Flashcards in Chapter Three Deck (25):
The cell is the basic unit of structure and function in the
Measured in micrometers
Cells with special characteristics are said to be differentiated.
Cells vary in size and shape; structure and function are inter-related.
Major Parts of a Cell
Cytoplasm consists of organelles, with specific functions, suspended in a liquid called cytosol. Contains all
organelles and cell parts.
Cell (Plasma) Membrane (characteristics)
Outer boundary of the cell
Maintains integrity of cell
Selectively permeable: regulates entry and exit of substances
Signal transduction: permits cell to receive and respond to messages
Consists mainly of lipids and proteins, with some carbohydrates
Organelle found in eukaryotic cells. Inside its fully enclosed nuclear membrane, it contains the
majority of the cell's genetic material
The main job of mitochondria is to perform cellular respiration. This means it takes in nutrients from the cell, breaks it down, and turns it into energy.
Lysomes are intercellular stomachs full of digestive enzymes that operate at low pH.
Membrane bound sacs used to break down fatty acids and other molecules, generating hydrogen peroxide in the process.
Vesicles are lysosomes, that contain digestive enzymes used to break down food particles and to get rid of unneeded cellular materials.
Movement of atoms, molecules, or ions, from region of higher concentration to region of lower concentration
Movement of water across a selectively permeable membrane from region of higher water concentration to region of lower water concentration
Osmotic Pressure (describe)
Ability of osmosis to generate enough pressure to lift a volume of water. Osmotic pressure increases as the concentration of impermeant solutes increases
Isotonic Solution (describe)
Same osmotic pressure. Cells in an isotonic solution have no net gain or loss of water
Hypertonic Solution (describe)
Higher osmotic pressure. Cells in a hypertonic solution lose water
Hypotonic Solution (describe)
Lower osmotic pressure. Cells in a hypotonic solution gain water
Process that forces molecules through membranes by exerting pressure. Used to separate solids from water, or small particles from large ones
Active Transport (describe)
Movement of substances across a membrane from region of lower concentration to region of higher concentration (against concentration gradient).
Uses carrier molecules in cell membrane
Movement of a substance into the cell inside a vesicle. Substances too large to enter by other methods can enter cell this way
Type of endocytosis: membrane engulfs droplets of liquid
Type of endocytosis: membrane engulfs solid particles
Receptor-mediated endocytosis (describe)
Type of endocytosis: membrane engulfs specific substances, which have bound to receptor proteins on the membrane
Release of substances/particles from cell. Vesicles containing particles fuse with cell membrane and release contents
The maturation and specialization of cells