Chapter 17 - Nutrition and Metabolism Flashcards
assimilation (nutrition)
the absorption and digestion of food or nutrients by the body or any biological system
metabolism
A biochemical process that allows an organism to live, grow, reproduce, heal, and adapt to its environment.
The three main purposes of metabolism are:
1. the conversion of the energy in food to energy available to run cellular processes
2. the conversion of food to building blocks for proteins, lipids, nucleic acids, and some carbohydrates
3. the elimination of metabolic wastes
anabolism vs catabolism
Anabolism and catabolism are two metabolic processes, or phases.
Anabolism refers to the process which builds molecules the body needs; it usually requires energy for completion.
Catabolism refers to the process that breaks down complex molecules into smaller molecules; it usually releases energy for the organism to use.
nucleic acid
Naturally occurring chemical compounds that serve as the primary information-carrying molecules in cells and make up the genetic material. Nucleic acids are found in abundance in all living things, where they create, encode, and then store information of every living cell of every life-form on Earth.
hepatic portal vein
a vessel that moves blood from the spleen and gastrointestinal tract to the liver
nutrients
components of foods that are digested and absorbed by the body
macronutrients vs micronutrients
In basic terms, macronutrients are the nutrients that the body requires in large amounts, while micronutrients are those required in smaller amounts.
The macronutrients are carbohydrates, proteins, fats, and water.
The micronutrients are vitamins and minerals.
essential nutrient
A nutrient required for normal physiological function that cannot be synthesized in the body – either at all or in sufficient quantities – and thus must be obtained from a dietary source.
In the case of humans, there are nine amino acids, two fatty acids, thirteen vitamins and fifteen minerals that are considered essential nutrients. Water is also an essential nutrient.
carbohydrate
The preferred energy nutrient of the body. The larger carbohydrate molecules are composed of smaller “building blocks,” primarily glucose. Human cells catabolize (break down) glucose rather than other substances as long as enough glucose enters them to supply their energy needs.
Carbohydrates are a biomolecule consisting of carbon (C), hydrogen (H) and oxygen (O) atoms. Carbohydrates are also called saccharides.
oligosaccharide
a saccharide that contains usually three to ten monosaccharide units
triglyceride
any of a group of lipids that are esters formed from one molecule of glycerol and three molecules of one or more fatty acids, are widespread in adipose tissue, and commonly circulate in the blood in the form of lipoproteins
glycerol
One of the sugar alcohols. Sugar alcohols belong to a class of polyols characterized by being white, water-soluble, organic compounds with a general chemical formula of (CHOH)nH2.
polyols
an organic compound containing multiple hydroxyl groups
hydroxyl group
a chemical group that consists of one atom of hydrogen and one of oxygen and is neutral or negatively charged
kilojoule (kJ)
A unit used for measuring calories outside the United States
A simple way to convert kilocalories to kilojoules is kcal × 4.2 = kJ.
(remember the nutritional “calorie” is actually 1000 kilocalories of energy”
glycogenolysis
process by which glycogen, the primary carbohydrate stored in the liver and muscle cells of animals, is broken down into glucose to provide immediate energy and to maintain blood glucose levels during fasting
glycogenesis
the formation of glycogen, the primary carbohydrate stored in the liver and muscle cells of animals, from glucose
carbohydrate loading
A number of athletes and others who must occasionally sustain endurance exercise for a significant period practice carbohydrate loading (also called glycogen loading). As with liver cells, some skeletal muscle fibers can take up and store glucose in the form of glycogen. By ceasing intense exercise and switching to a diet high in carbohydrates 2 or 3days before an endurance event, an athlete can cause the skeletal muscles to store almost twice as much glycogen as usual. This allows the muscles to sustain aerobic exercise for up to 50% longer than usual.
fats
Any ester of fatty acids, or a mixture of such compounds, most commonly those that occur in living beings or in food. They are primarily energy nutrients. As cells begin to run low on adequate amounts of glucose to catabolize a few hours after a meal, they immediately shift to the catabolism of fats for energy.
ester
any of a class of organic compounds that react with water to produce alcohols and organic or inorganic acids
alcohol (chemical)
any of a class of organic compounds characterized by one or more hydroxyl (―OH) groups attached to a carbon atom of an alkyl group (hydrocarbon chain).
alkyl group
a functional group of an organic chemical that contains only carbon and hydrogen atoms, which are arranged in a chain
protein
Any of various naturally occurring extremely complex substances that consist of amino-acid residues joined by peptide bonds; the body uses protein to build its structures.
essential amino acids vs non-essential amino acids
The body uses amino acids to build its structures. Amino acids come from protein. Essential amino acids are amino acids the body cannot produce itself, and thus must consume from outside sources. Non-essential amino acids are produced by the body and do not need to be consumed.
