Proteins Flashcards

Questions and Answers

What is the primary function of protein in the diet?

Building and maintaining body tissue.

Proteins are built from simpler organic compounds called?

Amino acids.

Nitrogen is the element that is contained in _______ and not contained in carbohydrates and fats.

Proteins.

What is an indispensable amino acid?

Amino acids that the body cannot make at all or cannot make enough of and must be supplied in the diet. Signup and view all the answers

How many indispensable amino acids are there?

Nine. Signup and view all the answers

What are dispensable amino acids?

Amino acids that the body synthesizes. Signup and view all the answers

What are conditionally indispensable amino acids?

Amino acids that are normally dispensable but become essential in certain circumstances. Signup and view all the answers

What is a complete protein?

Protein foods that contain all nine indispensable amino acids. Signup and view all the answers

Which of the following are considered animal proteins with high dietary value?

Meat Signup and view all the answers

What is an incomplete protein?

Protein foods that are deficient in one or more of the nine indispensable amino acids. Signup and view all the answers

In one diet, the greatest proportion of indispensable amino acids are provided by what foods?

Animal products. Signup and view all the answers

What is a negative nitrogen balance?

Condition occurring when the body excretes more nitrogen than it takes in. Signup and view all the answers

Name some foods that are high in protein.

Breast milk, cow's milk, eggs, cheese, meat, soybeans and soy products. Signup and view all the answers

What is a lacto-ovo vegetarian?

A mixed diet of plant and dairy excluding meat and fish. Signup and view all the answers

What is a lacto-vegetarian?

Vegetarian that only eats dairy products from animal sources. Signup and view all the answers

What is an octo-vegetarian?

Vegetarian that only includes eggs in their diet. Signup and view all the answers

What is a vegan?

No animal foods consumed. Signup and view all the answers

What are amino acids?

The building blocks of proteins. Signup and view all the answers

What is gelatin?

Animal origin protein with little dietary protein value. Signup and view all the answers

Why are proteins from plant resources such as grains, nuts, and legumes called incomplete proteins?

Because they lack one or more of the nine indispensable amino acids. Signup and view all the answers

What is the primary function of protein?

Building and repairing body tissues. Signup and view all the answers

What are complementary proteins?

Combining incomplete plant proteins with complete proteins. Signup and view all the answers

What are other functions of protein in the body?

Water balance, digestion and metabolism, cell signaling, transport, and immunity. Signup and view all the answers

What are two waste products of protein metabolism?

Ammonia Signup and view all the answers

What is positive nitrogen balance?

When the body takes in more nitrogen than it excretes. Signup and view all the answers

Name examples of conditions where positive nitrogen would be present.

Infancy, childhood, adolescence, pregnancy, lactation. Signup and view all the answers

What is the RDA for protein intake for healthy adults?

0.8g/kg per day. Signup and view all the answers

What does the state of stability refer to in protein metabolism?

The state of dynamic equilibrium where protein breakdown equals protein synthesis. Signup and view all the answers

What is protein balance?

The intake and output of protein and the nitrogen that it supplies. Signup and view all the answers

What is metabolism?

Processes responsible for synthesis and breakdown of proteins and amino acids. Signup and view all the answers

What is anabolism?

Re-synthesis of amino acids into new tissue proteins. Signup and view all the answers

What is catabolism?

Break down of proteins into amino acids. Signup and view all the answers

What are structural and functional proteins?

Proteins that provide structure and perform duties in the body. Signup and view all the answers

Study Notes

Protein Basics

Proteins primarily function to build and maintain body tissues.
Composed of simpler organic compounds including carbon, hydrogen, oxygen, and nitrogen.
Nitrogen is a unique element in proteins, absent in carbohydrates and fats.

Types of Amino Acids

Indispensable amino acids: cannot be synthesized by the body; must be obtained through diet; there are nine of these.
Dispensable amino acids: can be synthesized by the body.
Conditionally indispensable amino acids: typically synthesized but can become essential during illness.

Protein Quality

Complete proteins contain all nine indispensable amino acids in sufficient amounts for the body's needs.
Highest dietary value animal proteins include eggs, meat, milk, poultry, cheese, and fish.
Incomplete proteins lack one or more of the indispensable amino acids, typically found in plant sources.

Dietary Considerations

Animal products provide the greatest proportion of indispensable amino acids in diets.
High-protein foods include breast milk, cow's milk, eggs, cheese, meat, soybeans, and soy products.

Vegetarian Protein Sources

Lacto-ovo vegetarian: includes dairy and plant foods but excludes meat and fish.
Lacto-vegetarian: consumes only dairy along with grains, legumes, nuts, seeds, fruits, and vegetables.
Octo-vegetarian: includes eggs in the diet as a source of complete protein.
Vegan: excludes all animal foods.

Metabolism and Nitrogen Balance

Negative nitrogen balance: occurs when nitrogen output exceeds intake.
Positive nitrogen balance: when the body takes in more nitrogen than it expels, present in growth phases and during pregnancy.
RDA for protein intake for healthy adults is 0.8g/kg per day.

Protein Functionality

Proteins regulate water balance, digestion, metabolism, cell signaling, transport, and immunity.
Metabolic waste products of protein include urea and ammonia.
Protein metabolism involves two processes:
- Anabolism: synthesizes amino acids into tissue proteins.
- Catabolism: breaks down proteins into amino acids.
The state of dynamic equilibrium occurs when protein breakdown equals synthesis, known as protein balance.

Structural and Functional Proteins

Proteins can be reassembled into various forms once broken down into amino acids, highlighting their versatile roles in biological functions.

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Description

Test your knowledge about proteins with these flashcards. Learn about their functions, composition, and essential amino acids in your diet. Perfect for students studying biology or nutrition.