Chapter 6: Proteins and Amino Acids
fruits
Which of the following food groups provides the least protein in the diet?
3 oz chicken
Which of the following foods contains the highest amount of protein?
tuna
Which of the following foods has the highest PDCAAS score?
cheese
Which of the following foods is not in the meat and meat alternatives food group?
chicken breast
Which of the following foods is a source of complete protein?
maintaining fluid balance growth and maintenance of new tissue synthesis of certain hormones
Which of the following is a major function of protein in the human body?
soy milk
Which of the following is a source of complete protein?
tofu
Which of the following is an example of a complete protein?
pork
Which of the following sources of protein has the highest digestibility?
Pregnant women usually consume less nitrogen than they excrete.
Which of the following statements is FALSE regarding nitrogen balance?
refrigerating milk
Which of the following will not denature a protein?
nitrogen
Which of these elements is found in proteins but not in carbohydrates and lipids?
DNA
_____ contains all of the instructions for building the hundreds of thousands of proteins that are found in the human body.
Hormones
______ direct activity in the body and can be made of proteins or lipids.
Pepsin
______ is the active form of a digestive enzyme in the stomach that breaks polypeptide chains into smaller polypeptides.
Amino acid pools
_______ are stockpiles found in the blood and other cells of the body that can be used to build new proteins.
Transport proteins
_______ carry many substances through the blood or allow movement of substances in and out of cells.
Dipeptide
_______ describes an amino acid chain made up of two amino acids joined together.
Denaturation
_______ occurs when a protein is exposed to heat, acid, bases, or mechanical agitation resulting in unfolding of the protein, though the peptide bonds remain intact.
Kwashiorkor
______is a severe deficiency of dietary protein, resulting in swelling in the feet, legs, and stomach among other symptoms.
20 percent
An 8-ounce glass of low-fat chocolate milk contains 160 kilocalories (kcal) and 8 grams of protein. What percent of the kcal in the milk comes from protein?
stir-fried tofu and vegetables over brown rice a cheese and broccoli omelet baked ziti with ricotta cheese, spinach, and tomato sauce
An acceptable main dish for a lacto-ovo-vegetarian would be _____.
tripeptide
An amino acid chain made up of three amino acids joined together is called a _______.
hemoglobin
An example of a protein that functions to transport substances throughout the body is
hummus prepared with chickpeas and sesame seeds
An example of complemented proteins is ___.
false
Approximately 50 percent of every protein molecule is composed of nitrogen.
56 grams
Charlie is a 22-year-old male nonathlete who weighs 70 kilograms. How much protein should he consume daily?
False
Chemical digestion of protein begins in the mouth with enzymes found in the saliva.
polypeptide strands
Cleavage of proteins by pepsin in the stomach results in formation of _______ which get broken down further in the small intestine.
meat
Complete protein is found abundantly in _____.
heart disease, kidney problems, and calcium loss from bones
Consistently eating too many high-protein foods can lead to a higher risk for __________.
positive nitrogen balance
Growing children and adolescents are in ___.
Stomach
HCl denatures protein here.
Stomach
HCl is secreted here.
Ribosome
It reads the nucleotide sequence and helps build the corresponding sequence of amino acids.
Ribosome
It releases the amino acid chain once the chain is complete.
tRNA
It transfers specific amino acids to the growing amino acid chain.
there is a severe deficiency of protein in the diet but an adequate intake of energy
Kwashiorkor is a type of protein-energy malnutrition that develops when _____.
