Biochemistry Assignement.

7/29/2019 Biochemistry Assignement.

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Vitamin/Mineral:(How

Much/day)Why You Need It:

Best Sources To Find

It:

Vitamin A& Beta

Carotene (700 mcg)

Development of bonesand teeth grow vitamin

A prevents poor vision

at night or when light

intensity is low and

helps to fight

infections. Lack of

vitamin A also causes

blindness in children. A

woman needs to eat

plenty of vitamin A-rich

food during pregnancy

and while

breastfeeding.

Dark yellow andgreen leafyvegetables and

Liver, milk, eggs,

carrots, spinach,

green and yellow

vegetables, broccoli,

potatoes, pumpkin,

yellow fruits,

cantaloupe
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yellow fruits

contain lots of

vitamin A. Name

some of thesevegetables and

fruits.

Vitamin D(5 mcg)

Helps body use calcium

and phosphorus;

promotes strong teeth

and bones

Milk, fatty fish

Vitamin E (15 mg)

Helps body form and

use red blood cells and

muscles

Vegetable oil, wheat

germ, nuts, spinach,

fortified cereals

Vitamin C (80 - 85 mg)

An antioxidant that

protects tissues from

damage and helpsbody absorb iron;

builds healthy immune

system

Citrus fruits, bell

peppers, green

beans, strawberries,

papaya, potatoes,

broccoli, tomatoes

Thiamin/B1 (1.4 mg)

Raises energy level and

regulates nervous

system

Whole grain,

fortified cereals,

wheat germ, organ

meats, eggs, rice,pasta, berries, nuts,

legumes, pork

Riboflavin/B2 (1.4 mg)Maintains energy,

good eyesight, healthy

Meats, poultry, fish,

dairy products,
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skin fortified cereals,

eggs

Niacin/B3 (18 mg)Promotes healthy skin,

nerves and digestion

High-protein foods,

fortified cereals and

breads, meats, fish,

milk, eggs, peanuts

Pyridoxine/B6 (1.9 mg)

Helps form red blood

cells; helps with

morning sickness

Chicken, fish, liver,

pork, eggs,

soybeans, carrots,

cabbage,

cantaloupe, peas,spinach, wheat

germ, sunflower

seeds, bananas,

beans, broccoli,

brown rice, oats,

bran,

peanuts,walnuts

Folic Acid/Folate (600

mcg)

Helps support the

placenta, and

preventsspina

bifidaand other neural

tube defects

Oranges, orange

juice, strawberries,

green leafy

vegetables, spinach,

beets, broccoli,

cauliflower, fortified

cereals, peas, pasta,

beans, nuts

Calcium (1,000 - 1,300

mg)

Creates strong bones

and teeth, helps

prevent blood clots,

helps muscles and

Yogurt, milk,

cheddar cheese,

calcium-fortified

foods like soy milk,
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nerves function juices, breads,

cereals, dark green

leafy vegetables,

canned fish withbones

Iron (27 mg)

Helps in the production

of hemoglobin;

preventsanemia, low

birth weight,

andpremature birth

Beef, pork, dried

beans, spinach, dried

fruits, wheat germ,

oatmeal or grains

fortified with iron

Protein(60 mg)

Helps in the production

of amino acids; repairs

cells

Most animal foods,meat, poultry, eggs,

dairy products,

veggie burgers,

beans, legumes, nuts

Zinc

Helps produce insulin

and enzymesRed meats, poultry,

beans, nuts, whole

grains, fortified

cereals, oysters,

dairy products
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Iodine prevents goiter (swelling of the neck) and other problems in

adults. Lack of iodine in a pregnant woman can cause her child to have

cretinism, a disability that affects thinking and physical features.

The easiest way to get enough iodine is to use iodized salt instead of

regular salt (Figure 14.6). It is available in packet form labeled Iodized

salt in many market places.

2. No, herbal supplements are not the best option because herbal

supplement can sometime cross the placenta and have some effects

on the baby. Some herbal that can cross the placenta are:

Saw Palmetto - when used orally has hormonal activity. It mayaffect pregnancy-related hormones and lead to complication.

