Слайд 2
Plan
Functions of Proteins
Amino acids
Enzymes
How Much Protein?
Слайд 3
I. Functions of Proteins
Proteins • in the
body are polymers made from 20 different amino acids
• differ in characteristics and functions that depend on the order of amino acids that make up the protein • perform many different functions in the body, such as provide structure, transport oxygen, direct biological reactions, control against infection, and even be a source of energy
Слайд 4
I. Functions of Proteins
Proteins, composed of many amino
acids, (the molecular building blocks of proteins), 20 of
them are very important and are needed for muscle and tissue building, repair and maintenance. Cells, organs, the immune system, skin, hair, blood,cartilage, bones, fingernails, enzymes and some hormones. The body as a whole requires protein.
Слайд 5
Animal Sources of Protein
Meat, eggs, dairy products, poultry
and fish contain all of the essential amino acids to create
the proteins our bodies need. Some animal sources such as beef and egg yolk have a high amount of saturated fat and cholesterol with a concern for clogged arteries and heart disease.
My preferred animal sources are fish which contains Omega-3 fatty acids (essential fatty acids), then skinless chicken and turkey and egg whites, followed by low- fat and non-fat milk products and low fat cheese. Limited consumption of beef should be lean cuts of unprocessed meat
Слайд 6
Animal Sources of Protein
Vitamin B12 an essential nutrient is protein-bound
in animal foods, which maintains a healthy nervous system
and creates nerve coverings called myelin sheaths that protect nerve endings and supports red blood cell production.
As of 2004 no plant sources of vitamin B12 had been found, though many had been tested including various seaweeds, algae and fermented foods. Where claims have been made as to B12 being present in a plant source, it has not been based on the test for MMA levels, and any subsequent tests have found no reduction in MMA, proving the presence only of inactive analogues
Слайд 7
Plant Sources of Protein
Nuts, seeds, and legumes (such
as black beans and lentils kidney, lima, garbanzo, and
pinto beans, soybeans, and black-eyed peas. Plants are missing some of the essential amino acids our bodies need to produce protein.
Vegetarians and vegans can combine plant sources (complementary proteins) to obtain all of theessential amino acids the body needs by eating red beans with rice, lentils with rice, soybeans, green beans with almonds, ground sesame seeds, and corn tortillas with beans
Слайд 8
II. Amino acids
The body makes 10 of the
20 amino acids needed to produce protein. The other
10 essential amino acidsare essential because they can only be obtained from eating protein-rich foods. Amino Acids makeenzymes which are protein molecules.
The body does not store excess essential amino acids for later use. They must obtained from food every day. Essential amino acids, which aren't produced by our bodies, are found in meat, poultry, fish and dairy products
Слайд 9
II. Amino acids
The 10 amino acids that the body
can produce are alanine, asparagine, aspartic acid, cysteine, glutamic acid,
glutamine, glycine, proline, serine and tyrosine. The essential amino acids the body can't produce are arginine (required for the young, but not for adults), histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan, and valine
Слайд 10
II. Amino acids
Vegetarians and vegans can combine plant
sources (complementary proteins) to obtain all of theessential amino
acids the body needs by eating red beans with rice, lentils with rice, soybeans, green beans with almonds, ground sesame seeds, and corn tortillas with beans.
Essential Amino Acids and Essential Fatty Acids can't be produce by your body; they must be obtain from the food you eat
Слайд 11
Essential Fatty Acids
Your body needs Essential Fatty Acids to lubricate
skin and tissue (keep the outer walls of your
cells supple), allow cell membranes to function normally and the brain and nervous system to function properly.
Essential Fatty Acids (EFAs) are fats that your body doesn't manufacture, you can get them from extra virgin olive oil, flaxseeds, flaxseed meal, hempseed oil, hempseeds, walnuts, pumpkin seeds, whole nuts, grains, legumes, sesame seeds, avocados, some dark leafy green vegetables (kale, spinach, mustard greens, collards, etc.), coconut oil, canola oil (cold-pressed and unrefined, not from genetically modified soybeans), wheat germ oil, salmon, mackerel, sardines, anchovies, albacore tuna, trout, cantaloupe and papaya
Слайд 13
III. Enzymes
Enzymes made from amino acids are protein molecules that
act as catalysts that support biochemical reactions (allowing certain
chemical reactions to take place much quicker (accelerate) than the reactions would occur on their own), support hormones that influence metabolism (they speed up (accelerate) the rate at which metabolic processes and reactions occur in living organisms) and support hemoglobin which carries oxygen and antibodies to fight infection
Слайд 14
III. Enzymes
Digestive enzymes are used by your body to
digest protein, carbohydrates and fat (lipids). Your digestive system
receives the enzymes from the foods you eat and some of them are produced in your body by your digestive organs. They cause food that you eat to be broken down much faster (accelerate) than would occur without them
Слайд 16
Proteins as enzymes
This page is an introduction to
how proteins can work as enzymes - biological catalysts.
You should realise that this is written to cover the needs of a number of UK-based chemistrysyllabuses for 16 - 18 year olds. If you want detailed knowledge about enzymes for a biology or biochemistry course, you are probably in the wrong place! This is just an introduction
Слайд 17
Enzymes as catalysts
Enzymes are mainly globular proteins -
protein molecules where the tertiary structure has given the
molecule a generally rounded, ball shape (although perhaps a very squashed ball in some cases). The other type of proteins (fibrous proteins) have long thin structures and are found in tissues like muscle and hair. We aren't interested in those in this topic.
These globular proteins can be amazingly active catalysts. You are probably familiar with the use of catalysts like manganese(IV) oxide in decomposing hydrogen peroxide to give oxygen and water. The enzyme catalase will also do this - but at a spectacular rate compared with inorganic catalysts.
One molecule of catalase can decompose almost a hundred thousand molecules of hydrogen peroxide every second. That's very impressive!
Слайд 19
IV. How Much Protein?
Ideally, you should consume 0.36
grams of protein for every pound of body weight,
according to recommended daily allowances (RDA) set by the Food and Nutrition Board. So if you weigh 170 pounds, you need about 61 grams of protein each day
Слайд 20
IV. How Much Protein?
Protein should also make up
approximately 15% of your total daily caloric intake, also
according to the RDA. In a diet of 1,800 calories a day, for example, about 270 of those calories should come from protein