protein Flashcards
what is the definition for protein
any class of nitrogen organic compounds which have large molecules composed of one or more long chain of amino acids, and are an essential part of all organisms
name a function of contractile protein
actin and myosin in a muscle
what is includes in a basic building block of a protein
20 different type of amino acids
what does the indispensable categories of amino acid mean
essential
n=9
what does the dispensable categories of amino acid mean
non-essential
n=5
what does the conditionally indispensable categories of amino acid mean
n=6
what is a the primary structure of a protein determined by
amino acids
what is a the secondary structure of a protein determined by
weak electrical attraction within polypeptides, provides strength and rigidity
what is a the tertiary structure of a protein consist of
polypeptide chain twist and folds: side groups attracted = intricate shape
what is a the quaternary structure of a protein interaction with
between multiple polypeptides e.g. haemoglobin
the different levels of protein structure only important within the organism not in the diet, why?
because for food your are just trying to absorb amino acids into the body
according to the NRV what % intake of energy from protein are you recommended
10%
what are the top 3 main sources where we get our protein from
Bread, poultry, milk
what is protein quality mean
How good?
what does protein quality lead to
essential amino acids digestibility
what is protein quantity
how much?
what does protein quantity lead to
minimum or more proportional to body weight
what meal do we usually have most of our protein
dinner
what is a amino acid pool and do we need to equally distribute our protein intake through the day
the amount of protein that you have and can reach in and grab some protein when you need it through out the day - because of this you don’t need to equally distribute your protein intake
what is a limiting amino acid
when essential amino acids is not provided in adequate amount in the diet, protein synthesis is limited to the rate at which the essential amino acid is available
what do essential amino acids then become
limiting amino acids
how is limiting amino acids like a rain barrel
it limits how much protein synthesis is used because the amino acid don’t provide it with the right amount it needs in the diet. Just like when a rain barrel fills up it has reached its capacity point
what is a problem with protein quality
quality is superior, but these foods don’t always improve the quality of the diet or health
e.g. meat has high saturated fat
what is a problem of protein quality and traditional scoring system
they favour animal protein as they test a single food - eat a range of plant protein throughout the day gives you essential amino acids
what does it mean by complementary proteins
combine foods together to get whole amount of protein in a meal
- complement each other in a meal
T/F what you eat over the ay is more important than what you eat in just one meal
true
what do you have to take into consideration when determining protein quality
essential amino acids, digestibility and environmental impacts
what are is the outline of protein digestion
chewing > physical and chemical digestion > food in stomach (HCl & pepsin)> pancreatic and intestinal proenzyme > proenzymes activated by enteropeptidase
what are is the outline of protein digestion
chewing > physical and chemical digestion > food in stomach (HCl & pepsin)> pancreatic and intestinal proenzyme > proenzymes activated by enteropeptidase
proenzymes activated by
enteropeptidase
for protein metabolism what are peptides broken down to
amino acids in enterocytes
where is amino acids transported to … via ….
liver via hepatic portal vein
what are indispensable amino acids able to do
shift things around
- transamination
what are the four possible fats for amino acid when it joins amino acid pool
- used to make a dispensable AA
- oxidised for energy
- used to make a new protein
- used to make other compounds
if energy intake is a requirements then what will it be converted to
energy, protein and fat
if energy intake exceeds what would the 5th possible fate for amino acids when joined to amino acid pool
amino acids can turn fat
what is food hypersensitivity
allergy and reaction to foods
what 3 things does food hypersensitivity include
- food aversion
- food intolerance
- food allergy
what is food aversion
psychologically based food avoidance
- no reactions if food is hidden
what is an example of food aversion
getting food poisoning and vomiting, so the next time you see the food you are disgusted by it
what is food intolerance
any abnormal, non-psychologically mediated reaction to food
what is an example of food intolerance
lactose intolerance (refusing to eat dairy)
what is food allergy
group of disorders characterised by abnormal or exaggerated reproducible responses to specify food protein
what is an example of food allergy
cane be allergic to cow milk by not lactose intolerant
what is igE mediated reaction
rapid onset, involves skin, GIT, respiratory tract
- response to food
- IgE antibodies
what is IgE medication reaction
symptoms results in hour-days, difficult to assess in clinical setting
- doesn’t involve IgE antibodies
what is vegetarian diet
a person you doesn’t eat meat or fish by eats dairy
if a person eats dairy but not meat of fish what diet do they have
lacto-vegetarian
if a person doesn’t not eat any animal foods with animal products or may avoid the use of animal product what diet will they be having
vegan
how common is vertarianism in NZ
5% vegetarian
1% vegan
what are natural sources of protein
animal (meat, fish, dairy), plant protein (legumes, cereals)
what are manufactured sources of protein
plant-based alternatives, “cultured meat”
what are the key findings of the RCT protein content of weight gain etc during overeating study
- eating more energy than you need = gain body fat
- little protein in diet = reduction in lean body mass
- recommendation of protein 10-35% USA or 15-25% NZ
