BIO100 Chptr 3 Flashcards
1
Q
apo-
A
away, off, apart: apoptosis—a form of programmed cell death in which cells are shed from a developing structure or otherwise die.
2
Q
cyt-
A
cell: cytoplasm—fluid (cytosol) and organelles between the cell membrane and nuclear envelope.
3
Q
endo-
A
within: endoplasmic reticulum—membranous complex within the cytoplasm.
4
Q
hyper-
A
above: hypertonic—solution that has a greater osmotic pressure than the cytosol.
5
Q
hypo-
A
below: hypotonic—solution that has a lesser osmotic pressure than the cytosol.
6
Q
inter-
A
between: interphase—stage between mitotic divisions of a cell.
7
Q
iso-
A
equal: isotonic—solution that has an osmotic pressure equal to that of the cytosol.
8
Q
lys-
A
to break up: lysosome—organelle containing enzymes that break down proteins, carbohydrates, and nucleic acids.
9
Q
mit-
A
thread: mitosis—stage of cell division when chromosomes condense.
10
Q
phag-
A
to eat: phagocytosis—process by which a cell takes in solid particles.
11
Q
pino-
A
to drink: pinocytosis—process by which a cell takes in tiny droplets of liquid.
12
Q
pro-
A
before: prophase—first stage of mitosis.
13
Q
-som
A
body: ribosome—tiny, spherical organelle composed of protein and RNA that supports protein synthesis.
14
Q
vesic-
A
bladder: vesicle—small, saclike organelle that contains substances to be transported within the cell or secreted.
15
Q
differentiated
A
Cells with specialized characteristics are termed differentiated. Such specialized cells form from less specialized cells that divide and express specific genes.
16
Q
The three major parts of a cell
A
the nucleus (nu′kle-us), the cytoplasm (si′to-plazm), and the cell membrane
17
Q
organelles
A
The cytoplasm includes specialized structures called cytoplasmic organelles
18
Q
cytosol - liquid
A
organelles are suspended in a liquid called cytosol
19
Q
Cell Membrane
A
The cell membrane (also called a plasma membrane) is the outermost limit of a cell. It contains the cytoplasm, which surrounds the nucleus.
20
Q
Integral proteins
A
Form pores, channels, and carriers in the cell membrane; transduce signals
21
Q
Peripheral proteins-
A
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
22
Q
Proteins called cellular adhesion molecules, or CAMs
A
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.
23
Q
Ion Channels and Drug Action
A
Calcium channels-Antihypertensives Antiangina (chest pain)
Sodium channels-Antiarrhythmias, diuretics Local anesthetics
Chloride channels-Anticonvulsants Muscle relaxants
Potassium channels-Antihypertensives, antidiabetics (non-insulin-dependent)
24
Q
Cytoplasm
A
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
25
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.
26
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.
27
Vesicles
are membranous sacs that store or transport substances within a cell or between cells.
28
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
29
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.
30
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.”
31
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.
32
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.
33
Microfilaments, microtubules, and intermediate filaments
are types of threadlike structures in the cytoplasm. They are distinguished by protein type, diameter, and how they assemble. Other proteins connect these three types of structures, creating the cytoskeleton that provides strength and the cell’s ability to resist force and maintain shape.
34
Microfilaments
are tiny rods of the protein actin that form meshworks or bundles and provide cellular motility (movements). For example, microfilaments constitute myofibrils, which shorten or contract muscle cells. In other cell types, microfilaments associated with the inner surface of the cell membrane aid cell motility.
35
Microtubules
are long, slender tubes with diameters two or three times greater than those of microfilaments. Micro-tubules are composed of many pairs of the globular protein tubulin, attached in a spiral pattern to form a long tube. The rigidity that this structure imparts enables microtubules to maintain cell shapes. Microtubules move organelles and other cellular structures, discussed in the next sections. They also provide conduits for organelles, like the tracks of a roller coaster.
36
Intermediate filaments
Intermediate filaments take the general form of dimers (protein pairs) entwined into nested, coiled rods. Intermediate filaments made of proteins called keratins are abundant in the actively dividing cells in the deepest part of the outer skin layer, the epidermis. Here they form a strong inner scaffolding that helps the cells attach to form a barrier.