Goldenseal - when used orally may cross the placentaGoldensealGoldenseal is commonly used in hopes of passing a drug test

when drugs are in fact present in the system and is commonly

used for upper respiratory tract infections, colds, and stuffy noses.

Goldenseal may also be used for digestive problems, ulcers,

diarrhea, gas and constipation. Goldenseal or breastfeeding as it

may be unsafe for the baby. A dangerous chemical found in

goldenseal can pass through the placenta or into the breast milk.

Infants exposed to goldenseal have exhibited brain damagebecause of it.

Dong Quai - when used orally, due to uterine stimulant andrelaxant effects because it is known to cause uterine contractions

that could trigger premature labor or cause a miscarriage.


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Ephedra - when used orally Yohimbe - when used orally

Pay D Arco - when used orally in large doses; contraindicated

Passion Flower - when used orally Black Cohosh - when used orally in pregnant women who are not

at term

Blue Cohosh - when used orally; uterine stimulant and can inducelabor

Roman Chamomile - when used orally in medicinal amounts Pennyroyal - when used orally or topically

3. Nitrogen balance,

Nitrogen balance,

The relationship between the amount of nitrogen taken into the body,

usually as food, and that excreted from the body in urine and feces.

Most of the body's nitrogen is incorporated into protein. Positive

nitrogen balance, which occurs when the intake of nitrogen is greater

than its excretion, implies tissue formation and growth. Negative

nitrogen balance, which occurs when more nitrogen is excreted than is

taken in, indicates wasting or destruction of tissue.

n a determination made about the body's ability to meet its protein

needs which is reached by comparing the amount of nitrogen taken in

with the amount discharged via urine, hair, skin, or perspiration.


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nitrogen balance, negative,

n a condition in which nitrogen output exceeds nitrogen intake,

resulting in the body's need to draw on its own stores of protein for

energy; may be caused by dietary imbalances, illness, infection, anxiety,

or stress.

nitrogen balance, positive,

n a body condition in which nitrogen intake exceeds nitrogen output; a

normal state for children, pregnant women, or individuals recovering

from illness or surgery, whose bodies require extra protein in order to

build tissue.

Nitrogen balance should be positive in children, young adult, pregnant

woman and people recovering from surgery and injury. Also in athletes

people because they need the excess of nitrogen in order to build their

tissue.

In non pregnant woman or male adult the nitrogen balance should be

at equilibrium.

5.Negative nitrogen balance, that person's nitrogen output is greaterthan 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.

6. A)

The Recommended Daily Allowance (RDA) of iron for people who are

not iron deficient varies by age group and other risk factors. (Iron

supplements are rarely recommended in people without evidence of

iron deficiency or anemia.) The RDA for iron intake is:


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Infants 0 - 6 months: 0.27 mg Infants 7 - 12 months: 11 mg

Children 1 - 3 years old: 7 mg

Children 4 - 8 years old: 10 mg Children 9 -13 years old: 8 mg Teenage boys (14 - 18 years): 11 mg Teenage girls (14 - 18 years): 15 mg Men 19 - 50 years old: 8 mg Women 19 - 50 years old: 18 mg Pregnant women: 27 mg Older men and women (over age 50): 8 mg

B)

Age Group Hemoglobin Count (gm/dl)

Newborn Babies 17- 22

Children 11-13

Adults (Male) 14-18

Adults (Female) 12-16

Elderly (Male) 12.4-14.9

Elderly (Female) 11.7-13.8

C) At birth, the normal range of hematocrit can be anywhere from 42 to

64.


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After birth up until 1 month of age, the "normal" range is between 31

and 67.

Between 1 to 2 months, the normal range is between 28 to 55.

Between 2 and 6 months, the normal range is between 28 and 42.

Between 6 months to two years, the normal range is 33 to 40.

Between 2 to 6 years the normal range is between 34 to 40.

Between 6 to 12 years, the normal range is between 35 to 45.

For females between ages 12 and 18, the normal range is between 36to 46.

