Milady Chapter 3 Advanced Esthetics Advanced Histology of the Cell and Skin
humoral
(L. humor, "a fluid") pertaining to an endocrine secretion
fibrocyte
a cell that is not filly differentiated (it can go forward or backward in life), makes the most abundant protein in the body collagen, and originates from the mesenchymal tissue, also known as a fibroblast.
reticulocyte
a cell that is part of the blood cell line and forms from the acidophilic normoblast; it is 8 um in diameter and contains mitochondria
actin filaments
a protein in a muscle fiver that, together with myosin, is responsible for contraction and relaxation.
proteoglycans
a special class of glycoproteins found in the extracellular substance. They vary in size depending on the glycosaminoglycan chains attached to them
receptor
a special protein on a cell's surface within the cell that binds to specific ligands
G0
a stage of DNA synthesis; the resting cell
hemidesmosome
a structure that binds the basal layer to the basement membrane through different types of proteins
anchoring system
a system that ties the plaque to the cytoplasm through the cytoskeleton; it is located inside the cell behind the plasma membrane
B cell
a type of lymphocyte derived from bone marrow stem cells that matures into an immunologically competent cell (under the influence of bursa of fabricius in chickens, and the bone marrow of nonavian species); following interaction with antigen, it becomes a plasma cell, which synthesizes and secretes antibody molecules involved in humoral immunity. Also call B lymphocyte
T cell
a type of lymphocyte with a vital regulatory role in immune response; so called because they are processed through the thymus, Subsets of T cells may be stimulatory or inhibitory. They communicate with other cells by protein hormones called cytokines.
eosinophil
a while blood cell characterized by the presense of cytoplasmic granules that become stained by an acid (eosin) dye
basophil
a white blood cell characterized by the presence of blue cytoplasmic granules that become stained by a basophilic dye
What are the two families of keratins?
acidic and basic
What is a protein in a muscle fiber that, together with myocin, is responsible for contraction and relaxation?
actin
What is the process that requires expenditure of adenosine triphosphate (ATP) energy to move molecules across a cell membrane?
active transport
What are junctions that provide strong mechanical attachments between adjacent cells?
adherens junctions
What organic acids form the building blocks of proteins?
amino acids
elanunin
an elastin-type fiber found in the dermis believed to be an intermediate form of elastin
oxytalan
an elastin-type fiber found in the dermis that contains only microfibrils and is 10 - 12 nm in diameter
lysozyme
an enzyme capable of dissolving and digesting many types of biochemicals
What is the scientific name for chlorine bleach?
hypochlorous acid
mitochondria
in eukaryotes, subcellular organelles of a protein that conduct cellular respiration and produce most of the ATP in aerobic respiration (oxidative phosphorylation)
membrane
in living organisms, a phospholipid bilayers impregnated with protein and certain other compounds that is differently permeable
germ layer
in the animal embryo, one of three basic layers (ectoderm, endoderm, mesoderm) from which the various organs and tissues arise in the multicellular animal.
cytoskeleton
in the cytoplasm of eukaryotic cells, an internal framework of microtubules, microfilaments, and intermediate filaments that anchor, organize and moves organelles and other structures
What causes the release of interleukin-1?
injury to the skin
What body system is NOT controlled by the autonomic nervous system?
integumentary system
gap junctions
intercellular channels that allow free passage between the cells of ions and small molecules to pass between cells
What is vimentin?
intermediate filament found in fibroblasts
Where in the body is type V collagen found?
interstitial tissue
Merkel's discs
ivy shaped discs, sometimes called heiderform endings, that are in the epidermal tissue. Each disc includes receptors and consists of a modified epidermal cell, or Merkel cell, and its disc shaped terminal. These discs discriminate touch, shape and texture
adherens junctions
junctions that provide strong mechanical attachments between adjacent cells
What type of cell makes up the majority of the epidermis?
keratinocytes
What does the term "efferent" mean?
leading or conveying away from some organ
What is cholesterol?
lipid component of the stratum corneum
plaques
located in the cell membrane; they are made up of two proteins; desmoplakin and plakoglobin.
