NUSC 1165 TEST 2025-2026
Sources of Dietary Protein - CORRECT ANSWER-■Animal
-Meats: 3 oz. = 20 g protein
-Poultry
-Fish
-Eggs: 1 egg = 7 g Protein
-Dairy Products: 1 cup Milk = 8 g protein
■Plant
-Legumes: 6-10 g protein/half cup serving
-Nuts & Seeds: 5-10 g protein/quarter cup serving
-Grains: 2-3 g/slice or half cup serving
Protein-rich foods also provide important nutrients - CORRECT ANSWER-■Animal
Sources
-B Vitamins
-Minerals - Iron, zinc, calcium
■Plant Sources
-B Vitamins
-Minerals - Iron, zinc, calcium
-Fiber
-Phytochemicals
-Unsaturated Fats
Dietary sources of protein - CORRECT ANSWER-corn oil, olive oil, sunflower seeds,
peanut butter, tofu, kidney beans, eggs, salmon, beef, chicken breast, 1% milk, cheddar
cheese, cottage cheese, yogurt, orange, kiwi, banana, avocado, broccoli, corn, potato,
oatmeal, spaghetti, whole-wheat bread
Amino acid structure - CORRECT ANSWER-■Amino Acids: Building blocks of proteins.
■Central carbon atom
-Hydrogen atom
,-Amino Group
-Acid Group
-Side Chain
Essential amino acids - CORRECT ANSWER-histidine, isoleucine, leucine, lysine,
methionine, phenylalanine, threonine, tryptophan, valine
Nonessential amino acids - CORRECT ANSWER-alanine, arginine*, asparagine,
aspartic acid, cysteine*, glutamic acid, glutamine, glycine*, proline*, serine, tyrosine*
*considered conditionally essential
Transamination - CORRECT ANSWER-■Transfer of amino group to a carbon
compound to generate a new amino acid.
alanine + alpha-ketoglutarate <--> pyruvate + glutamate
alanine --> pyruvate (NH2 lost from alanine)
alpha-ketoglutarate --> glutamate
Conditionally essential amino acids - CORRECT ANSWER-■Amino acids that are
essential in the diet under specific conditions or at specific times of life.
■Examples:
-Phenylalanine --> Tyrosine
-Methionine --> Cysteine
Protein Structure - CORRECT ANSWER-■Peptide bonds hold amino acids together.
■Multiple amino acids joined together by a peptide bond form polypeptide chains.
The shape of the protein determines its function - CORRECT ANSWER-■Collagen &
alpha-keratin
-Provides strength to fingernails and ligaments.
■Hemoglobin (Red Blood Cells)
-Spherical shape
-Alteration in Amino Acids --> Hemoglobin loses its shape
■Sickle-Cell Anemia
■Denaturation
-Alteration of a protein's 3-D Structure
-Due to change in temperature or heat
Protein Digestion - CORRECT ANSWER-- Mouth: Mechanical processing of protein due
to chewing.
- Stomach:
Pepsinogen --> Pepsin (Activated by hydrocholoric acid)
,- Pancreas: Produces enzymes (trypsin, chymotrypsin, and carboxypeptidase)
Small Intestine:
Transport proteins move the protein digestion products into the intestinal mucosa.
a). Amino acids that share the same transport protein compete with each other for
absorption
b). Dipeptides and tripeptides enter the mucosal cell and then broken down into amino
acids.
- Amino acids pass from the mucosal cell and travel to the liver via the hepatic portal
vein.
***Little dietary protein lost in the feces
Amino acid absorption - CORRECT ANSWER-■Di- and tripeptides enter the mucosal
cells of the small intestine using one of several energy-requiring active transport
systems.
■Amino acids sharing the same transport system will compete for absorption.
- Example: Branched Chain Amino Acids: Leucine, isoleucine, and valine
- If leucine is in excess- What happens to isoleucine and valine?
Protein Digestion and Food Allergies - CORRECT ANSWER-■Occur when a dietary
protein is absorbed without being completely digested.
■Common sources:
-Milk, eggs, peanuts, tree nuts, wheat, soy, fish, and shellfish.
■Reaction of the Immune System:
-1st Time: Stimulation of the immune system
-2nd time: Immune system identifies protein as a foreign, harmful substance.
- Attacks Protein --> Allergic Reaction occurs
■Symptoms:
-Vomiting, diarrhea, rash, hives, drop in blood pressure, decreased breathing.
-Anaphalaxis: Most severe reaction - breathing difficulties, rapid drop in blood pressure.
