BIO100 Chptr 3 Flashcards
apo-
away, off, apart: apoptosis—a form of programmed cell death in which cells are shed from a developing structure or otherwise die.
cyt-
cell: cytoplasm—fluid (cytosol) and organelles between the cell membrane and nuclear envelope.
endo-
within: endoplasmic reticulum—membranous complex within the cytoplasm.
hyper-
above: hypertonic—solution that has a greater osmotic pressure than the cytosol.
hypo-
below: hypotonic—solution that has a lesser osmotic pressure than the cytosol.
inter-
between: interphase—stage between mitotic divisions of a cell.
iso-
equal: isotonic—solution that has an osmotic pressure equal to that of the cytosol.
lys-
to break up: lysosome—organelle containing enzymes that break down proteins, carbohydrates, and nucleic acids.
mit-
thread: mitosis—stage of cell division when chromosomes condense.
phag-
to eat: phagocytosis—process by which a cell takes in solid particles.
pino-
to drink: pinocytosis—process by which a cell takes in tiny droplets of liquid.
pro-
before: prophase—first stage of mitosis.
-som
body: ribosome—tiny, spherical organelle composed of protein and RNA that supports protein synthesis.
vesic-
bladder: vesicle—small, saclike organelle that contains substances to be transported within the cell or secreted.
differentiated
Cells with specialized characteristics are termed differentiated. Such specialized cells form from less specialized cells that divide and express specific genes.
The three major parts of a cell
the nucleus (nu′kle-us), the cytoplasm (si′to-plazm), and the cell membrane
organelles
The cytoplasm includes specialized structures called cytoplasmic organelles
cytosol - liquid
organelles are suspended in a liquid called cytosol
Cell Membrane
The cell membrane (also called a plasma membrane) is the outermost limit of a cell. It contains the cytoplasm, which surrounds the nucleus.
Integral proteins
Form pores, channels, and carriers in the cell membrane; transduce signals
Peripheral proteins-
Receptor proteins- Respond to extracellular signals
Enzymes - Catalyze chemical reactions
Cell surface proteins - Establish self
Cellular adhesion molecules - Enable cells to stick to each other
Proteins called cellular adhesion molecules, or CAMs
guide cells on the move.
CAMs guide cells surrounding an embryo to grow toward maternal cells and form the placenta, the supportive organ linking a pregnant woman to the fetus. Sequences of CAMs help establish the connections between nerve cells that underlie learning and memory.
Ion Channels and Drug Action
Calcium channels-Antihypertensives Antiangina (chest pain)
Sodium channels-Antiarrhythmias, diuretics Local anesthetics
Chloride channels-Anticonvulsants Muscle relaxants
Potassium channels-Antihypertensives, antidiabetics (non-insulin-dependent)
Cytoplasm
Cytoplasm usually appears clear with scattered specks
cytoplasm contains chemicals called inclusions - Inclusions include stored nutrients, such as glycogen and lipids, and pigments, such as melanin in the skin.
Cytoplasm also contains abundant protein rods and tubules that form a supportive framework called the cytoskeleton
Ribosomes
are tiny, spherical structures composed of protein and RNA. They provide a structural support and enzymatic activity to link amino acids to synthesize proteins . Unlike many of the other organelles, ribosomes are not composed of or contained in membranes. They are scattered in the cytoplasm and also bound to the endoplasmic reticulum, another organelle.
endoplasmic reticulum
(ER) is a complex organelle composed of membranous flattened sacs, cylinders, and fluid-filled bubblelike sacs called vesicles
ER is widespread in the cytoplasm, providing a tubular transport system for molecules throughout the cell.
Vesicles
are membranous sacs that store or transport substances within a cell or between cells.
Golgi apparatus
is a stack of five to eight flattened, membranous sacs called cisternae that resemble a stack of pancakes. This organelle refines, packages, and transports proteins synthesized on the rough ER
Mitochondria
are elongated, fluid-filled sacs 2–5 μm long that house most of the biochemical reactions that extract energy from the nutrient molecules in digested food. These organelles move slowly in the cytoplasm and can divide. A mitochondrion contains a small amount of DNA (37 genes) that encodes information for making a few types of proteins and specialized RNA. However, most proteins that mitochondria use are encoded in the DNA of the nucleus.
Lysosomes
are the “garbage disposals” of the cell, where enzymes dismantle debris. The process of a cell’s disposing of its own trash is called “autophagy,” which means “eating self.”
adenosine triphosphate ATP
These enzymes and others dissolved in the fluid in the mitochondrion, called the matrix, control many of the chemical reactions that release energy from glucose and other nutrients in a process called cellular respiration. The mitochondrion captures and transfers this newly released energy into special chemical bonds of the molecule adenosine triphosphate. Cells use ATP to power many cellular activities and can therefore be thought of as “cellular energy.” Because the mitochondrion supplies ATP, it is called the “powerhouse” of the cell.
Peroxisomes
are membranous sacs that resemble lysosomes in size and shape. They are in all human cells but are most abundant in cells of the liver and kidneys. Peroxisomes contain enzymes, called peroxidases, that catalyze metabolic reactions that release hydrogen peroxide (H2O2), which is toxic to cells. Peroxisomes also contain an enzyme called catalase, which decomposes hydrogen peroxide.