Chapter 2: Nutrients Released by Digestion Flashcards
What are macronutrients?
Macronutrients are nutrients required by the body in large amounts. They include proteins, carbohydrates, and fats.
What foods supply macronutrients?
Foods that supply macronutrients include a variety of sources such as meats, dairy products, grains, fruits, vegetables, legumes, nuts, and seeds.
Can foods provide more than one type of macronutrient?
Yes, some foods provide more than one type of macronutrient. For example, beans provide both protein and carbohydrates.
What is the recommendation regarding plant-based proteins and fats from the American Heart Association?
The American Heart Association states that an emphasis on plant-based proteins and fats is healthier for the body.
Why might some people prefer to avoid animal-based foods?
Some people may prefer to avoid animal-based foods for ethical, environmental, or health-related reasons.
What are proteins made of?
Proteins are made of long chains of amino acids.
What happens to proteins during digestion?
Proteins are broken down during digestion into their individual amino acids.
How are new proteins assembled in the body?
Cells rearrange amino acids obtained from digestion to assemble them into new proteins according to instructions from DNA in the genes.
What are proteins used for in the body?
Proteins are used to repair and replace tissues and to make most of the chemicals that the body uses for various functions.
What role does DNA play in protein synthesis?
DNA provides the instructions for building new proteins by specifying the order of amino acids in the protein chain.
What are essential amino acids?
Essential amino acids are amino acids that the body cannot make and must be obtained from the diet.
What are complete proteins?
Complete proteins are foods that contain all nine essential amino acids. Animal proteins such as meat, fish, eggs, and dairy products are complete proteins.
Which plant foods are complete proteins?
Soybeans, buckwheat, and quinoa are plant foods that are considered complete proteins.
How can vegetarians ensure they get all essential amino acids?
Vegetarians can obtain all essential amino acids by eating a variety of plant foods, such as grains, beans, and nuts, throughout the day.
What is the role of carbohydrates in the body?
Carbohydrates primarily supply energy to the body.
What are complex carbohydrates and where are they found
Complex carbohydrates are made up of chains of sugar molecules and are found in whole grains and vegetables.
How do complex carbohydrates differ from simple carbohydrates?
Complex carbohydrates take longer to digest than simple carbohydrates, providing a longer and more stable source of energy. They also do not cause wide swings in blood sugar levels like simple carbohydrates do.
Why do fruits behave more like complex carbohydrates?
Fruits contain fiber, which slows down digestion and absorption, making them behave more like complex carbohydrates despite containing simple sugars.
What happens to carbohydrates once they are broken down?
Carbohydrates are broken down into glucose molecules.
What are the components of a glucose molecule?
A glucose molecule contains six carbon atoms, twelve hydrogen atoms, and six oxygen atoms (C6H12O6).
What happens to glucose molecules in the body?
Glucose molecules circulate as blood glucose.
How is excess glucose stored in the body?
Excess glucose molecules bond together to form glycogen molecules, which are stored primarily in liver and muscle cells.
What is the function of glycogen in the body?
Glycogen serves as a storage form of glucose, ready to be broken back down into glucose molecules when needed for energy.
How is the energy stored in a glucose molecule released in a cell?
When a glucose molecule enters a cell, bonds between its atoms are gradually broken, releasing the energy stored in those bonds.
What prevents all the energy in a glucose molecule from being released at once in a cell?
ATP molecules store the energy released from glucose breakdown and release it gradually as needed by the cell.
What role does fiber play in the diet?
Fiber, such as cellulose, is an indigestible plant carbohydrate that helps food move more quickly through the intestines, absorbs water to soften feces, and stimulates intestinal wall contraction.
How does fiber reduce the risk of colon cancer?
Adequate fiber in the diet is thought to reduce the risk of colon cancer by reducing the time that waste products remain in the intestines, thus potentially decreasing exposure to harmful substances in the colon.
What are fats made of?
Fats are made up of carbon, oxygen, and hydrogen atoms.
How do the ratios of atoms in fats compare to those in carbohydrates?
Fats have a greater number of hydrogen atoms compared to carbon and oxygen atoms, unlike carbohydrates.
Can fat molecules be used for energy?
Yes, fat molecules can be used for energy if there is an insufficient intake of carbohydrate molecules to meet the body’s energy needs.
Why is fat often associated with negative health effects?
Consuming too much fat can lead to the formation of plaques in blood vessels (atherosclerosis) and the infiltration of blood vessel walls (arteriosclerosis), increasing the risk of heart attacks and strokes.
Why is some fat essential in the diet?
Some vitamins only dissolve in fat, and the body requires fat as an extra energy source. Additionally, important structures in the body, such as myelin surrounding neurons, are made up of fat.
What types of fats are healthier options?
Unsaturated fats, found in plant foods like nuts, seeds, avocados, olives, and olive oils, are healthier options compared to saturated fats found in butter, solid shortening, animal products, and coconut oil.
What are trans fats and where are they commonly found?
Trans fats are unsaturated fats that have been artificially hydrogenated to become saturated fats. They are commonly found in commercial baked goods.
