Nutrition Chapter 5

Besides containing atoms of carbon, hydrogen, and oxygen, proteins also contain?

Nitrogen

What are amino acids?

Amino acids are compounds that contain one amino group, one carboxyl group, one hydrogen and one variant group that provides the individual characteristic, shape, charge, and size. They are the single units of proteins

What are dipeptides, tripeptides, and polypeptides?

Dipeptide are two amino acids bonded together, Tripeptides are three amino acids bonded together, Polypeptides are four or more amino acids bonded together

What is the classification of proteins according to their shape?

Primary: single chain of amino acids Secondary: two chains of amino acids twisted together Tertiary: three chains of amino acids twisted and coiled Quaternary: four chains of amino acids twisted and coiled

What are ESSENTIAL amino acids?

Essential amino acids are those that cannot be manufactured by our bodies and therefore we must acquire from the foods we eat

How many ESSENTIAL amino acids are there and what are their names?

There are 9 essential amino acids: Leucine, Isoleucine, Histidine, Valine, Lysine, Methionine, Phenylalanine, Threonine, and Tryptophan

Home

Indicate at least ONE role of each of the essential amino acids

Leucine: promotes healing of skin and bones Isoleucine: promotes formation of hemoglobin Histidine: promotes production of red and white blood cells, it also absorbs UV light
Valine: Helps the brain to uptake neurotransmitter precursors
Lysine: Aids in the formation of cartilage
Methionine: Lowers high cholesterol levels Phenylalanine: Enhances memory, learning, and alertness
Threonine: Acts as a detoxifier -prevents fat build-up around the liver
Tryptophan: is a precursor of neurotransmitter serotonin, stimulates and releases growth hormones

What are the names of the 10 Non-essential amino acids?

Alanine, Aspartic Acid, Glutamic Acid, Cysteine, Glutamine, Glycine, Ornithine, Serine, Proline, and Taurine

What are the three amino acids that build up the immune system?

Alanine, Ornithine, and Serine

Which amino acid aids in the absorption and elimination of fats?

Taurine

Which non-essential amino acid is a precursor to manufacture other amino acids as in a needed basis?

Glutamic Acid

Which amino acids are conditionally essential and why?

Arginine: increases secretion of insulin and glucagon, aids in injury rehabilitation, increases sperm count. Is conditionally essential for people with diabetes, people recovering from injuries, and to increase men’s fertility. Cysteine: helps prevent damage from alcohol and smoking abuse. It is conditionally essential for alcoholics and smokers
Tyrosine: is a precursor of dopamine, norepinephrine, epinephrine and therefore elevates mood. It is conditionally essential for people who suffer from depression and mood swings.

What enzymes break down proteins in the process of digestion?

In the stomach: Pepsin
In the small intestine: Proteases

Besides enzymes, what other compound helps break down complex protein molecules into smaller polypeptides in the stomach?

Hydrochloric Acid (HCl)

If the body synthesizes more protein than it degrades, how is the Nitrogen balance and in what cases does it occur?

Nitrogen Balance is Positive, it happens in growing infants, people recovering from protein deficiency or illness (for new tissue, bone, skin, muscle, and blood)

If the body degrades more protein than it synthesizes, how is the nitrogen balance and in what cases does it occur?

Nitrogen Balance is Negative. It occurs in people who are starving or suffering severe stress such as burns, injuries, infections, fevers (body loses nitrogen as it breaks down muscle protein for energy

What are the roles of protein in the body?

Roles of Protein in the body:
As structural components of muscles, bones, organs, teeth, blood vessels and tissues.
As Enzymes breaking down macronutrients, ensemble and disassemble lipids, put together amino acids to build proteins, break apart compounds and put together other compounds
As transporters: they specialize in transporting other substances such as lipids, vitamins, and minerals around the body
Regulators of fluid and electrolyte balance contained in the spaces inside the blood vessels, intercellular and intracellular spaces
As regulators of Acid-Base Balance in the blood As Antibodies to defend the body against disease (antigens) As Hormones (chemical messengers carried in the blood) As a source of Energy (4 Kcal/g) As a source of Glucose (breaking down amino acids)

What are the consequences of Protein Deficiency?

Consequences of protein deficiency:
The body breaks down body tissue protein to liberate amino acids it needs for other critical processes The body’s life-sustaining activities come to a halt (slow growth, impaired brain and kidney function, weakened immune system, impaired nutrient absorption It leads to SAM, PEM and clinical expressions Kwashiorkor and Marasmus.

What are the consequences of Protein Excess?

It offers NO benefit and pose health risks for the heart and kidneys. A high protein intake increases the work of the kidneys, accelerating the detriment of these organs.

What is the daily intake of protein recommendation?

0.8 grams per kilogram of weight

What dictates the quality of protein?

Digestibility: Plant protein is less digestible, Animal protein is highly digestible Amino Acid composition: the higher the content of essential amino acids, the higher the quality of the protein

What is protein sparing?

Dietary protein, no matter how high the quality, will NOT be used efficiently and will not support growth when energy from Carbohydrate and fat is lacking. If needed the body will use the protein to derive energy and that leads to muscle wasting.

What type of diet excludes all animal-derived foods and what are the concerns?

Vegan diet: fail to provide food energy sufficient to support the growth of a child, and in general fails to provide all the needed nutrients, specially the essential nutrients, including essential amino acids, iron, zinc, calcium, and B-Vitamins.