For males between ages 12 and 18, the normal range is between 37

and 49.

esults indicating low hematocrit levels, cannot be ignored and is a

cause for worry. Low hemoglobin levels and pregnancy is commonly

associated with a decreased hematocrit range. Other reasons areelaborated below:

Anemia: This condition causes a significant reduction in the number of

red blood cells. When the RBC count is too less, there is a sharp drop in

hematocrit levels. In fact, a person with low hematocrit levels is said to

be suffering from anemia.

Hemolysis: This condition brings premature death of red blood cells. In

other words, hemolysis decreases the life span of red blood cells,

leading to significant reduction in RBC count, thereby causing lowered

hematocrit levels in the body.


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Nutritional Deficiencies: Deficiency of essential nutrients like vitamin

B12, iron and folate can also reduce the number of red blood cells in

the blood.

Chemotherapy Drugs: Chemotherapy drugs that are commonly used to

treat cancer can also have a negative impact on normal RBC count.

These drugs that are formulated to kill cancer cells may also destroy

healthy red blood cells. This in turn may reduce volume of red blood

cells (RBCs) in the blood.

Renal Failure: Less than normal hematocrit values may also signal renal

failure, in which the kidneys fail to perform their necessary function.

Renal failure can be either acute (rapid decrease in kidney function) or

may occur gradually over a period of time. In either case, the amount of

space occupied by red blood cells in the blood is bound to reduce

substantially.

People suffering from rheumatoid arthritis and leukemia have also

been diagnosed with hematocrit range that is far less than normal. So,

low or high hematocrit levels have to be taken seriously, as they

indicate overall health is not in good shape.

The hematocrit represents the volume of red blood cells in 100ml of

blood and is therefore reported as a percentage. A low hematocrit andhemoglobin usually indicates decreased production, excessive loss, or

destruction of red blood cells. Anemia is not a disease, but a term

indicating insufficient hemoglobin to deliver oxygen to the cells. It is

always a secondary phenomenon.


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Optimum values in an adult male are 42.0 to 48.0% and in an adult

female is 39.0 to 45.0%.

The conditions associated with an increased or decreased hematocrit

are the same as for hemoglobin. In addition, it has been suggested that

an elevated hematocrit may be due to spleen hyperfunction, and a

reduced hematocrit may indicate low thymus function.

D) Recommended Dietary Allowances (RDAs) for Folate [2]

Age Male Female Pregnant Lactating

Birth to 6months*

65 mcgDFE*

65 mcgDFE*

712 months* 80 mcg

DFE*

80 mcg

DFE*

13 years 150 mcg

DFE

150 mcg

DFE

48 years 200 mcg

DFE

200 mcg

DFE

913 years 300 mcg

DFE

300 mcg

DFE

1418 years 400 mcg

DFE

400 mcg

DFE

600 mcg

DFE

500 mcg

DFE

19+ years 400 mcg

DFE

400 mcg

DFE

600 mcg

DFE

500 mcg

DFE

* Adequate Intake (AI)
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Age Male Female Pregnancy Lactation

Birth to 6

months

Not possible to

establish*

Not possible to

establish*

712

months

Not possible to

establish*

Not possible to

establish*

13 years 300 mcg 300 mcg

4 8 years 400 mcg 400 mcg

913 years 600 mcg 600 mcg

1418 years 800 mcg 800 mcg 800 mcg 800 mcg

19+ years 1,000 mcg 1,000 mcg 1,000 mcg 1,000

mcg

* Breast milk, formula, and food should be t

7.Folic acid is used to make the extra blood your body needs duringpregnancy. All women of childbearing age should consume 400

micrograms of folic acid a day.

When should I start taking folic acid?

You should start taking folic acid prior to getting pregnant even if you

are not trying to conceive. Neural tube defects usually develop in thefirst 28 days of pregnancy, often before a woman even knows that she

is pregnant. If you find you are pregnant and have not been taking folic

acid, you should start now to help prevent any neural defects in the

first three months of pregnancy.


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What are the risks of not taking folic acid?

