Term
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Definition
| A methylated guanine nucleotide added to the 5' end of eukaryotic mRNA. The cap is necessary to initiate translation of the mRNA. |
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Definition
| The band of the sarcomere that extands the full length of the thick filament. This band includes regions of thick and thin filament overlap, as well as a region of thick filament only. These bands alternate with I bands to give skeletal and cardiac muscle tissue a striated appearance. This band does not shorten durig muscle contraction. |
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Term
| Absolute refractory period |
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Definition
| A period of time following an action potential during which no additional action potential can be evoked regardless of the level of stimulation. |
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Definition
| the three galnds in the male repoructive system that produce semen: the seminal vesicles, the prostate, and the bulbourethral glands |
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Term
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Definition
| 1. In the GI tract, organs that play a role in digestion, but are not directly part o fthe alimentary canal. These include the liver, the gallbladder, the pancreas, and the salivary glands. |
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Term
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Definition
| 2. In the reproductive systems, any iorgan involved in reproduction that is not a gonad (testis or ovary). |
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Definition
| The neurotransmitter usexc throughout the parasympathetic nervous system as well as at the neuromuscular junction. |
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Term
| Acetylcholinesterase (AChE) |
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Definition
| The enzyme taht breaks down acetylcholine in the synaptic cleft. |
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Term
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Definition
| The first substrate in the Krebs cycle, produced primarily from the oxidation of pyruvate by the pyruvate dehydrogenase complex, however this is also produced during fatty acid oxidation and protein catabolism. |
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Definition
| Enzymes that degrade various macromolecules and that require and acidic pH to function properly. Acid hydrolases are found within the lysosomes of cells. |
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Definition
| Cells that make up exocrine glands, and that secrete thier products into ducts. For example, in the pancreas, these secrete digestive enzymes; in the salivary glands, acinar cells secrete saliva. |
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Term
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Definition
| A region at the head of a sperm cell that contains digestive enzymes which, when released during the acrosome reaction, can facilitate penetration of the corona radiata of the oocyte and fertilization. |
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Term
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Definition
| A contractile protein. In skeletal and cardiac muscle, this polymerizes (along with other proteins) to form the thin filaments. This is involved in many contractile activities, such as cytokinesis, pseudopod formation, and muscle contraction. |
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Term
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Definition
| A localized change in a neuron's or muscle cell's membrane potential that can propagate itself away from its point of origin. These are an all-or-none process mediated by the opening of voltage-gated Na+ and K+ channels when the membrane is brought to the threshold potential; opening of the Na+ channels causes a characteristic depolarization, while opening of the K+ channels repolarizes the membrane. |
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Term
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Definition
| The amouont of energy required to produce the transition state of a chemical reaction. If the activation energy for a reation is very high, the reaction occurs very slowly. Enzymes (and other catalysts) increase reaction rates by reducing activation energy. |
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Term
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Definition
| The three-dimensional site on an enzyme where substrates (reactants) bind and a chemical reaction is facilitated. |
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Term
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Definition
| The movement of molecules through the plasma membrane against their concentration gradients. This requires input of cellular energy, often in the form of ATP. An example is the Na+/ K+ ATPase in the plasma membranes of all cells. |
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Term
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Definition
| One of the four aromatic bases found in DNA and RNA; also a component of ATP, NADH, and FADH2. Adenine is a purine; it pairs with thymine (in DNA) and with uracil (in RNA). |
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Definition
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Term
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Definition
| The inner region of the adrenal gland. This is part of the sympathetic nervous system, and releases epinephrine (adrenaline) and norepinephrine into the blood when stimulated. These hormones augent and prolong the effects of sympathetic stimulation in the body. |
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Term
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Definition
| A constant nervous input to the arteries that keeps them somehat constricted to maintain a basal level of blood pressure. |
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Term
| Adrenocorticotroic hormone (ACTH) |
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Definition
| A tropic hormone produced by the anterior pituitary gland that targets the adrenal cortex, stimulating it to release cortisol and aldosterone. |
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Term
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Definition
| The small artery that carries blood toward the capillaries of the glomerulus. |
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Term
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Definition
| A neuron that carries information (action potentials) to the central nervous system; a sensory neuron. |
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Term
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Definition
| A blood protein produced by the liver. This helps to maintain blood osmotic pressure (oncotic pressure). |
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Term
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Definition
| The principal mineralocorticoid secreted by the adrenal cortex. This steroid hormone targets the kidney tubules and increases renal reabsorption of sodium. |
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Term
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Definition
| Also known as the gastrointestinal (GI) tract or the digestive tract, this is the long muscular "tube" that includes the mouth, esophagus, stomach, small intestine, and large intestine. |
