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Question 1
Vitamins are not considered to be foods, yet they are a vitally important part of healthy diets. Explain .
vitamins are organic substances (made by plants or animals), which boost the immune system, support normal growth and development, and help cells and organs do their jobs. For example, Carrots are full of substances called carotenoids that your body converts into vitamin A, which helps prevent eye problems.Another vitamin, vitamin K, helps blood to clot (so cuts and scrapes stop bleeding quickly). You’ll find vitamin K in green leafy vegetables, broccoli, and soybeans. And so on so fourth.
Question 2
What are some typical symptoms of vitamin
deficiency?
Signs and symptoms of vitamin deficiency include:
· Fatigue
· Shortness of breath
· Dizziness
· Pale or yellowish skin
· Swollen tongue that may appear dark red
· Weight loss
· Diarrhea
· Numbness or tingling in your hands and feet
· Muscle weakness
· Irritability
· Unsteady movements
· Mental confusion or forgetfulness
bleeding gums,
dry hair,
rough skin,
nosebleeds,
anemia,
gingivitis,
easy bruising,
a decreased ability to fight infection.
weakness,
numbness or tingling in the extremities
following are specific problems associated to different vitamin deficiency
A Diet Low in This Vitamin
May Produce These Signs of Deficiency
Vitamin A
Poor night vision; dry, rough, or cracked skin; dry
mucous
membranes including the inside of the eye; slow wound healing; nerve damage; reduced ability to taste, hear, and smell; inability to perspire; reduced resistance to respiratory infections
Vitamin D
In children: rickets (weak muscles, delayed tooth development, and soft bones, all caused by the inability to absorb
minerals without vitamin D)
In adults: osteomalacia (soft, porous bones that fracture easily)
Vitamin E
Inability to absorb fat
Vitamin K
Blood fails to clot
Vitamin C
Scurvy (bleeding gums; tooth loss; nosebleeds; bruising; painful or swollen joints; shortness of breath; increased susceptibility to infection; slow wound healing; muscle pains; skin rashes)
Thiamin(
vitamin
B1)
Poor appetite; unintended weight loss; upset stomach; gastric upset (nausea, vomiting); mental depression; an inability to concentrate
Riboflavin(
vitamin
B2)
Inflamed mucous membranes, including cracked lips, sore tongue and mouth, burning eyes; skin rashes; anemia
Niacin
Pellagra (diarrhea; inflamed skin and mucous membranes; mental confusion and/or dementia)
Vitamin B6
Anemia; convulsions similar to epileptic seizures; skin rashes; upset stomach; nerve damage (in infants)
Folate
Anemia (immature red blood cells)
Vitamin
B12
Pernicious anemia (destruction of red blood cells, nerve damage, increased risk of stomach cancer attributed to damaged stomach tissue, neurological/psychiatric symptoms attributed to nerve cell damage)
Biotin
Loss of appetite; upset stomach; pale, dry, scaly skin; hair loss; emotional depression; skin rashes (in infants younger than 6 months)
Question 3
What chemical characteristics determine whether a vitamin is fat -soluble or water-soluble?
Vitamins are either water soluble or fat soluble, depending on their molecular structures. Water-soluble vitamins have many polar groups, so they are soluble in polar solvents such as water. Fat-soluble vitamins are predominantly non-polar and are soluble in non-polar solvents such as the fatty tissue of the body.
Question 4
Why must water-soluble vitamins be consumed more regularly than fat-soluble vitamin?
Water-soluble vitamins dissolve easily in water and, in general These are easily absorbed and eliminated from the body due to their limited storage capacity in the body and thus deficiency is more likely to occur. However, their toxicity is virtually nil. Because they are not as readily stored, more consistent intake is important.
Fat-soluble vitamins are absorbed through the
intestinal tract with the help of
lipids (fats). Because they are more likely to accumulate in the body, they are more likely to lead to
hypervitaminosis than are water-soluble vitamins.
Question 5
Why do RDA s for vitamins and minerals vary for individuals based on age and gender?
In all era s of ages like (Childhood, Adolescence, adulthood etc) Recommended dietary allowance is different because of ability and requirement of body to absorb the vitamins for example adolescent growth spurt marks a time when the body requires both more energy (Calories) and a greater quantity of essential vitamins and minerals. However for gender differences vitamins requirements does not vary a lot for normal adult. With the exception of iron, women generally require about the same or lower levels of most nutrients than men. Men and women also metabolize some nutrients differently, which means the nutritional supplementation recommended for active or athletic men may also differ from that for women. Children and pregnant or lactating women have different nutritional requirements than the average adult male and female. In pregnancy for females extra vitamin are needed because the baby poses extra requirement on the mother body.
