1. Cells and Tissues

2. Cells and Tissues Standards
SAP1. Students will analyze anatomical structures in relationship to their physiological functions. d. Relate cellular metabolism and transport to homeostasis and cellular reproduction. e. Describe how structure and function are related in terms of cell and tissue types.

3. Cells and Tissues
Carry out all chemical activities needed to sustain life
Cells are the building blocks of all living things
Tissues are groups of cells that are similar in structure and function

4. Anatomy of the Cell Cells are not all the same
All cells share general structures
Cells are organized into three main regions
Nucleus
Cytoplasm
Plasma membrane
Figure 3.1a

5. The Nucleus Control center of the cell Contains genetic material (DNA)
Three regions
Nuclear membrane
Nucleolus
Chromatin
Figure 3.1b

6. Nuclear Membrane Barrier of nucleus
Consists of a double phospholipid membrane
Contain nuclear pores that allow for exchange of material with the rest of the cell

7. Nucleoli Nucleus contains one or more nucleoli
Sites of ribosome production
Ribosomes then migrate to the cytoplasm through nuclear pores

8. Chromatin Composed of DNA and protein Scattered throughout the nucleus
Chromatin condenses to form chromosomes when the cell divides

9. Plasma Membrane Barrier for cell contents Phospholipid Bi-layer
Hydrophilic heads
Hydrophobic tails
Also contains proteins, cholesterol, glycolipids, and glycoproteins

10. Plasma Membrane
Figure 3.2

11. Functions of the Membrane(s)
Signaling
Barrier
Transport
Localization of function
Cell to cell communication

12. Signaling Membranes detect & respond to external signals
Transmit them into the cell
Which structure(s) in the membrane is responsible for signaling?

13. Barrier
Membranes provide a barrier to entry of water soluble molecules.
Non-polar, hydrophobic lipid tails are responsible for the barrier function.

14. Barrier Things that can cross: Small, non-polar molecules
Gases- CO2, O2, NO, CO, others
Steroids
Things that can not cross:
Charged particles: ions Na+, Cl-, K+, Ca2+
Large molecules- proteins, glucose

15. Transport Membranes are selectively permeable
Some things can cross others can not
Molecules that can not diffuse through the membrane must be TRANSPORTED.
Transport proteins- act as carriers or channels
Control movement into/out of the cell

16. Localization of function
Compartmentalization- membranes create physical barriers to separate cell functions
Allows cells to isolate chemical reactions
Create concentration gradients

17. Cell-to-Cell Communication
Membranes provide contacts between cells
Mediate communication through receptors

18. Journal
Why is the plasma membrane important for cell function and homeostasis?

19. Learning Goals Describe the structure of the plasma membrane.
Describe the function of the plasma membrane and its parts.
Understand Passive and Active Transport mechanisms.
Understand why the plasma membrane is important for homeostasis.

20. Plasma Membrane Barrier for cell contents Double phospholipid layer
Hydrophilic heads
Hydrophobic tails
Also contains protein, cholesterol, and glycoproteins
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MEMBRANE STRUCTURE ANIMATION

21. Plasma Membrane
Figure 3.2

22. Cellular Physiology: Membrane Transport
Membrane Transport – movement of substance into and out of the cell
Transport is by two basic methods
Passive transport
No energy is required
Active transport
The cell must provide metabolic energy

23. Solutions and Transport
Solution – homogeneous mixture of two or more components
Solvent – dissolving medium
Solutes – components in smaller quantities within a solution
Intracellular fluid – nucleoplasm and cytosol
Interstitial fluid – fluid on the exterior of the cell

24. Selective Permeability
The plasma membrane allows some materials to pass while excluding others
This permeability includes movement into and out of the cell

25. Passive Transport Processes
Diffusion
Particles tend to distribute themselves evenly within a solution
Movement is from high concentration to low concentration, or down a concentration gradient
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DIFFUSION ANIMATION
Figure 3.9

26. Passive Transport Processes
Types of diffusion
Simple diffusion
Unassisted process
Solutes are lipid-soluble materials or small enough to pass through membrane pores
Non-polar, cholesterol, steroid hormones, small lipids

