Unit 4 - Proteins Flashcards
what are proteins
- compounds made of carbon, hydrogen, oxygen, and nitrogen
what are two categories of proteins
- working proteins
2. structural proteins
what are some examples of working proteins (4)
- enzymes
- antibodies
- hormones
- oxygen carriers
what are some examples of structural proteins (3)? where can they can be found (4)?
- tendons
- ligaments
- fibres of muscles
- found in our bones, teeth, hair, and nails
what is the building blocks of proteins
- amino acids
what are amino acids made of (4)
- a single carbon atom
- an amine group
- acid group
- a side chain (R group)
why is the side group of amino acids important? (4)
it gives the amino acids its:
- identity
- shape
- function
- chemical nature
about how many amino acids are there?
~20 which makes up most of the proteins of living tissues
how many amino acids can the body make itself?
- can make about half of the 20 amino acids itself
- however, some are essential & the body cannot make those amino acids or make enough to meet the body’s needs
what are two amino acids bonded together called? three? four or more?
- 2 = dipeptide
- 3 = tripeptide
- 4 or more = polypeptide
what 4 parts of the body play a role in protein digestion & absorption? (see notes for chart)
- mouth & salivary glands
- stomach
- small intestine
- pancreas
what role does the mouth & salivary glands play in protein digestion & absorption
- mouth helps chew & crush protein-rich foods
- then mixed w salivia to be swallowed
what role does the stomach play in protein digestion & absorption?
- hydrochloric acid (HCl) uncoils protein strands & activates stomach enzymes (pepsin)
- this helps break the protein down into smaller polypeptides
what role does the small intestine & pancreas play in the absorption & digestion of proteins
- pancreatic & small intestinal enzymes split polypeptides further into tri & dipeptides, and amino acids
- then enzymes (peptidases) on the surface of the small intestinal cells hydrolyze the peptides & the cells absorbe them
what is protein turnover
- the process of protein creating & breakdown
protein –> amino acid –> bloodstream
what 5 ways can amino acids be used when it arrives at a cell?
- to build part of a growing protein
- altered to make another needed compound
- to build a different amino acid
- for energy or converted to glucose or fat for storage
- excreted from the cell then body as urine
what is an example of an amino acid that is altered to make another needed compound?
- the amino acid tryptophan can be converted to make niacin (B vitamin)
how can an amino acid be used to build a different amino acid?
- the cell can dismantle the amino acid & use the amine group to build a diff amino acid
describe how an amino acid can be used for energy or converted to glucose or fat for storage
- after the cell dismantles the amino acid to use the amine group to build a diff amino acid, the remainder is used for energy or converted to glucose or fat
when might an amino acid be excreted?
- if the body is not using the amine group to create a diff amino acid
what are protein recommendations based on?
- nitrogen balance studies
what is nitrogen balance studies
- where nitrogen lost thru excretion (in sweat, feces, urine) is compared to the nitrogen eaten in food
what is nitrogen equilibrium? when are people in this?
- this means that you have roughly the same amount of protein in their body at all time
- intake & output of nitrogen is equal
- under normal circumstances, a health adult is in this
what is a positive nitrogen balance
- more protein is being built than is being broken down
- more nitrogen intake than outtake
who might be in a positive nitrogen balance? (3)
- growing children
- pregnant women
- people recovering from protein defic
what is a negative nitrogen balance?
- muscle or protein tissue is being broken down & lost
- more nitrogen lost than built
when might someone experience negative nitrogen balance? (3)
- illness
- injuries such as burns & starvation
what are 5 important roles of protein in the body?
- structural
- transporting other substances around the body
- enzymes, hormones, antibodies
- maintain fluid & electrolyte balance and acid-base balance
- source of energy & glucose
describe the role of proteins as structural components (5)
- high conc of protein in muscle tissue
- provide part of the structure for:
1. teeth
2. bones
3. tendons
4. cartilage
what are some examples of things they help transport (3)
ex. lipids, vitamins, minerals
what are 3 examples of proteins that can bind & transfer substances
- hemoglobin
- lipoproteins
- albumin
what is the fnxn of enzymes
- catalyze (accelerate) the reactions which create & breakdown complex sygars, lipids and other compounds
what are antibodies
- protein molecules that play a role in fighting infection
what is a consequence of protein deficiency
- protein deficiency = less antibodies = immunocompromised
what are 2 examples of protein hormones? why are they important?
- insulin & glucagon
- both critical to regulating BG
describe how proteins help regulate fluid balance? what do they help prevent
- proteins within the diff body compartments (ICF, ECF, ISF) create colloid/oncotic pressure to maintain fluid balance
- they are hydrophilic and push fluid towards them
- prevents edema
describe how proteins help regulate electrolyte balance
- proteins in the body compartments help bind to & maintain conc of solutes thru their strong charges
- transport proteins in cell membranes also play a role
can proteins diffuse thru membranes
- no
describe how proteins play a role in acid-base balance
- the protein albumin binds hydrogen to maintain the acid-base balance & serves as a critical buffer system in the blood
describe how proteins can be as sources of energy?
- carbon, hydrogen, and oxygen are biproducts of broken down amino acids, which can be used to create new glucose molecules in gluconeogenesis
what are 2 types of protein deficiency?
- protein energy malnutrition
2. limiting amino acid
what is limiting amino acid
- deficiency in a certain amino acid
what is a protein-energy malnutrition? who is this seen in?
