Nutrition Module 6- Proteins and Amino Acids

What are amino acids?

building blocks of proteins

How are amino acids metabolized? Are the amino groups left intact or are they removed? Explain the processes of transamination and deamination and why they are important.

1. The amino group is removed by deamination. 2 Deamination of some amino acids produces three-carbon molecules that can be used to synthesize glucose, via gluconeogenesis.3 Deamination of some amino acids results in two-carbon molecules that form acetyl-CoA, which can enter the citric acid cycle or be used to synthesize fatty acids.4 Deamination of some amino acids forms molecules that are intermediates in the citric acid cycle.5 High-energy electrons from the breakdown of amino acids are transferred to the electron transport chain where the energy is trapped and used to produce ATP and water. Deamination= the process in which amino group is removed and converted to urea and exits the body Transamination=makes nonessential amino acids by transferring amino group

What is the "amino acid pool" and where do these amino acids come from?

A large mix of numerous amino acids that allow for availability. They are the left over single units of amino acids.

What effect does moderate exercise have on protein needs?

Average people need 0.8 g/kg of protein per day. Endurance athletes need 1.2-1.4 g/kg protein per day. Strength athletes need 1.2-1.7 g/kg protein per day.

List three structural and/or regulatory functions of proteins in the body.

Collagen- connective tissue Cell and tissue structure Enzyme and protein hormones (insulin) Transport proteins (lipoproteins) Immune system (antibodies) Regulate fluid balance Contractile proteins (actin and myosin)

What is protein complementation and when is it important?

Combining foods that have different limiting amino acids to ensure that you get all the essential amino acids that you need in your diet Ex. Rice and beans

Name 3 conditions where certain proteins or amino acids may be detrimental to health.

Food allergies: triggered when protein from diet absorbed without complete digestion. Immune system sees protein as foreign substance and attacks it. Phenylketonuria: inherited condition attributed to a defective gene. Requires low phenylalanine diet• Tyrosine is now an essential AA. Celiac disease: gluten intolerance, causes autoimmune reaction in certain people, body attacks lining of small intestine

Compare and contrast the causes and symptoms of kwashiorkor and marasmus

Kwashiorkor is when there is a pure protein deficiency. The diet is adequate in energy, but low in protein. It is often characterized by a big belly in children. It often occurs when the child stops breastfeeding. Marasmus is when there is an energy and protein deficiency. It is characterized by "skin and bones" look. An example of this is anorexia nervosa.

What foods are the richest sources of protein?

Legumes, nuts, seeds, fish, poultry, eggs, animal products

How does protein quality compare between animal and plant sources?

Plant proteins lack one or more amino acids that animal proteins have

Describe the general structure of a protein. How do they differ from other macronutrients?

Proteins are constructed of one or more folded chain-like structures. Contains C, H, O, and N

Explain how the shape of a protein is important for its function. What is protein denaturation and how do temperature and pH affect it?

Proteins are long chains of polypeptides that are folded into large structures. This structure is important so that it is functional. Temperature and pH affect proteins by changing the structure and can have irreversible affects. Denaturation is when the protein structure changes and is no longer functional.

What is a limiting amino acid and how does it affect protein synthesis?

They are essential amino acids available in shortest supply. They are when essential amino acids are limited in the diet. They limit protein synthesis.

What are conditionally essential amino acids? What are some examples that we talked about?

They are normally not essential (only essential under certain circumstances). They are essential when someone has a certain condition. Ex: Physical stress- trauma victims, stages of life- premature infancy, metabolic defects- phenylketonuria

Why is protein deficiency most common in infants and children?

They need more protein than adults when they are younger and often don't get the amount they need. They need about double the amount of protein as adults.

Explain how proteins are synthesized

Transcription and translation 1. In nucleus, code for protein copied from DNA into molecule of mRNA 2. mRNA takes genetic info from nucleus to ribosomes in cytosol 3. At ribosomes, tRNA reads codes and delivers needed AA to ribosome to form polypeptide chain

List some plant sources of protein

grains, legumes, soybeans, peanut, beans, chia seeds

What is protein turnover?

proteins are continually being made and broken down

What is an essential amino acid?

the body can't synthesize them in sufficient amounts; they must be consumed