Nutrition Chapter 6: Proteins Flashcards

Questions and Answers

What elements are proteins made of?

Carbon, hydrogen, oxygen, & nitrogen. Sometimes sulfur.

Define amino acids.

Nitrogen containing chemical compounds of which protein is composed.

Define polypeptides.

10 or more amino acids bonded together.

What are the 3 main functions of protein in the body?

Build & repair tissue, regulate body functions, provide energy. Signup and view all the answers

Give an example of contractile proteins.

Located in muscles. Signup and view all the answers

Give an example of fibrous proteins.

Found in bone, hair, nails, and skin. Signup and view all the answers

Describe the ways that protein works to regulate body functions.

Metabolism and digestion (enzymes, hormones), fluid/electrolyte balance (albumin). Signup and view all the answers

How many calories are in 1 gram of protein?

4 Signup and view all the answers

How many amino acids are there?

20 amino acids Signup and view all the answers

How many essential amino acids are there?

10 essential Signup and view all the answers

Which amino acids are only essential during childhood?

Arginine, histidine Signup and view all the answers

What is a complete protein? Give examples.

Contains all 10 essential amino acids. Ex: Eggs, dairy. Signup and view all the answers

What is an incomplete protein? Give examples.

Lacks 1 or more of the essential amino acids. Ex: Vegan. Signup and view all the answers

Define bioavailability.

Ability of a nutrient to be readily absorbed and used by the body. Signup and view all the answers

What are meat analogues? When would you recommend them?

Meat alternatives made from soy protein and other meat ingredients to simulate various kinds of meats. Give to strict vegetarians to meet protein needs. Signup and view all the answers

What are some examples of meat analogues?

Examples: Tofu, textured plant protein, veggie burgers. Signup and view all the answers

Define complementation and give examples.

Combining of incomplete proteins so that all essential amino acids are supplied. Ex: Corn and beans, bread and peanut butter. Signup and view all the answers

Be able to calculate protein needs.

Body weight/ 2.2kg. Kg * 0.8 = grams of protein. Signup and view all the answers

Describe the negative health effects of excess protein.

Heart disease, colon cancer, increased demand on kidneys. Signup and view all the answers

Discuss excess protein intake and weight management.

Not more than 15-20% of one's daily calorie intake. Signup and view all the answers

Define nitrogen balance.

Nitrogen intake equals nitrogen excreted. Signup and view all the answers

What is positive nitrogen balance?

Exists when nitrogen intake exceeds the amount excreted. Signup and view all the answers

What is negative nitrogen balance?

Exists when more nitrogen is lost than taken in. Signup and view all the answers

Define catabolism, its relationship to nitrogen balance, and give examples of when a person would be in this state.

Negative nitrogen balance. Ex: Fever, injury, surgery, burn. Signup and view all the answers

Define anabolism, its relationship to nitrogen balance, and give examples of when a person would be in this state.

Positive nitrogen balance. Ex: Pregnancy, growth periods, building of muscle, rebuilding tissue (trauma, burn). Signup and view all the answers

Define and describe protein deficiency.

Muscle wasting occurs. Albumin deficiency causes edema. Loss of appetite, strength, weight, depression, lethargy, slow wound healing. At risk? Elderly, poor, incapacitated. Signup and view all the answers

What is marasmus?

Results from severe malnutrition. Insufficient kilocalories and protein, no edema, dull dry hair, thin wrinkled skin. Signup and view all the answers

What is kwashiorkor?

Lack of protein containing food (may have enough carbohydrate/fat calories). Edema in abdominal area, painful skin lesions, changes in skin and hair pigment, high mortality rate. Signup and view all the answers

Study Notes

Protein Composition and Functions

Proteins are composed of carbon, hydrogen, oxygen, nitrogen, and sometimes sulfur.
Amino acids are nitrogen-containing compounds that form proteins.
Polypeptides consist of 10 or more bonded amino acids.
Proteins serve three main functions: building and repairing tissues, regulating body functions, and providing energy.

Types of Proteins

Contractile proteins are found in muscles.
Fibrous proteins are present in bones, hair, nails, and skin.

Protein Regulation and Requirements

Proteins regulate metabolism and digestion through enzymes and hormones, and maintain fluid/electrolyte balance via albumin.
One gram of protein provides 4 calories.
There are 20 amino acids, including 10 essential ones that the body cannot synthesize.
Arginine and histidine are essential only during childhood.

Protein Completeness

Complete proteins contain all 10 essential amino acids; examples include eggs and dairy.
Incomplete proteins lack one or more essential amino acids; common in vegan diets.

Nutritional Concepts

Bioavailability refers to the ease with which nutrients can be absorbed and utilized by the body.
Meat analogues are alternatives made from soy protein to replace meat, recommended for strict vegetarians.
Examples of meat analogues include tofu, textured plant protein, and veggie burgers.

Protein Complementation and Needs

Complementation involves combining incomplete proteins to provide all essential amino acids, e.g., corn with beans or bread with peanut butter.
Calculate protein needs by dividing body weight by 2.2 kg, then multiplying kg by 0.8 to get grams of protein.

Health Implications

Excess protein can lead to health issues such as heart disease, colon cancer, and increased kidney stress.
Protein intake should not exceed 15-20% of daily caloric intake.

Nitrogen Balance

Nitrogen balance occurs when nitrogen intake equals nitrogen excreted.
Positive nitrogen balance happens when intake exceeds excretion, typically during growth or recovery.
Negative nitrogen balance occurs when nitrogen loss exceeds intake, often due to illness or injury.

Protein Metabolism

Catabolism, indicating negative nitrogen balance, happens during periods such as fever, injury, or surgery.
Anabolism, indicative of positive nitrogen balance, occurs during pregnancy, muscle building, or recovery from trauma.

Protein Deficiency and Malnutrition

Protein deficiency leads to muscle wasting and may cause albumin deficiency resulting in edema and various health issues.
At-risk populations include the elderly, impoverished individuals, and those with disabilities.
Marasmus is a severe malnutrition condition characterized by insufficient calories and protein, resulting in dry hair and wrinkled skin without edema.
Kwashiorkor results from a lack of protein-containing foods despite adequate calorie intake, marked by abdominal edema and skin lesions.

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Description

This quiz covers key concepts from Chapter 6 of Nutrition, focusing on proteins. You'll explore the elements that compose proteins, the definition of amino acids, polypeptides, and the primary functions proteins serve in the body. Test your understanding of these essential nutrients!