The absence of folic acid increases the possibility of a neural tube

defect, a defect in the development of the spinal cord.

Spina bifidais a condition in which the spinal cord is exposed. Ifthe vertebrae (bones of the spinal column) surrounding the spinal

cord do not close properly during the first 28 days after

fertilization, the cord or spinal fluid bulge through, usually in the

lower back.

Anencephaly is the severe underdevelopment of the brain.What foods contain folic acid?

Approximately half of all pregnancies are unplanned, so the U.S. Food

and Drug Administration has taken steps to fortify certain foods so that

all women of childbearing age get a daily dose of folic acid. The

following foods can help you obtain your recommended amount of folic

acid:

Leafy green vegetables, such as a large spinach salad Citrus fruits, such as orange juice Beans Breads

Cereals Rice Pastas
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A daily vitamin with folic acid may be suggested by your health care

provider since the food listed above may not contain enough folic acid

to meet the daily requirement.

How do I know if I am at risk for having a baby with neural defects, and

how can I prevent this from happening?

Women who are at greatest risk are those that have had a previous

pregnancy that involved a neural defect. Women who are not eating a

balanced diet that includes folic acid are also at risk.

The best way to prevent neural defects is to take the recommended

400 micrograms of folic acid daily for one month before conception and

during the first three months of pregnancy. Multivitamins that include

folic acid should only be used as a supplement under the care of your

health care provider.

8.Why you need iron during pregnancyEven before you're pregnant, your body needs iron for several reasons:

It's essential for making hemoglobin, the protein in red blood cellsthat carries oxygen to other cells.

It's an important component of myoglobin (a protein that helpssupply oxygen to your muscles), collagen (a protein in bone,

cartilage, and other connective tissue), and many enzymes.

It helps you maintain a healthy immune system.But during pregnancy you need a lot more of this crucial mineral. Here's

why:


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The amount of blood in your body increases during pregnancyuntil you have almost 50 percent more blood than usual, so you

need more iron to make more hemoglobin.

You need extra iron for your growing baby and placenta,especially in the second and third trimesters.

Many women need more because they start their pregnancy withinsufficient stores of iron.

Iron-deficiency anemia during pregnancy is associatedwithpreterm delivery, low birth weight, and infant mortality.

How much iron you need

Pregnant women: 27 milligrams (mg) of iron per day

Non-pregnant women: 18 mg

You don't have to get the recommended amount of iron every day.

Instead, aim for that amount as an average over the course of a few

days or a week.

Food sources of iron

Red meat is one of the best sources of iron for pregnant women. (Liver

provides the highest concentration of iron, but because it contains

unsafe amounts ofvitamin A, it's best avoided during pregnancy.) If

your diet doesn't include animal protein, you can get iron from

legumes, vegetables, and grains.

There are two forms of iron: non-heme iron, which is found in plants (as

well as in meat, poultry, and fish), and heme iron, which is found only in

animal products. Heme iron is easier for your body to absorb. (Iron-
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fortified foods and supplements provide non-heme iron.) To make sure

you're getting enough, eat a variety of iron-rich foods every day.

Common sources of heme iron:

Red meat, poultry, and fish are all good sources of heme iron. (For easy

reference, 3 ounces of meat is about the size of a deck of cards.)

3 ounces lean beef chuck: 3.2 mg 3 ounces lean beef tenderloin: 3.0 mg 3 ounces roast turkey, dark meat: 2.0 mg 3 ounces roast turkey breast: 1.4 mg 3 ounces roast chicken, dark meat: 1.1 mg 3 ounces roast chicken breast: 1.1 mg 3 ounces halibut: 0.9 mg

3 ounces pork loin: 0.8 mg

Common sources of non-heme iron:

1 cup iron-fortified ready-to-eat cereal: 24 mg 1 cup fortified instant oatmeal: 10 mg 1 cup edamame (boiled soybeans): 8.8 mg 1 cup cooked lentils: 6.6 mg 1 cup cooked kidney beans: 5.2 mg