What is an enzyme capable of dissolving and digesting many types of biochemicals?
lysozyme
What is a protein that initiates part of the cellular division known as mitosis?
maturation promoting factor
What type of tissue transports signals to other organs?
nerve
free nerve terminals
nerve ending in the skin without myelin sheaths
corpuscles of ruffini
nerve endings in the subcutaneous tissue of the human finger that detect stretching of connective tissue and send slow continuous signals when stimulated. There are also heat detectors and are also known as organs of Ruffini
What do melanocytes originate?
neural crest
What part of a cell is responsible for creating ribosome components?
nucleolus
plasma membrane
see cellular membrane
What are the three types of muscle tissue?
skeletal, cardiac and smooth
ribosomes
small dense organelles that assemble proteins in cells
What are you MOST likely to find Meissner's corpsucles?
soles of the feet
What term refers to a cell capable of multiple divisions?
stem cell
What cells are also known as "mother cells"?
stem cells
keratinocytoblasts
stem cells that do not have a high rate of mitosis but do produce a transient amplifying cell
antigen
(1) a modified type of serum globulin synthesized by lymphoid tissue in response to antigenic stimulus; (2) any material that elicits an immune response
phagocyte
(G. phagein, "to eat," + kytos, "hollow vessel") any cell that engulfs and devours microorganisms or other particles (a process known as phagocytosis)
embryo
(Gr. "full of bursting") the first stage of human life; it starts with fertilization of a woman's egg (ovum) by a male's sperm
endoderm
(Gr. "inner") the deep primary germ layer of the embryo; it gives rise to the linings of the pharnyx, respiratory tree, digestive tract, urinary bladder and urethra
apoptosis
(Gr. apo, "away from," + ptosis, "a falling") genetically determined cell death; "programmed" cell death.
blastula
(Gr. blastos, "germ," + L. ula, "dim") an early stage in the development of an embryo; it consists of a sphere of cells enclosing a fluid-filled cavity (blastocoel).
ectoderm
(Gr. ektos, "outside," + derma, "skin") the outer layer of cells of an early embryo (gastrula stage); one of the germ layers, also sometimes used to include tissues derived from the ectoderm
epithelium
(Gr. epi, "on, upon," +thele, "nipple") a cellular tissue covering a free surface (internal and external) or lining a tube or cavity; it consists of cells joined by small amoints of cementing substances. Epithelial tissue is classified into types based on how many layers deep it is and the shape of the superficial cells.
erythrocyte
(Gr. erythros, "red," + kytos, "hollow vessel") A red blood cell that has hemoglobin to carry oxygen from lungs (or gills) to tissues; during their formation in mammals, erythrocytes lose their nuclei, but erythocytes of other vertebrates retain their nuclei.
cytotoxic (killer) T cell
(Gr. kytos, "hollow vessel") a special type of T cell activated during cell-mediated immune responses that recognizes and destroys virus-infected cells
cytokine
(Gr. kytos, "hollow vessel," + kinein, "to move") a molecule secreted by an activated or stimulated cell (e.g. macrophages) that causes chemical immune responses in certain other cells
lipase
(Gr. lipos, "fat") an enzyme that accelerates the hydrolysis, or synthesis of fats
macrophage
(Gr. makros, "long, large," + phago, "to eat") a phagoocytic cell type in vertebrates that performs crucial functions in the immune system response and inflammation, such as presenting antigens to T cells and producting several cytokines.
mesoderm
(Gr. mesos, "middle," + derma, "skin") the third germ layer, formed in the gastrula between the ectoderm; it gives rise to connective tissues, muscle, urogenital and vascular systems, and the peritoneum. This tissue from the mesoderm is called mesenchymal tissue.
myelin
(Gr. myelos, "marrow") fatty material forming the medullary sheath of nerve fibers
myosin
(Gr. mys, "muscle," + in, "belonging to") a large protein of contractile tissue that forms the thick myofilaments of striated muscle. During contraction, it combines with actin to form actomyosin.
afferent
(L. ad, "to lead," + ferre, "to bear") leading or bearing toward some organ, such as nerves conducting impulses toward the brain or blood vessels carrying blood toward and organ. Contrast with efferent.
corium
(L. corium, "leather") the deep layer of the skin; dermis
efferent
(L. ex, "out," + ferre, "to bear") leading or conveying away from some organ, such as nerve impluses conducted away from the brain, or blood conveyed away from an organ. Contrast with afferent
fibril
(L. fibra, "thread") strang of protoplasm produced by a cell and lying within the cell
granulocytes
(L. granules, "small grain." + Gr. kytos, "hollow vessel") white blood cells (neutrophils, eosinophils, and basophils) bearing granules (vacuoles) in their cytoplasm that stain deeply.
