Unit D: Human Systems Flashcards
Carbohydrate
a molecule composed of sugar subunits that contain carbon, hydrogen, and oxygen in a 1:2:1 ratio
Polymer
a molecule composed of three or more subunits
Monosaccharide
a single sugar unit
Disaccharide
a sugar formed by the joining of two monosaccharide subunits
Dehydration Synthesis
the process by which larger molecules are formed by the removal of water from two smaller molecules
Hydrolysis
the process by which larger molecules are split into smaller molecules by the addition of water
Polysaccharide
a carbohydrate composed of many single sugar subunits
Starch
a plant carbohydrate used to store energy
Glycogen
the form of carbohydrate storage in animals
Cellulose
a plant polysaccharide that makes up plant cell walls
Triglyceride
a lipid composed of glycerol and three fatty acids
Protein
a chain of amino acids that form the structural parts of the cells or act as antibodies or enzymes
Amino Acid
a chemical that contains nitrogen; can be linked together to form proteins
Peptide Bond
the bond that joins amino acids
Polypeptide
a chain of three or more amino acids
Denaturation
the process that occurs when the bonds of a protein molecule are disrupted, causing a temporary change in shape
Coagulation
that process that occurs when the bonds of a protein molecule are disrupted, causing a permanent change in shape
Catalyst
a chemical that increases the rate of chemical reactions without altering the products or being altered itself
Enzyme
a protein catalyst that permits chemical reactions to proceed at low temperatures
Substrate
a molecule in which an enzyme works
Active Site
the area of an enzyme that combines with the substrate
Cofactor
an inorganic ion that helps an enzyme combine with a substrate molecule
Coenzyme
an organic molecule synthesized from a vitamin that helps an enzyme to combine with a substrate molecule
Competitive Inhibitor
a molecule with a shape complementary to a specific enzyme that competes with the substrate for access to the active site of the enzyme and blocks chemical reactions
Precursor Activity
the activation of the last enzyme in a metabolic pathway by the initial substrate
Allosteric Activity
a change in an enzyme caused by the binding of a molecule
Amylase
an enzyme that breaks down complex carbohydrates
Peristalsis
rhythmic, wavelike contractions of muscle that move food along the gastrointestinal tract
Sphincter
a constrictor muscle that regulates the opening and closing of a tube-like structure
Mucus
a protective lubricating substance composed mostly of protein
Pepsin
a protein-digesting enzyme produced in the stomach
Ulcer
a lesion on the surface of an organ
Duodenum
the first segment of the small intestine
Villi
small, finger-like projections that extend into the small intestine to increase surface area for absorption
Microvilli
microscopic, finger-like projections of the cell membrane
Capillary
a blood vessel that connects arteries and veins; the site of fluid and gas exchange
Lacteal
a small vessel that transports the products of fat digestion to the circulatory system
Secretin
a hormone released from the duodenum that stimulates pancreatic and bile secretions
Enterokinase
an enzyme of the small intestine that converts trypsinogen to trypsin
Trypsin
a protein-digesting enzyme
Lipase
a lipid-digesting enzyme
Bile Salt
a component of bile that breaks down large fat globules
Detoxify
to remove the effects of a poison
Gallstone
crystals of bile salts that form in the gallbladder
Jaundice
the yellowish discoloration of the skin and other tissues brought about by the collection of bile pigments in the blood
Cirrhosis
chronic inflammation of the liver tissue characterized by growth of non-functioning fibrous tissue
Colon
the largest segment of the large intestine, where water reabsorption occurs
Cilia
tiny hair-like structures found on some cells that sweep away foreign debris
Pleural Membrane
a thin membrane that surrounds the outer surface of the lungs and lines the inner wall of the chest cavity
Hemoglobin
the oxygen-carrying molecule in red blood cells
Oxyhemoglobin
hemoglobin that is bond to oxygen
Carbonic Anhydrase
an enzyme found in red blood cells that speeds the conversion of carbon dioxide and water to carbonic acid
Buffer
a substance capable of neutralizing acids and bases, thus maintaining the original pH of the solution
Chemoreceptor
a specialized nerve receptor that is sensitive to specific chemicals
Flexor
the muscle that must contract to bend a joint
Extensor
the muscle that must contract to straighten a joint
Tendon
a band of connective tissue that joins muscle to bone
Pulse
change in the diameter of the arteries following heart contractions
Vasoconstriction
the narrowing of blood vessels, allowing less blood to the tissues
Vasodilation
the widening of blood vessels, allowing more blood to the tissues
Aneurysm
a bulge in the weakened wall of a blood vessel, usually an artery
Pulmonary Circulatory System
the system of blood vessels that carries deoxygenated blood to the lungs and oxygenated blood back to the heart
Systemic Circulatory System
the system of blood vessels that carries oxygenated blood to the tissues of the body and deoxygenated blood back to the heart
Diastole
relaxation (dilation) of the heart, during which the atria fill with blood
Systole
contraction of the heart, during which blood is pushed out of the heart
Leukocyte
a white blood cell
Erythrocyte
a red blood cell that contains hemoglobin and carries oxygen
Platelet
a component of blood responsible for initiating blood clotting
Antigen
a substance, usually a protein, that stimulates the formation of an antibody
Antibody
a protein formed within the blood that reacts with an antigen
T Cell
a lymphocyte that identifies and attacks foreign substances
B Cell
a lymphocyte that produces antibodies
Helper T Cell
a T cell with receptors that bind to fragments of antigens
Killer T Cell
a T cell that destroys microbes, body cells infected with viruses, and mutated cells by puncturing cell membranes
Suppressor T Cell
a T cell that turns off the immune system
Memory B Cell
a B cell that retains information about the shape of an antigen
Nephron
a functional unit of the kidney