Question 6
Describe the key steps in a titration, and explain how the process may be used to analyze a solution.
1. Take a clean conical flask and to ensure really clean [dust free] wash with distilled water from a wash bottle and pour out.
2. Pour some solution 1 you have been given [eg alkali] into a beaker. Using a 25mL pipette and pipette filler, suck up solution until it is above the graduation mark. Let it out slowly until the bottom of the liquid meniscus is just on the graduation mark.
3. Let the liquid from the pipette run into the clean conical flask. Do NOT blow into it speed it it, instead, when it has finished running out, just touch the tip of the pipette onto the surface of the liquid in the flask. You have now added a 25.00ml portion [aliquot].
4. Now take you burette and clamp it vertically. Rinse with a little of the titrating solution [eg acid] and then let it run into a spare beaker. Check the tap is closed. Put a clean dry funnel in the top and fill the burette to near the top. Remove the funnel … you don’t want drips dropping off during the actual titration giving inaccurate results! A lot of students forget this. Now let some acid run into a spare beaker until the liquid level is on the scale. DO NOT try and set it to 0.00 as this is very bad technique as it is rarely spot on. Instead read the scale carefully. Unfortunately not all teachers do this these days!
5. Place your measured alkali on a white tile under the burette and add a couple of drops of suitable indicator .. in this case methyl orange solution. Add the acid 1mL at a time, with swirling, until the indicator changes colour from yellow to red. Take the reading. This is called a rough titration and tells you roughly the end point [when the two solns just react and the indicator changes colour as it goes from alkaline to acid]
6. Repeat the whole procedure three more times, but if the end point was, for example, 20mL, you can safely run in say 18ML quite quickly, then proceed slowly, almost a drop at a time to get the EXACT end point. Just before the end, gently wash down the inside of the flask with your distilled water bottle so that anything that had got up there in swirling gets washed down again. Ideally your teacher should demonstrate all this to you rather than expect you to find out. It is a skill that you need to try a few times.
7. Record all your results in a table [1 rough, 3 accurate titrations] Show both start and end readings and TITRE [volume used]. Take the average of your three accurate experiments for the final answer. With skill, experience and practice, these should agree within 0.1mL
8. Use results to calculate concentration of of the unknown solution using the mole concept. You must know the concentration of one of them. This is usually a standard .. a subtance that can be obtained very pure that doesn’t react with air etc.
9. By chosing suitable indicators you can titrate all sorts of solutions.
Question 7
Can titration be used to determine both the amount and the identity of an unknown solute?
b. Explain.
(a) No,
(b) Titration just used to find the concentration of known solute as it is a quantitative analysis. Titration is a common laboratory method of quantitative/chemical analysis that can be used to determine the concentration of a known reactant (analyte). The basis of the method is a chemical reaction of a standard solution (titrant) with a solution of an analyte.
Question 8
a. What is meant by the “endpoint” of a tit ration?
b. What does the endpoint indicate about the progress of a reaction ?
(a) The endpoint is the point at which the titration is complete, At the titration endpoint, the quantity of reactant in the titrant added during the titration is stoichiometrically equivalent to the quantity of reactant in the analyte. This is ideally the same volume as the equivalence point.
(b) At the end point the reaction between acid and base reached to completion that is neutralization reaction completes with end point reached
Question 9
Following reaction determines the vitamin C concentration in a solution by a redox titration using iodine.
ascorbic acid + I2 → 2 I− + dehydroascorbic acid
Following reaction determines the vitamin C concentration in a solution by a acid- base titration .
Question 10
Name three minerals that are essential for human life.
Calcium,
phosphorus,
potassium,
sulfur,
sodium,
Question 11
What is the difference between a macromineral and a micromineral?
Micro Minerals are the ones that you need in small amounts, usually less than 100 milligrams a day, for healthy living.
Macro Minerals are their opposite, macro minerals, are those minerals in which quantities greater than 5 grams are stored in the body and also in which quantities greater than 100 milligrams per day are needed to replace losses and restore balance.
Question 12
What are some important roles of minerals in the body?
Different minerals have different but specific roles in the human body for example;
Potassium, Sodium; needed for proper fluid balance, nerve transmission, and muscle contraction.
Calcium; Important for healthy bones and teeth; helps muscles relax and contract; important in nerve functioning, blood clotting, blood pressure regulation, immune system health.
Chloride Needed for proper fluid balance and stomach acid.
