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 & vescilcesf. 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

Types of Cells on Earth

Prokaryotic cells- Lack a nucleus

Eukaryotic cells- Possess a nucleus and other organelles

Figure 2.2

Domains of Life• Three broad categories of organisms

• Archaea – Unicellular prokaryotes

• Bacteria – Unicellular prokaryotes

• Eukarya – Includes both unicellular and multicellular eukaryotes

Atoms/Elements

Molecules

Organelle

Cell

Tissue

Organ

Organ system

Organism(Family)

Population

Community

Ecosystem

Biosphere

Chemical world

Biological W

orld

Non-living

Living

Ascending

Descending

Emergent properties of life shared by cells and all levels if the biological organization

• Order• Regulation of internal conditions (Homeostasis)

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

Basic concepts

• Cells Interact: send, receive, respond to signalsaggregate 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.

Human Development

Sperm cell

NucleicontainingDNA

Egg cell

Fertilized eggwith DNA fromboth parents

(Zygote)

Embyro’s cells with copies of inherited DNA

Offspring with traitsinherited fromboth parents

Unspecialized replicating

cells

Different specialized

cells

Human Cells Gametes:

• sperms and eggs• haploid

Zygote• diploid

Somatic cells: • body cells • diploid

Germ cells:• gonad cells that

produce gametes• diploid

Mitosis and development

Multicellulardiploid adults

(2n = 46)

Diploidzygote

(2n = 46) 2n

Meiosis Fertilization

Egg cell

Sperm cell

n

Haploid gametes (n = 23)

n

• Cellular activities and abnormalities underlie our inherited traits, quirks, and illnesses

Lack ofdystrophin

Figure 2.1

Muscular Dystrophy

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

Smooth endoplasmicreticulum

Roughendoplasmicreticulum

CYTOSKELETON:

NUCLEUS:Nuclear envelopeChromosomesNucleolus

Ribosomes

Golgiapparatus

Plasma membrane

Mitochondrion

Peroxisome

Centriole

Lysosome

MicrotubuleIntermediatefilamentMicrofilament

Figure 2.3

Role of cell membranes in compartmentalization of cellular

functions

Hydrophilic head

Hydrophobic tail

Figure 2.8

A phospholipid bilayer- Phosphate end (hydrophilic)- Fatty acid chains (hydrophobic)

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

Figure 2.3

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 2.9

Figure 2.3

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

CytoskeletonA meshwork of protein

rods and tubulesIncludes three major

types of proteins- Microtubules- Microfilaments- Intermediate filaments

Figure 2.10

Figure 2.3

Cytoskeleton FunctionsMaintain 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

A network of protein fibers that functions in cell structural support and motility

Cytoskeleton

Microfilament

Actin subunit

7 nm

Intermediate filament

Fibrous subunits

10 nm

Microtubule

Tubulin subunit

25 nm

Nucleus

Nucleus

Figure 2.3

Inherited Disease caused by faulty connections between the plasma membrane and the

cytoskeleton

Hereditary Spherocytosis page 29

Figure 2.3

The NucleusThe largest structure in a cellSurrounded by a double-layered nuclear

envelopeContains:

- 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

Figure 2.4

The Nucleus

Figure 2.4

Figure 2.3

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

Golgi ApparatusStack 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

SecretionCoordination of function of organelles

Figure 2.5

Protein Traffickinghttp://vcell.ndsu.edu/animations/proteintrafficking/movie-flash.htm

Transport vesiclebuds off

Secretoryproteininside trans-port vesicle

GlycoproteinPolypeptide

Ribosome

Sugarchain

Rough ER

1

2

3

4

Nucleus

VacuoleLysosome Plasma membrane

Smooth ER

Nuclearmembrane

Golgiapparatus

Rough ER

Transportvesicle

Transportvesicle

Figure 2.3

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

http://www.ygyh.org/tay/whatisit.htm Figure 2.6

Lysosomes• Membrane-bounded sacs of hydrolytic enzymes

that digestive enzymes

http://highered.mcgraw-hill.com/sites/0072437316/student_view0/chapter5/animations.html#

Figure 2.3

PeroxisomesSacs with one membrane filled with several types of

enzymes- Break down lipids, rare biochemicals- Synthesize bile acids- Detoxify compounds from free radicals, H2O2, and

alcohol- Abundant in liver and kidney cells

Lorenzo’s oilAdrenoleukodystrophy absence of a peroxisomal enzyme leads

to accumulation of long-chain fatty acids in brain and spinal cord

Figure 2.3

MitochondriaSurrounded by two

membranes Site of ATP (energy)

productionContain their own

circular DNAHuman mitochondrial

DNA is inherited only from the mother

Lou Gehrig Disease

Figure 2.7

Structures and Functions of Organelles

Table 2.1

Prokaryotic & Eukaryotic Animal and Plant cellshttp://www.wisc-

online.com/objects/index.asp?objID=AP11604

Secretionhttp://www.youtube.com/watch?v=MrHULUxAsGg