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Term
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Definition
| A version of a gene. For example, the gene may be for eye color, and the alleles include those for brown eyes, those for blue eyes, those for green eyes, etc. At most, diploid organisms can possess only two alleles for a given gene. one on each of the two homologous chromosomes. |
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Term
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Definition
| The modification of enzyme activity through interaction of molecules with specific sites on the enzyme other than the active site. |
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Term
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Definition
| Tiny sacs, with walls only a single cell thick, found at the end of the respiratory brochiole tree. These are the sites of gas exchange in the respiratory system. |
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Term
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Definition
| The monomer of a protein; these have an amin group on one end of the molecule, a carboxylic acid group on the other, and one of 20 different side chains. |
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Term
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Definition
| The 3' end of a rTNA molecule that binds an amino acid. The nucleotide sequene at this end is CCA. |
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Term
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Definition
| A tRNA with an amino acid attached. This is made by an aminoacyl-tRNA synthetase, an enzyme that is specific to the amino acid being attached. |
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Term
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Definition
| A sac filled with fluid (amniotic fluid) that surrounds and protects a developing embryo. |
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Term
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Definition
| The characteristic of a molecule that has both polar (hydrophilic) and non-polar (hydrophobic) regions. |
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Term
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Definition
| An enzyme that digests starch into disaccharides. This is secreted by salivary glands and by the pancreas. |
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Term
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Definition
| The process of building complex structures out of simpler precursors (e.g., synthesizing proteins from amino acids). |
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Term
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Definition
| Pysical structures in two different organisms that have functional similarity due to their evolution in a common environemtn, but that have different underlying structure. These arise from convergent evolution. |
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Term
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Definition
| The valve that controls the release of feces from the rectum. It has an internal part made of smooth muscle (thus involuntary) and an external part made of skeletal muscle (thus voluntary). |
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Term
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Definition
| The third phase of mitosis. During this, replicated chromosomes are split apart at their centromeres (the sister chromatids are separated from each other) and moved to opposite sides of the cell. |
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Term
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Definition
| The third phase of meiosis I. During this the replicated homologous chromosomes are separated (the tetrad is split apart) and pulled to opposite sides of the cell. |
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Term
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Definition
| The third phase of meiosis II. During anaphase II the sister chromatids are finally separated at their centromeres and pulled to opposite sides of the cell. |
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Term
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Definition
| male sex hormones. Testosterone is the primary one. |
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Term
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Definition
| A normal blood protein produced by the liver, this is converted to angiotensin I by renin (secreted by the kidney when blood pressure falls). Angiotensin I is further converted to angiotensin II by ACE (angiotensin converting enzyme). Angiotensin II is a powerful systemic vasoconstrictor and stimulator of aldosterone release, both of which result in an increase in blood pressure. |
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Term
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Definition
| Something that acts to oppose the action of something else. For example, muscles that move a joint in opposite directions are said to be this. |
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Term
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Definition
| Also known as the adenohypophysis, this is made of glandular tissue. It makes and secretes six different hormones: FSH, LH, ACTH, TSH, prolactin, and growth hormone. This is controlled by releasing and inhibiting factors from the hypothalamus. |
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Term
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Definition
| Also called immunoglobulins, these are proteins secreted by activated B-cells (plasma cells) that bind in a highly specific manner to foreign proteins (such as those found on the surface of pathogens or transplanted tissues). The foreign proteins are called antigens. These generally do not destroy antigens directly, rather, they mark them for destruction through other methods, and can inactivate antigens by clumping them together or by covering necessary active sites. |
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Term
antidiuretic hormone (ADH)
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Definition
| This hormone is produced in the hypothalamus and secreted by the posterior pituitary gland. It targets the kidney tubules, increasing their permeability to water, and thus increasing water retention by the body. Also called vasopressin. |
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Term
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Definition
| Cells that possess MHC II (B cells and macrophages), and are able to display bits of ingested antigen on their surface in order to activate T cells. |
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Term
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Definition
| The largest artery in the body that carries oxygenated blood away from the left ventricle of the heart. |
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Term
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Definition
| A mass of lymphatic tissue at the beginning of the large intestine that helps trap ingested pathogens. |
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Term
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Definition
| A thin, watery fluid found in the anterior segment of the eye (between the lens and the cornea). This is constantly produced and drained, and helps to bring nutrients to the lens and cornea, as well as to remove metabolic wastes. |
