| Question |
Answer |
| active transport |
Membrane transport processes for which ATP is provided, e.g., solute pumping and endocytosis. |
| solute pumps |
ATP protein carriers |
| sodium-potassium pump |
simultaneously carries sodium ions (Na |
| vascular transport |
involves help from ATP, moving substances; once vesicle/sac is formed, detaches from plasma membrane & moves into the cytoplasm where it fuses w/lysosome & its contents digested by lysosomal enzymes. |
| phagocytosis |
Engulfing of foreign solids by cells; protective mechanism not means of getting nutrients. |
| pinocytosis |
cell gulps up droplets of extracellular fluid "cell drinking"; routine active in most cells, especially in those involved in absorption |
| receptor mediated endocytosis |
main cellular mechanism for taking up specific target molecules; plasma membrane receptor proteins bind only with certain substances including enzymes, some hormones, cholesterol & iron; flu viruses also use this routine to enter/attack our cells |
| cell life cycle |
series of changes from time it is formed until it divides |
| interphase |
cell grows & carries on its usual metabolic activities; also called metabolic phase |
| cell division |
cell reproduces itself |
| nucleotide |
Building block of nucleic acids; consists of a sugar, a nitrogen-containing base, and a phosphate group. |
| double helix |
ladder-like molecule coiled into a spiral staircase shape; upright parts alternating phosphate & sugar units and rungs are pairs of nitrogen-containing bases |
| nucleotides combine in a ___________ |
complementary way; (A) adenine always bonds w/ (T) thymine, (G) guanine always bonds w/ (C) cytosine |
| mitosis |
Process during which the chromosomes are redistributed to two daughter nuclei; nuclear division. Consists of prophase, metaphase, anaphase, and telophase; results in formation of (2) daughter nuclei w/exact same genes as mother nucleus |
| cytokenisis |
The division of cytoplasm that occurs after the cell nucleus has divided. |
| what are the four phases of mitosis? |
prophase, metaphase, anaphase & telophase |
| centromere |
small button like body which holds together the strands of chromatid during prophase |
| mitotic spindle |
this is directed to be assembled, when centrioles separate and begin to move towards opposite sides of the cell; composed of microtubules; it also provides a "scaffolding" for attach/movement of chromosomes during later mitotic phases |
| metaphase |
short stage, chromosomes cluster & become aligned at the metaphase plate(center of spindle midway between centrioles) so a straight line of chromosomes is seen |
| anaphase |
centromeres holding chromatid together split; chromatids become chromosomes & are slowly drawn towards opposite ends of the cell; this phase is over once chromosomes stop movement. |
| telophase |
prophase in reverse |
| cytokinesis |
The division of cytoplasm that occurs after the cell nucleus has divided. |
| cleavage furrow |
contractile ring made of microfilaments forms over the midline of the spindle, eventually squeezing/pinching original cytoplasmic mass into two parts. |
| binucleate/multinucleate cells |
condition where the cytoplasm is not divided during mitosis leading to the formation of two nuclei/multi nuclei; common in the liver |
| fibrous proteins |
major building materials for the cell; structural proteins |
| globular proteins |
do things other than build structures; functional proteins |
| enzymes |
protein that acts as a biological catalyst to speed up a chemical reaction |
| RNA stands for |
ribonucleic acid; Nucleic acid that contains ribose and the bases A, G, C, and U. Carries out DNA's instructions for protein synthesis |
| transfer RNA (tRNA) |
small clover leafed-shaped molecules |
| ribosomal RNA (rRNA) |
helps form the ribosomes, where proteins are built |
| messenger RNA (mRNA) |
long, single nucleotide strands that resemble half of a DNA molecule & carry the "message" containing instructions for protein synthesis from the DNA gene in the nucleus to the ribosomes in the cytoplasm |
| transcription |
transfer of info from DNA's base sequence into the complementary base sequence of mRNA |
| translation |
language of nucleic acids (base sequence)is translated into language of proteins (amino acid sequence); occurs in the cytoplasm & involves 3 major varieties of RNA |
| How many phases in protein synthesis? |
Two |
| triplet |
each three-base sequence specifying a particular amino acid on the DNA gene |
| codons |
corresponding three-base sequence on mRNA; form is different but same info is being conveyed. |
| anticodon |
special three-based sequence in tRNA that allows it to bind to the complementary codons on the mRNA |
| What are the four functions of epithelial tissue? |
protection, absorption, filtration & secretion |
| special characteristics of epithelial cells, except for granular epithelium: |
fit closely together forming continuous sheets, have one free surface/edge exposed to the bodies exterior/to cavity of an internal organ, lower surface rests on a basement membrane |
| no blood supply of their own depending on diffusion from capillaries in underlying connective tissue for food/oxygen & regenerate easily |
characteristics of epithelium |
| simple epithelium |
one layer of cells |
| stratified epithelium |
more than one cell layer |
| squamous cells |
flattened like fish scales |
| cuboidal cells |
cube shaped cells |
| columnar cells |
shaped like columns |
| stratified cells are named for the cells at the _________ _________ of the epithelial membrane |