In all cells, intermediate filaments composed of proteins called lamins support the inner surface of the membranous envelope that defines the nucleus. Lamins interact with DNA, influencing which genes a cell uses to manufacture proteins.
37
centrosome
(central body) is a structure in the cytoplasm near the nucleus. It is nonmembranous and consists of two cylinders, called centrioles, that are built of microtubules organized as nine groups of three. The centrioles usually lie at right angles to each other. During cell division, the centrioles migrate to either side of the nucleus, where they produce spindle fibers that pull on and distribute chromosomes (kro′mo-sōmz), which carry DNA information to the newly forming cells. Centrioles also produce the internal parts of cell membrane projections called cilia and flagella.
38
Cilia (sing., cilium) and flagella (sing., flagellum)
are motile extensions of the cell membranes of certain cell types. They are structurally similar and differ mainly in their length and abundance. Internally, both cilia and flagella consist of nine groups of three microtubules with two additional microtubules in the center, forming a distinct cylindrical pattern.
39
Cell Nucleus
A nucleus is a relatively large, usually spherical, organelle that contains the genetic material (DNA) that directs the activities of the cell.
40
chromatin
The extremely long molecules of DNA are complexed with proteins to form fibers called chromatin.
41
nuclear envelope
The nucleus is enclosed in a double-layered nuclear envelope, which consists of an inner and an outer lipid bilayer membrane. These two membranes have a narrow space between them, but are joined at places that surround openings called nuclear pores
42
nuclear pore
nuclear pore lets out molecules of messenger RNA that carry genetic information, but does not let out the DNA, which must stay in the nucleus to maintain the genetic information.
43
Cell membrane
Membrane mainly composed of protein and lipid molecules
Maintains integrity of the cell, controls the passage of materials into and out of the cell, and provides for signal transduction
44
Ribosomes
Particles composed of protein and RNA molecules
Synthesize proteins
45
Endoplasmic reticulum
Complex of connected, membrane-bound sacs, canals, and vesicles
Transports materials within the cell, provides attachment for ribosomes, and synthesizes lipids
46
Vesicles
Membranous sacs
Contain substances that recently entered the cell, store and transport newly synthesized molecules within the cell and to other cells
47
Golgi apparatus
Group of flattened, membranous sacs
Packages and modifies protein molecules for transport and secretion
48
Mitochondria
Membranous sacs with inner partitions
Release energy from food molecules and convert the energy into a usable form (ATP)
49
Lysosomes
Membranous sacs
Contain enzymes that break down worn cellular parts or substances that enter cells
50
Peroxisomes
Membranous sacs
Contain enzymes called peroxidases, important in the breakdown of many organic molecules
51
Centrosome
Nonmembranous structure composed of two rodlike centrioles
Helps distribute chromosomes to new cells during cell division, initiates formation of cilia
52
Cilia
Motile projections attached to basal bodies beneath the cell membrane
Some cilia propel fluids over cell surface; others are sensory
53
Flagellum
Projection attached to a basal body beneath the cell membrane
Enables sperm cell to move
54
Microfilaments and microtubules
Thin rods and tubules
Support cytoplasm, help move substances and organelles within the cytoplasm
55
Nuclear envelope
Selectively permeable double membrane that separates the nuclear contents from the cytoplasm
Maintains the integrity of the nucleus and controls passage of materials between the nucleus and cytoplasm
56
Chromatin
Fibers composed of protein and DNA molecules
Carries information for synthesizing proteins
Chromatin consists of the cell’s 46 chromosomes (kro′mōsomz), each of which contains DNA wound around many proteins
57
Nucleolus
Dense, nonmembranous body composed of protein and RNA molecules
Site of ribosome formation
58
Diffusion
(also called simple diffusion) is the tendency of atoms, molecules, and ions in a liquid (a solution) or air to move from areas of higher concentration to areas of lower concentration. As the particles move farther apart, they become more evenly distributed, or more diffuse.
59
Facilitated Diffusion
the process of spontaneous passive transport of molecules or ions across a biological membrane via specific transmembrane integral proteins.