Amino Acid Pool - CORRECT ANSWER-■Amino acids in the body's tissues and fluids,
available for use.
-Energy: 4 kcal/g
Dietary proteins --> digestion --> amino acid pool --> protein synthesis --> body proteins
Body proteins --> protein breakdown --> amino acid pool --> energy, synthesis of
glucose or fatty acids, synthesis of nonprotein molecules that contain nitrogen
Protein Turnover - CORRECT ANSWER-■Continuous synthesis and breakdown of
body proteins.
-Normal growth & maintenance of the body tissue
-Adaptation to situation changes
, ■Proteins that must be regulated and serve as chemical signals to the body have high
rates of synthesis and degradation.
-Insulin: Rapidly synthesized and broken down as it is based on the body's needs.
■Structure Protein: Slower rates of turnover
Collagen in Connective Tissue
Involvement of Genes in Protein Production or Synthesis - CORRECT ANSWER-
Transcription:
•First step in protein synthesis.
•Information is copied from DNA to a molecule of messenger RNA (mRNA).
Translation:
•Second step in protein synthesis.
•Transfer RNA (tRNA) translates the mRNA code into the amino acid sequence of the
polypeptide chain.
***Genes --> Contain instructions for the amino acids needed for making a body protein.
The Process of Protein Synthesis Involves Transcription and Translation - CORRECT
ANSWER-1) in the nucleus, the code for a protein is copied from the DNA into a
molecule of messenger RNA (mRNA)
2) the mRNA takes the genetic information from the nucleus to ribosomes in the cytosol,
where proteins are made
3) at the ribosomes, transfer RNA (tRNA) reads the genetic code and delivers the
needed amino acids to the ribosome to form a polypeptide chain.
Gene expression - CORRECT ANSWER-■Process where the information coded in a
gene is used to produce something that functions in the body.
-Protein or mRNA molecule
■Strictly Regulated
-Expressed in specific cells
■Example: Insulin and glucagon are secreted in the pancreatic cells.
-Need for protein in the body (Zinc)
-Nutrient Levels
■Vitamin A - Influences maturation and specialization of cells.
***Zinc --> when intake is high, gene expression for a metal-binding protein is turned on,
thus allowing more zinc to be bound
Limiting Amino Acids - CORRECT ANSWER-■Essential amino acid available in low
concentrations.
■Can stop the process of protein synthesis.
Sources of Dietary Protein - CORRECT ANSWER-■Animal
-Meats: 3 oz. = 20 g protein
-Poultry
-Fish
-Eggs: 1 egg = 7 g Protein
-Dairy Products: 1 cup Milk = 8 g protein
■Plant
-Legumes: 6-10 g protein/half cup serving
-Nuts & Seeds: 5-10 g protein/quarter cup serving
-Grains: 2-3 g/slice or half cup serving
Protein-rich foods also provide important nutrients - CORRECT ANSWER-■Animal
Sources
-B Vitamins
-Minerals - Iron, zinc, calcium
■Plant Sources
-B Vitamins
-Minerals - Iron, zinc, calcium
-Fiber
-Phytochemicals
-Unsaturated Fats
Dietary sources of protein - CORRECT ANSWER-corn oil, olive oil, sunflower seeds,
peanut butter, tofu, kidney beans, eggs, salmon, beef, chicken breast, 1% milk, cheddar
cheese, cottage cheese, yogurt, orange, kiwi, banana, avocado, broccoli, corn, potato,
oatmeal, spaghetti, whole-wheat bread
Amino acid structure - CORRECT ANSWER-■Amino Acids: Building blocks of proteins.
■Central carbon atom
-Hydrogen atom
,-Amino Group
-Acid Group
-Side Chain
Essential amino acids - CORRECT ANSWER-histidine, isoleucine, leucine, lysine,
methionine, phenylalanine, threonine, tryptophan, valine
Nonessential amino acids - CORRECT ANSWER-alanine, arginine*, asparagine,
aspartic acid, cysteine*, glutamic acid, glutamine, glycine*, proline*, serine, tyrosine*
*considered conditionally essential
Transamination - CORRECT ANSWER-■Transfer of amino group to a carbon
compound to generate a new amino acid.
alanine + alpha-ketoglutarate <--> pyruvate + glutamate
alanine --> pyruvate (NH2 lost from alanine)
alpha-ketoglutarate --> glutamate
Conditionally essential amino acids - CORRECT ANSWER-■Amino acids that are
essential in the diet under specific conditions or at specific times of life.
■Examples:
-Phenylalanine --> Tyrosine
-Methionine --> Cysteine
Protein Structure - CORRECT ANSWER-■Peptide bonds hold amino acids together.