lymphokine
(L. lympha, "water, goddess of water," + Gr. kinein, "to move") a molecule secreted by an activated or stimulated lymphocyte that causes physiological changes in certain other cells.
lymphocyte
(L. lympha, "water, goddess of water," + Gr. kytos, "hollow vessel") a type of white blood cell; a component of the immune system produced by stem cells in the bone marrow. It is important to the immune system for its ability to digest foreign invaders
nucleolus
(diminutive of L. nucleus, "kernel") a deeply staining body within the nucleus of a cell that contains RNA; nucleoli are specialized portions of certain chromosomes that carry multiple copies of the information to synthesize ribosomal RNA
How many types of collagen are there?
11
What is the normal turnover time for the stratum corneum?
28 to 30 days
What pH is required to maintain micrococci?
5.0
What type of cell forms the basis of the humoral immune system?
B Cell
What is a complex process that reproduces the critical information in each cell for proper functioning and reproduction?
DNA Synthesis
What is the FINAL stage of the cell cycle?
M for mitosis
What are circular or ovoid structures with a distinct connective tissue capsule that can transmit touch, pressure and cold?
Meissner's corpuscles
What statement about cells is correct?
The process of cellular differentiation occurs shortly after conception
What type of collagen is found in the skin, bone, and tendon?
Type |
epidermolysis bullosa
a blistering congenital disease caused by defects in keratins 5 and 14 in the basal layer
white blood cell (leukocyte)
a blood cell responsible for the body's defense mechanisms. White blood cells act by destroying disease-causing germs. Also called white corpuscles
basophilic normoblast
a blue-colored cell formed from the division of the pronormoblast; this cell (6- 18 um in diameter) produces polychromatic normoblasts
immune system
a bodily system made up of lymph, lymph nodes, the thymus gland, the spleen, and lymph vessels; it protects the body from disease by developing immunities and destroying disease-causing microorganisms as well as draining the tissues of excess interstitial fluids to the blood. This system carries waste and impurities away from the cells.
senescent cell
a cell arrested in G1 that cannot advance or go backward and in some cases is destroyed; a major cause of aging
pluripotential stem cell
a cell at the start of the blood cell line that is programmed to form all other cells in the bloodstream
stem cell
a cell capable of multiple divisions also known as the mother cell
mother cell
a cell capable of multiple divisions, as known as a stem cell
Langerhans Cells
a cell that fixes and processes cutaneous antigens; it contains large granules called Birbeck granules. Also known as dendritic cells.
polychromatic normoblast
a cell that is part of the blood cell line and forms from the basophilic normoblast; it is 9-12 um in diameter. It starts to make hemoglobin, but can no longer divide
pronormoblast
a cell that is part of the blood cell line and forms from the division of the hemocytoblast; it is 20 um in diameter. It continues to divide and forms the basophilic normoblasts
B Lymphocyte
a cell that manufactures antibodies involved in immunity
melanocyte
a cell that produces pigment granules/melanin in the basal layer of the epidermis
daughter cell
a cell that results after the division of a stem cell. The original cell is called the mother cell
cluster of differentiation (CD)
a cluster of cells in which all cells are coated with antigenic substances, each of the more than 160 clusters has a different chemical molecule that coats the surface. Every T and B cell has bout 10 molecules on its surface.
