Human Nutrition
Pyruvate acid
A 30carbon intermediate formed as a result of anaerobic metabolism.
Neurotransmitters
A compound made by a nerve cell that allows communication between it and other cells.
Phosphocreatine(PCr)
A high energy compound that can be used to re-form ATP from ADP. It is used primarily during short bursts of energy, such as lifting and jumping.
Glycolysis
A series of chemical reactions that converts the 6-carbon glucose to two 3-carbon pyruvate molecules with a net gain of 2 ATP.
Electron Transport Chain
A series of chemical reactions that unite the hydrogens derived from energy nutrients with oxygen to form water and the transformation of energy to ATP.
Lactate/Lactic acid
A three carbon acid; formed during anaerobic cell metabolism; a partial breakdown product of glucose.
Leptin
An appetite-suppressing hormone produced in fat cells that conveys information about body fat to the appetite centers of the brain. Believed to be involved in the maintenance of body composition.
Skinfold thickness
An inexpensive technique for assessing body composition by the use of calipers to measure the amount of fat under the skin, inaccuracy increases with obesity.
Krebs Cycle
Citric acid Cycle of Tricarboxylic Acid Cycle) A series of chemical reactions that participates in energy transformation reactions with a net gain of 1 ATP per cycle. Involves the B-vitamins thiamin, riboflavin, niacin and pantothenic acid.
Thyroxin
Hormone containing 4 atoms of iodine per molecule.
Calorimetry
Measurement of heat
Indirect Calorimetry
Measuring energy expenditure by measuring gas exchanges to estimate the amount of heat produced in a given period of time based on the amount of oxygen inhaled and the amount of carbon dioxide exhaled.
Direct Calorimetry
Measuring energy expenditure directly by using a human calorimeter.
Aerobic metabolism
Metabolism requiring oxygen.
Anaerobic metabolism
Metabolism that occurs without oxygen.
Set point
Often refers to the close regulation of body weight. It is not known what cells control this set point nor how it actually functions in weight regulation. There is evidence, however, that mechanisms exist that help regulate weight.
Gastroplasty
Surgery performed on the stomach to limit the value to approximately 50 milliliters, the size of a shot glass.
Resting metabolic rate (RMR)
The amount of energy used during rest, without stringently controlling rescent physical activity. Essential the same as the basal metabolic rate, but the subject does not need to meet the strict conditions used for a basal metabolic rate determination. Today, both terms are often used interchangeably.
Thermic effect of food
The increase in metabolism that occurs during the digestion, absorption, and metabolism called diet-induced thermogenesis; this represents about 5% to 10% of energy consumed.
Basal metabolism
The minimal energy the body requires to support itself when resting and awake. It amounts to roughly 1kcal/minute, or about 1400kcal per day.
Lean body mass
The part of the human body that is free of all but essential body fat. About 2% of body weight as fat is essential. The rest of the fat in the body represents storage and so is not part of lean body mass. Lean body mass includes brain, muscle, bone, organs, connective tissue, skin and other body parts, including body fluids, such as blood.
Basal metabolic rate (BMR)
The rate at which the body uses energy to support its basal metabolism.
Upper-body obesity
The type of obesity also called android, in which fat is stored primarily in the abdominal area; defined as a waist-to-hipcircumference ratio of greater than 1.0 in men and 0.8 in women; closely associated with a high risk of heart disease, high blood pressure, and diabetes.
Lower body obesity
The type of obesity, also called gynoid, in which fat storage is primarily located in the buttocks and thigh area.
Body Mass Index (BMI)
Weight (in kilograms) divided by height squared (in meters). A value of 25 or greater indicates a higher risk for obesity-related health disorders.