Unit 4 - Protein Flashcards
What are proteins made up of?
Carbon, hydrogen, oxygen, and nitrogen
How many amino acids can the body produce?
11, so 9 are essential
What are conditionally essential amino acids?
Amino acids that are normally nonessential but must be supplied by the diet in special circumstances when the need for it becomes greater than the body’s ability to produce it
Why do proteins have different shapes?
It enables them to perform different tasks in the body
How do the mouth and salivary glands aid in protein digestion?
Chewing and crushing moisten protein-rich foods and mix them w/ saliva to be swallowed
How does the stomach aid in protein digestion?
HCl uncoils protein strands and activates stomach enzymes
How do the small intestine and pancreas aid in protein digestion?
Pancreatic and small intestinal enzymes split polypeptides further, then enzymes on the surface of the small intestinal cells hydrolyze these peptides and the cells absorb them
What is protein turnover?
Within each cell, proteins are continually being made and broken down
What happens when proteins are broken down?
- Their amino acids are liberated w/in the cells or released into the bloodstream
- Some amino acids are promptly recycled into other proteins, while others are striped of their nitrogen and used for energy
What are nitrogen balance studies used for?
Estimation of protein requirements
What is nitrogen balance?
Comparing nitrogen lost through excretion with the nitrogen eaten in food
What is a positive nitrogen balance?
More protein is being built than is being broken down
Which populations will have a positive nitrogen balance?
- Growing children
- Adolescents
- Pregnant women
- People recovering from protein deficiency or illness
What is a negative protein balance?
Muscle or other protein tissue is being broken down and lost to use for energy
Which populations will have a negative nitrogen balance?
- Illness
- Injury
- Those that are starving
- Infections
- Fever
What directs the making of the body’s proteins?
The unique combination of genes
What are the major roles of protein in the body?
- Structural components
- Transporting other substances around the body
- Enzymes, hormones, and antibodies
- Maintaining fluid and electrolyte balance and acid-base balance
- As sources of energy and glucose
Where is the majority of the body’s protein found?
In muscle tissue
What are 2 examples of transporter proteins?
- Hemoglobin carries oxygen from lungs to cells
- Lipoproteins transport lipids in the blood
What are the 2 most important protein hormones?
Insulin and glucagon
How do proteins maintain water balance?
Since they can’t pass freely across membranes and they are attracted to water, cells that want water can manufacture proteins and the proteins can hold water
Which protein helps to prevent acid-base inbalances?
Albumin
What is the DRI for protein?
0.8g/kg of healthy body weight
What is the DRI AMDR for protein?
10-35% total energy
What are complementary proteins?
- Proteins containing all the essential amino acids in amounts sufficient to support health
- Come from at least 2 protein-rich foods that both eaten throughout the same day
What is the difference between severe acute malnutrition and chronic malnutrition?
- Severe acute malnutrition is characterized by sudden inadequate food intake (ex: drought or war)
- Chronic malnutrition is long-term inadequate food intake
What is severe acute malnutrition?
When the diet delivers too little protein, too little energy, or both
What are the 2 types of severe acute malnutrition?
1) Kwashiorkor
2) Marasmus
What is kwashiorkor?
- “A sickness that infects the first child when the second child is born”
- Distinguishing feature is edema of the child’s face, limbs, and abdomen
What is marasmus?
- Prolonged deprivation of food
- Characterized by extreme loss of fat and muscle (just skin and bones)
What is chronic malnutrition?
- Children have enough food to survive but not thrive
- Children are normally short b/c they lack nutrients required for normal growth
What are the most recognizable consequences of protein deficiency?
- Slow growth in children
- Impaired brain and kidney function
- Weakened immune defences
- Impaired nutrient absorption
Consuming too much protein can pose health risks for ____
The heart and for weakened kidneys
What does excretion of the end products of protein metabolism depend on?
Adequate fluid intake and healthy kidneys
Does a higher intake of protein damage kidneys?
No, it just increases the work of the kidneys
Which food group is protein found in?