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Term
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Definition
| A protein complex found in the inner membrane of the mitochondria. It is essentially a channel that allows H+ ions to flow from the intermembrane space to the matrix (down the gradient producd by the enzyme complexes of the electron transport chain); as the H+ ions flow through the channel, ATP is synthesized from ADP and Pi. |
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Term
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Definition
| Also known as the bundle of His, this is the first portion of the cardiac conduction system after the AV node. |
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Term
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Definition
| The second major node of the cardiac conduction system (after the SA node). The cardiac impulse is delayed slightly at the AV node, allowing the ventricles to contract just after the atria contract. |
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Term
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Definition
| The division of the peripheral nervous system that innervates and controls the visceral organs (everything but the skeletal muscles). It is also known as the involuntary nervous system and can be subdivided into the sympathetic and parasympathetic division. |
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Term
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Definition
| A chromosome that does not determine gender (is not a sex chromosome). Humans have two sex chromosomes and 22 autosomes. |
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Term
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Definition
| A bacterium that cannot survive on minimal medium because it lacks the ability to synthesize a molecule it needs to live. These must have the needed substance added to their medium in order to survive. They are typically denoted by the substance they require followed by a "-" sign in superscript. For example, a bacterium that cannot synthesize leucine would be a leucine auxotroph, and would be indicated as leu-. |
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Term
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Definition
| lacking a blood supply (e.g. cartilage). |
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Term
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Definition
| A sensory receptor that responds to changes in pressure; for example, there are baroreceptors in the carotid arteries and the aortic arch that monitor blood pressure. |
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Term
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Definition
| A layer of collagen fibers that separates epithelial tissue from connective tissue. |
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Term
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Definition
| The flexible membrane in the cochlea that supports the organ of Corti (the structure that contains the hearing receptors). The fibers of this are short and stiff near the oval window and long and flexible near the apex of the conchlea. This difference in structure allows this membrane to help transduce pitch. |
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Term
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Definition
| A type of lymphocyte that can recognize (bind to) an antigen and secrete an antibody specific for that antigen. When activated by binding an antigen, these mature into plasma cells (that secrete antibody) and memory cells (that patrol the body for future encounters with that antigen). |
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Term
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Definition
| A fluid-filled sphere formed about 5 days after fertilization of an ovum that is made up of an outer ring of cells and an inner cell mass. This is the structure that implants in the endometrium of the uterus. |
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Term
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Definition
| The transfer of DNA or proteins from an electrophoresis gel to a nitrocellulose filter. |
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Term
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Definition
A non-bony material that fills the hollow spaces inside bones.
Red bone marrow is found in regions of spongy bone and is the site of blood cell production.
Yellow bone marrow is found in the diaphysis (shaft) of long bones, is mostly fat, and is inactive. |
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Term
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Definition
| The region of the nephron that surrounds the glomerulus. The capsule collects the plama that is filtered from the capillaries in the glomerulus. |
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Term
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Definition
| Enzymes secreted by the mucosal cells lining the intestine. These enzymes are disaccharidases and dipeptidases that digest the smallest carbohydrates and peptides into their respective monomers. |
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Term
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Definition
| A hormone produced by the C-cells of the thyroid gland that decreases serum calcium levels. It targets the bones (stimulates osteoblasts) and the kidneys (reduces calcium reabsorption). |
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Term
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Definition
| A hormone produced from vitamin D that acts to increase serum calcium levels. |
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Term
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Definition
| A cytoplasmic Ca2+ binding protein. This is particularly important in smooth muscle cells, where binding of Ca2+ allows calmodulin to activate myosin light-chain kinase, the first step in smooth muscle cell contraction. |
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Term
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Definition
| Very small tube or channel, such as is found between lacunae (connecting them together) in compact bone. |
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Term
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Definition
| An increase in the fragility of the membranes of sperm cells when exposed to the female reprouctive tract. This is required so that the acrosomal enzymes can be released to facilitate fertilization. |
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Term
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Definition
| The smallest of all blodd vessels. They have very thin walls to facilitate the exchange of material between the blood and the tissues. |
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Term
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Definition
| The outer protein coat of a virus. |
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Term
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Definition
| An enzyme present in erythrocytes (as well as in other places) that catalyzes the conversion of CO2 and H2O into carbonic acid. |
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Term
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Definition
This is striated, uninucleate, and under involuntary control. It is the muscle tissue of the heart.
