Nutrition-132: Exam 2

Know how to combine foods to provide a complete protein.

**list of suggestions, not sure how to answer this Consider eating a combination of foods to create a complete protein. Combine a food item that lacks 1 or more amino acids with another food that contains the missing and essential amino acids. Know the foods that can be combined to form a complete protein like beans with rice, corn with wheat, or grains with dairy. Combining these in the same meal creates a complete protein. Put cheese on legumes or mix it with other vegetables or grain dishes to create a tasty, complete protein meal. Have some lentil or bean soup with whole grain crackers or a peanut butter sandwich on whole grain bread for lunch or a light dinner. Other good protein choices include whole grain pasta with peas or broccoli, pita bread with hummus or a veggie burger with or without cheese on a whole grain roll.

Why may elderly people need to take vitamin B12 by injection?

*assumption, not based on fact. correct if wrong elderly need vit B12 injection because as the body ages, it loses its ability to absorb vit B12 (gives it more of a chance to get absorb some of it).

What does the body do when energy from carbs and fat is lacking (how does it use protein)?

...

Where are proteins denatured?

...Denaturation is a process in which proteins or nucleic acids lose the tertiary structure and secondary structure which is present in their native state, by application of some external stress or compound such as a strong acid or base, a concentrated inorganic salt, an organic solvent (e.g., alcohol or chloroform), or heat. If proteins in a living cell are denatured, this results in disruption of cell activity and possibly cell death. Denatured proteins can exhibit a wide range of characteristics, from loss of solubility to communal aggregation.

Know general differences between fat and water soluble vitamins.

..Fat soluble vitamins are absorbed into the lymph, transported attached to protein carriers, and stored in the body. Water soluble vitamins are absorbed into the blood, transported freely (most), and not stored in the body. . *** Review differences in water vs. fat soluble Absorption and transport Storage Ease of loss Roles

What are the functions of fat?

1. The main function of fats in the body is to provide energy: By supplying energy, fats save proteins from being used for energy and allow them to perform their more important role of building and repairing tissues. Fats on oxidation provide almost twice as much energy as that given by carbohydrates. The fats provide on oxidation about 37 kJ of energy per gram as compared to 17kj of energy per gram of carbohydrates. Fats yield more energy than carbohydrates because fats contain less percentage of oxygen and higher percentage of carbon and hydrogen as compared with carbohydrates. Fats can also be stored in body for subsequent use. When we consume food which has more energy than is required by the body for performing various functions, the excess food is deposited under our skin in the from of subcutaneous fat. 2. In addition to supplying energy, fats also help in forming structural material of cells and tissues such as the cell membrane. 3. Fats also carry the fats soluble vitamins A, D, E and K into the body and help in the absorption of these vitamins in the intestines. 4. Some fats supply essential fatty acids.

What are two main functions of vitamin C?

1. antioxidant activity 2. collagen synthesis 3. cardiovascular health 4. immune health *someone pick which 2 matter most...i assume 3 and 4? **this is in the vitamin ppt review she uploaded: functions of vitamin c: Connective tissue antioxidant

What is scurvy?

1.Scurvy often presents itself initially as symptoms of malaise and lethargy, followed by formation of spots on the skin, spongy gums, and bleeding from the mucous membranes. Spots are most abundant on the thighs and legs, and a person with the ailment looks pale, feels depressed, and is partially immobilized. As scurvy advances, there can be open, suppurating wounds, loss of teeth, jaundice, fever, neuropathy and death.

Pellagra?

2. pellagra is a disease caused by decrease of vitamin B (niacin, tryptophan, and sometimes leucine) the disease causes dermatitis in exposed skin areas such as hands, feet and neck; dermatitis - the skin becomes red, sore, or inflamed

Beriberi?

