone—matrix is hard and calcified  Forms structural building blocks called osteons  Function in support and protection, stores calcium  Cartilage—chondrocyte is cell type  Differs from bone; matrix is consistency of a firm plastic or gristle-like gel  Blood and hematopoietic  Blood—matrix is fluid  Hematopoietic—bloodlike connective tissue found in marrow cavities

49 Copyright (c) 2008, 2005 by Mosby, Inc., an affiliate of Elsevier Inc. All rights reserved. Tissues (cont’d.) Muscle tissue  Types  Skeletal—also called striated or voluntary o Attaches to bones o Control is voluntary o Striations apparent when viewed under a microscope

50 Copyright (c) 2008, 2005 by Mosby, Inc., an affiliate of Elsevier Inc. All rights reserved. Tissues (cont’d.) Muscle tissue types  Cardiac—also called striated involuntary  Produces regular, involuntary contractions of cardiac muscle to produce heartbeat  Has faint cross striations and thicker dark bands called intercalated disks  Smooth—also called visceral  Involuntary control  Appears smooth; without cross striations  Has only one nucleus per fiber  Forms walls of blood vessels, hollow organs such as intestines and other tube-shaped structures

51 Copyright (c) 2008, 2005 by Mosby, Inc., an affiliate of Elsevier Inc. All rights reserved. Tissues (cont’d.) Nervous tissue  Provides rapid communication between body structures and for control of body functions  Example is spinal cord tissue  Consists of two cell types: neuron and glia  Glia (neuroglia)—supportive and connecting cells  Neurons—conducting cell