free surface |
| simple epithelial are most concerned with |
absorption, secretion & filtration |
| protection is not one of their specialties, because they are usually very thin |
simple epithelia |
| simple squamous epithelium |
single layer of thin squamous cells resting on a basement membrane |
| example of simple squamous epithelium |
air sacs of the lungs and walls of the capillaries |
| serous membranes/serosae |
simple squamous epithelium that form slick membranes lining the ventral body cavity & cover the organs in that cavity |
| simple cuboidal epithelium |
one layer of cuboidal cells resting on a basement membrane |
| example(s) of simple cuboidal epithelium |
gland ducts (salivary glands & pancreas), walls of the kidney tubules & surface of ovaries |
| simple columnar epithelium |
single layer of tall cells fit closely together |
| goblet cells |
Individual cells (unicellular glands) that produce mucus. |
| examples of simple columnar epithelium |
lining of the entire length of the digestive tract from the stomach to the anus |
| mucosae/mucus membranes |
epithelial membranes that line body cavities open to the body exterior |
| pseudostratidified columnar epithelium |
all cells rest on basement membrane; some cells are shorter than others and their nuclei appear at different heights above the basement membrane |
| this epithelium gives a false impression that it is stratified |
pseudostratidified columnar epithelium |
| pseudostratidified ciliated columnar epithelium |
lines most of the respiratory tract; goblets cells produce mucus which traps dust & other debris, and cilia propel the mucus upward and away from the lungs |
| more durable than simple epithelia & function primarily to protect |
stratified epithelia |
| stratified squamous epithelium |
consists of several layers of cells; at the free edge are squamous cells & cuboidal/columnar cells at those close to the basement membrane |
| what is the most common epithelia in the body |
stratified squamous epithelium |
| esophagus, mouth & outer portion of the skin contain _____________ _______ __________ because they can withstand more friction/abuse. |
stratified squamous epithelium |
| stratified cuboidal epilethium |
typically has just two cell layers with (at least) the surface cells being cuboidal in shape |
| surface cells are columnar while the basal cells vary in size/shape |
stratified columnar epilethium |
| both types of epithelia are fairly rare in the body; mainly in the ducts of large glands |
stratified cuboidal & columnar epilethium |
| transitional epithelium |
highly modified, stratified squamous epithelium; allows for the cells to stretch |
| only a few organs, organs of the urinary system, contain this type of epithelium |
transitional epithelium |
| gland |
Organ specialized to secrete or excrete substances for further use in the body or for elimination. |
| gland secretion |
typically contains proteins in an aqueous fluid |
| secretion |
(1) The passage of material formed by a cell to its exterior; (2) Cell product that is transported to the exterior of a cell. |
| two major types of glands develop from epithelial sheets |
endocrine & exocrine glands |
| endocrine glands |
Ductless glands that empty their hormonal products directly into the blood; internal only because they lose their connection to the surface. |
| exocrine glands |
Glands that have ducts through which their secretions are carried to a particular site; both internal & external |
| thyroid, adrenal & pituitary |
the endocrine glands |
| sweat/oil glands, liver & pancreas |
the exocrine glands |
| connective tissue |
A primary tissue; form and function vary extensively. Functions include support, storage, and protection. |
| tissue primarily involved in protecting, supporting & binding together other body tissues |
connective tissue |
| the two characteristics of connective tissue are |
variations in blood supply & extracellular matrix |
| variations in blood supply |
most connective tissues are well vascularized but tendons & ligaments are not; cartilages are avascular |
| heal very slowly |
tendons, ligaments & cartilage |
| extracellular matrix |
Nonliving material that separates the living cells in connective tissue consisting of ground substance and fibers. |
| ground substance of the extracellular matrix |
composed largely of water plus some adhesion proteins and large, charged polysaccharide molecules |
| cell adhesion proteins, in the extracellular matrix, serve as ______ to allow the connective tissue cells to attach to the embedded matrix fibers |
glue |
| what causes the matrix to vary from fluid to gel-like to rock-hard in consistency? |
abundance of charged polysaccharide molecules which trap water as they intertwine. |
| collagen fibers |
white fibers distinguished by high tensile strength |
| elastic fibers |
yellow; key characteristic ability to be stretched & then recoil. |
| reticular fibers |
fine collagen fibers which form internal skeleton of soft organs |
| Where can you find reticular fibers? |
spleen |
| monomers |
building blocks of these fibers are made by the connective tissue cells & secreted into the ground substance in the extracellular space |
| extracellular space |
where monomers join together to form various fiber types |
| Fat cells are composed mostly of cells, so the matrix is ______ |
soft |
| bone & cartilage have very few cells and large amounts of _____ _____ |
hard matrix |
Linnette Francois
on 2009-10-09
Science Vocab 147928