60
Osmosis
is the movement of water across a selectively permeable membrane into a compartment containing solute that cannot cross that membrane (impermeant solute).
61
osmotic pressure
the pressure that would have to be applied to a pure solvent to prevent it from passing into a given solution by osmosis, often used to express the concentration of the solution.
62
isotonic
Any solution that has the same osmotic pressure as body fluids is called isotonic
63
hypertonic
Solutions that have a higher osmotic pressure than body fluids are called hypertonic. ells are put into a hypertonic solution, water moves by osmosis out of the cells into the surrounding solution, and the cells shrink.
64
hypotonic
cells put into a hypotonic solution, which has a lower osmotic pressure than body fluids, gain water by osmosis and swell
65
Filtration
is another process that forces molecules through membranes by exerting pressure.
66
Active Transport
the movement of ions or molecules across a cell membrane into a region of higher concentration, assisted by enzymes and requiring energy.
67
Endocytosis
is the process of actively transporting molecules into the cell by engulfing it with its membrane. Endocytosis and exocytosis are used by all cells to transport molecules that cannot pass through the membrane passively.
68
pinocytosis
the ingestion of liquid into a cell by the budding of small vesicles from the cell membrane.
69
Phagocytosis
process by which certain living cells called phagocytes ingest or engulf other cells or particles. The phagocyte may be a free-living one-celled organism, such as an amoeba, or one of the body cells, such as a white blood cell.
70
transcytosis
(also known as cytopempsis) is a type of transcellular transport in which various macromolecules are transported across the interior of a cell. Macromolecules are captured in vesicles on one side of the cell, drawn across the cell, and ejected on the other side.
71
Exocytosis
a process by which a cell transports secretory products through the cytoplasm to the plasma membrane. Secretory products are packaged into transport vesicles (membrane-bound spheres).
72
Interphase
. During interphase, the cell acquires nutrients, creates and uses proteins and other molecules, and starts the process of cell division by replicating the DNA.
73
Mitosis
The process in cell division by which the nucleus divides, typically consisting of four stages, prophase, metaphase, anaphase, and telophase, and normally resulting in two new nuclei, each of which contains a complete copy of the parental chromosomes.
74
Prophase
Chromatin condenses into chromosomes; centrioles move to opposite sides of cytoplasm; nuclear membrane and nucleolus disperse; microtubules assemble and associate with centrioles and the two sister chromatids making up each chromosome.
75
Metaphase
Spindle fibers from the centrioles attach to the centromeres of the sister chromatids of each chromosome; chromosomes align midway between the centrioles.y between the centrioles.
76
Anaphase
Centromeres separate, and sister chromatids move apart, with each chromatid now an individual chromosome; spindle fibers shorten and pull these new individual chromosomes toward the centrioles.
77
Telophase
Chromosomes elongate and form chromatin threads; nuclear membranes form around each chromosome set; nucleoli form; microtubules break down.
78
Characteristics of Cancer Cells
Loss of cell cycle control
Heritability (a cancer cell divides to form more cancer cells)
Transplantability (a cancer cell implanted into another individual will cause cancer to develop)
Dedifferentiation (loss of specialized characteristics)
Loss of contact inhibition
Ability to induce local blood vessel extension (angiogenesis)
Invasiveness
Ability to metastasize (spread)
79
Oncogenes
is a sequence of deoxyribonucleic acid (DNA) that has been altered or mutated from its original form, the proto-oncogene. Operating as a positive growth regulator, the proto-oncogene is involved in promoting the differentiation and proliferation of normal cells
80
stem cell
Stem cells are cells of the body (somatic cells) which can divide and become differentiated. When an organism grows, stem cells specialize, and take specific functions. For instance, mature tissues like skin, muscle, blood, bone, liver, nerves, all have different types of cells.
81
progenitor cell
is a unipotent, or sometimes oligopotent, cell that directs differentiation. Like a stem cell, progenitor cells specify into particular cell types, however they are the direct predecessors to these cell types, unlike stem cells.
82
Apoptosis
is a form of cell death also called “programmed cell death”