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1 cup chickpeas: 4.8 mg 1 cup lima beans: 4.5 mg

1 ounce roasted pumpkin seeds: 4.2 mg

1 cup cooked black or pinto beans: 3.6 mg 1 tablespoon blackstrap molasses: 3.5 mg 1/2 cup raw firm tofu: 3.4 mg 1/2 cup boiled spinach: 3.2 mg 1 cup prune juice: 3.0 mg 1 slice whole wheat or enriched white bread: 0.9 mg 1/4 cup raisins: 0.75 mg

9.Protein requirements in pregnancy rise to 1.1 g/kg/day (71 g),amounting to more than a 50% increase in protein intake to allow for

fetal growth and milk production. The source of protein may be asimportant as the quantity, however. Some evidence suggests that

protein requirements can be more safely met by vegetable than by

animal protein. Meat is a major source of saturated fat and cholesterol;

it is also a common source of ingestible pathogens29

and a rich source

of arachidonic acid, a precursor of the immunosuppressive eicosanoid

PGE2.

Pregnant women also should not meet their increased need for protein

by the intake of certain types of fish, such as shark, swordfish,

mackerel, and tilefish, which often contain high levels of

methylmercury, a potent human neurotoxin that readily crosses the

placenta.30 Other mercurycontaminated fish, including tuna and fish


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taken from polluted waters (pike, walleye, and bass), should be

especially avoided.31

There is no nutritional requirement for fish or fish

oils. Vegetable protein sources, aside from meeting protein needs, can

help meet the increased needs for folate, potassium, and magnesiumand provide fiber, which can help reduce the constipation that is a

common complaint during pregnancy.

roteins

Proteins, from the Greekproteiosmeaning first, are important

biological molecules (biomolecules) that consist of strings of smaller

units called amino acids, the building blocks of proteins. These aminoacids are linked together in sequence as polypeptide chains that fold

into compact shapes. Proteins vary in

The three functions of macronutrients

Provide energy Promote growth and

development

Regulate body

functions

Carbohydrates Proteins Proteins

Poteins Lipids Lipids

Lipids (fats and

oils)

Vitamins Vitamins

Minerals Minerals

Water Water

(Illustration by GGS Information Services/Thomson Gale.)


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shape and size, some consisting only of ^20-30 amino acids and others

of several thousands. They are present in every living cell. In the skin,

hair, callus, cartilage, muscles, tendons and ligaments, proteins hold

together, protect, and provide structure to the body. As enzymes,hormones, antibodies, and globulins, they catalyze, regulate, and

protect the body chemistry. Important biomolecules like hemoglobin,

myoglobin and various lipoproteins, that carry oxygen and other

substances within the body are also proteins.

Besides providing energy to the body, dietary protein is also required

for growthespecially by children, teenagers, and pregnant women,

tissue repair, immune system function, hormone and enzyme

production, and for lean muscle mass and tone maintenance. When

eaten, the proteins contained in foods are broken down into amino

acids, an important dietary source of nitrogen. To make the proteins

that it needs (protein biosynthesis), the body also needs them. There

are 20 amino acids and the body can make some of them from

components within the body, but it cannot synthesize nine of them,accordingly called the essential amino acids since they must be

provided in the diet. They include: histidine, isoleucine, leucine,

methionine, phenylalanine, threonine, tryptophan, and valine. Protein

that comes from animal sources are called complete proteins

because they contains all of the essential amino acids while protein

from plants, legumes, grains, nuts, seeds and vegetables are called

incomplete proteins because they are lacking one or more essentialamino acid(s).

Proteins are complex molecules and the body needs time to break

them down. This is why they are a slower and longer-lasting source of

energy than carbohydrates. According to the Dietary Reference Intakes


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(RDI)published by the Unites States Department of Agriculture (USDA),

adults need to eat about 60 grams of protein per day (0.8 g per kg of

weight). Adults who are physically very active or trying to build muscle

need slightly more. Children also need more. If more protein isconsumed than is needed, the body stores its components as fat, which

can be broken down and used for energy as need arises. Proteins are

broken down during digestion, which exposes them to acid in the

stomach and to degradation by the action of enzymes called proteases.

