Bio

deamination

removal of an amino group from an organic compound

urea

nitrogen waste formed from two molecules of ammonia and one molecule of carbon dioxide

uric acid

a waste product formed from the breakdown of nucleic acids

ureter

a tube that conducts urine from the kidney to the bladder

urethra

the tube that carries urine from the bladder to the exterior of the body

cortex

the outer layer of the kidney

medulla

the area inside of the cortex

renal pelvis

the hollow area where the kidney joins the ureter

nephron

a functional unit of the kidney

afferent arteriole

a small branch of the renal artery that carries blood to the glomerulus

glomerulus

the high-pressure capillary bed that is the site of filtration

efferent arteriole

a small branch of the renal artery that carries blood away from the glomerulus to the peritubular capillaries

peritubular capillary

a member of the network of small blood vessels that surround the tubule of the nephron

Bowman's capsule

the cup like structure that surrounds the glomerulus

proximal tubule

the section of the nephron joining the Bowman's capsule with the loop of Henle

loop of Henle

the section of the tubule that carries filtrate from the proximal tubule to the distal tubule

distal tubule

distal tubule conducts urine from the loop of Henle to the collecting duct

collecting duct

a tube that carries urine from nephrons to the renal pelvis

threshold level

the maximum amount of a substance that can be moved across the nephron

interstitial fluid

the fluid that surrounds the body cells

venule

carries filtered blood out of the nephron

kidney functions

filter waste, water balance, pH regulation

duodenum

the first segment of the small intestine

villi

small, fingerlike projections that extend into the small intestine to increase surface area for absorption

microvilli

microscopic, fingerlike projections of the cell membrane

capillary

a blood vessel that connects arteries and veins; the site of fluid and gas exchange

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

erepsin

an enzyme that completes protein digestion by converting short-chain peptides to amino acids

lipase

breaks down lipids/fats to glycerol and fatty acids

bile salt

a component of bile that breaks down large fat globules

cholecystokinin

a hormone secreted by the small intestine that stimulates the release of bile salts

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 the growth of nonfunctioning fibrous tissue

colon

the largest segment of the large intestine, where water reabsorption occurs

gastrin

a hormone secreted by the stomach that stimulates the release of HCl

enterogastrone

a hormone secreted by the small intestine that decreases gastric secretions and motility

mouth

chewing of food and digestion of starch occurs here

stomach

storage of food and initial digestion of proteins occurs here

small intestine

digestion of carbohydrates, proteins, lipids; the absorption of nutrients occurs here

pancreas

production of digestive enzymes that act on food in the small intestine and storage of bicarbonate ions that neutralize stomach acid in the small intestine occurs here

large intestine

absorption of water and storage of undigested food occurs here

salivary amylase

initiates the breakdown of polysaccharides to simpler carbohydrates

stomach acid

converts pepsinogen to pepsin; kills microbes

pepsinogen

when converted to pepsin, initiates the digestion of proteins

mucus

protects the stomach from pepsin and HCl

pancreatic amylase

continues the breakdown of carbohydrates into disaccharides

bicarbonate ions

neutalize HCl from the stomach

trypsinogen

when activated to trypsin, converts long chain peptides into short-chain peptides

gall bladder

stores and secretes concentrated bile from the liver

bile

emulsifies fat; produced in the liver and stored in the gall bladder

ingestion

the taking in of nutrients

digestion

the breakdown of complex organic molecules into smaller components by enzymes

absorption

the transport of digested nutrients to the cells of the body

egestion

the removal of food waste from the body

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 tubelike structure

pepsin

a protein-digesting enzyme produced in the stomach

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 on 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

feedback inhibition

the inhibition of an enzyme in a metabolic pathway by the final product of that pathway

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

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

isomer

one of a group of chemicals that have the same chemical formula but different arrangements of the atoms

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

fat

a lipid composed of glycerol and saturated fatty acids; solid at room temperature

oil

a lipid composed of glycerol and unsaturated fatty acids; liquid at room temperature

phospholipid

a lipid with a phosphate molecule attached to the glycerol backbone, making the molecule polar; the major components of cell membranes

wax

a long-chain lipid that is insoluble in water

protein

a chain of amino acids that form the structural parts of 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

essential amino acid

an amino acid that must be obtained from the diet

denaturation

the process that occurs when the bonds of a protein molecule are disrupted, causing a temporary change in shape

coagulation

the process that occurs when the bonds of a protein molecule are disrupted, causing a permanent change in shape

chlorophyll

the light-absorbing green-coloured pigment that begins the process of photosynthesis

chloroplast

a membrane-bound organelle in green plant and algal cells that carries out photosynthesis

stroma

the protein-rich semiliquid material in the interior of a chloroplast

thylakoid

a system of interconnected flattened membrane sacs forming a separate compartment within the stroma of a chloroplast

grana (singular: granum)

stacks of thylakoids