Proteins and Vegetables
Legumes are in which two USDA MyPlate groups?
amino acid pools
Limited amounts of surplus amino acids are stored in the body in _____.
vitamins D and B12, calcium, and iron
Unless carefully planned, vegan diets may be low in which of the following essential micronutrients?
positive nitrogen balance
A body that retains more nitrogen than it excretes is in _______.
antibodies
A healthy immune system depends on an adequate supply of proteins that bind to and neutralize harmful invaders. What are these proteins known as?
kidney stones
A high-protein diet can increase the risk of ______.
diabetes
A high-protein diet may increase the risk of all of the following except
sickle cell anemia
A medical condition that is a genetic defect caused by a change in the amino acid sequence is __________.
insulin
A protein that acts as a hormone is __________.
gene
A segment of DNA that encodes for the production of a specific protein is called a(n) ______.
tRNA
A type of RNA that plays the important role of transferring specific amino acids to the growing amino acid chain in the ribosomes is called ______.
omega-3 fatty acids and vitamins B12 and D
A vegetarian diet may be low in __________.
small intestine
After a person consumes a glass of soy milk, where does the majority of the digestion and absorption of the protein occur?
nitrogen
All amino acids contain carbon, hydrogen, oxygen, and ___.
denaturation
Alteration of the three-dimensional shape of a protein by heat or acid is called
Liver
Amino acids that enter the bloodstream from the small intestine travel to here.
essential amino acids
Amino acids that the body can never synthesize are called ___.
mRNA
DNA does not build or synthesize a protein it encodes for; instead, DNA contains information that is copied by an enzyme to make _____, which leaves the nucleus and goes to the ribosome where the protein is built.
kwashiorkor
Edema is a classic symptom of which type of PEM, which is caused by a severe protein deficiency?
Pancreas
Enzymes that digest amino acid chains are produced here and delivered via a duct to the small intestine.
measuring the amount of nitrogen consumed with the amount of nitrogen excreted
How do we determine whether we are in protein balance?
If calorie intake is inadequate, amino acids can be used for production of energy. The liver uses amino acids to create glucose. Amino acids are used to create new proteins.
How does your body use the protein once it has been ingested? Consider the following statements and select the correct ones regarding protein use.
9
How many amino acids are considered essential to consume in the diet?
20
How many different kinds of amino acids make up proteins?
protein-energy malnutrition
Inadequate intake of protein and/or calories is known as _______.
DNA
Instructions on how to build all proteins are stored in this molecule, housed in the nucleus of the cell.
mRNA
It carries a copy of the DNA instructions that dictate the sequence of amino acids for making a specific protein.
10
It is recommended that at least ________ percent of daily calories should be consumed in the form of protein.
Mouth
Mechanical digestion begins here.
coenzymes
Most enzymes are proteins, but some may utilize ______ in the form of vitamins to help with reactions.
those who are starving.
Negative nitrogen balance would normally occur in
Stomach
Pepsin is formed from pepsinogen here.
Vegans must obtain vitamin B12 from supplements or fortified foods. A lacto-ovo-vegetarian consumes eggs and dairy products. Complementary proteins do not need to be consumed in the same meal. Submit
Please choose the correct statements about vegetarian diets.
The mutation that causes sickle-cell anemia results in production of hemoglobin proteins which crystallize causing misshapen red blood cells; some of them look like half-moons.
Protein Abnormalities Due to Genetic Mutations
more expensive plus higher in saturated fat and sugar
Protein bars, compared to a peanut butter sandwich, are most likely to be __________.
deoxyribonucleic acid (DNA)
Protein synthesis is directed by a compound in the cell nucleus called ___________.
DNA
Protein synthesis is directed by the ______ in the nucleus of the cell.
buffers
Proteins act as ____________ and help to maintain proper pH in blood by picking up or donating hydrogen ions.
stomach and small intestine
Proteins are digested by enzymes in the __________.
antibodies
Proteins called _____ aid the immune system in its fight against bacteria, viruses, and other foreign substance by binding to them and helping to inactivate or destroy them.
20
Proteins consist of a chain of some combination of ____ unique amino acids.
buffers
Proteins help control the acid-base balance in the body by acting as _____.
buffers
Proteins help to maintain the pH of your body fluids within a normal range by functioning as
fighting off the flu and other infections transporting nutrients through the blood aiding in digestion
Proteins play important roles in the body, including _____.