DNA Synthesis
a complex process that reproduces the critical information in each cell for proper function
complement system
a complex series of enzymes in the blood that coats microbes with special molecules, making them more susceptible to phagocytosis
extracellular matrix (ECM)
a composite material having both solid and liquid protein structures that serve as support materials and monitoring systems in the skin
interleukin-1 (IL-1)
a ctyokine produced by macrophages that stimulates T helper lymphocytes
endoplasmic reticulum (ER)
a cytoplasmic organelle composed of a system of interconnected membranous tubules and vesicles; rough ER has ribosomes attached to the side of the membrane facing the cytoplasm and smooth ER does not. Rough ER functions in protein synthesis; smooth ER functions in lipid synthesis
lysosome
a cytoplasmic, membrane-bounded organelle that contains digestive and hydrolytic enzymes, which are typically most active at the acid pH found in the lumen lysosomes. It digests foreign matter considered potentially threatening to the body
zygote
a diploid cell produced by the fusion of an egg and sperm; a fertilized egg cell
blastocoel
a fluid-filled or yolk-filled cavity surrounded by a blastoderm
dermatan sulfate
a glycosaminoglycan; a complex carbohydrate in the dermis
platelet-derived growth factor (PDGF)
a growth-regulating cytokine thought to be responsible for initiating proliferation of fibroblasts and other connective-tissue cellls
insulin-like growth factor (IGF-1)
a growth-regulating cytokine thought to be responsible for initiating proliferation of fibroblasts and other connective-tissue cells
cornified envelope
a highly cross-linked layer of proteins found in the stratum corneum
melanocyte stimulation hormone (MSH)
a hormone that stimulates melanocytes to make melanin
monocyte
a large white blood cell, or leukocyte, that travels the bloodstream neutralizing pathogens; it becomes a phagocytic cell (macrophage) after moving into tissues
external ectoderm
a layer of the ectoderm germ layer that supplies the skin
neural tube
a layer of the ectoderm germ layer; it provides most of the central nervous system
free fatty acid
a lipid component of the stratum corneum
desmogleins
a member of the desmosome family; it projects cadherin proteins, is calcium binding, and extends from the plaques that interlock with identical proteins from the adjacent cell
desmocollins
a member of the desmosome family; it projects proteins, is calcium dependent, and extends from the plaques that interlock with identical proteins from the adjacent cell
lipid bilayer
a molecular structure composed of hydrophilic and hydrophobic components
adenosine triphosphate (ATP)
a multifunctional nucleotide that transports chemical energy within cells for metabolism and converts oxygen to carbon dioxide
sensory (afferent) neuron
a nerve that carries impulses or messages from the sense organs to the brain, where sensations to touch, cold, heat, sight, hearing, taste, smell, pain and pressure are experienced
Akt
a pathway used as an intermediate signal as part of the DNA signaling cascade
JNK
a pathway used as an intermediate signal as part of the DNA signaling cascade
MAPK
a pathway used as an intermediate signal as part of the DNA signaling cascade
fibroblast growth factor (FGF)
a peptide that stimulates fibroblasts to grow fibrocytes
gastrulation
a process during which the cells migrate to the interior of the blastula and from three germ layers
active transport
a process that requires expenditure of ATP energy to move molecules across a cell membrane, also called facilitated transport
respiratory burst
a process that uses oxygen in the kill action of neutrophils
catenin
a protein important in stabilizing cell adherence to avoid abnormal spread of cells
cyclin
a protein important in the control of the cell division cycle and mitosis
receptor site
a protein on the cell membrane, within the cytoplasm, or on the cell nucleus that binds to a specific molecule (a ligand), such as a neurotransmitter, hormone, or other substance and initiates the cellular response
p27 protein
a protein that binds to cyclin and CdK, blocking entry into thee S phase
tubulin
a protein that forms parts of the microtubules
integrin
a protein that holds the plaque to the basal lamina
maturation promoting factor (MPF)
a protein that initiates part of the cellular division known as mitosis. Specifically, it initiates the prophase of mitosis and also functions in the process of mitosis by activating other proteins through the mechanism of phosphorylation; that is, it adds phosphorous to the protein, thereby making it an active protein
chondroitin sulfate
a proteoglycan found in the dermis
keratin sulfate
a proteoglycan found in the dermis
versican sulfate
a proteoglycan found in the dermis; it provides turgor and tautness to the skin by interacting with elastin and hyaluronic acid
tight juntion
a region of actual fusion of cell membranes between two adjacent cells
cycle
a repeating unit that makes up the pattern of biological rhythms
pacinian corpuscles
a sensory receptor in skin, muscles, body joints, body organs and tendons that involved with the vibratory sense and firm pressure on the skin; also called lamellated corpuscles
reflex arc
a structure that is critical to the autonomic nervous system (ANS). It has two parts; the sensory (afferent) arm and the motor (efferent or effector) arm
fourth germ layer
a the component of the ectoderm known as the neural crest
p53 protein
a tumor-suppressor protein with critical functions in normal cells. A mutation in the gene that encodes it, p53, can result in loss of control over cell division and, thus cancer
mast cell
a type of cell in various tissues that releases pharmacologically active substances with a role in inflammation
cyclin-dependent kinase (CdK)
an enzyme that adds phosphate to a protein along with cyclins and is a major control switch for the cell cycle
myeloperoxidase
an enzyme used in the killing action of neutrophils
pro-enzyme
an inactive form of chymotropic enzyme found in the lamellar bodies of the stratum granulosum
vimentin
an intermediate filament found in fibroblasts
neurofilament
an intermediate filament found in nerve cells
golgi apparatus
an organelle of membranous, hollow sacs arranged in a stack; it functions in modification store, and packaging of secretion materials. It may be called a dictyosome in plants. Also known as the Golgi complex
superoxide
an unstable, reactive single oxygen atom
What term refers to the system that controls involuntary functions of the circulatory, respiratory, endocrine and digestive systems?
