Unit 2 Cells & Viruses

Cells

SB1. Students will analyze the nature of the relationships between structures and functionsin living cells. Explain the role of cell organelles for both prokaryotic and eukaryotic cells, including the cell membrane, in maintaining homeostasis and cell reproduction.SB3. Students will derive the relationship between single-celled and multi-celled organismsand the increasing complexity of systemsCompare and contrast viruses with living organisms.

22 Clicker Questions..Get Ready!1Cell DiscoveryHow did cells get their name?

Robert Hooke (1665) Looked at a piece of cork under his microscope Looked like little chambers in a monastery The monks lived in chambers called cells Hooke called the chambers in the cork cells Were, in fact, cell walls of dead plant cells

2Cell DiscoveryWho saw the first living cells?

van Leeuwenhoek (1678) Father of Microbiology Improved microscope design First to observe and describe microorganisms Called them animalcules

3Scientific MethodWhat is the difference between a hypothesis, theory, and a law?Theory: A theory is an explanation of a set of related observations or events based upon proven hypotheses and verified multiple times by detached groups of researchers. One scientist cannot create a theory; he can only create a hypothesis. (Example: Theory of Relativitypertains to gravity, time, & space)Hypothesis: This is an educated guess based upon observation. It is a rational explanation of a single event or phenomenon based upon what is observed, but which has not been proved. Most hypotheses can be supported or refuted by experimentation or continued observation. Law: In general, both a scientific theory and a scientific law are accepted to be true by the scientific community as a whole. But law describes a single action where a theory explains an entire group of related phenomena. (Example: Law of Gravitypertains to gravity alone)4Cell Theorydeveloped by Schwann and Schleiden (1835); Virchow (1855)All living organisms are composed of one or more cells.Cells are the basic unit of structure and function in all living organisms.Cells arise only from previous existing cells, with cells passing copies of their genetic material on to their daughter cells.

5Clicker Question #1Who gave cells their name?

Charles Darwin Robert Hooke Albert Einstein Gregor Mendel 6Clicker Question #2Which of the following best describes a theory?

It is an ideaIt is a statement based on an observationIt describes a single action in science and is accepted by all scientistsIt is a scientifically accepted explanation based on a hypothesis that has been verified by many scientists

7Clicker Question #3Which of the following statements is supported by the Cell Theory to identify if an amoeba is composed of a cell?

Amoebas have the ability to split to create another genetically identical amoeba.Amoebas can move and hunt for food.Amoebas need oxygen.Amoebas must eat.8Cell MembraneWhat is the cell (plasma) membrane? A phospholipid bi-layer that separates the inside of the cell from the outside environment It is semi-permeable, which means that only certain substances can pass freely through

9CytoplasmWhat is the cytoplasm? A thick gel-like solution of water, salts, and proteins that fills the interior of cells

10NucleusWhat is a nucleus? A distinct central organelle that contains the cells genetic information in the form of DNA. Controls all of the cells activities

11Basic Cell TypesWhat are the two basic types of cells?1. Prokaryotic: Cells do NOT have a nucleus or organelles. Example: ALL BacteriaE. coli, Strep, & Salmonella

How to Remember TrickPro has NO nucleus12ProkaryotesHave NO nucleus

Have nucleoid (like a nucleusbut not a real one) with DNA in a circular plasmid

Have almost NO organelles(but they DO have ribosomes)

REMEMBER.Pro has NO nucleus13Basic Cell TypesWhat are the two basic types of cells?2. Eukaryotic: Cells HAVE a nucleus and organelles. Examples: Plants, animals, fungusAll other cells

How to Remember TrickEu has TRUE nucleus14

EukaryotesHave a true/real nucleus

Have many different organellesEu has TRUE nucleusREMEMBER.15Clicker Question #4If a cell has a nucleus, it is considered a(n):

Prokaryote Eukaryote Plant Animal16Clicker Question #5If a cell does NOT have a nucleus, it is considered a(n):

Prokaryote Eukaryote Plant Animal17Clicker Question #6Which of the following is an example of an eukaryote?

a virus Staphylococcus a sunflower bacteria18Clicker Question #7Which of the following is an example of a prokaryote?

mushrooms Escherichia coli an oak tree humans19 Cell Organelles Function More Info Found inCytoskeletonRibosome

Endoplasmic ReticulumGolgi ApparatusLysosome20CytoskeletonDefined: Supporting network of protein fibers that provide a framework for the cell within the cytoplasm

Function: Aids in cell & organelle movement & support

2 substructures: Microtubules & Microfilaments (euk only)

21CytoskeletonSupporting networkMicrofilaments & MicrotubulesProkaryotes and eukaryotesRibosome

Endoplasmic ReticulumGolgi ApparatusLysosome Cell Organelles Function More Info Found in22RibosomeDefined: Simple cell organelle that helps manufacture proteins.

