LS7C midterm keywords

signaling cell

the source of the signaling molecule

signaling molecule

the carrier of information transmitted when the signaling molecule binds to a receptor; also referred to as a ligand

receptor protein

the molecule on the responding cell that binds to the signaling molecule.

responding cell

the cell that receives information from the signaling molecule

receptor activation

the "turning on" of a receptor

signal transduction

the process in which an extracellular molecule acts as a signal to activate a receptor

response

a change in cellular behavior

termination

in protein translation

endocrine signaling

signaling by molecules that travel through the bloodstream

paracrine signaling

signaling by a molecule that travels a short distance to the nearest neighboring cell to bind its receptor and deliver its message

growth factoring

any one of a group of small

autocrine signaling

signaling between different parts of a cell; the signaling cell and the responding cell are one and the same

ligand

alternative term for a signaling molecule that binds with a receptor

ligand-binding site

the specific location on the receptor protein where a signaling molecule binds

G protein-coupled receptor

a receptor that couples to G proteins

G protein

a protein that binds to the guanine nucleotides GTP and GDP

receptor kinase

a receptor that is an enzyme that adds a phosphate group to another molecule

phosphatase

an enzyme that removes a phosphate group from another molecule

ion channels

cell-surface receptors that open and close

second messenger

an intermediate cytosolic signaling molecule that transmits signals from a receptor to a target within the cell; (first messengers transmit signals from outside the cell to a receptor)

binding affinity

the tightness of the binding between the receptor and the signaling molecule

tissue

a collection of cells that work together to perform a specialized function

organ

two or more tissues that combine and function together

cytoskeleton

in eukaryotes

cell junction

a complex of proteins in the plasma membrane where a cell makes contact with another cell or the extracellular matrix; allows tissues to be held together so that they can function as a unit; physically connect one cell to another and anchor cells to the cellular matrix

extracellular matrix

a meshwork of proteins and polysaccharides outside the cell; the main constituent of connective tissue; important for strong

epidermis

the outer layer of skin which serves as a water-resistant

dermis

the layer of skin beneath the epidermis

basal lamina

a specialized form of extracellular matrix that underlies and supports all epithelial tissues

microtubule

a hollow

microfilament

a helical polymer of actin monomers

intermediate filament

only in animal cells; a polymer of proteins

tubulin

dimers (composed of an α tubulin and a β tubulin) that assemble into microfilaments; one α tubulin and one β tubulin combine to make a tubulin dimer and the tubulin dimers are assembled to form the microtubule

centrosome

a compact structure that is the microtubule organizing center for animal cells

actin

a protein subunit that makes up microfilaments; used by both striated and smooth muscles to contract and generate force; microfilaments are polymers of these monomers arranged to form a helix

dynamic instability

cycles of shrinkage and growth in microtubules

motor protein

any of various proteins that are involved in intracellular transport or cause muscle contraction by moving the actin microfilaments inside muscle cells

kinesin

a motor protein

dynein

a motor protein that carries cargo away from the plasma membrane toward the minus ends of microtubules

cilium

a hairlike organelle that propels the movement of cells or of substances within cells or out of the body; shorter than a flagellum

flagellum

an organelle that propels the movement of cells or of substances within cells; longer than a cilium

myosin

a motor protein found in cells that carries cargo to the plus ends of microfilaments and is also used by both striated and smooth muscles to contract and generate force; muscle contraction depends on the interaction of this with microfilaments

cell adhesion molecule

a cell-surface protein that attaches cells to one another and to the extracellular matrix

cadherins

transmembrane proteins; a calcium-dependent adherence protein

integrin

a transmembrane protein

adherens junction

a beltlike junctional complex composed of cadherins that attaches a band of actin to the plasma membrane

desmosome

a buttonlike point of adhesion that holds the plasma membranes of adjacent cells together; cell junctions that allow cells to adhere to one another

hemidesmosome

a type of desmosome in which integrins are the prominent cell adhesion molecules; integrins are the prominent cell adhesion molecules in these

tight junctions

establish a seal between cells so that the only way a substance can travel from one side of a sheet of epithelial cells to the other is by moving through the cells by means of one of the cellular transport mechanisms

