1. Chapter 3
Cells and Tissue

2. Learning Objectives
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 act to move substances through cell membranes.

3. Learning Objectives (cont’d.)
Compare and discuss DNA and RNA and their function in protein synthesis.
Discuss the stages of mitosis and explain the importance of cellular reproduction.

4. Learning Objectives (cont’d.)
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.

5. Chapter 3 Lesson 3.1

6. Size and Shape Composition Human cells vary considerably in size.
All are microscopic.
Cells differ notably in shape.
Cytoplasm contains specialized organelles surrounded by a plasma membrane.
Composition
Cytoplasm contains specialized organelles.
Plasma membrane surrounds each cell.
Organization of cytoplasmic substances is important for life.
The small, circular body called the nucleus is inside the cell.
An ovum has a diameter of 150 micrometers.
A red blood cell has a diameter of 7.5 micrometer.
What are some of the shapes of different cell types?

7. Composition General Characteristics of the cell
Ask students to cite the functions of specific cell parts.
What are the three parts of a cell?

8. Parts of the Cell 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
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.
What is cholesterol, and what is its function?
What are some of the other functions of the plasma membrane?

9. Parts of the Cell (cont’d.)
Endoplasmic reticulum (ER)
network of connecting sacs and canals
carries substances through cytoplasm
Golgi apparatus
group of flattened sacs stacked on one another near nucleus
Mitochondria
composed of inner and outer membranes
each contains one DNA molecule
What are the two types of ER? How do they function?

10. Parts of the 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
Cilia
fine hairlike extensions found on free or exposed surfaces of some cells
Flagellum
single projection extending from cell surfaces
much larger than cilia
Describe the protective function of lysosomes.
What is the role that centrioles play during cell division?

11. Parts of the Cell (cont’d.)
Nucleus
controls every organelle in the cytoplasm, along with cell reproduction
contains the genetic code
component structures include nuclear envelope, nucleoplasm, and chromatin granules
What is the genetic code?

12. Relationship of 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.
What are some examples of specialized organelles?

13. Movement of Substances Through Cell Membranes
Passive transport processes
processes do not require added energy and result in movement “down a concentration gradient”
types of passive transport include:
diffusion
osmosis
dialysis
filtration
What are the two transport processes for moving substances into and out of cells? How are they different?

14. Movement of Substances Through Cell Membranes (cont’d.)
Passive Transport Processes
To form urine in the kidney, wastes are filtered out of the blood into the kidney tubules because of differences in hydrostatic pressure.

15. Movement of Substances Through Cell Membranes (cont’d.)
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.
What are osmosis and dialysis?
What are solutes?

16. Movement of Substances Through Cell Membranes (cont’d.)
Passive transport processes
Filtration
Movement of water and solutes through a membrane because of a greater pushing force on one side of the membrane than on the other.
This force is called hydrostatic pressure.
Responsible for urine formation.
Give some additional examples of filtration.

17. Movement of Substances Through Cell Membranes (cont’d.)
Active transport processes
occurs only in living cells
movement of substances is “ against/up the concentration gradient”
requires energy from adenosine triphosphate (ATP)
What is adenosine triphosphate (ATP)?

18. Movement of Substances Through Cell Membranes (cont’d.)
Active Transport Processes

19. Movement of Substances Through Cell Membranes (cont’d.)
Active transport processes
Ion pumps
An ion pump is protein complex in cell membrane called a carrier.
Ion pumps use energy from ATP to move substances across cell membranes against their concentration gradients
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.

20. Chapter 3 Lesson 3.2

21. Cell Reproduction Mitosis
the process of cell reproduction, one cell divides to become two cells.
tied closely to the production of proteins
What molecules play a crucial role in protein synthesis and mitosis? (DNA and RNA)

22. Cell Reproduction (cont’d.)
DNA Molecule and Genetic Information
Chromosomes are composed largely of DNA.
DNA shaped like a long, narrow spiral staircase.
Each step in the DNA ladder consists of pair of bases.
Only two combinations of bases will occur A-T or
C-G.
Called complementary base pairing.
What are the components of DNA? (Sugar, phosphate, nitrogen bases)
What are the base pairs? (adenine–thymine and guanine-cytosine)

23. 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
How many chromosomes are in human body cells? (46)

24. Genetic Code (cont’d.) RNA Molecules and Protein Synthesis
Ribonucleic acid (RNA) transfers genetic information from the nucleus to the cytoplasm.
RNA is made up of:
sugar: ribose
phosphate
nitrogen bases: cytosine, guanine, adenine, uracil
Where does protein synthesis occur?

25. 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.

26. 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 amino acids are assembled into proper sequence, a protein strand forms.
What happens after the protein strand is formed?

27. Genetic Code (cont’d.) Protein synthesis
Go through the steps of transcription and translation as shown in the figure.

28. 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
Happens before mitosis
What is interphase?

29. 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
Name the four stages of mitosis. (prophase, metaphase, anaphase, telophase)

30. Stages of Mitosis Prophase—first stage
Chromatin granules become organized.
Chromosomes (pairs of linked chromatids) appear.
Chromatids are held together by beadlike structure called centromere.
Centrioles move away from each other.
Spindle fibers form between centrioles.
Nuclear envelope disappears, freeing genetic material.

31. Stages of Mitosis (cont’d.)
Metaphase—second stage
Nuclear envelope and nucleolus have disappeared.
Chromosomes align across center of cell.
Spindle fibers attach themselves to each chromatid.
What do spindle fibers resemble?

32. 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 cell.
Cleavage furrow develops at end of anaphase.
Beginning to divide cell into two daughter cells
Daughter cells have identical genetic characteristics. Each may later undergo mitosis.

33. 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.
What are the results of cell division?
Discuss neoplasm

34. Chapter 3
Lesson 3.3
Epithelial Tissue types

35. Tissues Epithelial tissue Covers body and lines body cavities
Cells packed closely together with little matrix
Classified by shape and arrangement of cells
Epithelial tissue types
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
What are the four shapes of epithelial cells?
In what ways can they be arranged?

36. Tissues (cont’d.) Epithelial tissue types 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
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
What is the special function of simple columnar epithelium?
Where can these cells be found?

37. Tissues (cont’d.)
Classification
of epithelial
tissues

38. 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
Types
Areolar—glue that holds organs together
Adipose (fat)—lipid storage is primary function
Fibrous—consists of strong, white collagen fibers
Where is connective tissue found?

39. 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 because its matrix has the consistency of a firm plastic or gristle-like gel
Blood and Hemopoietic
Blood—matrix is fluid
Hemopoietic—bloodlike connective tissue found in marrow cavities
Osteons are also called Haversian systems.
What is the function of hemopoietic tissue?

40. Tissues (cont’d.) Muscle tissue Types
Skeletal—also called striated or voluntary
attaches to bones
control is voluntary
striations apparent when viewed under a microscope
Describe the structure and distinctive traits of skeletal muscle cells.

41. 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
Give some examples of smooth muscles. (digestive tract, respiratory tubes)

42. Tissues (cont’d.) Nervous tissue
Provides rapid communication between body structures and 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
Give a general description of a neuron.
What does an axon do?
What does a dendrite do?