Beriberi is a disease in which the body does not have enough thiamine (vitamin B1). Causes, incidence, and risk factors There are two major types of beriberi: Wet beriberi affects the cardiovascular system. Dry beriberi and Wernicke-Korsakoff syndrome affect the nervous system. Beriberi is rare in the United States because most foods are now vitamin enriched. If you eat a normal, healthy diet, you should get enough thiamine. Today, beriberi occurs mostly in patients who abuse alcohol. Drinking heavily can lead to poor nutrition, and excess alcohol makes it harder for the body to absorb and store thiamine. A rare condition known as genetic beriberi is inherited (passed down through families). People with genetic beriberi lose the ability to absorb thiamine from foods. This can happen slowly over time and symptoms occur when the person is an adult. However, because doctors may not consider beriberi in nonalcoholics, this diagnosis is often missed. Beriberi can occur in breast-fed infants when the mother's body is lacking in thiamine. The condition can also affect infants who are fed unusual formulas that don't have enough thiamine. Getting dialysis and taking high doses of diuretics raise your risk of beriberi. Symptoms Symptoms of dry beriberi include: Difficulty walking Loss of feeling (sensation) in hands and feet Loss of muscle function or paralysis of the lower legs Mental confusion/speech difficulties Pain Strange eye movements (nystagmus) Tingling Vomiting Symptoms of wet beriberi include: Awakening at night short of breath Increased heart rate Shortness of breath with activity Swelling of the lower legs Signs and tests A physical examination may show signs of congestive heart failure, including: Difficulty breathing with neck veins that stick out Enlarged heart Fluid in the lungs Rapid heartbeat Swelling in both lower legs A person with late-stage beriberi may be confused or have memory loss and delusions. The person may be less able to sense vibrations. A neurological exam may show signs of: Changes in the walk Coordination problems Decreased reflexes Drooping of the eyelids The following tests may be done: Blood tests to measure the amount of thiamine in the blood Urine tests to see if thiamine is passing through the urine

Cholesterol

Cholesterol is a lipid that consists of four hydrocarbon rings attached to a hydroxyl--hydrogen bound to oxygen--group. The four-ring structure makes cholesterol a steroid, and the hydroxyl group provides it with the amphipathic property of being both hydrophilic and hydrophobic. Cholesterol is found in the cells and bloodstream of humans. Because it is not soluble in blood, due to the hydrophobic portion, it must be carried to cells with the help of lipoproteins. Although too much cholesterol can be bad for the body, cholesterol is an important molecule. It is needed to form cell membranes, and it is the precursor for other steroids, such as testosterone and estradiol.

Name the four lipoproteins and what each does.

Chylomicrons-they act as emulsifiers, they attract both water and fat to enable their large lipid passengers to travel dispersed in the watery body fluids. Very-low-density lipoproteins (VLDL): carry triglycerides and other lipids made in the liver to the body cells. low-density lipoproteins (LDL): Transport cholesterol and other lipids to the tissues. high-density lipoproteins (HDL): carry cholesterol away from body cells to the liver for disposal.

What are the three classes of lipids? Know examples of each.

Define/Explain: Lipids - Fats, oils, phospholipids, and steroids - All are hydrophobic (water-hating) 1. Triacylglycerols (fats and oils) Structure: Made from 1 glycerol + 3 fatty acid tails = tri-acylglycerol TWO major functions of fats & oils. a.energy storage and insulation. 2. Diacylglycerides (phospholipids): lipid bilayers (the plasma membrane of every cell and the membranes within eukaryotic cells) Structure - similar to a triacylglycerol, but has only 2 fatty acid tails, and in addition has a phosphate group = (1 glycerol, 2 fatty acids, and a -PO4) The -PO4 makes the glycerol "head" water soluble, or hydrophilic. The long hydrocarbon tail is hydrophobic. Function: Due to this "amphipathic" nature (both water-loving and water-hating regions in a single molecule), phospholipids self assemble into bilayers that shield the tail from water = forming membranes (phospholipid bilayers). 3. Steroids: (cholesterol, steroid hormones) Structure: Considered to be a "cousin" of fats - and are made from lipids. Have no fatty acids in their structure, but are very hydrophobic , see Fig 3.10b in your book Functions of Chloesterol: (1) Help to maintain membrane fluidity, pliability and resilience in membranes of animals, which have high amounts or rigid, saturated fatty acids. (2) Sex hormones (testosterone, estrogen and progesterone) are all made from cholesterol Cholesterol gets a 'bad rap" in our diet, but has CRUCIAL roles in the functioning of our cells - we couldn't live without cholesterol!!! However, too much cholestereol in the diet is known to be a factor in atherosclerosis and heart disease. Cholesterol circulates in the bloodstream bound to carrier 'lipo-proteins'. High Density Lipoprotein (HDL - the "Good" kind) carries blood cholesterol to the liver where is can be eliminated from the body. Low Density Lipoprotein (LDL - the "Bad" kind) deposits blood cholesterol in the artery walls, where it can lead to constriction of blood vessels, heart disease, heart attacks, etc." **3 different classes: triglycerieds phospholipids sterols

Fatty acids differ from one another in two basic ways. What are they?