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Term
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Definition
| A strong connective tissue with varying degrees of flexibility. |
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Term
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Definition
| The process of breaking down large molecules into smaller precursors, e.g. digestion of starch into glucose |
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Term
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Definition
| the primary enzyme in peroxisomes; catalase catalyzes the hydrolysis of hydrogen peroxide into water and oxygen |
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Term
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Definition
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Term
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Definition
| the first part of the large intestine |
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Term
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Definition
| The hollow center of an osteon, also known as a Haversian canal. This contains blood vessels, lumphatic vessels, and nerves. Bone is laid down around this in concentric rings called lamellae. |
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Term
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Definition
| Receptors in the CNS that monitor the pH of cerebrospinal fluid to help regulate ventilation rate. |
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Term
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Definition
| A thin layer of gray matter on the surface of the cerebral hemispheres. The cerebral cortex is the conscious mind, and is functionally divided into four pairs of lobes: the frontal lobes, the parietal lobes, the temporal lobes, and the occipital lobes. |
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Term
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Definition
| a gland that secretes a waxy product, found in the external ear canal. |
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Term
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Definition
| pepsinogen-secreting cells found at the bottom of the gastric glands of the stomach. |
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Term
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Definition
| A polysaccharide found in the cell walls of fungi and in the exoskeletons of insects. |
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Term
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Definition
| A hormone secreted by the small intestine (duodenum) in response to the presences of fats. It promotes release of bile from the gallbladder and pancreatic juice from the pancreas, and reduces stomach motility. |
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Term
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Definition
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Term
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Definition
| the portion of the placenta derived from the zygote. The chorionic villi secrete hCG to help maintain the endometrium during the first trimester of a pregnancy. |
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Term
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Definition
| The darkly pigmented middle layer of the eyeball, found between the sclera (outer layer) and the retina (inner layer). |
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Term
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Definition
| A type of lipoprotein; the form in which absorbed fats from the intestines are transported to the circulatory system. |
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Term
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Definition
| partially digested, semiliquid food mixed with digestive enzymes and acids in the stomach. |
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Term
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Definition
| one of the main pancreatic proteases; it is activated (from chymotrypsinogen) by trypsin. |
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Term
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Definition
| muscles that help focus light on the retina by controlling the curvature of the lens of the eye. |
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Term
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Definition
| The inner layer of smooth muscle in the wall of the digestive tract. When this, the tube diameter is reduced. Certain areas of the circular muscle are thickened to act as valves (sphincters). |
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Term
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Definition
| A fibrous protein found on the intracellular side of the plasma membrane (also found associated with the Golgi Complex) that helps to invaginate the membrane. |
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Term
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Definition
| The rapid mitotic divisions of a zygote that begin within 24-36 hours after fertilization. |
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Term
| The difference between a cofactor and a coenzyme |
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Definition
Coenzyme= organic molecule
cofactor=inorganic molecule |
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Term
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Definition
| A protein fiber with a unique triple-helix structure that gives it great strength. Tissues with a lot of this are typically very strong, e.g., bone, tendons, ligaments, etc. |
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Term
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Definition
| The portion of the nephron where water reabsorption is regulated via antidiuretic hormone (ADH). Several nephrons empty into each collecting duct, and this is the final region through which urine must pass on its way to the ureter. |
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Term
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Definition
| a group of blood proteins that bind non-specifically to the surface proteins of foreign cells (such as bacteria), ultimately leading to the destruction of the foreign cell. |
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Term
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Definition
| photoreceptors in the retina of the eye that respond to bright light and provide COlor vision. |
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Term
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Definition
| A form of genetic recombination in bacteria in which plasmid and/or genomic DNA is transferred from one bacterium to the other through a conjugation bridge. |
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Term
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Definition
| A supportive tissue Consisting of relatively few cells scattered amond a great deal of extracellular material (matrix), and includes adipose tissue (fat), bone, cartilage, the dermis of the skin, tendons, ligaments, and blood. |
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Term
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Definition
| the clear portion of the tough outer layer of the eyeball, found over the iris and pupil |
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Term
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Definition
| The layer of granulosa cells that surround an oocyte after it has been ovulated. |
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Term
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Definition
| The blood vessels that carry blood to and from cawrdiac muscle. |
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Term
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Definition
| the alrgest bundle of white matter (axons) connecting the two cerebral hemispheres. |
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Term
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Definition
| "Yellow body." The remnants of an ovarian follicle after ovulation has occurred. The cells enlarge and begin secreting progesterone, the dominant female hormone during the second half of the menstrual cycle. Some estrogen is also secreted. |
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Term
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Definition
| Steroid hormones secreted from the adrenal cortex. The two major classes are the mineralocorticoids and glucocorticoids. Aldosterone is the principal mineralocorticoid, and cortisol is the principal glucocorticoid. |
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Term
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Definition
| The principal glucocorticoid secreted from the adrenal corex. This steroid hormone is released during stress, causing increased blood glucose levels and reducing inflammation. The latter effect has led to a clinical use of cortisol as an anti-inflammatory agent. |
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Term
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Definition
| An energy storage molecule used by muscle tissue. The phosphate from this can be removed and attached to an ADP to generate ATP quickly. |
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Term
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Definition
| The connection of a myosin head group to an actin filament during muscle contraction (the sliding filament theory). |
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Term
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Definition
| The exchange of DNA between paired homologous chromosomes (tetrads) during prophase I of meiosis. |
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Term
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Definition
| The phase of mitosis during which the cell physically splits into two daughter cells. This begins near the end of anaphase, and is completed during telophase. |
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Term
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Definition
| one of the four aromatic bases found in DNA and RNA. This is a pyrimidine; it pairs with guanine. |
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