Unit 5 DB: Animal-Based and Plant-Based Proteins

Proteins

● Like carbohydrates and lipids, proteins are macronutrients.

● Unlike carbohydrates and lipids, proteins contain nitrogen in addition to carbon, hydrogen, and oxygen.

● Some proteins also contain sulfur and phosphorus.

● Like carbohydrates, proteins supply 4 Calories per gram. ● Unlike carbohydrates which are used as an energy source, the body

uses proteins for: ○ Cell and tissue maintenance and repair ○ Catalyzing chemical reactions (as enzymes) ○ Fighting disease (play a role in the immune response)

Examples of structural proteins, transport proteins, and peptide hormones:

● Keratin - fingernails and toenails ● Collagen - skin ● Actin - muscle (thin filaments) ● Myosin - muscle (thick filaments)

● Hemoglobin - red blood cells ● Insulin - hormone (lowers blood sugar) ● Glucagon - hormone (raises blood sugar) ● Antibodies - fight infection ● Interferon - helps fight viral infections ● Albumin - in egg white

Examples of enzymes (catalytic proteins), specifically hydrolases (for digestion of nutrients):

● Amylase - digest carbs (amylose) ● Maltase - digest carbs (maltose) ● Lactase - digest carbs (lactose) ● Lipases - digest fats (lipids) ● Proteases - digest proteins ● Pepsin - primary enzyme/protease in the stomach

● Other major enzymes: ○ DNA polymerase - involved in DNA replication (copy genetic code) ○ ATP synthetase - synthesize ATP (high-energy compound)

● The chemical names of enzymes generally end in -ase

● The monomers (building blocks) of proteins are amino acids.

○ Essential amino acids - required in your diet ○ Non-essential amino acids - synthesized by the body

Recall the artificial sweetener aspartame used in diet foods and beverages ...concerns for people with PKU?

● Proteins can be complete or incomplete.

● Complete proteins contain all the essential amino acids. ○ Found in animals (meat, eggs, dairy)

● Incomplete proteins lack 1 or more essential amino acids. ○ Found in plants (fruits and vegetables) ○ Legumes - beans, nuts, peas (better plant sources of protein)

● Vegan - strict vegetarian: eat wide variety of fruits and vegetables to prevent protein deficiency (complementary sources)

Vegan Diets

• There are many types of vegetarians today. Fruits and vegetables make up the bulk of their diets, but may include certain animal-based foods such as fish, eggs, or dairy.

• Strict vegetarians are vegans. They consume only plants, with no animal products in their diet at all. • Vegans must choose their foods wisely to avoid amino acid deficiencies.

– Recall: Amino acids are the monomeric building blocks of proteins. – Virtually all plants contain incomplete proteins, meaning they are missing 1 or more of the essential amino acids. (Legumes tend to be good

sources of plant-based protein: beans, peas, lentils, peanuts.) • Soy protein is a complete protein in that it meets all the essential amino acid requirements to support normal growth and development of infants and

children. Soy protein is also low in fat and free of saturated fat and cholesterol. It is an ideal protein source to boost the nutrient density of foods.

– There are 9 essential amino acids required in the human diet.

Protein-rich foods ...which do you consume?

...are there any foods you don’t consume but might consider adding to your diet?

Protein digestion begins in the stomach.

Besides other health benefits, regular exercise

maintains or builds muscle ...how often do you visit a gym,

play sports, or participate in some type of physical activity?