Chapter 3 Flashcards
or cell membrane, forms the outer boundary of the cell, through which the cell interacts with its external environment.
plasma membrane
is usually located centrally; it directs cell activities
nucleus
located between the plasma membrane and the nucleus
cytoplasm
involves all chemical reactions that occur within a cell. These metabolic reactions often involve energy transfers, meaning the energy released by one reaction is then used in another reaction.
Cell metabolism and energy use
produce, various types of molecules, including proteins, nucleic acids, and lipids. The structural and functional characteristics of cells are determined by the types of molecules they produce.
Synthesis of molecules
with each other by using chemical and electrical signals.
Communication
Most cells contain a complete copy of all the genetic information of the individual. This genetic information ultimately determines the structural and functional characteristics of the cell.
Reproduction and inheritance
allow us to visualize the general features of cells, such as the nucleus. But the magnification of light microscopes is limited, so not all cell structures can be thoroughly investigated.
Light microscopes
can reveal features of the cell surface and the surfaces of internal structures.
scanning electron microscope (SEM)
allows us to see “through” parts of the cell and thus to discover detailed aspects of cell structure. A more detailed description of microscopes and their use appears in Clinical Impact, “Microscopic Imaging,” in this chapter.
transmission electron microscope (TEM)
is a result of the cell’s regulation of ion movement into and out of the cell. Because there are more positively charged ions immediately on the outside of the plasma membrane and more negatively charged ions and proteins inside, the outside of the plasma membrane is positively charged, compared with the inside of the plasma membrane.
membrane potential
is the collection of glycolipids, glycoproteins, and carbohydrates on the outer surface of the plasma membrane.
glycocalyx
are integral proteins that allow ions or molecules to move from one side of the plasma membrane to the other. Transport proteins have three characteristics that are important to their function: specificity, saturation, and competition.
Transport proteins
means that each transport protein binds to and transports only a certain type of molecule or ion
Specificity
is the result of molecules with simlilar shape binding to the transport protein
Competition
means that the rate of movement of molecules across the membrane is limited by the number of available transport proteins
Saturation
are one or more integral membrane proteins arranged so that they form a tiny channel through the plasma membrane
Channel proteins
is a generic term for any chemical signal molecule used by cells to communicate with each other
Ligand
is a genetic disorder that affects chloride ion channels. The failure of these ion channels to function causes the affected cells to produce thick, viscous secretions.
Cystic fibrosis
or transporters, are integral membrane proteins that move ions or molecules from one side of the plasma membrane to the other.
Carrier proteins,
are transport proteins that require cellular energy to move specific ions or molecules from one side of the plasma membrane to the other. The activity of ATP-powered pumps is fueled by the breakdown of adenosine triphosphate (ATP).
ATP-powered pumps
acts as an intermediary between a receptor and other cellular proteins. The G protein complex consists of three proteins: alpha (α), beta (β), and gamma (γ) proteins.
G protein complex
that is, it allows only certain substances to pass through it. The intracellular material has a different composition than the extracellular material, and the cell’s survival depends on the maintenance of these differences.
selectively permeable
The liquid or gas
solvent
the substances dissolved
solutes
A concentration difference occurs when the solutes are not evenly distributed in a solvent. The concentration difference between two points, divided by the distance between the two points
concentration gradient
is a measure of a fluid’s resistance to flow. A fluid with a low viscosity flows more easily, and a fluid with a high viscosity flows less easily.
Viscosity
is the diffusion of water (solvent) across a selectively permeable membrane, such as a plasma membrane (
Osmosis
or water channel proteins, that open and close to adjust membrane permeability to water. Water diffuses from a solution with proportionately more water, across a selectively permeable membrane, and into a solution with proportionately less water.
aquaporins
is the force required to prevent water from moving by osmosis across a selectively permeable membrane. The osmotic pressure of a solution can be determined by placing the solution into a tube that is closed at one end by a selectively permeable membrane
Osmotic pressure
If the cell swells enough, it can rupture
lysis
the cellular material outside the nucleus but inside the plasma membrane, is about half cytosol and half organelles.
Cytoplasm
is a colloid, a viscous solution containing dissolved ions and molecules as well as suspended molecules, especially proteins.
cytosol
supports the cell and holds the nucleus and other organelles in place. In addition, some components of the cytoskeleton are responsible for changes in cell shape and the movement of cell organelles.
cytoskeleton
is a large, membrane-bound structure usually located near the center of the cell. It may be spherical, elongated, or lobed, depending on the cell type. All body cells have a nucleus at some point in their life cycle
nucleus
are hollow tubes composed primarily of protein units called tubulin. They are about 25 nanometers (nm) in diameter, with walls about 5 nm thick.
Microtubules
which means “cell-eating,” solid particles are ingested and phagocytic vesicles are formed. White blood cells and some other cell types phagocytize bacteria, cell debris, and foreign particles
phagocytosis
is composed of flattened, membranous sacs, containing cisternae, stacked on each other like dinner plates, it is thought to be a packaging and distribution center because it modifies, packages, and distributes proteins and lipids manufactured by the rough and smooth endoplasmic reticula
Golgi apparatus
consists of three nucleotides and is complementary to a particular codon of mRNA. On the basis of the pairing relationships between nucleotides, the anticodon can combine only with its matched codon. For example, the tRNA that has the anticodon CUA combines with the codon GAU of mRNA. T
anticodon
refers to abnormal tissue growth from rapid cell proliferation that continues after normal growth would have stopped.
neoplasm
is the study of tumors and the problems they cause.
Oncology
with malice or intent to cause harm, able to spread and become worse.
malignant
Cancer cells can dislodge; enter blood vessels, lymphatic vessels, or body cavities; and travel to distant sites, where they invade tissues. The process by which cancer spreads to distant sites
metastasis
is the division of the cell’s cytoplasm to produce two new cells, begins in anaphase and continues through telophase
Cytokinesis
