Flashcards in Exam 2 chap 6 Deck (30)
____ are unique among the energy nutrients in that they possess nitrogen-containing amine groups and are composed of 20 different amino acid units.
Of the __ amino acids, some are essential and some are essential only in special circumstances.
Amino acids link into long strands that make a wide variety of different proteins.
Each type of protein has a distinctive sequence of amino acids and so has great functional ______.
Often, cells _______ in synthesizing particular types of proteins in addition to the proteins necessary to all cells.
Nutrients can greatly affect genetic expression.
Proteins can be denatured by all but one of the following:
heat, cold, acids, bases, alcohol, or the salts of heavy metals.
______ begins the process of digesting food protein and can also destroy body proteins.
Digestion of protein involves denaturation by stomach acid and enzymatic digestion in the stomach and small intestine to amino acids, dipeptides, and tripeptides.
The cells of the _____ _____ complete digestion, absorb amino acids and some larger peptides, and release them into the bloodstream for use by the body's cells.
The body needs dietary ___ _____ to grow new cells and to replace worn-out ones.
____help regulate gene expression; provide structure and movement; serve as enzymes, hormones, and antibodies; provide molecular transport; help regulate fluid and electrolyte balance; buffer the blood; contribute to blood clotting; and provide energy.
Amino acids can be used as fuel or converted to _____ or fat.
No storage form of protein exists in the body.
There is a storage form of protein exists in the body.
Amino acids can be metabolized to protein, nitrogen plus energy, glucose, or fat.
Amino acids will be _______ to protein only if sufficient energy is present from other sources.
When energy is lacking, the ______ part is removed from each amino acid, and the resulting fragment is oxidized for energy.
The protein intake recommendation depends on size and stage of growth.
The DRI recommended intake for adults is ___ grams of protein per kilogram of body weight.
Factors concerning both the body and food sources modify an individual's protein need.
Protein recommendations are based on _____ balance studies, which compare _____ excreted from the body with ____ ingested in food (same element)
____ of protein varies from food to food, and cooking can improve or impair it.
A protein's____ ____ assortment greatly influences its usefulness to the body.
Food proteins that lack essential amino acids can be used by the body only if those amino acids are present from other sources.
Protein ____ becomes more important whenever food supplies are limited.
protein quality is determined by
how complete their amino acid composition is
Most U.S. protein intakes fall within the DRI recommended protein intake range of __ to __ percent of calories.
10 - 35
No Tolerable Upper Intake Level exists for protein, but health risks may follow the _________ of protein-rich foods.