B3 Science Flashcards
Active site
the site on an enzyme where the reactants bind
Amino acids
molecules made up of carbon, hydrogen, oxygen, and nitrogen that are the building blocks of proteins
Amylase
enzyme that speeds up the digestion of starch into sugars
Bile
neutralises stomach acid to give a high pH for the enzymes from the pancreas and small intestine to work well. It is not an enzyme
Carbohydrases
enzymes that speed up the breakdown of carbohydrates into simple sugars
Carbohydrates
molecules that contain only carbon, hydrogen, and oxygen. They provide the energy for the metabolism and are found in foods such as rice, potatoes, and bread
Catalyst
a substance that speeds up the rate of another reaction but is not used up or changed itself
Denatured
the breakdown of the molecular structure of a protein so it no longer functions
Differentiate
the process where cells become specialised for a particular function
Digestive system
organ system where food is digested and absorbed
Enzymes
biological catalysts, usually proteins
Fatty acids
part of the structure of a lipid molecule
Glycerol
part of the structure of a lipid molecule
Lipase
enzymes that speed up the breakdown of lipids into fatty acids and glycerol
Lipids
include fats and oils and are found in foods such as butter, olive oil, and crisps. They are made of carbon, hydrogen and oxygen
Metabolism
the sum of all the reactions taking place in a cell or the body of an organism
Organ
an aggregation (collection ) of different tissues working together to carry out specific functions
Protease
enzymes that speed up the breakdown of proteins into amino acids
Proteins
molecules that contain carbon, hydrogen, oxygen, and nitrogen and are made of long chains of amino acids. They are used for building the cells and tissues of the body and to form enzymes
Simple sugars
small carbohydrate units, for example glucose
Tissues
a group of specialised cells with a similar structure and function
Organelle
Cell structure that is specialised to carry out a particular function or job
Cell
Basic structural and functional unit of a living organism
Tissue
Group of cells with similar structures, working together to perform a shared function
Organ
Structure made up of a group of tissues, working together to perform specific functions
Organ system
Group of organs with related functions, working together to perform body functions
Mouth
Working together with your teeth, the mouth grinds food and mixes it with saliva. The mouth is where digestion begins and “solid food” is changed into “chewed food”.
Salivary Glands
These glands make saliva which contains an enzyme that changes some of the starches in the food to sugar
Epiglottis
Flap that closes windpipe during swallowing
Trachea (wind pipe)
Not part of the digestive system. Shown here with reference to the epiglottis
Gullet
Also known as the gullet. It is a tough, muscular tube that pushes food from the mouth to the stomach by contractions of its walls.
Stomach
Makes digestive juices called gastric juices, which break down “chewed food” into “partly digested food” before it goes to the small intestine for final digestion. Gastric juices are stored in tiny sacs (or bags) in the lining of the stomach. The stomach also serves as a storage tank for food.
Small intestine
Fluids from the liver and pancreas dilute and further digest the “partly digested food”. “Digested food”, now in a liquid form, is absorbed into the bloodstream through the tiny blood vessels in the small intestine walls. The “indigestible food” goes on to the large intestine.
Pancreas
Makes enzymes that break down all types of food. The pancreas sends enzymes and digestive juices into the small intestine to help reduce food to a liquid form.
Liver
Produces and discharges bile, a greenish-yellow digestive fluid. Bile travels from the liver to the small intestine, where it aids in the digestion of fats. The liver stores food which it releases into the blood whenever the body needs it. Also changes some digested food into compounds needed by the body’s cells.
Gallbladder
A pear-shaped pouch that lies under the liver. Extra bile is stored here in the gallbladder. Bile aids digestion by breaking up large molecules of fatty foods.
Large intestine
Fluids are absorbed from “indigestible food” which becomes “solid waste”. The large intestine stores the waste material until the body is ready to get rid of it.
Appendix
A small, worm-shaped organ attached to the large intestine. It does not seem to serve any purpose in the human body.
Anus
End of digestive tract, where food wastes leave the body
Ascending colon
the part of the large intestine that run upwards; it is located after the cecum.
Chyme
food in the stomach that is partly digested and mixed with stomach acids. Chyme goes on to the small intestine for further digestion.
Descending colon
the part of the large intestine that run downwards after the transverse colon and before the sigmoid colon.
Rectum
the lower part of the large intestine, where feces are stored before they are excreted.
Transverse colon
the part of the large intestine that runs horizontally across the abdomen.