Magnesium; Found in bones; needed for making protein, muscle contraction, nerve transmission, immune system health
Question 13
Although high temperatures can destroy vitamins in foods, they rarely affect the quality of minerals in the foods. Explain.
Vitamins especially water soluble vitamins are quite vulnerable to heat. However the almost all the minerals remain virtually unaffected by addition of heat to them. This is due to their very stable nature. The degree to which the amount of an ingested nutrient is absorbed and available to the body is called bioavailability. In fact, they are often made far more bioavailable by cooking because the cooking breaks down fiber in the food so that the minerals contained in the food can be absorbed much more easily.
Question 14
Regarding minerals in the diet, some people believe that “if a little is good, more must be better.” Evaluate that idea in terms of the quantity of minerals needed in a healthy diet.
This beleive is not right rather it may be dangerous as excess intake of one mineral can influence the absorption and
metabolism of other minerals. For example, the presence of a large amount of zinc in the diet decreases the absorption of iron and copper.
Trace minerals can be toxic at higher intakes, especially for those minerals whose absorption is not regulated in the body (e.g., selenium and iodine). Thus, it is important not to habitually exceed the recommended intake levels. Although toxicity from dietary sources is unlikely, certain genetic disorders can make people vulnerable to overloads from food or supplements. One such disorder, hereditary hemochromatosis, is characterized by iron deposition in the liver and other tissues due to increased intestinal iron absorption over many years.
In summary, minerals, both major and trace, play vital roles in human health, and care must be taken to obtain adequate intakes from a wide variety of whole foods. The most common result of deficiencies is poor growth and development in children. Minerals interact with each other and with other nutrients, and caution is required when using supplements, as excess intake of one mineral can lead to the deficiency of another nutrient.
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Question: 1
Name three tissues in your body for which protein is the main structural component.
Protein is the main structural component of
muscle tissue,
collagen, and connective tissues
Connective Tissues
1. Areolar (Loose) Connective Tissue
2. Adipose Connective Tissue
3. Cartilage connective tissue
Muscle
Tissues
1. Skeletal muscle tissue
2. Smooth muscle tissue
3. Cardiac muscle tissue
Nervous Tissues
1. Nervous tissue for brain
2. Nervous tissue for spinal cord etc.
Question 2
The name “protein” comes from a Greek word meaning “of prime importance.” Why is this name appropriate for proteins?
Protein are of prime importance as these are building blocks of Muscles, enzymes, antibodies, cellular construction workers, blood, nerves etc. even the genetic code is generated by the formation of different combination of proteins.
Question 3
What are some cellular functions for which proteins are particularly important?
P
roteins are very important molecules in our
cells. They are involved in virtually all cell functions. Each protein within the body has a specific function. Some proteins are involved in structural support, while others are involved in bodily movement, or in defense against germs. Below is a list of several types of proteins and their functions.
Protein Functions
·
Antibodies – are specialized proteins involved in defending the body from antigens (foreign invaders)..
·
Contractile Proteins – are responsible for movement. Examples include action and myosin. These proteins are involved in
muscle contraction and movement.
·
Enzymes – are proteins that facilitate biochemical reactions. They are often referred to as catalysts because they speed up chemical reactions. Examples include the enzymes lactase and pepsin.
·
Hormonal Proteins – are messenger proteins which help to coordinate certain bodily activities. Examples include insulin, oxytocin, and somatotropin.
·
Structural Proteins – are fibrous and stringy and provide support. Examples include keratin, collagen, and elastin. Keratins strengthen protective coverings such as hair, quills, feathers, horns, and beaks. Collagens and elastin provide support for
connective tissues such as tendons and ligaments.
·
Storage Proteins – store amino acids. Examples include ovalbumin and casein. Ovalbumin is found in egg whites and casein is a milk-based protein.
·
Transport Proteins – are carrier proteins which move molecules from one place to another around the body. Examples include hemoglobin and cytochromes. Hemoglobin transports oxygen through the blood. Cytochromes operate in the
electron transport chain as electron carrier proteins.
Question 4
Name five food items that are made primarily of protein.
1.Meat
2.Eggs
3.Nuts and seeds
4.Yogurt, Milk, and Soymilk
5.Beans
Question 5
How does the relatively small number of different amino acids account for the vast variety of proteins found in nature?
Proteins are chains of amino acids that fold into a three-dimensional shape. Proteins come in a wide variety of
amino acid sequences, sizes, and three-dimensional structures, which reflect their diverse roles in nearly all cellular functions.When different amino acids join together to make a protein, the unique properties of each amino acid determine how the protein folds into its final 3D shape. The shape of the protein makes it possible to perform a specific function in our cells.
