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Unit 4 Cells Unit 4 Cells

Discovery of the Cell § § § Robert Hooke: coined the term “cell”. He Discovery of the Cell § § § Robert Hooke: coined the term “cell”. He was actually looking at cell walls. Anton Van Leeuwenhoek: developed the first microscope; was the 1 st to look at cells Mathias Schleiden: botanist, stated all plants are made up of cells Theordore Schwann: zoologist, stated all animals are made up of cells. Rudoulf Virchow: stated all living cells come from other living cells.

 • These scientists along with others helped to develop the “Cell Theory” • • These scientists along with others helped to develop the “Cell Theory” • 3 Main ideas of the Cell Theory: 1. All organisms are composed of one or more cells 2. The cell is the basic unit of organization of organisms 3. All cells come from preexisting cells

Exploring Cells Using Microscopes • Compound Light Microscope—can magnify up to 1, 500 times—used Exploring Cells Using Microscopes • Compound Light Microscope—can magnify up to 1, 500 times—used to view living cells, small organisms and preserved cells • SEM (scanning electron microscope)—can magnify up to 60, 000 times—used to view surface of cells • TEM (transmission electron microscope)—can magnify up hundreds of thousands of times—used to view structures inside the cell • Stains and dyes may be used on specimens so that certain structures can be viewed better

Light microscope image of amoeba Magnified 100 x Light microscope image of amoeba Magnified 100 x

SEM image of housefly SEM image of housefly

SEM of spider SEM of spider

Basic Cell Types 1. Prokaryotes 2. Eukaryotes Basic Cell Types 1. Prokaryotes 2. Eukaryotes

1. v v v Prokaryotes: small unicellular evolved first no nucleus no membrane bound 1. v v v Prokaryotes: small unicellular evolved first no nucleus no membrane bound organelles v circular DN v ex. bacteria

Basic Cell Types 2. Eukaryotes: v unicellular or multicellular v has nucleus v has Basic Cell Types 2. Eukaryotes: v unicellular or multicellular v has nucleus v has membranebound organelles v linear DNA v ex. plants, animals, yeast, algae

Both Contain: • Cell membrane • Ribosomes • Cytoplasm • DNA & RNA **Prokaryotes Both Contain: • Cell membrane • Ribosomes • Cytoplasm • DNA & RNA **Prokaryotes have circular DNA called plasmids **Eukaryotes have DNA in the Nucleus

Prokaryote & Eukaryote Recap • Prokaryote---No true nucleus, smaller than eukaryotes, simple, no membrane Prokaryote & Eukaryote Recap • Prokaryote---No true nucleus, smaller than eukaryotes, simple, no membrane bound organelles, circular DNA strands called plasmids, example: bacteria • Eukaryote--- True nucleus, larger than prokaryotes, complex, membrane bound organelles, DNA found in nucleus, example: plant and animal cells • Both---Ribosomes, DNA/RNA, cytoplasm, cell membrane

Cell Membrane aka. Plasma Membrane “Gatekeeper” • Function – separates cell from its environment Cell Membrane aka. Plasma Membrane “Gatekeeper” • Function – separates cell from its environment – maintains homeostasis – controls what enters or leaves cell (has selective permeability) – recognizes signals from other cells – allows communication between cells

Cell Membrane • Structure Made up of 2 layers of phospholipids (lipid bilayer) 1. Cell Membrane • Structure Made up of 2 layers of phospholipids (lipid bilayer) 1. Polar Head (phosphate)—exposed to water (head is hydrophilic…love water)-polar 2. Nonpolar Tail (fatty acid)—not exposed to water-- (tail is hydrophobic…avoids water)--nonpolar phosphate “head” lipid “tail”

The model of the plasma membrane is called the fluid mosaic model—because it is The model of the plasma membrane is called the fluid mosaic model—because it is flexible (it can move and flow), also due to the proteins embedded in the membrane

v. Extracellular—refers to anything outside of the cell v. Intracellular—refers to anything inside of v. Extracellular—refers to anything outside of the cell v. Intracellular—refers to anything inside of the cell Transport Proteins—these create the selective permeable membrane—they allow materials to move through the membrane

Movement MOVEMENT • Flagella: whip like structure • Cilia: hair like structures Both structures Movement MOVEMENT • Flagella: whip like structure • Cilia: hair like structures Both structures help cells with locomotion.

Inside the Cell Inside the Cell

Organelles “little organs” • Specialized structures inside EUKARYOTIC cells – each structure has a Organelles “little organs” • Specialized structures inside EUKARYOTIC cells – each structure has a job to do

 • Nucleus: It is the “Control Center” or “Brains” of the cell. The • Nucleus: It is the “Control Center” or “Brains” of the cell. The nucleus directs all activities of the cell. • Nucleolus: Plays an indirect role in making proteins. Found inside the nucleus. • Nuclear Membrane: Enables the nucleus to maintain a different environment. Organelles in the Cell

Other Cellular Organelles • Chlorophyll: Green pigment in plants • Chloroplast: contains the green Other Cellular Organelles • Chlorophyll: Green pigment in plants • Chloroplast: contains the green pigment used in photosynthesis (only in plants) HAS ITS OWN DNA! • Cell wall: provides protection and support for the cell. (Plants only) • Cell membrane or plasma membrane: found in plants and animals. Function is to regulate movement of materials in and out of the cell. “Gate keeper” and “Maintains Homeostasis”