All 4
What is protein quality used for?
Used to determine how well a diet supports the growth of children and health of adults
What influences protein quality?
- Digestibility of protein
- Amino acid composition
What does a high quality protein have?
Ample amounts of all essential amino acids
Proteins derived from ____ are high quality
Animal foods
Proteins derived from _____ are lower quality
Plant foods
Are amino acid supplements a good idea?
No b/c the body is designed to handle whole proteins best
Why shouldn’t someone take amino acid supplements?
- An excess of one amino acid can produce a demand for a carrier that it limits the absorption of another amino acid, creating a temporary imbalance
- Amino acids in concentrated supplements cause excess water to flow into the GI tract, causing diarrhea
What is celiac disease?
An immune disorder that is characterized by damage to the intestinal tract caused by exposure to gluten, resulting in an inability of the body to absorb nutrients
What are common symptoms of celiac disease?
- Anemia
- Chronic diarrhea
- Weight loss
- Fatigue
- Cramps and bloating
- Irritability
How is celiac disease diagnosed?
1) Blood screening tests
2) Biopsy of bowel
What is the treatment for celiac disease?
- No cure
- Can usually be effectively treated and controlled with a gluten-free diet
What can happen to someone with celiac disease who doesn’t eliminate gluten from their diet?
Are at an increased risk of developing intestinal and lymphatic cancers
What is dermatitis herpetiformis?
A chronic skin condition w/ a characteristic rash w/ intense itching and burning sensations
What are the causes of dermatitis herpetiformis?
- Genetic factors
- Immune system
- Gluten sensitivity
Is dermatitis herpetiformis more common in males or females?
Males
What is the typical onset for dermatitis herpetiformis?
20’s-40’s
What is the treatment for dermatitis herpetiformis?
- Medications
- Gluten-free diet
How can you diagnosis non-celiac gluten sensitivity?
Exclude celiac disease by serological tests
What are some health and nutritional complications that can arise w/ celiac disease?
- Iron deficiency anemia
- Lactose intolerance
- Osteoporosis
- Folate, vit. B12, and other vitamin deficiencies
- Diarrhea/constipation
- Growth failure in children
- Calorie/protein excess or deficiency
Why does lactose intolerance occur in some people w/ celiac disease?
May occur temporarily in newly diagnosed patients as a result of damaged villi and decreased lactase production
Will someone w/ celiac disease have lactose intolerance for life?
No, the symptoms should disappear w/in 6 months - 1 year w/ a strict gluten-free diet
Which health complications occur due to malabsorption?
- Osteoporosis
- Folate deficiency
- Vitamin B12 deficiency
- Diarrhea
- Calorie/protein deficiency
Will a gluten-free diet get rid of osteoporosis?
Not always
Will a gluten-free diet get rid of a vitamin B12 deficiency?
Yes
What are potential causes of diarrhea in a patient w/ celiac disease?
- Damaged villi
- Malabsorption
- Lactose intolerance
When does constipation usually occur in patients w/ celiac disease and why?
When gluten-free diet is initiated b/c it tends to be low in fibre
What are potential causes of calorie/protein deficiency in patients w/ celiac disease?
- Poor intake secondary to GI symptoms
- Malabsorption
What is overweight/obesity common in patients w/ celiac disease?
Gluten-free prepared foods tends to be higher in fat, carbs, and calories and lower in fibre
Why should a person only initiate a gluten-free diet AFTER blood test and intestinal biopsy?
The person must be eating gluten daily for the tests to properly work
Why is an intestinal biopsy performed after a blood test to diagnose celiac disease?
B/c of the 10% possibility of a falsely positive blood test
What are common oral and dental manifestations of celiac disease?
- Enamel defects (pitting, grooving, sometimes complete loss of enamel)
- Delayed eruption
- Recurrent aphthous ulcers
Oral and dental defects in patients w/ celiac disease usually develop before age __
7
Can you diagnose celiac disease based on enamel defects alone?
No