27. Passive Transport Processes
Types of diffusion
Osmosis – simple diffusion of water
Highly polar water can cross the plasma membrane
Facilitated diffusion
Substances require a protein carrier for passive transport

28. Diffusion through the Plasma Membrane
Figure 3.10

29. Passive Transport Processes
Filtration
Water and solutes are forced through a membrane by fluid, or hydrostatic pressure
A pressure gradient must exist
Solute-containing fluid is pushed from a high pressure area to a lower pressure area

30. Journal
What is a concentration gradient? What property of the cell membrane allows cells to create gradients?

32. Active Transport Processes
Transport substances that are unable to pass by diffusion
They may be too large
They may not be able to dissolve in the fat core of the membrane
They may have to move against a concentration gradient
Two common forms of active transport
Solute pumping
Bulk transport

33. Active Transport Processes
Solute pumping
Amino acids, some sugars and ions are transported by solute pumps
ATP energizes protein carriers, and in most cases, moves substances against concentration gradients
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ACTIVE TRANSPORT ANIMATION

34. Active Transport Processes
Figure 3.11

35. Active Transport Processes
Bulk transport
Exocytosis
Moves materials out of the cell
Material is carried in a membranous vesicle
Vesicle migrates to plasma membrane
Vesicle combines with plasma membrane
Material is emptied to the outside

36. Exocytosis
Figure 3.12a

37. Active Transport Processes
Bulk transport
Endocytosis
Extracellular substances are engulfed by being enclosed in a membranous vesicle
Types of endocytosis
Phagocytosis – cell eating
Pinocytosis – cell drinking

38. Endocytosis
Figure 3.13a

39. Journal
Explain how the cell membrane plays a role in the transportation of substances in and out of the cell.

40. Journal
Which mechanism of membrane transport is the most important? Why?

41. Georgia Performance Standards
SAP1. Students will analyze anatomical structures in relationship to their physiological functions.
d. Relate cellular metabolism and transport to homeostasis and cellular reproduction.
e. Describe how structure and function are related in terms of cell and tissue types.

42. Plasma Membrane Specializations
Microvilli
Finger-like projections that increase surface area for absorption
Figure 3.3

43. Plasma Membrane Specializations
Membrane junctions
Tight junctions
Desmosomes
Gap junctions
Figure 3.3

44. Cytoplasm Material outside the nucleus and inside the plasma membrane
Cytosol
Fluid that suspends other elements
Organelles
Metabolic machinery of the cell
Inclusions
Non-functioning units

45. Cytoplasmic Organelles
Figure 3.4

46. Cytoplasmic Organelles
Ribosomes
Made of protein and RNA
Sites of protein synthesis
Found at two locations
Free in the cytoplasm
Attached to rough endoplasmic reticulum

47. Cytoplasmic Organelles
Endoplasmic reticulum (ER)
Fluid-filled tubules for carrying substances
Two types of ER
Rough Endoplasmic Reticulum
Studded with ribosomes
Site where building materials of cellular membrane are formed
Smooth Endoplasmic Reticulum
Functions in cholesterol synthesis and breakdown, fat metabolism, and detoxification of drugs

48. Cytoplasmic Organelles
Golgi apparatus
Modifies and packages proteins
Produces different types of packages
Secretory vesicles
Cell membrane components
Lysosomes

49. Golgi Apparatus
Figure 3.6

50. Cytoplasmic Organelles
Lysosomes
Contain enzymes that digest nonusable materials within the cell
Peroxisomes
Membranous sacs of oxidase enzymes
Detoxify harmful substances
Break down free radicals (highly reactive chemicals)
Replicate by pinching in half

51. Cytoplasmic Organelles
Mitochondria
“Powerhouses” of the cell
Change shape continuously
Carry out reactions where oxygen is used to break down food
Provides ATP for cellular energy

52. Cytoplasmic Organelles
Cytoskeleton
Network of protein structures that extend throughout the cytoplasm
Provides the cell with an internal framework
Figure 3.7a

53. Cytoplasmic Organelles
Cytoskeleton
Three different types
Microfilaments
Intermediate filaments
Microtubules
Figure 3.7b–d

54. Cytoplasmic Organelles
Centrioles
Rod-shaped bodies made of microtubules
Direct formation of mitotic spindle during cell division

55. Cellular Projections Not found in all cells Used for movement
Cilia moves materials across the cell surface
Flagellum propels the cell

56. Cell Diversity and Specialization
Journal and EQ: How does the internal structure (amount and type of organelles) of a cell influence its function?