Function: Synthesizes/make proteinsCan be found attached to E.R. or free in the cell

23CytoskeletonSupporting networkMicrofilaments & MicrotubulesProkaryotes and eukaryotesRibosome

Make proteinsFree & attachedProkaryotes and eukaryotesEndoplasmic ReticulumGolgi ApparatusLysosome Cell Organelles Function More Info Found in24Endoplasmic ReticulumDefined: Highly folded membrane system in eukaryotic cells that is the site for protein and lipid synthesis.

Function: Rough ER synthesizes proteins Smooth ER synthesizes lipids

25CytoskeletonSupporting networkMicrofilaments & MicrotubulesProkaryotes and eukaryotesRibosome

Make proteinsFree & attachedProkaryotes and eukaryotesEndoplasmic ReticulumTransport systemRough ER (ribosomes attached)Smooth ER(No ribosomes attached)

EukaryotesGolgi ApparatusLysosome Cell Organelles Function More Info Found in26Golgi ApparatusDefined: Flattened stack of tubular membranes that modifies, sorts, and packages proteins into vesicles and transports them to another organelle or out of the cell.

Function: Modifies and packages proteins

27CytoskeletonSupporting networkMicrofilaments & MicrotubulesProkaryotes and eukaryotesRibosome

Make proteinsFree & attachedProkaryotes and eukaryotesEndoplasmic ReticulumTransport systemRough ER (ribosomes attached)Smooth ER(No ribosomes attached)

EukaryotesGolgi ApparatusModifies & packages proteinsCreate lysosomesEukaryotesLysosome Cell Organelles Function More Info Found in28LysosomeDefined: Vesicle produced by the Golgi that uses enzymes to digest excess or worn-out cellular substances.

Function: Digests

29CytoskeletonSupporting networkMicrofilaments & MicrotubulesProkaryotes and eukaryotesRibosomes

Make proteinsFree & attachedProkaryotes and eukaryotesEndoplasmic ReticulumTransport systemRough ER (ribosomes attached)Smooth ER(No ribosomes attached)

EukaryotesGolgi ApparatusModifies & packages proteinsCreate lysosomesEukaryotesLysosomesDigests food & dead organellesFilled with enzymesEukaryotes Cell Organelles Function More Info Found in30Clicker Question #8This organelle is composed of microfilaments and micotubules:

Lysosome Ribosome Cytoskeleton Endoplasmic reticulum31Clicker Question #9This organelle synthesizes proteins:

Lysosome Ribosome Cytoskeleton Endoplasmic reticulum32Clicker Question #10This organelle modifies proteins:

Lysosome Ribosome Golgi Apparatus Endoplasmic reticulum33Clicker Question #11This organelle is filled with enzymes for digestion purposes:

Lysosome Ribosome Golgi Apparatus Endoplasmic reticulum34MitochondrionDefined: Double membraned organelle that converts fuel into energy (ATP) that is available to the rest of the cell.

Function: Converts food into energy = Cellular respiration

35VacuoleCilia &FlagellaMitochondrionConverts food into energyCellular RespirationProduces ATPEukaryotesChloroplastCell Wall Cell Organelles Function More Info Found in36ChloroplastDefined: Double-membraned organelle that captures light energy & converts it to chemical energy (glucose) through photosynthesis.

Function: Converts light, H2O, & CO2 into food = Photosynthesis

37VacuoleCilia &FlagellaMitochondrionConverts food into energyCellular RespirationProduces ATPEukaryotesChloroplastMakes food from sunlightPhotosynthesisContains chlorophyll Plants ONLYCell Wall Cell Organelles Function More Info Found in38Cell WallDefined: A rigid barrier that surrounds the outside of the plasma membrane

Function: Provides support and protection

OrganismCell Wall is made of:PlantsCelluloseBacteriaPeptidoglycanFungiChitin39VacuoleCilia &FlagellaMitochondrionConverts food into energyCellular RespirationProduces ATPEukaryotesChloroplastMakes food from sunlightPhotosynthesisPlants ONLYCell WallSupports & protectsNOT found in animals!PlantsBacteriaFungi Cell Organelles Function More Info Found inContains chlorophyll40VacuoleDefined: Vesicle for temporary storage of materials such as food, water, enzymes, and wastes.

Function: Storage (in all plants and fungi, some others)

41VacuoleCilia &FlagellaMitochondrionConverts food into energyCellular RespirationProduces ATPEukaryotesChloroplastMakes food from sunlightPhotosynthesisPlants ONLYCell WallSupports & protectsNOT found in animals!PlantsBacteriaFungiStores water, food, & wasteVery large in plantsSome eukaryotes and prokaryotes Cell Organelles Function More Info Found inContains chlorophyll42Cilium & FlagellumCilia: Hair-like projections that function in cell movement or sensory

Flagellum: Long tail-like projection with a whip-like motion that helps a cell swim.

