A&P Lab unit 4 Cytology

mitosis

cell division in which the nucleus divides into nuclei containing the same number of chromosomes

telophase

final stage of mitosis and of meiosis I and II, in which the chromosomes reach the spindle poles, nuclear envelopes form around each set of daughter chromosomes, and the nucleoli reappear

prophase

first phase of mitosis in which chromosomes become visible and nuclear membraine disappears

flagella

whiplike tails found in one-celled organisms to aid in movement

peroxisome

A microbody containing enzymes that transfer hydrogen from various substrates to oxygen, producing and then degrading hydrogen peroxide.

mitotic spindle

An assemblage of microtubules and associated proteins that is involved in the movements of chromosomes during mitosis.

smooth endoplasmic reticulum

An endomembrane system where lipids are synthesized, calcium levels are regulated, and toxic substances are broken down.

centrioles

Located near the nucleus and help to organize cell division

mitochondria

Powerhouse of the cell, organelle that is the site of ATP (energy) production

peripheral proteins

Protein appendages loosely bound to the surface of the membrane and not embedded in the lipid bilayer.

rough endoplasmic reticulum

System of internal membranes within the cytoplasm. Membranes are rough due to the presence of ribosomes. functions in transport of substances such as proteins within the cytoplasm

tonicity

The ability of a solution to cause a cell within it to gain or lose water.

cytoplasm

The entire contents of the cell, exclusive of the nucleus, and bounded by the plasma membrane.

G2

The final period of interphase during which the cell prepares for mitosis.

cytokinesis

The final stage of the cell cycle, in which the cell's cytoplasm divides, distributing the organelles into each of the two new cells.

S phase I

The synthesis phase of the cell cycle; the portion of interphase during which DNA is replicated.

intermediate filaments

Threadlike proteins in the cell's cytoskeleton that are roughly twice as thick as microfilaments

microvilli

Tiny hair-like projections of the cytoplasmic membrane located only in the small intestine to facilitate absorption by increasing surface area.

cholesterol

a fatty substance that travels through the blood and is found in all parts of the body

phospholipid

a lipid made of a phosphate group and two fatty acids

cytoskeleton

a network of fibers that holds the cell together, helps the cell to keep its shape, and aids in movement

nucleus

a part of the cell containing DNA and RNA and responsible for growth and reproduction

glycoproteins

a protein with one or more carbohydrates covalently attached to it.

plasma membrane

a thin membrane around the cytoplasm of a cell

actin filaments

a thin type of protein filament composed of actin proteins that forms part of the cytoskeleton and supports the plasma membrane and plays a key role in cell strength, shape and movement

centromere

area where the chromatids of a chromosome are attached

lysosome

cell organelle filled with enzymes needed to break down certain materials in the cell

osmosis

diffusion of molecules through a semipermeable membrane from a place of higher concentration to a place of lower concentration until the concentration on both sides is equal

G1

first phase of interphase; cell grows in size

cillia

hairlike structures with the capacity for movement

microtubules

hollow tubes of protein about 25 nanometers in diameter, support the cell and moves organelles within the cell

interphase

period of the cell cycle between cell divisions

diffusion

process by which molecules tend to move from an area where they are more concentrated to an area where they are less concentrated

metaphase

second phase of mitosis, during which the chromosomes line up across the center of the cell

cell cycle

series of events that cells go through as they grow and divide

ribosome

small particle in the cell on which proteins are assembled; made of RNA and protein

centrosome

small region of cytoplasm adjacent to the nucleus

organelles

small structures in the cytoplasm that do special jobs

spindle fibers

special microtubules which grow in mitosis, connect to chromosomes, and move the chromosomes around

Golgi apparatus

stack of membranes in the cell that modifies, sorts, and packages proteins from the endoplasmic reticulum

cytosol

the aqueous part of the cytoplasm within which various particles and organelles are suspended

integral proteins

the proteins of a membrane that penetrate the hydrophobic core of the lipid bilayer; hydrophobic regions consist of nonpolar amino acids, while hydrophilic regions are exposed to aqueous solution on either side of membrane

anaphase

the third phase of mitosis, during which the chromosome pairs separate and move toward opposite poles

chromatids

two identical chromosomes that split and contain the same genetic material