1. Understand & describe the basic components necessary for a functional cell. 2. Review the order of appearance of cells on earth and explain the

endosymbiotic theory. 3. Compare and contrast prokaryotic and eukaryotic cells 4. Review the emergent functional properties of a eukaryotic cells. 5. Review the structure of membranes and explain the importance of different

proteins for creating intracellular membranous compartments where different cellular functions can take place.

6. Identify the components of the cytoskeleton and their role in cellular structural support, movement, and communication.

7. Describe the flow of genetic information within a living cell from DNA into proteins and the processes involved.

8. Explain the structure and role of membranes in compartmentalization of eukaryotic cell functions.

9. Identify the cellular organelles of the endomembrane system and the role of each in the manufacture and breakdown of important cellular molecules and intracellular trafficking of biomolecules.

10.Identify the cellular organelles that are involved in energy transformation and recycling of matter and the forms of energy and matter they transform.

11.Identify peroxisomes and their cellular function. 12.Explain the source and importance of the extracellular matrix and intercellular

junctions.

Cell (Learning Objectives)

Cell (Outline) - Components of a functional cell - Major Events in the History of Earth: abiotic and biotic phases;

anaerobic and aerobic atmosphere - Prokaryotic cells impact on the biosphere - Origin of Eukaryotic cells - Emergent properties of eukaryotic cells: animal and plant cells - Role of cellular membranes: external and internal - Cytoskeleton: structure and functions - Flow of genetic information: DNA to protein - The endo-membrane system - Other organelles: Fatty acid metabolism and Energy Processing - Cell surface and extracellular matrix

Components of a functional cell

• Boundary-membrane • Cytoplasm: Cytosol (soluble components)

& particulates • DNA-information • Ribosomes-protein synthesis

Major Events in the History of Earth Cenozoic

Humans

Land plants

Animals

Multicellular eukaryotes

Single-celled eukaryotes

Origin of solar system and Earth

1

2

4

3

Proterozoic eon

Archaean eon

Atmospheric oxygen

Prokaryotes

Anaerobic

Aerobic

Copyright © 2002 Pearson Education, Inc., publishing as Benjamin Cummings

Prokaryotic Cell Structure

Eukaryotic Cell Structure

Evolution of larger Eukaryotic cells increase in

surface area/volume ratio

“The Endo-symbiotic Theory”

Cenozoic

Humans

Land plants

Animals

Multicellular eukaryotes

Single-celled eukaryotes

Origin of solar system and Earth

1

2

4

3

Proterozoic eon

Archaean eon

Atmospheric oxygen

Prokaryotes

• For single-celled organisms- - physical force of diffusion of material in and out of

the cells. - Increase in size is limited by surface area : volume ratio

• For multi-cellular organisms - Number of cells increases size. - Individual cells vary in size

Size Limitations

The Endo-symbiotic Theory:

Origin of Eukaryotes

Engulfing of photosynthetic prokaryote

Chloroplast

Mitochondrion

Some cells

Host cell

Mitochondrion

Host cell Engulfing of aerobic prokaryote

Ancestral eukaryotic cells two or more prokaryotic cells in a state of endo-symbiosis:

• animal cell- 2 different prokaryotes

• plant cell- 3 different prokaryotes

Differ in - size - complexity - internal membrane, creating

organelles

(Sub-cellular compartments where different cell functions of eukaryotic cells are carried out)

Comparing Prokaryotic and Eukaryotic Cells

Emergent Properties of Eukaryotic cells

Functions – Structural support, movement, and

communication – Manufacturing of molecules – Breakdown of molecules – Energy processing

Eukaryotic cells structures and organelles

specialize for functions

Cell Animation

Copyright © 2002 Pearson Education, Inc., publishing as Benjamin Cummings

Role of Cell membranes in Compartmentalization of cellular

functions

A. Plasma membrane - Boundary of the cell - Surrounds the cytoplasm - Selective barrier - Allows passage of oxygen, nutrients, and wastes.

B. Internal membranes of eukaryotes

Partitioning the cell into compartments

- Sites of metabolic

reactions, enzymes - Local environments

that facilitate specific metabolic functions

The cytoskeleton is 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

Cytoskeleton fibers

Microtubules: cell shape, movement of organelles, chromosome separation during cell division, and cilia and flagella (hollow/tubulin)

Microfilaments three-dimensional network just inside the

plasma membrane (actin) Actin and myosin/cell motility and cytoplasmic flow http://staffa.wi.mit.edu/microscopy/macrophage.shtml http://www.nytimes.com/2009/06/09/science/09cell.html?_r=1 Intermediate filaments They reinforce cell shape and fix

organelle location (keratin)

Components of the cytoskeleton pull past each other

Vesicles or organelles carried to various destinations along “monorails’ of microtubules.

