1. Concepts and Applications Eighth Edition
Powerpoint Lecture Outline
Human Genetics
Concepts and Applications
Eighth Edition
Ricki Lewis
Prepared by
Dubear Kroening
University of Wisconsin-Fox Valley

2. Chapter 2 Cells

3. Cells The Basic Unit of Life
Organisms can be single cells or collections of many cells
Mutations affect whether the cell functions normally
Cell numbers are important, critical to growth, development, and healing

4. Human Cells > 260 cell types Four categories Epithelial Muscle
Nerve
Connective

5. Types of Cells Prokaryotic cells Lack a nucleus Eukaryotic cells
Contain a nucleus
and complex organelles
Figure 2.2

6. Domains of Life Genetic material Domain in a compartment? Example
Archaea no (prokaryote) Methanopyrus
Bacteria no (prokaryote) E. coli
Eukarya yes (eukaryote) amoeba, plant, human

7. Macromolecules in Cells
Carbohydrates sugars, starches energy
Lipids fats, oils membranes
Proteins myosin, collagen structures, enzymes
Nucleic acids DNA, RNA genetic material

8. An Animal Cell Surrounded by the plasma membrane
Contains a nucleus and cytoplasm with specialized organelles
Figure 2.3

9. Structures and Functions of Organelles
Table 2.1

10. The Nucleus Surrounded by double layered nuclear membrane Contains
Nuclear pores that allow movement of some molecules in and out
Nucleolus, which is the site of RNA production
Chromosomes composed of DNA and proteins

11. Figure 2.4
Figure 2.3

12. Secretion
Figure 2.5

13. Endoplasmic Reticulum (ER)
Interconnected membranous tubules and sacs
Rough ER contains ribosomes, site of protein synthesis
Smooth ER does not contain ribosomes and is important in lipid synthesis
Figure 2.3

14. Golgi Apparatus Final protein folding Stores secreted material
Forms sugars, glycoproteins, and glycolipids
Vesicles of material are released
Figure 2.3

15. Lysosomes Break down bacteria, cellular debris, and nutrients
Contain > 40 types of digestive enzymes
Tay-Sachs is an inherited lysosomal storage disorder
Figure 2.6

16. Peroxisomes Contain several types of enzymes
Break down lipids, rare biochemicals
Synthesize bile acids
Detoxify compounds from free radicals
Abundant in liver and kidney cells

17. Mitochondria Site of ATP (energy) production Has its own circular DNA
Mitochondrial genes are inherited from the mother
Figure 2.7

18. Plasma Membrane Selectively permeable
A phospholipid bilayer forms a hydrophobic barrier
Contains proteins, glycoproteins, and glycolipids
Important to cell function and interactions
May be receptors
Form channels for ions
Figure 2.8

19. Figure 2.9

20. Faulty Ion Channels May Cause Inherited Diseases
Sodium channels – ability to detect pain
Potassium channels – Long-QT syndrome
Chloride channels – cystic fibrosis

21. Cytoskeleton Fibers, filaments, and their associated proteins Dynamic
Functions:
Maintain cell shape
Connect cells to each other
Transport organelles and small molecules
Provide cell motility (some cell types)
Move chromosomes in cell division
Compose cilia

22. Cytoskeleton
Figure 2.10

23. Cell Division and Death
Are required for normal growth and development.
Mitosis produces new cells
Mitosis occurs in somatic cells (all cells but egg and sperm)
Apoptosis is cell death that is part of normal development
Necrosis is cell death in response to injury

24. Figure 2.12

25. The Cell Cycle The sequence of events associated with cell division
S phase: DNA synthesis
G phase: gap for growth
M phase: mitosis (nuclear division)
Cell division or cytokinesis follows
Figure 2.13

26. Stages of the Cell Cycle
Interphase
Prepares for cell division
Replicates DNA and subcellular structures
Composed of G1, S, and G2
Cells may progress to mitosis or enter G0, a quiescent phase
Mitosis division of the nucleus
Cytokinesis division of the cytoplasm

27. Replication of Chromosomes
Process of duplicating a chromosome
Occurs prior to division, during S of interphase
Produces sister chromatids
Held together at centromere
Replication is the process of duplicating chromosome. The new copy of a chromosome is formed by DNA synthesis during S-phase. The chromosome copies are called sister chromatids. Sister chromatids are held together at the centromere.
Figure 2.14

28. Mitosis Produces two identical daughter cells
Replicated chromosomes align
Sister chromatids separate and move to opposite poles.
Nuclear membranes form around each new nucleus
Division of cytoplasm or cytokinesis occurs.

29. Overview of Mitosis Continuous process divided into Prophase Metaphase
Anaphase
Telophase

30. Mitosis in a Human Cell
Figure 2.15

31. Prophase Replicated chromosomes condense
Microtubules organize into a spindle
Nuclear membrane breaks down
Figure 2.15

32. Metaphase Chromosomes line up on the metaphase plate
Spindle microtubules are attached to centromeres of chromosomes
Figure 2.15

33. Anaphase Centromeres divide
Chromosomes move to opposite ends of the cell
Figure 2.15

34. Telophase Chromosomes uncoil Nuclear membranes form Spindle disappears
Figure 2.15

35. Cytokinesis
Cytoplasmic division occurs after nuclear division is complete.
Two cells are formed.

36. Cell Cycle Control Proteins called “checkpoint proteins” monitor
progression through the cell cycle.
Figure 2.16

37. Telomeres Located at the ends of the chromosomes
Contain hundreds to thousands of six nucleotide repeats
Most cells lose repeats after each cell division
After about 50 divisions, shortened telomeres signal the cell to stop dividing
Sperm, eggs, bone marrow, and cancer cells produce telomerase that prevent shortening of telomere

38. Apoptosis Orderly destruction, stepwise process
Caspases destroy cellular components, signal phagocytes to clean up
Mitosis and apotosis work together to form functional body
Cancer can result from too much mitosis, too little apotosis

39. Apoptosis Programmed cell death is part of normal development
Figure 2.18

40. Cell-Cell Interaction: Signal Transduction
The process of transmitting a signal from the environment to a cell
Figure 2.19

41. Signal Transduction Receptor binds to messenger
Interacts with regulator
Causes enzyme to produce second messenger
Activates enzymes
Amplification due to cascade
Defects cause disease

42. Cell-Cell Interactions: Cell Adhesion Molecules (CAMs)
Figure 2.20

43. Stem Cells and Cell Specialization
Stem cells and progenitor cells renew tissues
Retain the ability to divide and specialize
Described in terms of potential
Totipotent
Pluripotent

44. Figure 2.22

45. Medical Treatments Using Stem Cells
Regenerative medicine
Sources of stem cells
Early embryos from fertility clinics
Somatic cell nuclear transfer
Tissue-based (adult) stem cells
Ethical issues associated with use of embryos

46. Figure 2.24