chapter 17: nutrition and metabolism Flashcards
the term that refers to the food we eat and nutrients they contain
nutrition
____ is a nutritional guid that promotes variety, moderation and better food choices
Myplate
how the body uses nutrients after they have been digested, absorbed and transported to cells
metabolism
occurs when nutrient molecules enter cells and undergo various chemical changes
assimilation
releases energy as it breaks down nutrient molecules into smaller molecules
catabolism
is the process that builds up nutirnt molecules and combines smaller molecules into more complex chemical compounds
anabolism
the ____ plays a major role in metabolism
liver
- the liver helps maintain normal blood glucose levels
-the liver cells carry on the first steps of protein and lipid metabolism
-the liver can detoxify toxic substances such as bacteria and drugs
the liver stores iron, vitamin A and D
prothrombin and fibrinogen are plasma proteins formed by liver cells that are blood clotting
albumin is another protein made by liver cells - it helps maintain normal blood volume
the hepatic portal vein delivers blood directly from the gastrointestinal tract to the liver
the big 3 nutrients in our diet are macronutrients
-carbohydrates (carbs)
-lipids (fat and oils)
-proteins
vitamins and minerals = micronutrients
only required in small quantities
carbs are the most preferred energy nutrient of the body , because it composed of smaller building blocks of glucose
glucose is the preferred source of energy for body cells
glucose catabolism invovles 3 series of chemical reactions “metabolic pathways”
1. Glycolysis
2.Citric Acid Cycle - mostly where glucose is released
3.Electron Transportation System- mostly where gulcose is released
electrin transportation system, transfers energy from these electrons to molecules of ATP
direct source of energy
ATP
glycognesis- builds up glycogen
glycogenolysis- breaks down glycogen
insulin increases glucose transportation through cell membranes.
insulin secretion increases = more glucose leaves the blood and enter liver cells
hyperglycemia = high blood glucose
growth hormone, cortisol, epinephrine and glucagon increase blood glucose
amino acids- must be built
essential amino acids- must be provided in diet
nonessenitial amino acids- can be missing from the diet and made up by the body
vitamins = organic molecules needed in small quantities for normal metabolism
(molecules consist of enzymes)
vitamin A = detecting light in sensory cells of the retina
Vitamin D = can be converted to a hormone that helps regulate calcium homeostasis in the body
Vitamin E = acts as a antioxidant that prevents highly reactive oxygen molecules from damaging DNA molecules in cell membranes
lipid soluble vitamins = A,D,E,K
the body stores in liver for later use
water soluble vitamins = B and C (the body cannot store so they must be supplied in our diet)
mineral = inorganic elements
the _____ is the diencephalon of the brain
which promotes the appetite center (how hungry we are) and the satiety center (how full we are)
hypothalamus
the basal metabolic rate (BMR) is the number of calories of heat that must be produced per hour by catabolism to keep the body alive, awake and warm
(how nutrients are breaken down in basal conditions)
the total metabolic rate (TMR) is the total amountof energy used per day
when the number of calories = TMR your weight remains the same
when food intake provides more calories than your TMR = you gain weight
when you food intake has fewer calories than your TMR = you loss weight
maintaining homeostasis of body temperture
thermoregulation
normal range of temperture (36VC - 37.6 C) or
(97 F - 100 F)
when body is over heated blood flow to the skin increases
flow of heat waves from the blood and skin
radiation
transfer of heat energy to the skin and then to cooler external environment (ice pack)
conduction
transfer of heat energy to cooler air that is continually flowing away from the skin
(ice pack)
convection
escape of heat from the blood and skin by water (sweat) vaporation
evaporation
