CH 6 protein Flashcards
(22 cards)
How does protein differ from carbs and fats?
Proteins have nitrogen.
Essential vs. nonessential amino acids + why essential ones are important
Essential amino acids: You must get them from food.
Nonessential amino acids: Your body can make them.
If you don’t get all essential ones, your body can’t build proteins properly.
What is a ‘limiting amino acid’?
It’s the essential amino acid you don’t have enough of. Without it, your body can’t finish building a protein.
High-quality vs. low-quality proteins + examples
High-quality proteins: Have all essential amino acids. Example: Meat, eggs, dairy, soy.
Low-quality proteins: Missing some essential amino acids. Example: Beans, grains, nuts, vegetables.
Two examples of complementary proteins
Rice + beans
Peanut butter + whole wheat bread
They work together to give you all essential amino acids.
RDA for protein (179 lb man)
179 lbs ÷ 2.2 = 81.4 kg
81.4 × 0.8 = ~65 grams of protein per day.
Nitrogen balance
Positive: Taking in more than you lose (pregnancy, muscle building).
Negative: Losing more than you take in (sickness, starvation).
Equilibrium: Balanced (healthy adults).
Protein structure (4 levels)
Primary: Straight chain of amino acids.
Secondary: Coils or folds (like spirals or zig-zags).
Tertiary: Twisted 3D shape.
Quaternary: 2+ chains working together (like hemoglobin).
Why is protein shape important?
Shape = function. If the shape is wrong, the protein can’t do its job.
What can change (denature) a protein’s shape?
Heat (cooking an egg).
Acids or bases (like lemon juice or vinegar).
Beating or stirring (like whipping egg whites).
What is protein turnover?
Your body is always breaking down and rebuilding proteins. You need amino acids ready to go to fix, heal, and grow.
How is protein digested and absorbed?
Starts in the stomach (acid and enzymes break it down). Finished in the small intestine → broken into individual amino acids. Amino acids go to the liver, then out to the body.
How does the body get rid of ammonia (NH₃)?
Ammonia is toxic, so the liver turns it into urea. Kidneys filter it out in urine.
What happens to extra protein?
If you eat too much: → Body converts it to fat or energy → Extra nitrogen is peeled off and excreted.
Main functions of protein
Builds muscles, hair, skin, and nails. Helps with enzymes, hormones, immune system. Transports things (like oxygen in blood). Can be used for energy.
How do proteins help the immune system?
Your antibodies (fight germs) are made of protein.
Types of protein malnutrition
Kwashiorkor: Not enough protein, but some calories → bloated belly.
Marasmus: Not enough protein or calories → very skinny, muscle loss.
How does kwashiorkor differ from marasmus?
Kwashiorkor: Swollen belly, some fat/muscle left.
Marasmus: No fat, no muscle, very thin.
Why can too much protein be harmful?
Can strain your kidneys. May cause bone calcium loss. Often means less fiber, more saturated fat.
Food allergies – symptoms & treatment
Caused by the body attacking proteins in food. Common symptoms: rash, swelling, trouble breathing. Severe cases = anaphylaxis → needs EpiPen or emergency care.
Vegan vs. lacto-vegetarian
Vegan: No animal products at all (no milk, eggs, or honey).
Lacto-vegetarian: No meat, but does eat dairy.
Nutrients often low in a vegan diet
Vitamin B12, Calcium, Iron, Vitamin D, Omega-3 fats, High-quality protein (if not eating a variety).