Flagella

43VacuoleCilium &FlagellumMitochondrionConverts food into energyCellular RespirationProduces ATPEukaryotesChloroplastMakes food from sunlightPhotosynthesisPlants ONLYCell WallSupports & protectsNOT found in animals!PlantsBacteriaFungiStores water, food, & wasteVery large in plantsSome eukaryotes and prokaryotes

Aids in movementCilia (many hairlike)Flagella (whip like)Prokaryotes and eukaryotes Cell Organelles Function More Info Found inContains chlorophyll44Clicker Question #12These are hair-like and aid cells in swimming/locomotion:

Cilia Flagella Flagellum Tails45Clicker Question #13Photosynthesis occurs here:

Chloroplast Mitochondria Cell Wall Vacuole46Clicker Question #14These two organelles are NOT found in animal cells:

Chloroplast & Mitochondria Cilia & Vacuoles Cell Wall & Chloroplast Mitochondria & Vacuoles47Clicker Question #15These are very large in plants and provides support when filled with water:

Chloroplast Mitochondria Cell Wall Vacuole48Clicker Question #16Which of the following has a cell wall?

Mushroom Sunflower E. coli All of the above49Endosymbiotic Theory Endosymbiotic Theory proposes that eukaryotic cells arose from living communities formed by prokaryotic organisms.

Endo- means inside

-symbiotic means a relationship where both partners benefit

50Endosymbiotic Theory Prokaryotes entered ancestral eukaryotes

Prokaryotes did NOT act as a parasite by infecting the host (eukaryote)

Eukaryotes did NOT digest the prokaryotes

Instead, the smaller prokaryotes began LIVING inside the larger cell giving rise to eukaryotes51

52Evidence Supporting the Endosymbiotic Theory1st - Mitochondria & Chloroplasts have DNA similar to bacterial DNA.

2nd Mitochondria & Chloroplasts have ribosomes whose size & structure resembles those of bacteria.

3rd Like bacteria, Mitochondria & Chloroplasts reproduce by binary fission when the cells containing them divide by mitosis.

Click Here For Animation Tutorial53Clicker Question #17Which of the following summarizes the Endosymbiotic Theory?

Mitochondria & chloroplasts in eukaryotes were once prokaryotes Ribosomes & lysosomes in eukaryotes were once prokaryotes Mitochondria & chloroplasts are now found inside prokaryotes None of the above54Clicker Question #18Which of the following are true?

Mitochondria has DNA similar to prokaryotesRibosomes in eukaryotes are similar to prokaryotes When mitochondria create more of themselves, they divide similar to how prokaryotes divideAll of the above55VirusesVirus comes from the Latin word for poison

Viruses are particles of nucleic acid, protein, and in some cases lipids, that can reproduce only by infecting living cells.

Viruses are so small that they can only be seen using an electron microscope.

AIDS VirusFlu Virus

Ebola Virus

Bacteriaphage56VirusesViruses have NO organelles!

A typical virus is composed of a core of either DNA or RNA surrounded by a protein coat.

Common Cold Virus

Small Pox Virus

Polio Virus

Herpes Virus57VirusesA viruss outer protein coat is called its capsid.

A capsid is an outer protein coat that enables a virus to enter a host cell.

The capsid binds to the surface of a cell and tricks the cell into allowing it inside.

58VirusesOnce inside the cell, the viral genes take over.

The cell transcribes (reads and copies) the viral genes, putting the genetic program of the virus into effect.

And often times the virus destroys the host cell

Viral Infection Animation59Viruses Vaccine: A preparation of a weakened or killed pathogen, upon injection, stimulates antibody production or cellular immunity against the pathogen but is incapable of causing severe infection (sickness).

A world wide vaccination program was able to eliminate smallpox!

Antibiotics NEVER cure viral infections!!...ONLY Bacteria

Click here to compare size!

Small pox60Compare & Contrast Cells & Viruses

Bacteria(cells)VirusesBoth Has organelles Reproduces on their own Has NO organelles Must have host to reproduce Large in size Extremely small in size DNA or RNA Cause disease Capsid for protection Cell wall for protection61Clicker Question #19Which of the following statements is true about viruses?

Viruses do not have DNA Viruses must have a host to reproduce Antibiotics kill viruses Viruses have organelles62Clicker Question #20Which of the following is the smallest?

White blood cell Pollen Bacteria Virus63Clicker Question #21Which of the following do viruses NOT have?

Organelles Capsid Genetic material They have all of the above64Clicker Question #22DNA is located here:

Chloroplast Nucleus Lysosomes Vacuoles65The End66Answers1. B6. C11. A16. D2. D7. B12. A17. A3. A8. C13. C18. D4. B9. B14. D19. B5. A10. C15. B20. D 21. A22. B

67