C: Diet & Digestion Flashcards
Absorption
Uptake of digested food molecules from the gut into the body (via the bloodstream or lymph). Mainly happened in small intestines.
Amino acids
Molecules which form the building-blocks of proteins.
Amylase
Enzyme that digests starch (eventually to glucose), produces by both salivary glands and pancreas.
Assimilation
The incorporation of the products of digestion into the body, where they are used to provide energy or for growth and repair of tissues.
Benedict’s solution/test
Test for glucose (or other ‘reducing sugars’). The sample is mixed with Benedict’s solution and heated to >90C. If an orange/red precipitate is formed the result is positive.
Bile
Green liquid produced in the liver and stored in the gall bladder, which contains alkali to neutralise stomach acid, and bile salts to emulsify lipids, increasing their surface area for faster digestion.
Carbohydrase
Enzyme (e.g. amylase) that breaks down carbohydrates.
Carbohydrate
Food belonging to the group consisting of sugars, starch and cellulose. They are vital for energy in humans and will be stored as fats if eaten in access. In plants, carbohydrates are produces by photosynthesis.
Colon
The large intestine, where water is absorbed into the blood.
Denature/denaturation
Inactivation of an enzyme (e.g. with heat) by putting its active site ‘out of shape’ so it no longer fits the substrate.
Digestive system
System of organs are involved with the ingestion, digestion, absorption of food.
Duodenum
The first part of the small intestine; site of digestion and absorption. Receives bile from the liver and pancreatic juice from the pancreas.
Egestion
Getting rid of undigested material from the body; = defaecation.
Emulsified
Converted into tiny droplets (e.g. by Bile).
Enzyme
Proteins which catalyse chemical reactions inside our bodies. Enzymes are a vital in chemical digestion of food in the gut.
Fats
Fats are the more solid lipids.
Fatty acids
Long-chain molecules made up of hydrogen and carbon atoms.
Fibre
Non-digestible carbohydrates. Fibre is essential as a bulking agent to help food pass quickly and easily through the bowel. A lack of fibre in the diet can lead to constipation, and increased risk of cancer.
Glucose
A simple sugar made by the body from food, which is used by cells to make energy in respiration.
Glycerol
A soluble carbohydrate which is converted into glucose by the liver.
Ileum
The longest part of the small intestine, where food is completely digested.
Ingestion
Intake of food.
Iodine solution/test
Test for starch in which iodine solution (I2 dissolved inn KI) is dripped on the sample. A blue-black colour is positive.
Lipase
Enzyme which digests lipids into fatty acids and glycerol. mainly produced by the pancreas.
Lipids
One of the maid food groups, including fats and oils. Lipids are used for energy and insulation. Usually made of glycerol & fatty acids.
Liver
Organ which constitutes the largest gland in the body. It produces bile to aid the digestion of fats, stored glucose in the form of glycogen, and helps break down protein and carbohydrates.
Mineral ions
Minerals needed by the body which are absorbed as charged ions ( e.g. Ca2+ and Fe3+) and not as part of proteins, fats or carbohydrates.
Oesophagus
Tube from the mouth to stomach; food is moved along it by peristalsis.
Oils
The more liquid types of lipids.
Peristalsis
Wave-like muscular contractions in the smooth wall of the gut which move food through the alimentary canal. Also happens in sperm ducts during ejaculation of sperm.
Proteins
Organic compounds made up of amino acid molecules. One of the three main food groups, proteins are needed by the body for cell growth and repair.
Protease
Type of enzyme which digests proteins to amino acids. Different proteases are adapted to conditions in the stomach (pepsin) and duodenum (trypsin).
Saliva
Fluid secreted by glands in the mouth which moistens and softens food. It contains the enzyme amylase which digests starch, and turn it back into glucose when it is needed for respiration.
Starch
A type of carbohydrate. Plants can turn the glucose produced in photosynthesis into starch for storage, and turn it back into glucose when it is needed for respiration.
Substrate
A substance on which enzymes act.
Sugar
Soluble, sweet-tasting carbohydrate (e.g. glucose, sucrose)
Villi ( singular = villus)
Minute finger-like projections which cover the lining of the small intestine, They aid digestion by greatly enlarging the gut’s surface area.
Vitamins
Organic substances which are essential in small amounts to regulate the metabolism and maintain the immune system. Named by letter, e.g. Vitamin C (=ascorbic acid) promotes healthy gums & prevents scurvy.
