Cells Anatomy Cells and Tissues Carry out all

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Cells Anatomy

Cells Anatomy

Cells and Tissues • Carry out all chemical activities • Cells are the building

Cells and Tissues • Carry out all chemical activities • Cells are the building blocks of all living things • Tissues are groups of cells that are similar in structure and function

Anatomy of the Cell • Cells are not all the same • All cells

Anatomy of the Cell • Cells are not all the same • All cells share general structures • All cells have three main regions ▫ Nucleus ▫ Cytoplasm ▫ Plasma membrane

The Nucleus • Control center of the cell ▫ Contains genetic material (DNA)

The Nucleus • Control center of the cell ▫ Contains genetic material (DNA)

The Nucleus • Three regions ▫ Nuclear envelope (membrane) ▫ Nucleolus ▫ Chromatin

The Nucleus • Three regions ▫ Nuclear envelope (membrane) ▫ Nucleolus ▫ Chromatin

The Nucleus

The Nucleus

The Nucleus • Nuclear envelope (membrane) ▫ Double membrane ▫ nuclear pores - exchange

The Nucleus • Nuclear envelope (membrane) ▫ Double membrane ▫ nuclear pores - exchange of material

The Nucleus • Nucleoli ▫ Sites of ribosome assembly ▫ Ribosomes move into the

The Nucleus • Nucleoli ▫ Sites of ribosome assembly ▫ Ribosomes move into the cytoplasm through nuclear pores

The Nucleus • Chromatin ▫ DNA and protein ▫ Present when the cell is

The Nucleus • Chromatin ▫ DNA and protein ▫ Present when the cell is not dividing

Plasma Membrane • Barrier for cell contents • Double phospholipid layer ▫ Hydrophilic heads

Plasma Membrane • Barrier for cell contents • Double phospholipid layer ▫ Hydrophilic heads ▫ Hydrophobic tails

Plasma Membrane

Plasma Membrane

Plasma Membrane Specializations • Microvilli ▫ Finger-like projections that increase surface area for absorption

Plasma Membrane Specializations • Microvilli ▫ Finger-like projections that increase surface area for absorption ▫ Do all cells have microvilli?

Plasma Membrane Specializations • Membrane junctions ▫ Tight junctions ▫ Desmosomes ▫ Gap junctions

Plasma Membrane Specializations • Membrane junctions ▫ Tight junctions ▫ Desmosomes ▫ Gap junctions

Plasma Membrane Specializations ▫ Tight junctions �Impermeable junctions �Bind cells together into leak-proof sheets

Plasma Membrane Specializations ▫ Tight junctions �Impermeable junctions �Bind cells together into leak-proof sheets ▫ Desmosomes �Anchoring junctions that prevent cells from being pulled apart (Think ANCHORS) ▫ Gap junctions �Allow communication between cells (GAPS)

Plasma Membrane Specializations

Plasma Membrane Specializations

Cytoplasm • Cytoplasm is the material outside the nucleus and inside the plasma membrane

Cytoplasm • Cytoplasm is the material outside the nucleus and inside the plasma membrane

Cytoplasm • Cytosol �Fluid that suspends other elements • Organelles �“Little organs” that perform

Cytoplasm • Cytosol �Fluid that suspends other elements • Organelles �“Little organs” that perform functions • Inclusions �Stored nutrients or cell products

Cytoplasmic Organelles

Cytoplasmic Organelles

Cytoplasmic Organelles • Mitochondria ▫ “Powerhouses” of the cell ▫ Carry out reactions: oxygen

Cytoplasmic Organelles • Mitochondria ▫ “Powerhouses” of the cell ▫ Carry out reactions: oxygen used to break down food ▫ Provides ATP

Cytoplasmic Organelles • Ribosomes ▫ Sites of protein synthesis ▫ Found at two locations:

Cytoplasmic Organelles • Ribosomes ▫ Sites of protein synthesis ▫ Found at two locations: �Free in cytoplasm �Part of the Rough ER

Cytoplasmic Organelles • Endoplasmic reticulum (ER) ▫ Fluid-filled tubules for carrying substances

Cytoplasmic Organelles • Endoplasmic reticulum (ER) ▫ Fluid-filled tubules for carrying substances

Cytoplasmic Organelles • Rough ER �Studded with ribosomes �Synthesizes proteins • Smooth ER �Lipid

Cytoplasmic Organelles • Rough ER �Studded with ribosomes �Synthesizes proteins • Smooth ER �Lipid metabolism and detoxification of drugs and pesticides

Cytoplasmic Organelles • Golgi apparatus ▫ Modifies and packages proteins:

Cytoplasmic Organelles • Golgi apparatus ▫ Modifies and packages proteins:

Proteins in cisterna Rough ER Cisterna Lysosome fuses with ingested substances Membrane Transport vesicle

Proteins in cisterna Rough ER Cisterna Lysosome fuses with ingested substances Membrane Transport vesicle Golgi vesicle containing digestive enzymes becomes a lysosome Pathway 3 Golgi apparatus Pathway 1 Golgi vesicle containing proteins to be secreted becomes a secretory vesicle Pathway 2 Secretory vesicles Proteins Secretion by exocytosis Golgi vesicle containing membrane components fuses with the plasma membrane Plasma membrane Extracellular fluid

Cytoplasmic Organelles • Lysosomes ▫ Contain enzymes that digest worn-out or non-usable materials within

Cytoplasmic Organelles • Lysosomes ▫ Contain enzymes that digest worn-out or non-usable materials within the cell

Cytoplasmic Organelles • Peroxisomes ▫ Membranous sacs of oxidase enzymes �Detoxify harmful substances �Break

Cytoplasmic Organelles • Peroxisomes ▫ Membranous sacs of oxidase enzymes �Detoxify harmful substances �Break down free radicals (highly reactive chemicals) ▫ Replicate by pinching in half

Cytoplasmic Organelles • Cytoskeleton ▫ Internal framework/structure

Cytoplasmic Organelles • Cytoskeleton ▫ Internal framework/structure

Cytoplasmic Organelles • Cytoskeleton ▫ Three different types: �Microfilaments (largest) �Intermediate filaments �Microtubules (smallest)

Cytoplasmic Organelles • Cytoskeleton ▫ Three different types: �Microfilaments (largest) �Intermediate filaments �Microtubules (smallest)

Cytoplasmic Organelles • Centrioles ▫ Rod-shaped structure made off microtubules ▫ Direct the formation

Cytoplasmic Organelles • Centrioles ▫ Rod-shaped structure made off microtubules ▫ Direct the formation of mitotic spindle during cell division

Cellular Projections • Not found in all cells • Used for movement

Cellular Projections • Not found in all cells • Used for movement

Cellular Projections • Cilia: move materials across the cell surface �Located in the respiratory

Cellular Projections • Cilia: move materials across the cell surface �Located in the respiratory system to move mucus • Flagella: propel the cell �The only cell in the human body with flagella is sperm