Nutrition and Metabolism Flashcards
What are the 3 main “fates” of food molecules absorbed by the GI tract?
- To supply energy
- To serve as building blocks
Storage for future use
What does food absorbed by the GI tract supply energy for?
- Sustaining life processes “MC-DAMP”
- maintenance of body temperature
- cell division
- DNA replication
- active transport
- muscle contraction
- protein synthesis
What do food molecules act as building blocks for?
- Synthesis of more complex molecules
- muscle proteins
- hormones
- enzymes
Where are tryglycerides stored?
adipose cells.
What does metabolism refer to?What does metabolic rate refer to?
All chemical reactions of the body.
rate: energy expenditure required by these reactions
What factors can affect Metabolic Rate?
- genetics
- age
- size
- physical activity level
- eating habits
What are the 6 main nutrients that body cells need?
- carbohydrtes
- lipids
- proteins
- water
- minerals
- vitamins
What is an essential nutrient?
Nutrients that must be obtained frm the diet because body can’t make enough of them.
What is “anabolic”?
Building molecules. Uses more energy than it produces. Energy used is supplied by catabolic reactions.
What is Catabolic?
Breaking molecules down. Release energy stored in organic molecules, energy transfers to ATP.
How many Calories foes each gram of protein, carbohydrate and fat provide?
Carb= 4 Calories
Protein=4 Calories
Lipid=9 Calories
WHat is a mineral? Name a few minerals with known functions. How are excess amounts gotten rid of?
An inorganic element. Concentrated mostly in skeleton. Excess excreted in urine.
- calcium
- phosphorus
- potassium
- sulfur
- sodium
- chloride
- magnesium
- iron
- iodide
- manganese
- copper
- cobalt
- zinc
- fluoride selenium
- chromium
What are major roles of minerals?
- Help regulate enzymatic reactions
- Some are coenzymes
- Some are catalysts
- Some work with buffer systems.
What are Vitamins?
Organic nutrients required in small amounts to maintain growth and normal metabolism.
Do not provide energy or serve as building material
Most serve as coenzymes
Body cannot synthesize vitamins!
WHat is the difference between vitamins and minerals?
Vitamics are organic
Minerals are inorganic
How are VItamins divided?
Fat-soluble(lipoproteins) and water-soluble
What are the fat-soluble vitamins?How are they absorbed, where are they stored?
Vitamins A,D,E,K
absorbed with dietary lipids in small intestine and packaged into CHYLOMICRONS.
May be stored in cells, especially the liver
What are the water-soluble vitamins?How are they absorbed?What happens to extra?
Vitamins B and C.
Dissolved in body Fluids.
Excess are not stored, they are removed in urine.
What are the antioxidant vitamins?
Vitamins C,E, and beta-carotene
They inactivate oxygen free radicals
What is a free radical?
highly reactive ions/molecules that carry an unpaired electron in their outermost electron shell.
Damage cell membrane, DNA and other cellular structures that contribute to formation of formation of atherosclerotic plaques
What is an enzyme and a coenzyme?give examples of coenzyme
Enzyme: serve as catalysts to speed up chemical reactions. (some require presence of an ion)
Coenzyme: Work with enzymes. Function as temporary carriers of atoms being removed from or added to a substrate during a reaction. Many derived from vitamins. Examples: NAD+ and FAD
During Digestion what are carbohydrates broken down into?
Polysaccharides, disaccharides are broken down into monosaccharides (glucose, fructose, galactose). Monosaccharides are absorbed in small intestine. After absorption fructose and galactose are converted to glucose.
What happens to glucose when digested?
If cells need immediate energy (ATP) they oxidize glucose.
Glucose not needed for immediate ATP may be converted to glycogen for storage
What is glycogen? How is it stored?
Stored glucose.
storage in liver cells and skeletal muscle fibers.
If these storage places are full, liver cells transform glucose to glycerol of triglycerides for storage in adipose cells. (can be converted back to glucose)