Differ in chain, length, and degree of saturation. Affects solubility and melting point.

What are the functions of Vitamin A?

Epithelial cell health Growth Cell Multiplication Eye Sight >>2 ways

What happens when amino acids are consumed in amounts greater than a person's needs?

Excess amino acids (from protein) that are not used to (re)build tissue are sent to liver. Once in the liver, excess amino acids are converted into other molecules or oxidized and eliminated as waste. *body cannot store amino acids. it must be used or excreted.

What is the main function of vitamin D? What are the deficiency diseases called?

Function: -Can be made when body is exposed to sunlight. -Factors that affect production -Activation requires liver and kidney. -Bone Deficiencies: In children is called Rickets. In adults is called Osteomalacia.

Glycolipids

Glycolipids are lipid molecules that contain a sugar unit, such as glucose or galactose. Glycolipids can be simple, such as cerebroside, containing only one sugar molecule, or more complex. Complex glycolipids, such as gangliosides, found in nerve cells, can contain a chain consisting of 7 sugar molecules, as noted by the book "Biochemistry," by Jeremy M. Berg, et al. Glycolipids are always oriented with their sugar molecule on the outside of the membrane. This enables them to serve as a marker for cellular recognition. In addition, glycolipids provide energy for cells to use.

Imagine you have blood work done. Do you want each of the following to be high or low? HDL, LDL, total cholesterol, and triglycerides

HDL: High. LDL: Low. Total Cholesterol: Low. Triglycerides: low? http://ck022.k12.sd.us/images/pi%20day/pigraphic.jpg

Which B vitamin is involved in protein metabolism?

HELP either: B1, B6, or B12

What strategies can you use to increase your HDL? Lower your LDL?

Increase HDL: Exercise, quit smoking if you're a smoker Decrease LDL: Increase intake of soluble fiber, reduce intake of saturated fat.

What types of fish are highest in mercury?

Larger fish are usually higher in mercury.

How are fats packaged for absorption?

Packaged in micelle prior to absorption -Long chain fats are absorbed into Lymphatic system

Phospholipids

Phospholipids consist of two fatty acid chains, a phosphate group and a glycerol group. Phospholipids are characterized by their hydrophobic--not soluble on water--tails, formed by the fatty acid chains and hydrophilic--soluble in water--heads. This makes them ideal for being the main molecule found in cellular membranes. Each cell, which is the basic unit of life, in a living organism contains genetic material and structures to help it carry out its own specialized function. In order to protect its contents, cells have membranes. In addition to providing protection, these membranes regulate the movement of water, nutrients and wastes into and out of the cell, as described by toxicologist Anthony Carpi of John Jay College To form a cellular membrane, phospholipids form a bilayer with the hydrophilic heads facing outward, allowing the cell to interact with its environment. The hydrophobic tails form an inner core that helps to regulate the flow of proteins, nutrients, water and waste into the cell.

What is the main function of vitamin K?

Primary function is blood clotting. Can be made in body by intestinal bacteria.

What is the main function of vitamin E? What are some good food sources?

Primary function: Antioxidant Dietary sources include vegetable oils. Some of the best food sources of vitamin E are vegetable oils and margarines, including soybean oil, canola oil, wheat germ oil, and corn oil. On the other hand, getting too many of these oils isn't a good for overall health, since they're high in calories and fats. Some of the healthier foods containing vitamin E include sunflower seeds, almonds, hazelnuts, and peanuts. Green vegetables, such as broccoli, spinach, turnip greens, and collard greens are good sources of vitamin E - and have the added benefit of being good sources of other antioxidants. Olives are another notable source. Here's a quick way to get the benefits of foods containing vitamin E. Prepare a spinach salad, and top it off with olives, almonds, sunflower seeds, along with a serving of an oil-based dressing. Instead of snacking on chips and other less nutritious snacks, munch on nuts and seeds instead - to help boost vitamin E levels.

What is kwashiorkor? Marasmus?

Protein energy malnutrition: Complete starvation is called marasmus. When protein is lacking but adequate calories are provided, a person experiences kwashiorkor.

List the functions of proteins.