Question 6
What is the range for the total number of amino acids in various protein molecules?
the total number of amino acids are twenty in various protein molecules. However their types varies 2 to several thousands
Question 7
From where does the name “amino acid” come?
They are acids because they are electron donors in a chemical bonding. The “amino” part of the name stems from the fact that they all have an amine group ( -NH2 ) at one end.
Amino acids are called this due to the Amine N-R3 group and the O-C=O carboxylic acid group found in all of them.
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Question 9
What are fatty acids? In what ways are these substances similar to or
different from inorganic acids
?
Fatty acids are a large group of organic acids, especially those found in animal and vegetable fats and oils. Fatty acids are mainly composed of long chains of hydrocarbons ending in a carboxyl group. A fatty acid is saturated when the bonds between carbon atoms are all single bonds. It is unsaturated when any of these bonds is a double bond.
Fatty acids are different from inorganic acids due to carbon atoms. Inorganic acid is a compound containing no carbon while fatty acids are monobasic aliphatic acid containing only carbon, hydrogen and oxygen.
Question 10
Describe the reaction that chemically combines three fatty acid molecules to a molecule of glycerol.
Fat molecules are constructed from one molecule of glycerol and three fatty acid molecules. This is why fats are also called triacylglycerols.
Fat Molecule
From the figure below, we can envision glycerol as the “backbone” of a fat molecule to which three fatty acid molecules are chemically bonded.
______
_
This type of bonding in fats is called esterification. Fat is an ester of glycerol and three fatty acids. The alcohol (-OH) part of glycerol reacts with the carboxylic acid (-COOH) part of the individual fatty acids, forming the fatty acid ester and releasing H2O in the process. This is illustrated by the following reaction:
___
___Esterification
Question 11
Fats are examples of “triglycerides.”Why does that name provide an appropriate description of all fats?
The word “triglyceride” reflects the fact that a triglyceride consists of three (“tri-“) molecules of fatty acid combined with a molecule of the alcohol glycerol (“-glyceride”) that serves as the backbone in many types of lipids (fats). Triglycerides are a common type of fat that accounts for about 95 per cent of all dietary fats. Both animal and vegetable fats contain triglycerides. Once digested, triglycerides circulate in the bloodstream to be used as energy by the cells. Any leftovers are stored in body fat to fuel the body between meals. Triglycerides account for about 99 percent of the fat stored in our bodies. These triglyceride-laden fats serve as the most important source of long-term energy for the body, since they are stored in a much denser form than starches or muscle proteins.
Question 12
With what is a “saturated fat” actually saturated?
Fats with only carbon-carbon single bonds are called saturated fats. The more hydrogen than carbon a fatty acid molecule has, the more saturated it is.
Saturated
fats are usually solid at room temperature. The less hydrogen than carbon, the more liquid it is and is more unsaturated . ____
Question 13
How does the degree of un- saturation- affect the properties of a fat?
By increasing the degree of un-saturation the physical properties of the fats changes for example its melting point reduces, its physical state at room temperature changes etc.
Question 14
Some margarines are advertised as “partially hydrogenated.”
a.
What property does the product gain as a result of partial hydrogenation?
b.
Why do you think a manufacturer might decide against completely hydrogenating the margarine?
(a) As a result of partial hydrogenation some physical properties of margarine changes (e.g. M.P decrease).In addition its detrimental health effects reduces. As more the unsaturated fats more the chances of increase o f blood cholesterol.
(b) Companies do not sale a completely hydrogenated product probably for
i. It might become liquid at room temperature when completely saturated which may not be easy to sale as margarine.
ii. Even if saturated Margarine becomes more suitable in health aspect, it would be less favorable among the most people who like traditional solid margarine.
Question 15
What are some natural sources of
a. saturated fats b. unsaturated fats?
a. saturated fats
In general, the main sources of saturated fat are from animal products: red meat and whole-milk dairy products, including
cheese, sour cream, ice cream and butter. But there are also plant-based sources of saturated fat, principally coconut oil and coconut milk, palm kernel oil, cocoa butter, and palm oil.
b. unsaturated fats
Polyunsaturated and monounsaturated fats are the two unsaturated fats. They’re found mainly in many fish, nuts, seeds and oils from plants. Some examples of foods that contain these fats include salmon, trout, herring, avocados, olives, walnuts and liquid vegetable oils such as soybean, corn, safflower, canola, olive and sunflower. They are also found in some plant foods such as avocado.
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