Some ingested amino acids are converted to carbohydrates

(gluconeogene-sis), which is also used under starvation conditions to

generate glucose from the bodys own proteins, particularly those

found in muscle.

Carbohydrates

There are two basic types of carbohydrates, depending on their size.

Simple carbohydrates (mono-sachharides) are those that cannot be

broken down into simpler sugars. They include various forms of sugar,

such as glucose and fructose. Complex carbohydrates are larger and

consist of long strings of simple carbohydrates (disachharides,

oligosachharides, poly-sachharides). They include sucrose, lactose,

maltose, maltodextrins, fructo-oligo-saccharides, starch, amy-lose, and

amylopectin. The human body uses carbohydrates in the form of

glucose and it can convert both simple and complex carbohydrates into

energy very quickly. The brain needs to use glucose as an energy

source, since it cannot use fat for this purpose. This is why the level of

glucose in the blood must be constantly maintained above the

minimum level. The body also stores very small amounts of excess

carbohydrate as energy reserve. The liver stores some as glycogen, a

complex carbohydrate that the body can easily and rapidly convert to


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energy. Muscles also store glycogen, which they use during periods of

intense physical activity. The amount of carbohydrates stored as

glycogen is equivalent to about a days worth of calories. A few other

body tissues store carbohydrates as complex carbohydrates that cannotbe used to provide energy.

Carbohydrates have two major roles: they are the primary energy

source for the brain and they are a source of calories to maintain body

weight. A diet containing an optimum level of carbohydrates may help

prevent body fat accumulation. They are also involved in the

construction of the body organs and nerve cells, and in the definition of

a persons biological identity such as their blood group. Dietary fiber,

which is a carbohydrate, also helps keep the bowel functioning

properly. Because they are smaller, simple carbohydrates can be

broken down by the body more quickly and they are the fastest source

of energy. Fruits, dairy products, honey, and maple syrup contain large

amounts of simple carbohydrates, which provide the sweet taste in

most candies and cakes.

carbohydrates occur in a wide variety of foods. For example, table

sugar (sucrose) is a combination of the glucose and fructose that occurs

naturally in sugar beet, sugar cane and fruits. Lactose is the main sugar

in milk and dairy products and maltose is a sugar occurring in malt.

Another type of carbohydrate are the polyols, the so-called sugar

alcohols. They do occur naturally but most are made commercially by

the transformation of sugars. Complex carbohydrates also include

starch, the main energy reserve in root vegetables and cereals. Non-

starch carbohydrates are the main components of dietary fiber. These

are the indigestible portion of plant foods, such as cellulose, the major

component of plant cell walls that consists of several thousand glucose


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units. Simple sugars are absorbed directly by the small intestine into

the bloodstream, where they are then transported to where they are

required. Complex carbohydrates are broken down by enzymes into

their constituent sugars which are then absorbed into the bloodstreamwhile dietary fiber moves food through the digestive system.

Fats

Besides being a source of energy, fat stores protect the internal organs

of the body. Some essential fats are also required for the formation of

hormones. Fats are the slowest source of energy but the most energy-

efficient form of food. Each gram of fat supplies the body with about 9calories, more than twice

that supplied by the two other macronutrients. Because fats are such

an efficient form of energy, they are stored by the body either in the

abdomen (omental fat) or under the skin (subcutaneous fat) for use

when the body needs more energy. Fats that are in foods are

combinations of four main types:

Saturated fats: These fats consist of fatty acid chains that have nodouble bonds between the carbon atoms of the chain. They are

called saturated because they are fully saturated with hydrogen

atoms and cannot incorporate more. They are solid at room

temperature and are most often of animal origin. Examples are

butter, cheese, and lard. These fats provide a concentrated source

of energy in the diet and building blocks for cell membranes and a

variety of hormones and hormone-like substances. An excess of

these fats in the diet however, is believed to raise the cholesterol

level in the bloodstream.