gap junction

a type of connection between the plasma membranes of adjacent animal cells that permits materials to pass directly from the cytoplasm of one cell to the cytoplasm of another; a complex of integral membrane proteins called connexins arranged in a ring

plasmodesmata

connections between the plasma membranes of adjacent plant cells that permit molecules to pass directly from the cytoplasm of one cell to the cytoplasm of another; the plasma membranes of the two connected cells are actually continuous

molting

periodic shedding

metamorphosis

the process in some animals in which the body changes dramatically at key stages in development

neurosecretory cell

a neuron in the hypothalamus that secretes hormones into the bloodstream

pituitary gland

A gland beneath the brain that produces a number of hormones

peptide hormone

hydrophilic hormone

amine hormone

hydrophilic hormone

steroid hormone

hydrophobic hormone; a hormone that is derived from cholesterol; sex hormones are these type of hormones

releasing factor

a peptide hormone that signals to the anterior pituitary gland through blood vessels

anterior pituitary gland

the region of the pituitary gland that forms from epithelial cells that develop and push up from the roof of the mouth; it receives hormones from the hypothalamus that stimulate it to release hormones in turn

posterior pituitary gland

the region of the pituitary gland that develops from neural tissue at the base of the brain and into which neurosecretory cells of the hypothalamus extend that secrete releasing factors

tropic hormone

a hormone that controls the release of other hormones

oxytocin

a posterior pituitary gland hormone that causes uterine contraction during labor and stimulates the release of milk during breastfeeding

antidiuretic hormone (ADH)

a posterior pituitary gland hormone that acts on the kidneys and controls the water permeability of the collecting ducts

thyroid gland

a gland located in the front of the neck that leads to the release of two peptide hormones

adrenal glands

paired glands located adjacent to the kidneys that secrete cortisol in times of stress

parathyroid gland

a gland adjacent to the thyroid gland that secretes parathyroid hormone (PTH)

pineal gland

a gland located in the thalamic region of the brain that responds to autonomic nervous system input by secreting melatonin

adrenal medulla

the inner part of the adrenal gland

acclimatization

an adaptive change in body function to a new environment

paracrine function

chemical compounds that act locally; ex. growth factors and histamines

autocrine function

chemical compounds that act on the secreting cell itself; the chemical signals may stimulate or inhibit their own secretion

pheromone

a water- or airborne chemical compound released by animals into the environment that signals and influences the behavior of other members of their species

external fertilization

fertilization that takes place outside the body of the female; in aquatic organisms

internal fertilization

fertilization that takes place inside the body of the female

r-strategist

a species that produces large numbers of offspring but provides few resources for their support

k-strategist

a species that produces relatively few young but invests considerable resources into their support

yolk

a substance in the eggs of animals with external fertilization that provides all the nutrients that the developing embryo needs until it hatches

amnion

in the amniotic egg

allantois

in the amniotic egg

chorion

in the amniotic egg

extraembryonic membrane

in the amniotic egg

oviparity

internal fertilization egg birth; animals that lay eggs; used by most insects

ovoviviparity

giving birth to live young

viviparity

giving birth to live young

placenta

in placental mammals

gonads

in mammals

acrosome

an organelle that surrounds the head of the sperm containing enzymes that enable sperm to transverse the outer coating of the egg

scrotum

a sac outside the abdominal cavity of the male that holds the testes

seminiferous tubules

a series of tubes in the testes where sperm are produced

epididymis

an organ that lies above the testes where sperm become motile and are stored prior to ejaculation

vas deferens

a long

ejaculatory duct

the duct through which sperm travel from the vas deferens to the urethra

urethra

a tube from the bladder that in males carries semen as well as urine from the body

prostate gland

an exocrine gland that produces a thin

seminal vesicles

two glands at the junction of the vas deferens and the prostate gland that secrete a protein- and sugar-rich fluid that makes up most of the semen and provides energy for sperm motility

bulbourethral glands

glands below the prostate gland that produce a clear fluid that lubricates the urethra for passage of the sperm

oocyte

the unfertilized egg cell produced by the mother; the developing female gamete

fallopian tube (oviduct)

a tube from each ovary

uterus

a hollow organ within the reproductive tract of female mammals with thick