The smallest unit of life that can perform all life processes. Cell The smallest unit of life that can perform all life processes.

CHOGER “Life is macromolecules that can perform unique functions because they are enclosed in a structural compartment that is separate from the external environment. This separation allows living things to maintain a constant internal environment (homeostasis)”. Purves, pg. 61 and the Cell

“little wretched beasties” Antone van Leeuwenhoek - lenses

“cells” Robert Hooke

The Cell Theory (3 parts) Matthias Schleiden (botonist) Theodor Schwann (zoologist) 1. All organisms are made of one or more cells. 2. The cell is the basic unit of all living things.

3. All cells come from pre-existing cells All organisms are made of one or more cells The cell is the basic unit of all living things Redi – spontaneous generation 3. All cells come from pre-existing cells Pasteur – spontaneous generation

Structure and Function 2 types of cells eukaryote prokaryote Cells that have a membrane around their nucleus. Cells that DO NOT have a cell membrane around their nucleus. Plant and Animal Cells Example – Bacteria Eukaryote cells usually 10X larger than Prokaryote cells.

eukaryotic cells The basic Eukaryotic cell contains: Plasma membrane around their nucleus Cytoplasm (the semi fluid substance inside the membrane. A cytoskeleton – gives it shape, and allows for the cell’s motion. Has membrane enclosed organelles.

the plasma membrane fluid mosaic model Lipid bilayer with embedded proteins

plant cell wall cellulose

cell wall

Cells r Us

structure and function Cell Review: structure and function

animal cell plant cell

nucleus ribosome golgi apparatus lysosome mitochondria

nucleus

the nucleus contains the genetic material

endomembrane system

endoplasmic reticulum

rough ER transports newly synthesized proteins alters proteins folds into tertiary structures

smooth ER site for synthesis of lipids and steroids site for hydrolysis of glycogen modifies (detox.) small molecules

golgi apparatus recieves proteins from ER – further modifications Concentrates, packages, sorts proteins Polysacc. for plant cell walls synthesized

secreting side flow of material receiving side

Vesicles and vacuoles The function and importance of vacuoles varies greatly according to the type of cell in which they are present.

functions of the vacuole include: Isolating materials that might be harmful or a threat to the cell. Breaking down products taken into the cell to be used in metabolism. Exporting unwanted substances from the cell. Allows plants to support structures such as leaves and flowers. Exporting manufactured products from the cell.

endocytosis and exocytosis taking in expelling pinocytosis phagocytosis Uses energy Encloses material in vesicles

special vesicles and vacuoles lysosomes contain hydrolytic enzymes - break down cellular waste products, fats, carbohydrates, proteins, and other macromolecules into simple compounds, which are then transferred back into the cytoplasm as new cell-building materials

autophagy - recycles the cell's organic material

special vesicles and vacuoles peroxisomes the most common vesicle in cells found in all eukaryotes contain enzymes to rid the cell of hydrogen peroxide (convert the hydrogen peroxide to water) some detoxify alcohol and other harmful compounds by transferring hydrogen from the poisons to molecules of oxygen (oxidation). others initiate production of phospholipids

special vesicles and vacuoles Helps maintain homeostasis for water balance (osmotic equilibrium) central vacuole contractile vacuole

central vacuole (plants ONLY) Maintaining internal hydrostatic pressure or turgor within the cell

contractile vacuole (animals ONLY) found in certain unicellular organisms pumps fluid from in the cell to the outside by alternately filling and then contracting

ribosomes site of protein synthesis

mitochondria

chloroplasts

microfilaments & microtubules

microfilaments - actin intermediate filaments – protein polymers such as keratin

microtubules - conveyer belts inside the cells They move vesicles, granules and organelles via special attachment proteins. They also serve a cytoskeletal role. Structurally, they are linear polymers of tubulin (a globular protein). The tubulin molecules are the bead like structures.  Microtubules may work alone, or join with other proteins to form cilia, flagella or centrioles.

centrioles

Molecular "tags" on microtubules direct traffic inside cells

lab time