automatic nervous system
What type of granulocytes are LEAST common?
basophils
What is an embryo called after 100 cells have been produced following conception?
blastula
keratinohyaline granules
both horny and hyaline, a distinguishing feature of the cells in the granular layer
What is NOT one of the four basic tissues of the body?
cardiac
What is a protein important in stabilizing cell adherence to avoid abnormal spread of cells?
catenin
memory T cells
cells that are programmed to recognize and respond to a pathogen once it has been invaded and repelled
dendritic cell
cells that fix and process cutaneous antigens; they contain large granules called Birbeck granules. Also known as Langerhans cells.
suppressor T cells
cells that inhibit the production of cytotoxic cells once they are no longer needed so they do not cause more damage than necessary
islet of Langerhans cells in the pancreas
cells that make insulin and are responsible for diabetes when they fail to function
neuroglia
cells that provide support and nutrition to the tissues
helper T cells
cells that serve as managers and direct the immune response, they also secrete lymphokines
What statement about charged compounds is correct?
charged compounds tend to interact with proteins in the skin
hypochlorous acid
chlorine bleach, HOCI
Meissner's corpuscles
circular or ovoid structures with a distinct connective tissue capsule that transmit touch, pressure and cold
What is the MOST abundant protein in the body?
collagen
intermediate filaments
complex fibers that help maintain cell shape, but also add strength to cells and hold them together
antibodies
components of the immune system that neutralize antigens
Where are organelles found?
cytoplasm of eukaryotic cells
What happens to a cell during apoptosis?
death of the cell
What is a zygote?
diploid cell produced by the fusion of an egg and sperm
neural crest
early nerve tissue in the embyro; the site of origin for melanocytes and a layer of the ectoderm germ layer
mesenchymal tissue
embryonic connective tissue
What cranial nerve is the maxillary nerve a branch of?
fifth
How long should the stratum corneum be allowed to recover between chemical peels?
four weeks
thymidine dinucleotide fragments
fragments produced by damaged DNA, triggering the release of MSH, which can then bind to melanocytes to produce melanin
What are nerve endings in the skin without myelin sheaths?
free nerve terminals
What type cellular bond forms intercellular channels that allow free passage between the cells of ions and small molecules?
gap junctions
What is apoptosis?
genetically determined cell death
polymorphonuclear cells (PMNs)
granulocytes
What are the two major types of white cells?
granulocytes and lymphocytes
What to the corpsucles of Ruffini detect?
heat
What are cells that serve as managers and direct the immune response?
helper T cells
What structures bind the basal layer to the basement membrane through different types of proteins?
hemidesmosomes
What is the study of tiny structures found in living tissues?
histology
What two glycosaminoglycans account for most of the proteoglycans?
hyaluronic acid and dermatan sulfate
What characteristics BEST describe the lipid tail of a phospholipid?
hydrophobic and nonpolar
What is a phospholipid bilayer in living organisms that is impregnated with protein and certain other compounds and that is differentially permeable?
membrane
vacuoles
membrane-bound compartments within some eukaryotic cells that can serve a variety of secretory, excretory and storage function
What are cells that are programmed to recognize and respond to a pathogen once it has invaded and been repelled?
memory T cells
What is the fatty material forming the medullary sheath of nerve fibers?
myelin
What is a layer of the ectoderm germ layer that provides most of the central nervous system?
neural tube
What part of the ectoderm germ layer provides cells to most of the central nervous system?
neural tube
What is the basic unit of the nervous system, consisting of a cell body, a nucleus, dendrites and an axon?
neuron
What type of cells kill infected cells with oxygen in a process called respiratory burst?
neutrophils
heparan sulfate
one of seven glycosaminoglycans that make up the proteoglycans found in the skin
heparin
one of seven glycosaminoglycans that make up the proteoglycans in the skin
desmoplakin
one of the two proteins that make up the plaques in the cell membrane
plakoglobin
one of the two proteins that make up the plaques in the cell membrane
amino acids
organic acids that form the building blocks of proteins. Twenty amino acids are used within the human body; nine of these are essential amino acids and muse be supplied by the diet.
