Cells and Organelles (Learning Objectives)

Transcription

1 Cells and Organelles (Learning Objectives) Compare and contrast prokaryotic and eukaryotic cells. List their similarities and differences. Learn the three domains of living organisms and the 6 emergent feature of cells and living organisms. Compare and contrast gamete, zygote, somatic cells, and germ cells. Review the structure of membranes and explain the importance of different proteins for creating intracellular membranous compartments where different cellular functions can take place. Learn the structure and functions of each of the following, and where applicable relate to specific known genetic diseases; a. Plasma membrane b. Cytoskeleton c. Nucleus d. Endoplasmic reticulum (smooth and rough) e. Golgi apparatus & vescilces f. Lysosomes g. Peroxisomes h. Mitochondria Explain the coordination of functions of several organelles that bring about cellular functions such as secretion and flow of genetic information from DNA to protein

2 Types of Cells on Earth Prokaryotic cells - Lack a nucleus Eukaryotic cells - Possess a nucleus and other organelles Figure 2.2

3 Domains of Life Three broad categories of organisms Archaea Unicellular prokaryotes Bacteria Unicellular prokaryotes Eukarya Includes both unicellular and multicellular eukaryotes

4 Ascending Non-living Atoms/Elements Molecules Chemical world Organelle Cell Living Tissue Organ Organ system Organism Biological World (Family) Population Community Descending Ecosystem Biosphere

5 Emergent properties of life shared by cells and all levels if the biological organization Order Regulation of internal conditions (Homeostasis)

6 Growth and development Energy use Response to environmental stimuli The ability to reproduce

7 Basic concepts Cells Interact: send, receive, respond to signals aggregate to form tissues, organs and organ systems Health state- balance between cell division and cell death Specialization of cell function- expression of different subsets of genes.

8 Nuclei containing DNA Sperm cell Human Development Unspecialized replicating cells Different specialized cells Egg cell Fertilized egg with DNA from both parents (Zygote) Embyro s cells with copies of inherited DNA Offspring with traits inherited from both parents

9 Human Cells Gametes: sperms and eggs haploid Zygote diploid Somatic cells: body cells diploid Germ cells: gonad cells that produce gametes diploid Meiosis Haploid gametes (n = 23) n Egg cell n Sperm cell Diploid zygote Multicellular (2n = 46) 2n diploid adults (2n = 46) Mitosis and development Fertilization

10 Cellular activities and abnormalities underlie our inherited traits, quirks, and illnesses Figure 2.1 Lack of dystrophin Muscular Dystrophy

11 A animal cell is a living unit greater than the sum of its parts Boundary-plasma membrane Cytoplasm: Compartment (division of labor) o Cytosol (soluble components) o Organelles surrounded by membranes to partition functions Nucleus DNA-information

12 Figure 2.3 Rough endoplasmic reticulum Smooth endoplasmic reticulum NUCLEUS: Nuclear envelope Chromosomes Nucleolus Lysosome Centriole Peroxisome CYTOSKELETON: Microtubule Intermediate filament Microfilament Ribosomes Golgi apparatus Plasma membrane Mitochondrion

13 Role of cell membranes in compartmentalization of cellular functions Hydrophilic head A phospholipid bilayer - Phosphate end (hydrophilic) - Fatty acid chains (hydrophobic) Hydrophobic tail Figure 2.8

14 Compartmentalized functions of animal cells Manufacturing, processing, and shipping of molecules to appropriate destination: DNA, proteins, carbohydrates, lipids Breakdown of molecules: large structures, lipids, detoxification of certain substances Energy processing: forming cellular energy form Structural support, movement, and communication

15 Plasma Membrane Forms a selective barrier Contains proteins, glycoproteins, and glycolipids - Important to cell function and interactions - May be receptors - Form channels for ions Figure 2.3 Figure 2.9

16 Inherited Diseases caused by Faulty Ion Channels Sodium channels - Mutations lead to absence or extreme pain Potassium channels - Mutations lead to impaired heart function and one form of deafness Chloride channels - Mutations lead to cystic fibrosis Reading 2.2, page 27 Figure 2.3

17 A meshwork of protein rods and tubules Includes three major types of proteins - Microtubules - Microfilaments - Intermediate filaments Cytoskeleton Figure 2.3 Figure 2.10

18 Cytoskeleton 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 Figure 2.3

19 Cytoskeleton A network of protein fibers that functions in cell structural support and motility Nucleus Nucleus Actin subunit Fibrous subunits Tubulin subunit 7 nm 10 nm 25 nm Microfilament Intermediate filament Microtubule

20 Inherited Disease caused by faulty connections between the plasma membrane and the cytoskeleton Hereditary Spherocytosis page 29 Figure 2.3

21 The Nucleus The largest structure in a cell Surrounded by a double-layered nuclear envelope Contains: - Nuclear pores that allow movement of some molecules in and out - Nucleolus, which is the site of ribosome production - Chromosomes composed of DNA and proteins Figure 2.3

22 The Nucleus Figure 2.4 Figure 2.3 Figure 2.4

23 Endoplasmic Reticulum (ER) Interconnected membranous tubules & sacs Winds from the nuclear envelope to the plasma membrane Rough ER contains ribosomes and is involved in protein synthesis Smooth ER does not contain ribosomes and is important in lipid synthesis Figure 2.3

24 Golgi Apparatus Stack of flat membrane-enclosed sacs Processing center of added sugars that form glycoproteins and glycolipids Site of final protein folding Products are released into vesicles that bud off to the plasma membrane Figure 2.3

25 Secretion Coordination of function of organelles Figure 2.5 Protein Trafficking

26 Transport vesicle buds off 4 Ribosome Secretory protein inside transport vesicle 1 3 Sugar chain Polypeptide 2 Glycoprotein Rough ER

27 Nucleus Nuclear membrane Rough ER Smooth ER Transport vesicle Transport vesicle Golgi apparatus Lysosome Vacuole Plasma membrane

28 Lysosomes Membrane-bound sacs containing > 40 types of digestive enzymes Break down bacteria, cellular debris, and nutrients Tay-Sachs is an inherited lysosomal storage disorder Figure 2.3 Figure 2.6

29 Lysosomes Membrane-bounded sacs of hydrolytic enzymes that digestive enzymes

30 Peroxisomes Sacs with one membrane filled with several types of enzymes - Break down lipids, rare biochemicals - Synthesize bile acids - Detoxify compounds from free radicals, H 2 O 2, and alcohol - Abundant in liver and kidney cells Lorenzo s oil Adrenoleukodystrophy absence of a peroxisomal enzyme leads to accumulation of long-chain fatty acids in brain and spinal cord Figure 2.3

31 Mitochondria Surrounded by two membranes Site of ATP (energy) production Contain their own circular DNA Human mitochondrial DNA is inherited only from the mother Figure 2.7 Lou Gehrig Disease Figure 2.3

32 Structures and Functions of Organelles Table 2.1

33 Prokaryotic & Eukaryotic Animal and Plant cells Secretion