Unit 4: Proteins Flashcards
(34 cards)
What are amino acids?
The building blocks of proteins. Composed of a single carbon atom with an amine group and an acid group attached.
What are protein recommendations based upon?
Nitrogen balance studies, which compare nitrogen lost through excretion with the nitrogen eaten in food.
What is nitrogen equilibrium?
Healthy adults should have roughly the same amount of protein in their body at all times.
What is positive nitrogen balance?
More protein is being built than being broken down. In growing children and pregnant women.
What is negative nitrogen balance?
Muscle or other protein tissue is being broken down and lost. In illness and injury.
What are some of the roles of proteins in the body?
Structural components, transporting other substances (lipids, vitamins, minerals, oxygen) around the body, enzymes (protein catalysts), some hormones (usually lipids), antibodies, maintain fluid and electrolyte balance and acid-base balance and as sources of energy and glucose.
What is severe acute malnutrition (SAM)?
Characterized by sudden inadequate food intake (caused by drought).
Affects 10% of children, chronic affects 25% of children.
What are some of the effects of consuming too much protein?
Heart disease (high fat protein), kidney disease (increases work on kidneys)
What is the DRI and ADMR for protein?
0.8g/kg body weight (higher for infants, children, pregnant and lactating women) and 10-35% of total energy
What are some examples of essential amino acids?
Histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan and valine
What is a conditionally essential amino acid?
A nonessential amino acid that becomes essential because of special circumstances that the need for it is greater than the body’s ability to produce it.
How are proteins broken down in the body?
Proteins broken down by pesin and HCl in the stomach to polypeptides which are broken into tri- and dipeptides and amino acids by pancreatic and intestinal proteases. Peptides are broken down by intestinal tri- and dipeptidases to amino acids.
How do proteins help fluid distribution?
They cannot pass freely across membranes and they are attracted to water.
A cell wants a certain amount of water inside of it, so it will manufacture enough proteins to hold the water.
How do proteins control the acid-base balance of the blood?
Proteins like albumin in the blood act as buffers by gathering up extra hydrogen (acid) ions when there are too many and releasing them when there are too few.
What happens when the blood becomes too acidic or basic?
Vital proteins undergo denaturation, losing their shape and ability to function if acidosis or alkalosis occurs.
How do proteins play a role in the immune system?
When the body detects antigens, it makes giant protein molecules called antibodies designed specifically to combat them before they even begin.
What are some protein based hormones?
Glucagon and insulin
What happens when amino acids are broken down for energy use?
The nitrogen-containing amine groups are stripped off and used elsewhere or are incorporated by the liver into urea and sent to kidneys for excretion via urine.
What is kwashiorkor?
A clinical expression of SAM, can appear individually or with marasmus.
Failure to grow and develop, edema, changes in the pigmentation of hair and skin, fatty liver, anemia and apathy.
What is marasmus?
A clinical expression of SAM, can appear individually or with kwashiorkor.
Poor growth, dramatic weight loss, loss of body fat and muscle and apathy.
What is chronic malnutrition?
When a person has enough food to survive, but not to thrive.
Stunted growth
How can chronic malnutrition be treated?
Supplemental foods in the community
How can SAM be treated?
Requires hospitalization, which means intensive nursing care, diet and medication.
What is celiac disease?
An immune disorder in which the absorptive surface of the small intestine is damaged due to an abnormal response to gluten. This results in an inability of the body to absorb nutrients: protein, fat, carbohydrates, vitamins and minerals,
Treated by a gluten free diet for life