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Monounsaturated fats: These are composed mostly ofmonounsaturated fatty acids, meaning molecules with one

double-bonded carbon, with all the others carbons being single-

bonded. They are liquid at room temperature. Examples are olive,peanut and canola oil. They appear to protect against heart

disease, in that they reduce blood cholesterol levels.

Polyunsaturated fats: These fats are composed mostly of fattyacids such as linoleic or linolenic acids which have two or more

double bonds in each molecule, as for example corn oil and

safflower oil. They are also liquid at room temperature and can be

further divided into the omega-6 and the omega-3 families.

Polyunsaturated fats are thought to reduce the risk of coronary

heart disease. The omega-3 forms are believed to have a positive

impact on heart health and to play an important role in brain and

eye function. Oily fish such as salmon, herring and mackerel are

examples of omega-3s, and they are also found in walnuts and

some oils like soybean and rapeseed.

Trans fatty acids. Unsaturated fats come in different chemicalstructures: a bent cis form or a straight trans form. When they

adopt the trans form, they are called transfatty acids. They are

produced by the partial hydrogenation of vegetable oils and

present in hardened vegetable oils, most margarines, commercial

baked foods, and many fried foods. An excess of these fats in the

diet is thought to increase the risk of heart disease.

Description


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The three types of macronutrients do not have the same chemical

composition. When compared with carbohydrates and fats, proteins

are very different.

Fats largely consist of hydrocarbon chains, containing 75-85% carbon.

Carbohydrates are roughly 50% oxygen, and like fats, they usually have

less than 5% nitrogen or none at all. Proteins, on the other hand,

consist of 15-25% nitrogen and about an equal amount of oxygen. The

three macronutrients are often found together in most foods, but in

varying amounts, or alone in other foods. The Nutrition Facts labels

provide a breakdown of the macronutrient composition of various

foods.

Proteins

According to RDI, between 10 and 35% of calories should come from

protein.

Foods that are a source of protein include:

Animal protein: Meat, poultry, fish, eggs, milk, cheese and yogurtprovide high biological value proteins, because they contains all

the essential amino acids.

Plant proteins: Plants, legumes, grains, nuts, seeds and vegetablesprovide low biological value proteins. However, combining

proteins from different plant sources in the same meal often

results in a mixture of higher biological value. Examples of such

combinations are: beans with rice, pasta or manioc, chickpeas

with bread, lentils with potatoes, vegetables with cereals.

Carbohydrates


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According to the RDI, between 50 and 55% of calories should come

from carbohydrates and 20-35 g dietary fiber per day should be taken

by all those over two years of age.

Sources of dietary carbohydrates include:

Monosaccharides: fruits, berries, vegetables and honey. Disaccharides: table sugar, sugar beet, sugar cane and fruits. Polyols: Isomalt Oligosaccharides: grains and vegetables Starch polysaccharides: cereals, whole grains, rice, pasta,

potatoes, peas, corn and legumes.

Non-starch polysaccharides: dietary fiber such as cellulose,hemicelluloses, pectins and gums.

Fats

Sources of dietary fats include:

Saturated: Butter, cheese, meat, meat products (sausages,hamburgers), whole milk and yoghurt, pies, pastries, lard,

dripping, hard margarines and baking fats, coconut and palm oil.

Monounsaturated: Olives, rapeseed, nuts (pistachio, almonds,hazelnuts, macadamia, cashew, pecan), peanuts, avocados, and

their oils.

Omega-3 polyunsaturated: Salmon, mackerel, herring, trout(particularly rich in the long chain omega-3 fatty acids EPA or


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eicosapentaenoic acid and DHA or docosahexaenoic acid),

walnuts, rape-seed, soybean flax seed, and their oils.

Omega-6 polyunsaturated: Sunflower seeds, wheat germ, sesame,walnuts, soybean, corn and their oils. Certain margarines

Trans fatty acids: Some frying and baking fats (hydrogenatedvegetable oils) used in biscuits, cakes and pastries, dairy products,

fatty meat from beef and sheep.

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Biochemistry Assignement.

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