Lecture 5 - Macronutrients (PROTEINS) Flashcards
Energy, essential amino acids, and nitrogen (to make non-essential amino acids) are provided by…
Dietary protein
____________ amino acids are nutritionally required in amounts the animal cannot synthesize on its own
Essential
What are some physiological functions that rely on protein?
Enzyme activity, cellular function, barrier/skin function, growth and reproduction
How many types of amino acids are used as building blocks for protein or as free amino acids?
20
True or False: Amino acids consist of an amine group and a carbonyl group, and the type of amino acid is determined by the side chain
True
True or False: Amino acids can never be metabolized from other amino acids
False; SOME amino acids can be metabolized from other amino acids
What are some sources of dietary protein?
Animal proteins (meat/dairy/eggs), plant proteins (legumes/grains), and microbial proteins
True or False: Obligate carnivores, such as cats, tend to have higher protein requirements than most other species
True
Even when protein intake is low, cats cannot regulate deamination of ______ ______ within their bodies to compensate
Amino acids
Why do protein requirements increase in animals that do more strenuous physical activity?
Sufficient protein is needed to build muscle, and lack of protein can lead to physiological complications
A type of non-regenerative anemia in athletes where protein intake is insufficient
Sports anemia
How do proteins and amino acids affect palatability in omnivores and carnivores?
Specific amino acids have a naturally stronger flavor and odor that can drive palatability
Example: methionine
What are the three significant branched chain amino acids (BCAA)?
Valine, leucine, isoleucine
Why is leucine considered “special” amongst the BCAAs?
It promotes muscle-protein synthesis
(Extra info: leucine is abundant in meat products)
What is the Kjeldahl method used to analyze?
Crude protein content in food (specifically provides the weight of nitrogen in all of the analyzed matter)
Where does enzymatic digestion occur in carnivores and omnivores? (2 places in the body)
Stomach and intestines
What occurs during enzymatic digestion and absorption of proteins in omnivores and carnivores?
Proteins are broken down to smaller peptides/amino acids, and amino acids are absorbed via transporters
What happens to undigested amino acids in omnivores and carnivores?
They are converted into ammonia by microbes in the large intestine, which is captured by the liver and catabolized to urea
In forestomach fermenters, what term describes the nitrogenous compounds that pass through the forestomach and are metabolized by microbial organisms?
Degradable Intake Protein (DIP)