■Multiple amino acids joined together by a peptide bond form polypeptide chains.
The shape of the protein determines its function - CORRECT ANSWER-■Collagen &
alpha-keratin
-Provides strength to fingernails and ligaments.
■Hemoglobin (Red Blood Cells)
-Spherical shape
-Alteration in Amino Acids --> Hemoglobin loses its shape
■Sickle-Cell Anemia
■Denaturation
-Alteration of a protein's 3-D Structure
-Due to change in temperature or heat
Protein Digestion - CORRECT ANSWER-- Mouth: Mechanical processing of protein due
to chewing.
- Stomach:
Pepsinogen --> Pepsin (Activated by hydrocholoric acid)
,- Pancreas: Produces enzymes (trypsin, chymotrypsin, and carboxypeptidase)
Small Intestine:
Transport proteins move the protein digestion products into the intestinal mucosa.
a). Amino acids that share the same transport protein compete with each other for
absorption
b). Dipeptides and tripeptides enter the mucosal cell and then broken down into amino
acids.
- Amino acids pass from the mucosal cell and travel to the liver via the hepatic portal
vein.
***Little dietary protein lost in the feces
Amino acid absorption - CORRECT ANSWER-■Di- and tripeptides enter the mucosal
cells of the small intestine using one of several energy-requiring active transport
systems.
■Amino acids sharing the same transport system will compete for absorption.
- Example: Branched Chain Amino Acids: Leucine, isoleucine, and valine
- If leucine is in excess- What happens to isoleucine and valine?
Protein Digestion and Food Allergies - CORRECT ANSWER-■Occur when a dietary
protein is absorbed without being completely digested.
■Common sources:
-Milk, eggs, peanuts, tree nuts, wheat, soy, fish, and shellfish.
■Reaction of the Immune System:
-1st Time: Stimulation of the immune system
-2nd time: Immune system identifies protein as a foreign, harmful substance.
- Attacks Protein --> Allergic Reaction occurs
■Symptoms:
-Vomiting, diarrhea, rash, hives, drop in blood pressure, decreased breathing.
-Anaphalaxis: Most severe reaction - breathing difficulties, rapid drop in blood pressure.
Amino Acid Pool - CORRECT ANSWER-■Amino acids in the body's tissues and fluids,
available for use.
-Energy: 4 kcal/g
Dietary proteins --> digestion --> amino acid pool --> protein synthesis --> body proteins
Body proteins --> protein breakdown --> amino acid pool --> energy, synthesis of
glucose or fatty acids, synthesis of nonprotein molecules that contain nitrogen
Protein Turnover - CORRECT ANSWER-■Continuous synthesis and breakdown of
body proteins.
-Normal growth & maintenance of the body tissue
-Adaptation to situation changes
, ■Proteins that must be regulated and serve as chemical signals to the body have high
rates of synthesis and degradation.
-Insulin: Rapidly synthesized and broken down as it is based on the body's needs.
■Structure Protein: Slower rates of turnover
Collagen in Connective Tissue
Involvement of Genes in Protein Production or Synthesis - CORRECT ANSWER-
Transcription:
•First step in protein synthesis.
•Information is copied from DNA to a molecule of messenger RNA (mRNA).
Translation:
•Second step in protein synthesis.
•Transfer RNA (tRNA) translates the mRNA code into the amino acid sequence of the
polypeptide chain.
***Genes --> Contain instructions for the amino acids needed for making a body protein.
The Process of Protein Synthesis Involves Transcription and Translation - CORRECT
ANSWER-1) in the nucleus, the code for a protein is copied from the DNA into a
molecule of messenger RNA (mRNA)
2) the mRNA takes the genetic information from the nucleus to ribosomes in the cytosol,
where proteins are made
3) at the ribosomes, transfer RNA (tRNA) reads the genetic code and delivers the
needed amino acids to the ribosome to form a polypeptide chain.
Gene expression - CORRECT ANSWER-■Process where the information coded in a
gene is used to produce something that functions in the body.
-Protein or mRNA molecule
■Strictly Regulated
-Expressed in specific cells
■Example: Insulin and glucagon are secreted in the pancreatic cells.
-Need for protein in the body (Zinc)
-Nutrient Levels
■Vitamin A - Influences maturation and specialization of cells.
***Zinc --> when intake is high, gene expression for a metal-binding protein is turned on,
thus allowing more zinc to be bound
Limiting Amino Acids - CORRECT ANSWER-■Essential amino acid available in low
concentrations.
■Can stop the process of protein synthesis.
