Metabolism Flashcards
What was the USDA’s 1992 Food Guide Pyramid’s main focus regarding fats?
Emphasis on reducing animal fats, replacing them with plant oils and nuts.
What foods should be restricted in the USDA 1992 Food Guide Pyramid?
- Red meats
- sweets
- starchy foods.
How much water does the USDA recommend daily?
At least 8 glasses of water per day.
Where do most dietary carbohydrates come from?
Most carbohydrates come from plants, except for lactose (milk) and a small amount of glycogen (meats).
What daily activity does the USDA recommend for health?
30 minutes of moderate exercise daily.
What are the dietary sources of starch?
- Grains
- legumes
- root vegetables
What are the dietary sources of sugars?
- Fruits
- sugar cane
- sugar beets
- honey
- milk.
What is cellulose and where is it found?
A type of fiber found in most vegetables, providing roughage.
What happens if blood glucose is too high?
Excess glucose is converted to glycogen (stored in liver/muscles) and fat (stored in adipose tissue).
What is glucose used for in the body?
Major fuel for making ATP; neurons and RBCs rely on glucose for energy.
What is the minimum daily carbohydrate intake recommended for optimal brain function?
~100 grams/day to maintain blood glucose levels.
What is the recommended daily carbohydrate intake according to the USDA?
130 grams/day, primarily from complex carbs (whole grains and vegetables).
What happens if carbohydrate intake falls below 50 grams/day?
The body may enter a state of ketosis, using fats for fuel instead of carbohydrates (glycose/ glycogen).
What are the main sources of dietary lipids?
Saturated fats from meat, dairy, and coconut oil; unsaturated fats from seeds, nuts, olive oil, and most vegetable oils.
What are essential fatty acids and why are they important?
Linoleic and linolenic acids are essential because the body cannot produce them; they must be obtained from the diet.
What is the recommended daily intake of cholesterol?
Less than 300 mg/day (equivalent to 1 egg yolk)
What is the American Heart Association’s recommendation for fat intake?
Fat should be less than 30% of total caloric intake; saturated fats should be less than 10%.
Why are dietary fats important in the body?
They help absorb fat-soluble vitamins, provide energy, and are essential for the structure of myelin sheaths and plasma membranes.
What are complete proteins and where are they found?
Complete proteins contain all essential amino acids and are found in animal products such as eggs, milk, fish, and meat.
What are the primary structural uses of proteins in the body?
Keratin of skin, collagen & elastin of connective tissue, muscle proteins.
What are examples of incomplete proteins?
Legumes, nuts, and cereals; these lack one or more essential amino acids (e.g., cereals are low in lysine, legumes are low in methionine).
What are the primary functional uses of proteins in the body?
Enzymes, hemoglobin, peptide hormones.
When are proteins used for energy in the body?
As a last resort, when carbohydrates and fats are too low.
What determines protein requirements?
Age, size, and nitrogen balance
What are the general roles of vitamins in the body?
Essential for growth and health, not used directly for energy but help in using proteins/carbs, often serve as coenzymes in metabolic reactions.
What is the recommended protein intake for an average adult?
0.8 g x kg of body weight (e.g., 56g for a 70-kg man; 48g for a 58-kg woman).
What are the two main classes of vitamins?
Water-soluble: B-complex and C (typically not stored, absorbed with water).
Fat-soluble: A, D, E and, K
How much protein is in a small serving of fish + one glass of milk?
Approximately 30g of protein.
What are some examples of vitamins acting as coenzymes?
Riboflavin and niacin help metabolize glucose; Vitamin K is essential for clotting proteins.
What is a pro-vitamin and an example of one?
A substance that the body can convert into a vitamin; e.g., β-carotene (pro-vitamin A).
What are the antioxidant vitamins, and what do they do?
Vitamins A, C, and E; they neutralize free radicals and may help prevent cancer and atherosclerosis.
Where are most vitamins obtained from?
Most vitamins are not made by the body, except for Vitamin D (from skin), some B vitamins, and Vitamin K (from intestinal bacteria).
What is the role of minerals in the body?
Provide strength (e.g., calcium for bones), act as co-factors (e.g., iron in hemoglobin), serve as electrolytes (e.g., sodium and chloride), and aid in hormone production (e.g., iodine in thyroid hormones).
Why is it important to have a balanced diet regarding vitamins?
No single food contains all vitamins, so a variety is needed for overall health.
What minerals are needed in moderate amounts?
Calcium, phosphorus, potassium, sulfur, sodium, chloride, magnesium.
What are some trace minerals needed by the body?
Iron, iodine, manganese, copper, zinc, cobalt, fluorine, selenium, chromium.
What is the significance of water in the body?
Carries nutrients, cleanses blood of wastes, participates in chemical reactions, lubricates joints, absorbs shock, and aids in temperature regulation.
What are the two main types of metabolism?
- Anabolism: Constructing body molecules.
- Catabolism: Generating energy, mainly in the form of ATP.
What are the three steps in processing energy-containing nutrients?
Digestion, absorption, and metabolism.
What is the all-or-none rile of protein synthesis?
all the amino acids have to be present or else the polypeptide chain won’t be created
What is nitrogen balance?
the difference between the amount of nitrogen consumed and the amount excreted from the body
What is the effect of anabolic hormones/ steroid on protein?
increase protein synthesis and reduce protein breakdown, promoting muscle growth and preserving lean tissue
- long-term can lead to hormonal imbalances and cardiovascular disease
