Question 1

Rosa is a teenager who has an eating disorder characterized by self-imposed starvation.Based on this information,her body is in ____ nitrogen balance.

Accepted Answer

When someone is experiencing self-imposed starvation, they are not consuming enough nutrients to support their bodily functions. This means that their body is using up its own stores of energy and nutrients to keep functioning, resulting in a negative nitrogen balance. Nitrogen balance is a measure of the nitrogen that is taken into the body (usually through protein intake) versus the nitrogen that is excreted. When the body is in a negative nitrogen balance, it means that more nitrogen is being excreted than is being taken in, which can lead to muscle wasting and other negative health effects.

Question 2

May is 89 years of age.Her heart is weak,so she spends most of her time lying in bed or sitting in a chair.Although she takes medication for hypertension,she has been unable to keep her blood pressure in the normal range.Her diet consists mainly of apples,leafy vegetables,gelatin,toast,butter,tea,and chocolate candy.May's lower legs and feet and swollen.Based on this information,the swelling is probably the result of a(an)________.

Accepted Answer

May's diet is lacking in protein and essential nutrients, which can lead to edema (swelling) due to low protein levels in the blood, causing fluid to accumulate in tissues.

Question 3

Instructions for making proteins are coded in a cell's ________.

Accepted Answer

The code for making proteins is stored in the DNA of a cell. The other options play important roles in cellular functions, but they are not directly involved in protein synthesis.

Question 4

Two-month-old Deanna is not growing normally.After Deanna underwent numerous tests,her physicians determined that she was born with a condition in which fat deposits form in cells that are not designed to store fat.The fat deposits eventually kill the cells.Her older brother died as a result of the same disorder when he was 8 months of age.Based on this information,Deanna has ________.

Accepted Answer

The information provided suggests that Deanna was born with a genetic disorder that affects how fat is stored in cells. This is likely due to defective DNA, as the disorder affected her older brother as well. Type 1 diabetes and celiac disease are not related to this specific condition, and metabolic syndrome typically develops later in life and is linked to lifestyle factors.

Question 5

_____ is an essential amino acid.

Accepted Answer

Threonine is an essential amino acid, which means it cannot be synthesized by the human body and must be obtained from the diet. Serine and alanine are non-essential amino acids, meaning they can be synthesized by the body. Homocysteine is not an amino acid, but rather a metabolite of the amino acid methionine.

Question 6

_____ is the process that changes the normal shape of a protein and,as a result,the molecule loses its usual functions.

Accepted Answer

Denaturation is the process by which a protein loses its three-dimensional structure and function. This can occur due to various factors like changes in temperature, pH, or exposure to certain chemicals.

Question 7

The _____ is main site of deamination in the body.

Accepted Answer

Liver is the main site of deamination in the body. Deamination is the process by which nitrogenous compounds, such as amino acids, are converted to their corresponding keto acids and ammonia. The liver plays a crucial role in this process, as it contains enzymes that facilitate deamination and help to remove excess nitrogen from the body.

Question 8

During digestion,which of the following substances denatures the proteins in food?

Accepted Answer

Stomach acid, or hydrochloric acid, denatures proteins by unfolding their complex 3D structures, which allows digestive enzymes to break them down into smaller peptides and amino acids.

Question 9

A team of food scientists wants to develop a formula diet for newborns that is a nutritionally complete food that replaces human milk.To support normal infant development,the formula must have _____ as an ingredient.

Accepted Answer

The answer of A team of food scientists wants to...

Question 10

The chemical attraction between the acid group of one amino acid and the amino group of another amino acid can form a _______.

Accepted Answer

A peptide bond is formed through a chemical reaction between the carboxyl group of one amino acid and the amino group of another amino acid, resulting in the release of a water molecule. This linkage is crucial in the formation of proteins, as it allows for the creation of a linear chain of amino acids.

Question 11

To tenderize a thin piece of raw meat before cooking it,place the meat in a marinade that contains ________.

Accepted Answer

Red wine contains enzymes and acids that break down proteins in the meat, making it more tender. Cooked mushrooms, olive oil, and plain water do not have the same tenderizing properties.

Question 12

Which of the following statements is true?

Accepted Answer

Transamination is the process of transferring an amino group from one amino acid to a keto acid, forming a new amino acid.

Question 13

Jacob is a healthy,active 14-year-old boy.Recently,he began to experience a growth spurt.Based on this information,his body is in ____ nitrogen balance.

Accepted Answer

During a growth spurt, Jacob's body would require more protein to support muscle and tissue growth. A positive nitrogen balance occurs when the body is retaining more nitrogen than it is excreting, indicating that protein synthesis is occurring at a greater rate. This is likely the case for Jacob as he experiences his growth spurt.

Question 14

The deamination process forms ________.

Accepted Answer

Deamination is the process by which amino acids are broken down, where the amino group is removed from the amino acid. This process produces ammonia, which the body further converts to urea for excretion.

Question 15

A gene is a

Accepted Answer

A gene is a segment of DNA that codes for a specific protein. In other words, it provides the instructions for making a protein, which is a crucial component of cells and essential for many biological processes.

Question 16

Three-year old Jamie is a healthy,active child.Based on this information,his body is in ____ nitrogen balance.

Accepted Answer

A positive nitrogen balance means that the body is retaining more nitrogen than it is excreting. This is a sign that the body is in a state of growth and repair, which is typical for a healthy, active child like Jamie.

Question 17

The ____ is the primary site for nonessential amino acid production in humans.

Accepted Answer

The liver is the primary site for nonessential amino acid production in humans. It also plays a major role in metabolism, detoxification, and storage of nutrients. The other options (pituitary gland, pancreas, small intestine) are not directly involved in amino acid synthesis.

Question 18

A team of food scientists wants to develop a formula diet for newborns that is a nutritionally complete food that replaces human milk.To support normal infant development,the formula must have all of the following ingredients,except ________.

Accepted Answer

Phenylalanine, methionine, and tryptophan are essential amino acids necessary for proper infant growth and development. Homocysteine, on the other hand, is not an essential amino acid and is not needed in the formula diet for newborns. In fact, high levels of homocysteine have been associated with various health issues in adults.

Question 19

Roberta is 25 years of age,healthy,and pregnant.Based on this information,her body is in ____ nitrogen balance.

Accepted Answer

Pregnant women require an increased amount of protein to support fetal growth and development. In a positive nitrogen balance, the body is synthesizing more protein (anabolic state) than it is breaking down, indicating adequate protein intake. Therefore, based on the given information, Roberta's body is likely in a positive nitrogen balance.

Question 20

Leona is making lemon pudding from "scratch." Her ingredients include fat-free milk,corn starch,lemon juice,egg yolks,salt,sugar,and butter.When she added some of the ingredients together,little clumps formed in the mixture before she could heat it.What happened to those ingredients?

Accepted Answer

The acid in the lemon juice can denature or coagulate the milk proteins, causing little clumps or curdles to form in the mixture before it is heated.

Quiz 7: Proteins