Mechanical digestion in the mouth breaks down the food. A bolus enters the stomach. Hydrochloric acid denatures proteins and activates pepsinogen to form pepsin. Pepsin breaks down proteins into polypeptide strands. Chyme travels from the stomach to the small intestine. Enzymes from the pancreas are secreted into the small intestine. Enzymes in the small intestine break down polypeptide strands into mostly tripeptides and dipeptides. Tripeptides and dipeptides are broken down into single amino acids that enter the blood and travel to the liver.
Rank in the correct order from the first bite to the amino acids entering the circulatory system.
Mechanical digestion results in the formation of a bolus. Stomach acid denatures proteins. Background Image Pepsin breaks the polypeptide chains into shorter chains. Pancreatic enzymes cleave peptide bonds,leaving dipeptides, tripeptides, and single amino acids. Enzymes from the small intestine lining act on protein remnants, breaking them into single amino acids, which are absorbed into the cells of the lining. Single amino acids travel through the bloodstream to the portal vein and then to the liver.
Rank the steps of protein digestion in order, starting with the step that occurs first.
portal vein
Single amino acids that are absorbed in the small intestine travel to the liver via the ______.
Small Intestine
Single amino acids, dipeptides, and tripeptides are absorbed here.
catalysts
Substances that speed up reactions without being changed or used up are ___.
amino acids
The 20 different _______ are the building blocks used for protein synthesis.
An mRNA molecule is a copy of a gene on the DNA molecule. Nuclear DNA cannot leave the nucleus.
The Role of DNA in Protein Synthesis
acid group
The ______ is also known as the carboxyl group.
ribosome
The ______ reads the mRNA strand, and with the help of tRNA, builds the corresponding amino acid chain.
amino acids.
The basic building blocks of proteins are
There are 11 nonessential amino acids.
The body uses two types of amino acids: essential and nonessential. Which of the following statements about essential and nonessential amino acids is correct?
peptide bonds
The chemical bonds that connect amino acids are called __________.
protein turnover
The continual process of degrading and synthesizing protein is called _______.
10 to 35 percent
The latest AMDR for protein is _____ of one's daily energy intake.
amine group.
The nitrogen-containing part of an amino acid is called the
liver
The organ that determines what happens to the amino acids after they enter the bloodstream is the ___.
amine group
The part of an amino acid that contains nitrogen is called the ______.
amine group
The part of the protein molecule that contains nitrogen is called the ________.
kidneys
The primary organ responsible for excreting nitrogen-containing waste is the ___.
denaturation
The process that destroys the shape and activity of proteins when heat, acid, salts, or pressure is applied is known as ______.
collagen
The protein that is found in the body's connective tissues is
digestibility of the protein and the types and amounts of amino acids
The quality of a protein is determined by the ____________.
60
The recommended daily protein intake for a healthy adult weighing 165 pounds is __________ grams.
mRNA
The ribosome moves along this and reads the encoded information.
nucleus
The structure in the cell that contains DNA is called the ______.
black beans almonds tofu
What food can be eaten with brown rice to ensure all of the body's amino acid needs are met?
A limited supply of all amino acids remains in amino acid pools in the blood and inside the cells. Some amino acids are degraded and the nitrogen excreted in urine while the carbon, hydrogen, and oxygen remains are used for energy, or are stored as fat. Many amino acids are used to build and maintain body tissues, make new clotting proteins, enzymes, antibodies, neurotransmitters, and other products.
What happens to the amino acids that are absorbed after the digestive process is complete?
Soy foods provide high-quality protein.
What is a benefit of consuming soy foods?
the uncoiling of the protein molecule by hydrochloric acid in the stomach Submit
What is denaturation?
48 grams
What is the protein RDA for a woman who weighs 132 lb (60 kg)?
proteases secreted from the pancreas and the small intestine saliva from the salivary glands in the mouth hydrochloric acid and pepsin in the stomach
What secretions are needed to digest complex proteins into single amino acids for absorption?
used for energy
When the amine group is removed, the carbon-containing component of amino acids can be ___.