specialized structures in cells that perform

jelly-like substance that holds organelles

a structure that encloses the cytoplasm

Smallest units of life - Cell metabolism and energy use - Synthesis of molecules - Communication - Reproduction and inheritance

the outermost component of a cell. - It forms a boundary between material in inside the cell and the outside.

it is the model used to describe the cell membrane structure.

has a polar head region that is hydrophilic and a nonpolar tail region that is hydrophobic.

allows only certain substances to pass in and out of the cell.

route of transport through the membrane depends on the size, shape, and charge of the substance.

does not require the cell to expend energy. it include diffusion, osmosis, and facilitated diffusion.

does require the cell to expend energy, usually in the form of ATP. include active transport, secondary active transport, endocytosis, and exocytosis.

involves movement of substances in a solution down a concentration gradient.

is generally composed of two major parts, solutes and the solvent.

steeper when the concentration difference is large and/or the distance is small.

depends on the difference of solution concentrations inside a cell relative to outside the cell.

is the diffusion of water (a solvent) across a selectively permeable membrane from a region of higher water concentration to one of lower water concentration.

may be placed in solutions that are either hypotonic, isotonic, or hypertonic compared to the cell cytoplasm.

solution has a lower concentration of solutes and a higher concentration of water relative to the cytoplasm of the cell

A cell immersed in an isotonic solution has the same solute concentrations inside and outside the cell.

The cytoplasm of a cell in a hypertonic solution has a lower solute concentration and higher

uses the energy provided by a concentration gradient established by the active transport of one substance

occurs when a specific substance binds to the receptor molecule and is transported into the cell.

is a process that that brings materials into cell using vesicles.

used for endocytosis when solid particles are ingested.

has much smaller vesicles formed, and they contain liquid rather than solid particles.

involves the use of membrane-bound sacs called secretory vesicles that accumulate materials for release from the cell.

large organelle usually located near the center of the cell. bounded by a nuclear envelope, which consists of outer and inner membranes with a narrow space between them.

components are produced in the nucleolus. organelles where proteins are produced.

series of membranes forming sacs and tubules that extends from the outer nuclear membrane into the cytoplasm.

has no attached ribosomes and is a site for lipid synthesis, cellular detoxification, and it stores calcium ions in skeletal muscle cells.

consists of closely packed stacks of curved, membrane-bound sacs. - It collects, modifies, packages, and distributes proteins and lipids manufactured by the ER.

contain a variety of enzymes that function as intracellular digestive systems.

small, membrane-bound vesicles containing enzymes that break down fatty acids, amino acids, and hydrogen peroxide

responsible for producing considerable amounts of ATP by aerobic (with O2) metabolism. - They have inner and outer membranes separated by a space. - The outer membranes have a smooth contour, but the inner membranes have numerous folds, called cristae, which project into the interior of the mitochondria.

gives internal framework to the cell. - It consists of protein structures that support the cell, hold organelles in place, and enable the cell to change shape. - These protein structures are microtubules, microfilaments, and intermediate filaments.

structures formed from protein subunits.

small fibrils formed from protein subunits that structurally support the cytoplasm, determining cell shape. - in muscle cells enable the cells to shorten, or contract.

fibrils formed from protein subunits that are smaller in diameter than microtubules but larger in diameter than microfilaments. - provide mechanical support to the cell.

involved in the process of mitosis. -organazing microtubules that serve as the cells skeletal system

surface of certain cells. responsible for the movement of materials over the top of cells, such as mucus.

-have a structure similar to that of cilia but are much longer, and they usually occur only one per cell. - Sperm cells each have one flagellum, which propels the sperm cell. -assist the cell in movement

specialized extensions of the cell membrane that are supported by microfilaments. - They do not actively move as cilia and flagella do. -numerous on cells that have them and they increase the surface area of those cells. - They are abundant on the surface of cells that line the intestine, kidney, and other areas in which absorption is an important function.

involves copying DNA into messenger RNA. - DNA determines the structure of mRNA

involves messenger RNA being used to produce a protein. - occurs in the cell cytoplasm after mRNA has exited the nucleus through the nuclear pores.

involves formation of 2 daughter cells from a single parent cell. - divided into four phases: prophase, metaphase, anaphase, and telophase.

the chromatin condenses to form visible chromosomes.

the chromosomes align near the center of the cell. - The movement of the chromosomes is regulated by the attached spindle fibers.

the chromatids separate and each chromatid is called a chromosome.

the chromosomes in each of the daughter cells become organized to form two separate nuclei, one in each newly formed daughter cell.

The process by which cells develop with specialized structures and functions is called