What type of dermal fibers contain ONLY microfibrils?
oxytalan fibers
What type of infections do eosinophils target in the body?
parasitic
acidophilic normoblasts
part of the blood cell line and formed from the polychromatic normoblast, this cell (8 - 20 um in diameter) loses its nucleus at this stage
hemocytoblast
part of the blood cell line, this multipotential cell can form white blood cells, red blood cells, and any other cells in the blood
cutaneous
pertaining to the skin
What do MOST of the clones produced through clonal selection become?
plasma cells
microfilaments
protein strands made of actin, they are responsible for cell movement and cell shape
keratin proteins
proteins that are made in the skin and hair that resist water and frictions
What is the process that uses oxygen in the killing action of neutrophils?
respiratory burst
Which organelle is the protein construction department of the cell?
ribosome
What layer of the epidermis contains the MOST Langerhans cells?
stratum spinosum
lymphotoxins
substances that, when released by cytotoxic or killer T cells, cause cell lysis
glial cells
supportive cells closely associated with neurons
selective permeability
the ability of the plasma membrane to let some substances in and keep others out; permeable to small molecules, usually H2O, O2, and CO2, but not permeable to larger molecules or ions
proteolysis
the act of breaking the desmosomal bounds of connecting proteins
protein-tyrosine kinase (PTK) activity
the action of a complex enzyme that catalyzes the phosphorylation of tyrosine residues. There are 91 identified PTK enzymes, which are involved in cellular signaling pathways and regulate key cell functions such as proliferation, differentiation, anti-apoptotic signaling, and neurite outgrowth. Unregulated activation of these enzymes, through mechanisms such as point mutations or overexpression, can lead to various forms of cancer as well as benign proliferative conditions. The imporatance of PTKs in health and disease is further underscored by the existence of aberrations in PTK signaling occurring in inflammatory diseases and diabetes. In short, this is a very important enzyme that activates other enzymes.
cleavage
the early mitotic and cytoplasmic divisions of an embryo
trigeminal nerve
the main sensory nerve of the face; it has three major brances
nuclear membrane
the membrane surrounding the nucleus of eukaryotic cells
neutrophils
the most abundant polymorphonuclear leukocytes; phagocytic white blood cells
gastrula
the name for an embryo during the gastrulation process
G2
the part of interphase after the synthesis of DNA and before the start of nuclear division; also known as Gap 2
G1
the part of interphase that is the time of active metabolism in the cell cycle; also known as Gap 1
cell-mediated immunity
the part of the immune system that destroys viruses using T cells instead of antibodies
blastoderm
the primary epithelium formed in early embryonic development of many arthropods when the nuclei migrate to the periphery and undergo superficial cleavage; usually encloses the central yolk mass
homeostasis
the process of feedback and regulation that keeps the body in a state of equilibrium within its environment.
melanogenesis
the process of making the pigment melanin inside the melanocyte
cell cycle
the regular sequence of events in the life of a cell, during which the cell grows, prepares for division, duplicates its contents, and divides to form two daughter cells
cell wall
the rigid outermost layer of the cells found in plants, some protists (a type of single-cell organism), and most bacteria. Found in plants composed principally of cellulose. Not found in animal cells.
transit time
the time it takes for cells to move through the epidermal stages of growth
end-bulbs Krause
thermoreceptors that detect cold; they are found in the skin; the conjuctiva of the eye, the mucous membranes of the lips and tongue, the penis and clitoris, and the fingertips.
What is a region of actual fusion of cell membranes between two adjacent cells?
tight junction
microtubules
tiny, cylindrical tubes composed of a protein called tubulin; its major function is to separate chromosomes during cellular division
cadherins
transmembrane protein that go from cell to cell and bind to each other
connexins
transmembrane proteins that permit the flow of ions that cause contraction of the heart muscle and strong contraction of the uterus during labor
What is a superoxide?
unstable, reactive single oxygen atom
What are membrane-bound compartments within some eukaryotic cells that can serve a variety of secretory, excretory and storage functions?
vacuoles
What causes tissue to release epidermal growth factor (EGF)?
wound