Proteins

Question 1

what is protein?

Answer 1

-forms the components of every living cell
-protein come in various sizes and shapes and are composed of different amino acids joined in various proportions and sequences

Question 2

what are proteins made of?

Answer 2

-large complex molecules composed of individual building blocks called amino acids
-they are made from hydrogen, oxygen, carbon and nitrogen

Question 3

what is unique to each to each amino acid?

Answer 3

-their nitrogen component

Question 4

what does the shape of a protein determine?

Answer 4

-how it functions

Question 5

how is protein stored?

Answer 5

-as muscle, bone, skin, cartilage and lymph

Question 6

what is the primary function of protein?

Answer 6

-growth, repair and maintenance of body structures and tissues
-body cells are always making proteins to replace those that are broken down from normal wear

Question 7

proteins are involved in the manufacturing of? what are some examples?

Answer 7

-hormones such as insulin and epinephrine

Question 8

plasma proteins maintains what?

Answer 8

-plasma proteins such as albumin maintain fluid and electrolyte balance by attracting water and causing changes in osmotic pressure

Question 9

in what way may proteins may act as enzymes?

Answer 9

-they may bring about certain chemical reactions such as digestion or protein synthesis

Question 10

what do amino acids contain? what can these do?

Answer 10

-an acid and a base which can neutralize excesses of either acids bases in the body thereby maintaining a normal pH

Question 11

what do proteins help transport?

Answer 11

-they help transport other substances through the blood e.g. hemoglobin transports oxygen and lipoproteins transports lipids

Question 12

what is protein function within the immune system?

Answer 12

-they help to create lymphocytes and antibodies that protect the body from infection and disease

Question 13

how is protein used as a source of energy?

Answer 13

-can be used as a source of energy 1g=4kcal when intake of carbohydrates and fat is inadequate

Question 14

how is TVP made?

Answer 14

-made from defatted soya bean flour- the product of soya beans which have their oil removed. it needs to be rehydrated before use

Question 15

what does TVP stand for?

Answer 15

-Textured vegetable protein

Question 16

what is the process involved in making TVP?

Answer 16

-defatted flour is mixed to a dough with water
-it is forced through a small hole under pressure
-this cooks the dough, opens up its texture and gives it a fibrous meat like texture

Question 17

what are examples of foods that contain TVP?

Answer 17

-available in plain or white with a savory meat flavor
-comes in dried granules, mince or chunks
-e.g. bachelors bean feast

Question 18

what is tofu?

Answer 18

-a soya milk curd the texture, appearance and flavor is very different from meat
-not widely used in the UK

Question 19

what is the nutritional value of quorn?

Answer 19

-nigh protein food containing less protein on weight for weight basis than meat or fish

Question 20

what is the proteins levels of TVP comparable to?

Answer 20

-cottage cheese

Question 21

what are the advantages of eating Quorn for vegetarians / vegans

Answer 21

-good value supplement to cereal based diets as it contains amino acids which may be low in some diets
-good fiber content

Question 22

what is Quorn products made from?

Answer 22

• made from mycoprotein

Question 23

what are 8 advantages of using quorn based products?

Answer 23

-good nutritional low fat product
-similar shelf life to meat
-not altered by freezing or cooking
-absorbs flavor
-free from fat, gristle and bone
-ideal for vegetarians
-only needs heating through
-texture and color similar to chicken

Question 24

how many amino acids does the body need and how many can the body make?

Answer 24

-the body needs 20 amino acids
-it can make 10 called dispensable and these are non essential amino acids (AA)
-the body cannot make 10 and these are called indispensable amino acids which are essential in the diet (IAA’s)

Question 25

what is a HBV protein? what are the sources of HBV protein?

Answer 25

-a high biological value protein is a food that provides all IAA’s
-mostly from animal sources e.g. meat, poultry, eggs and dairy

Question 26

what are the only two plant based products that are HBV?

Answer 26

-soya beans and soya products e.g. TVP are HBV

Question 27

what are LBV proteins and what are the sources of these?

Answer 27

-foods that only provide some of the IAA’s
-plant sources e.g. pulses such as peas, beans and lentils and cereals such as pasta, bread and rice

Question 28

what is the full definition of protein complementation?

Answer 28

-protein complementation is when two LBV foods e.g. a pulse and a cereal are eaten together in one meal e.g. beans on toast, lentil soup and bread, chickpea curry and rice. The IAA’s in the food will compensate for the limiting IAA’s in the other food resulting in a HBV meal. This is particularly useful for vegetarians and vegans

Question 29

what is nitrogen balance?

Answer 29

-when the amount of protein made is equal to the amount used, as in healthy adults, the body has a neutral

Question 30

what results in a positive nitrogen balance?

Answer 30

-if protein synthesis exceeds protein breakdown such as during growth or recovery from injury a positive nitrogen balance exists

Question 31

what results in a negative nitrogen balance?

Answer 31

-a negative nitrogen balance exists when proteins breakdown exceeds protein synthesis such as during starvation

Question 32

what are the positives and negatives of eating red meat as a protein source?

Answer 32

-haem iron which is easily absorbed
-LDL cholesterol which can increase risk of CVD
–high in calories which can contribute to weight gain
-no fiber
-too much can increase risk of certain types of cancers
-sat fat which raises cholesterol

Question 33

what are the positives and negatives for eating Quorn as a protein source?

Answer 33

-fiber which helps maintain blood cholesterol levels
-non haem iron which is not as easily absorbed by the body
-low in calories which helps with weight management
-low in sat fat is it originates from vegetables
-Quorn is free from cholesterol

Question 34

what are the positives and negatives of eating fish as a protein source?

Answer 34

-HBV protein
-provides EFA’s which are essential for normal brain development in unborn babies, and help maintain a healthy heart by lowering blood pressure
-most fish is low in fat
-haem iron which is easier t absorb
-lean source of protein
-fish has no fiber
-oily fish provide fat soluble vitmains A and D

Question 35

what are the positives and negative of eating pulses as a protein source?

Answer 35

-LBV however if eaten along with grains result in a HBV meal
-do not provide any EFA’s
-low in fat
-higher iron content than fish however this iron is non haem is is harder to absorb that haem
-excellent source of fiber which helps lower LDL cholesterol and the risk of CVD
-are not good sources of fat soluble or water soluble vitamins

Question 36

what are the positives and negatives of dairy products in terms of versatility as a protein source?

Answer 36

-used in a number of recipes and as snacks throughout the day
-perishable and must be refrigerated and have a short shelf life
-they do not have a long preparation time
-some people have an allergy to intolerance to dairy products

Question 37

what are the positives and negatives of pulses in terms of versatility as a protein source?

Answer 37

-can be used in recipes and as snack throughout the day
-long shelf life
-most need to be soaked for at least 24 hrs before use to improve digestibility
-not many have an allergy or intolerance to pulses