More Organelles in the Cell • Cytoplasm: clear gel-like material. Carries on anaerobic respiration. More Organelles in the Cell • Cytoplasm: clear gel-like material. Carries on anaerobic respiration. (Life functions are carried out in the cytoplasm) • Golgi Bodies: Sorts and packages proteins for transport out of the cell “Post Office” • Centrioles: (Animals only) important in reproduction and cell division • Ribosomes: site for making proteins (protein synthesis). “Protein Factory”

More Cell Organelles • Endoplasmic Reticulum: Involved in making and transporting proteins (2 types More Cell Organelles • Endoplasmic Reticulum: Involved in making and transporting proteins (2 types Smooth and Rough) Ribosomes attached to the Rough ER • Mitochondria: site of cellular respiration “Power House” HAS ITS OWN DNA **Cristae (folded inner membrane) of mitochondria that increases surface area for energy productions—more ATP

Mitochondria are in both cells!! animal cells plant cells mitochondria chloroplast Mitochondria are in both cells!! animal cells plant cells mitochondria chloroplast

More Cell Organelles • Vacuole: storage of food, enzymes and things needed by the More Cell Organelles • Vacuole: storage of food, enzymes and things needed by the cell. “Store House” – ***Generally larger in plant cells. *** • Lysosomes: contain digestive enzymes sometimes referred to as “suicide sacs” gets rid of cell wastes

PLANT CELLS • Cell wall • Chloroplasts • Large Central Vacuoles • No centrioles PLANT CELLS • Cell wall • Chloroplasts • Large Central Vacuoles • No centrioles

nucleus control cell protects DNA cytoplasm jelly-like material around organelles mitochondria make ATP in nucleus control cell protects DNA cytoplasm jelly-like material around organelles mitochondria make ATP in cellular respiration cell membrane cell boundary controls movement of materials in & out recognizes signals ribosomes make proteins central vacuole storage: food, water or waste cell wall support chloroplast make ATP & sugars in photosynthesis

What structures do Animal Cells lack? Plant cells? What structures do Animal Cells lack? Plant cells?

Cellular Levels of Organization Cells Tissues Organ System Organism Cellular Levels of Organization Cells Tissues Organ System Organism

 • All living things are made of one or more CELLS. • Humans, • All living things are made of one or more CELLS. • Humans, plants, animals, and bacteria.

Cell Differentiation • All cells begin undifferentiated/nonspecialized • All cells in an organism contain Cell Differentiation • All cells begin undifferentiated/nonspecialized • All cells in an organism contain the same DNA • As cells grow certain proteins are made that allow specific genes in the cell to be expressed

Cell Differentiation Cont. • Differentiation = specific parts of DNA are activated “turned on”; Cell Differentiation Cont. • Differentiation = specific parts of DNA are activated “turned on”; Only certain genes are expressed • Parts of DNA that are activated determine the function and specialized structure of a cell

Cell Specialization • As cell go through differentiation they become specialized (specialization) • That Cell Specialization • As cell go through differentiation they become specialized (specialization) • That cell develops a particular structure or shape to performs a specific function • Each cell has a unique shape, size and features allowing it to do its job accurately

Specialized Cells The shape of a cell is often related to its function: Ex. Specialized Cells The shape of a cell is often related to its function: Ex. --Neurons (nerve cells) are long and thin and able to send information from one part of the body to another Red Blood Cells have a flattened/round shape so they can flow easily through blood vessels to carry oxygen throughout the body Sperm Cells have a strong tail and distinctive shaped head to help them travel to the egg and enter it for fertilization Muscle Cells Long, skinny cells that lengthen and shorten to move muscles

The Nerve Cell The Nerve Cell

Red Blood Cells Red Blood Cells

Sperm Cells Head contains enzymes & nucleus Designed to Fertilize eggs Found in the Sperm Cells Head contains enzymes & nucleus Designed to Fertilize eggs Found in the Testes Tail

Muscle Cells Muscle Cells

Chapter 7 Review Questions Chapter 7 Review Questions

Stem Cells • Cells that have not gone through differentiation or specialization • They Stem Cells • Cells that have not gone through differentiation or specialization • They have not develop a specific shape for a specific function • Only stem cells can differentiate into one or more types of specialized cells.

Types of Stem Cells • There are 2 types of Stem Cells: 1. Adult Types of Stem Cells • There are 2 types of Stem Cells: 1. Adult Stem Cells—found in adults in their bone marrow 2. Embryonic Stem Cells—found in embryos v Both embryonic and adult, with the right laboratory culture conditions, can differentiate into specialized cells.

Where are Stem Cells? Where are Stem Cells?

Cord Blood Cell Banking? • The blood found in an umbilical cord immediately after Cord Blood Cell Banking? • The blood found in an umbilical cord immediately after the birth of a child is a rich source of stem cells. • These stem cells can develop into various kinds of blood cells. • The blood collected from the cord can be banked (or stored) in the event it is needed later in the child’s or a sibling’s life.

How can Stem Cells be Used? • For diseases such as leukemia, stem cells How can Stem Cells be Used? • For diseases such as leukemia, stem cells collected from healthy blood can be injected into a patient’s blood after the diseased cells have been killed. • The healthy cells then grow in the patient’s bone marrow and produce healthy, cancer-free blood cells. • http: //www. dnalc. org/resources/animations/stemcells. html • http: //youtu. be/O 5 r-T 6 ANKto