Proteins have many functions. They serve as enzymatic catalysts, are used as transport molecules (hemoglobin transports oxygen) and storage molecules (iron is stored in the liver as a complex with the protein ferritin); they are used in movement (proteins are the major component of muscles); they are needed for mechanical support (skin and bone contain collagen-a fibrous protein); they mediate cell responses (rhodopsin is a protein in the eye which is used for vision); antibody proteins are needed for immune protection; control of growth and cell differentiation uses proteins (hormones). These are just a few examples of the many, many functions of proteins. *** Three categories: structure regulation energy >>Regulatory Roles How do proteins affect fluid balance? Protein attracts fluid What are some other regulatory roles of protein? acid- base balance Enzyme function Immunity Transport of substances in the body (examples)

What are the essential fatty acids? Which do we typically get more of?

The essential fatty acids are omega 3 and 6. We typically get more of omega 6. **linolenic Also known as omega-3 linoleic Also known as omega-6 **she says you shouldn't have to know the terms linolenic/linoleic, just a "so you know" kinda thing

What are the recommendations for increasing omega-3 intake from fish?

The recommendations is to eat 2 fatty fish servings totaling 8 ounces a week.

Which vitamin reduces the risk of neural tube defects? What have we done to increase intakes of this vitamin in the US?

deficiency in vitamin B12 (which B vitamin?); added to grain products like bread

How is vitamin A involved in the cornea and retina?

deficiency of vit A makes cornea very dry and damages retina and cornea. TAKE VITAMIN A!! supports healthy cornea and retina health? Vitamin A is a family of fat-soluble compounds that play an important role in vision, bone growth, reproduction, cell division, and cell differentiation (in which a cell becomes part of the brain, muscle, lungs, etc.). Vitamin A helps regulate the immune system, which helps prevent or fight off infections by making white blood cells that destroy harmful bacteria and viruses. Vitamin A also may help lymphocytes, a type of white blood cell, fight infections more effectively. Vitamin A promotes healthy surface linings of the eyes and the respiratory, urinary, and intestinal tracts. When those linings break down, it becomes easier for bacteria to enter the body and cause infection. Vitamin A also helps maintain the integrity of skin and mucous membranes, which also function as a barrier to bacteria and viruses.

What is the general function of B vitamins?

growth, development, and other body functions. play a major role in the activities of enzymes, protines that regulate chemical reactions in the body (important for turning food into energyand other needed substances.

Which nutrients may be lacking in a vegetarian diet?

harder to meet proper amounts of protein (adequate amount of protein from plant protein if extremely varied), omega-3 fatty acids (found in fish, organ meats and eggs), *iron is easier to absorb from animal foods, but is still possible with plan food **nutrients that are lacking in a vegetarian diet: Iron, zinc, B12, calcium, vitamin D

What are the essential amino acids?

histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan, valine

Where does the majority of fat absorption take place?

in the small intestines

Riboflavin can be destroyed by ________.

light

Where do fats go after absorption: blood or lymph?

lymph

Proteins contain carbon, hydrogen, oxygen, and _________.

nitrogen (and on occasion, sulfur)

Which is more absorbable: animal proteins or plant proteins?

not sure but in the slides animal protein is an example of a high quality protein so I am going to assume animal protein is more absorbable

Amino acids are joined by _____ bonds.

peptide bonds

Know examples of situations in which positive and negative nitrogen balance might occur.

positive nitrogen balance: it means that person is consuming more protein than his body needs. This is an ideal state for athletes and body builders, because the extra protein will most likely contribute to muscle growth. Excess protein can also help athletes and body builders recover faster from workouts. negative nitrogen balance: nitrogen output is greater than his nitrogen input. Because protein is the only macronutrient containing a nitrogen molecule, a negative nitrogen balance can be a sign of inadequate protein consumption and malnutrition. ***Positive: pregnancy, growth, muscle building Negative: critical illness, starvation, astronauts

What is the RDA for protein?

recommended dietary allowances: 0.8g/kg body weight

You are serving strawberries as a part of a meal. To preserve vitamin C, should you cut them soon before serving or hours before serving?

soon before serving

What are trans fats? Why should we avoid them?

trans fats are made when polyunsaturated oils are hardened by hydrogenation, some of the unsaturated fatty acids end up changing their shapes instead of becoming saturated. Those acids are then known as the trans fats. They are usually found in commercially prepared foods. We should avoid them because they lower HDL (the healthy cholesterol) and raise LDL (the lousy/unhealthy cholesterol.)