The Flow of Genetic Information: The “Central Dogma” of Molecular Biology

The sequence of bases in DNA determines the sequence of amino acids in proteins - DNA codes for the production of messenger RNA. - Messenger RNA codes for the production of protein. - Proteins do not code for the production of protein, RNA or DNA

Cell organelles and structures involved with the flow of genetic information

• Nucleus • Ribosomes

• Home of most genetic material (DNA)

• Double membrane with pores, nuclear envelope

• Shape maintained by nuclear lamina, a network of protein filaments

Nucleus

The Nucleus: • Site of transcription of messenger RNA

(mRNA) The nucleolus • Site of ribosomal RNA (rRNA)synthesis

and ribosome assembly

Ribosomes • Made of rRNA and protein. • two subunits that combine to carry out protein

synthesis • Number of ribosomes vary between cells • Free and bound ribosomes (to endoplasmic

reticulum)

The Endomembrane System Sub-cellular components

Nuclear envelope Endoplasmic reticulum Golgi apparatus Vesicles Lysosomes Vacuoles Plasma membrane

Function - Sites of certain metabolic functions in the cell (Synthesis, modification, & breakdown of macromolecules) - Regulation of protein traffic within the cell

Two connected regions of ER that differ in structure and function. – Smooth ER

(No ribosomes) – Rough ER

(bound ribosomes) are attached to the outside

Smooth ER Contains enzymes for – synthesis of lipids, phospholipid, steroids – Metabolism of carbohydrates – Detoxification of poison – Storage of Ca+2 for in muscle cells (necessary

for contraction)

Rough ER (membrane factory) - Produces proteins and membranes for

transport by vesicles, destined for secretion - Membrane-embedded and secretory proteins - Site of protein glycosylation (glycoproteins)

Transport vesicle buds off

Secretory protein inside trans- port vesicle

Glycoprotein Polypeptide

Ribosome

Sugar chain

Rough ER

1

2

3

4

The Golgi Apparatus • Finishing, sorting, and shipping cell products • Transport vesicles from the ER travel to the Golgi

apparatus for modification of their contents • Extensive in cells specialized for secretion. http://vcell.ndsu.edu/animations/proteintrafficking/movie-

flash.htm

Lysosomes • Digestive compartment within the cells. Membrane-

bounded sacs of hydrolytic enzymes that digests large particles made of macromolecules: proteins, fats, polysaccharides, and nucleic acids.

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

The lysosomal enzymes and membrane are synthesized by rough ER and then transferred to the Golgi.

Vacuoles

• Larger versions of vesicles • Many functions in cell maintenance

– Food vacuoles – Contractile vacuoles, found in freshwater

protists, pump excess water out of the cell. – Central vacuoles- mature plant cells storage

of some pigments.

Other Membranous Organelles not part of the endomembrane system

• Peroxisomes – generate and degrade H2O2 in performing various

metabolic functions – Fatty Acid metabolism

• Mitochondria and chloroplasts- sites of energy transformation from one form to another and of recycling of matter - Mitochondria (respiration) are present in animal &

plant cells - Chloroplasts (photosynthesis) only in plant cells

Peroxisomes

• A single membrane • Abundant in liver and

kidney - breakdown of fatty

acids for transport to mitochondria for fuel

- detoxify alcohol and other harmful compounds.

- Conversion of fatty acids in seeds to sugars.

Mitochondria and Chloroplasts

• Contain their own ribosomes and cytosol • Contain small quantities of DNA that direct

the synthesis of the polypeptides produced by these internal ribosomes.

• Grow and reproduce as semi-autonomous organelles

• Not part of the endomembrane system

• Matrix-contains DNA and ribosomes

• Cristae-contains enzymes for ATP generation during cellular respiration

Mitochondria Video (4)

Chloroplasts • Present in plants and eukaryotic algae are the • Sites of photosynthesis-production of sugar from

CO2 and water (high levels of the green pigment chlorophyll)

• Mitochondria and chloroplasts - dynamic structures. - mobile and move around the cell along

tracks in the cytoskeleton. - have double membranes.

Cytoplasmic Streaming Video Campbell

Review of Functional Compartments of Eukaryotic cells

• Structural support, movement, and communication: cytoskeleton, plasma membrane, and cell wall

• Manufacturing: nucleus, ribosomes, endoplasmic reticulum, and Golgi apparatus • Breakdown of molecules: lysosomes, vacuoles, and

peroxisomes

• Energy processing: chloroplasts & mitochondria

• Cell wall in some organisms proteins and polysaccharides, in plant cells

• The extracellular matrix (ECM) proteins and polysaccharides, in animal cells

• Extracellular components and connections between cells help coordinate cellular activities

Cell Surfaces

Polysaccharide molecule

Carbo- hydrates

Proteoglycan molecule

Core protein

A proteoglycan complex

Functions of the ECM include – Support – Adhesion – Movement – Regulation

EXTRACELLULAR FLUID

Microfilaments

Collagen fiber

Connecting glycoprotein

Integrin

Plasma membrane

Glycoprotein complex with long polysaccharide

CYTOPLASM

Intercellular junctions

• Plants- Plasmodesmata

• Animals- Tight junctions Desmosomes Gap junctions

Activity: Cell Junctions