57. Georgia Performance Standards
SAP1. Students will analyze anatomical structures in relationship to their physiological functions.
d. Relate cellular metabolism and transport to homeostasis and cellular reproduction.
e. Describe how structure and function are related in terms of cell and tissue types.

58. Cells that connect Fibroblast- produce protein fibers
Extensive ER and Golgi body
Erythrocyte
No organelles, only hemoglobin to carry O2

59. Cells that Cover & Line Epithelial Tight sheets
Abundant intermediate filaments to resist tearing

60. Cells that move Organs & Body Parts
Skeletal muscle
Elongated cells
Contractile filaments
Abundant mitochondria for ATP production
Smooth ER to store calcium
Multinucleated

61. Cells that Store Nutrients
Adipocyte- fat cell
Fat vacuole stores lipids

62. Cells that Fight Disease
Macrophage- pseudopods extend cytoplasm, many lysosomes
B-Lymphocytes- secrete huge amounts of protein antibodies

63. Cells that Communicate
Nerve Cell- neuron
Long processes to receive and send signals
Extensive Rough ER to synthesize membrane proteins
Extensive Golgi for secretion
Cytoskeleton important for vesicle transport

64. Cells of Reproduction Oocyte- egg cell
Many copies of organelles for rapid divisions that occur after fertilization
Sperm
Flagella to propel to the oocyte
Mitochondria to power the flagella

65. Journal
Why does the body need so many different types of cells?

66. SAP1. Students will analyze anatomical structures in relationship to their physiological functions.
d. Relate cellular metabolism and transport to homeostasis and cellular reproduction.
Disruptions in metabolism and transport often lead to homeostatic imbalance or in cellular reproduction.

67. Cell Life Cycle Cells have two major periods Interphase Cell grows
Cell carries on metabolic processes
Cell division
Cell replicates itself
Function is to produce more cells for growth and repair processes

68. DNA Replication Genetic material duplicated
Readies cell for division into two cells
Occurs toward the end of interphase
DNA uncoils and each side acts as a template
Figure 3.14

69. Events of Cell Division
Mitosis
Division of the nucleus
Results in the formation of two daughter nuclei
Cytokinesis
Division of the cytoplasm
Begins when mitosis is near completion
Results in the formation of two daughter cells

70. Interphase is NOT a part of Mitosis
No cell division occurs
The cell carries out normal metabolic activity and growth

71. Stages of Mitosis Prophase First part of cell division
Centromeres migrate to the poles

72. Stages of Mitosis Metaphase
Spindle from centromeres attached to chromosomes
Chromosomes aligned in the center of the cell

73. Stages of Mitosis Anaphase
Daughter chromosomes are pulled toward the poles
The cell begins to elongate

74. Stages of Mitosis Telophase Daughter nuclei begin forming
A cleavage furrow (for cell division) begins to form

75. Stages of Mitosis
Figure 3.15

76. Stages of Mitosis
Figure 3.15(cont)

77. Journal
Why is it important to understand cellular reproduction?

78. Protein Synthesis
Gene – DNA segment that carries a blueprint for building one protein
Proteins have many functions
Building materials for cells
Act as enzymes (biological catalysts)
RNA is essential for protein synthesis

79. Protein Synthesis
Gene – DNA segment that carries a blueprint for building one protein
Proteins have many functions
Building materials for cells
Act as enzymes (biological catalysts)
RNA is essential for protein synthesis

80. Role of RNA Transfer RNA (tRNA)
Transfers appropriate amino acids to the ribosome for building the protein
Ribosomal RNA (rRNA)
Helps form the ribosomes where proteins are built
Messenger RNA
Carries the instructions for building a protein from the nucleus to the ribosome

81. Transcription and Translation
Transfer of information from DNA’s base sequence to the complimentary base sequence of mRNA
Translation
Base sequence of nucleic acid is translated to an amino acid sequence
Amino acids are the building blocks of proteins

82. Protein Synthesis
Figure 3.16