- refers to a diet too low in protein, energy, or both
- seen in chronic diseases like cancer & AIDS, burn victims
what are 2 forms of protein energy malnutrition
- severe acute malnutrition
2. chronic malnutrition
what is severe acute malnutrition (SAM)
- sudden inadequate food intake
who does SAM effect
- about 10% of children worldwide
what are 2 examples of SAM?
- kwashiorkor
- marasmus
what is marasmus? what does it cause (5)?
physiological response to malnutrition
- lean & fat tissues wasted away = extremely thin
- child’s metabolism slows
- cold
- vital muscles (ex. heart) waste away
- digestive enzyme shortage & deterioration of stomach lining impacts absorption of food consumes
what is kwashiorkor? what does it cause (3)?
physiological response to malnutrition
- fluid shifting causing abdominal edema
- loss of hair color
- impaired wound healing
what is chronic malnutrition
- long-term inadequate food intake
who does chronic malnutrition affect?
- ~25% of the world’s children
what are 4 consequences of chronic malnutrition
- short for their age
- increased risk of infection
- increased risk of diarrhea
- vitamin & nutritional deficiencies
what are 2 general consequences of excess protein intake?
- health risks for heart
- weakened kidneys
describe how excess protein might cause negative effects on the heart
- animal derived protein sources constitute a high protein die
- but, they also contain hgih levels of saturated fats = risk to cardio health
describe how excess protein might cause negative effects on the kidneys (2)
- increases the work of kidneys
- can cause decline in cases of pre-existing kidney disease
what is the DRI recommendations for protein intake (include how many g/kg of weight & ADMR
- 0.8g/kg body weight
2. AMDR: 10-35 % total energy
why do athletes increase protein intake thru the use of protein powders? is this supported?
- under the belief that bc the body builds muscle protein from amino acids, extra protein will stimulate muscle growth
- if an athlete consumes adequate food they do not need extra protein from supplements
why should people take caution against taking single amino acids as supplements?
- amino acids of the same type compete for the same absorptive carriers
- therefore, consuming a large dose of any aminoc acid may limit the absorption of other amino acids of the same general type
is the body designed to handle amino acids or whole proteins best
- whole proteins
why is it important to consume protein after exercise?
- after intense exercise it helps build & maintain muscle
- helps repair muscle damage
what should be your first choice as a protein for after exercise? give 7 examples
nutritious, protein-rich foods
- meat
- fish
- poultry
- milk
- yogurt
- eggs
- soy
why might protein supplements be used instead of protein-rich foods after exercise
- its easy and a portable way to meet ur protein needs
how much protein is helpful after intense exercise
- 10-20 g of protein
what is a good type of supplement to use after exercise
- whey protein
what are the benefits of whey protein (3)
- contains all essential amino acids
- rapidly digested
- contains high levels of the amino acid leucine
why is leucine important?
- its important in help your body build muscle
what can we do to get the most from protein supplements
- eat enough total calories & carbs to meet the body’s needs
- otherwise, the protein may be used as an energy source
what food groups is protein found in?
- all 4 food groups
what 6 good sources of protein
- meat
- fish
- chicken
- meat alternatives (pulses, soy)
- milk
- milk products
what 3 things contribute smaller amounts of protein
- veggies
- fruit
- whole grains
why is protein quality important?
- it helps determine how well a diet supports the growth of children & health of adults
what 2 things influence protein quality
- the digestibility of the protein
2. its amino acid composition
do animal or plant protein products have higher digestibility
- amino acids from animal proteins are most easily digested & absorbed
what are high quality proteins
- ones with ample amounts of all essential amino acids
do animal or plant based foods have more amino acids
- plant based foods are often more limited in some essential amino acids
how can people still receive the essential amino acids by consuming plant products? what is this called
by eating a variety of plant based foods throughout the day:
- the amino acids limited in one food are provided by another food
= complimentary proteins
what is limiting amino acid
- the essential amino acid which is available in the shortest supply relative to the amount needed to maintain protein synthesis
define vegetarian diet
- a general term used to describe an eating pattern that include plant-based foods and eliminates some or all of animal-derived foods
define vegan diet; what does it include? exclude?
an eating pattern that includes only plant-based foods:
- excludes all animal-derived foods (ex. milk)
what are 3 other names for a vegan diet
- strict vegetarian
- pure vegetarian
- total vegetarian
define partial vegetarian diet; what does it include? exclude?
term used to describe an eating pattern that includes:
- seafood
- poultry
- eggs
- milk & milk products
- excludes certain meats, such as red meat
define lacto vegetarian diet; what does it include? exclude?
an eating patttern that includes:
- milk
- milk products
excludes:
- meat
- poultry
- seafood
- eggs
define ovo-vegetarian diet; what does it include? exclude?
an eating pattern that includes:
- eggs
excludes:
- meat
- poultry
- seafood
- milk
- milk products
define lacto-ovo vegetarian diet; what does it include? exclude?
eating pattern that includes:
- milk
- milk products
- eggs
excludes:
- meat
- poultry
- seafood
define macrobiotic diet
a philosophical eating pattern based of mostly plant foods such as:
- whole grains
- legumes
- certain veggies
- small amts of fish, fruit, nuts, and seeds
what do vegetarian diets reduce the risk of? (5)
reduces the risk of:
- heart disease
- HTN
- diabetes
- some types of cancer
- obesity
what are 4 other benefits of vegetarian diets
- higher in fibre
- lower in sat fats
- lower cholesterol
- overall healthier than meat eaters
what is the main concern when planning a diet? how can this be avoided?
- concern of meeting all nutritional needs
- this can be avided thru use of complementary proteins
describe the relationship between vegan diets & children
- can fail to provide enoough food energy for children
what do vegan diets often lack? how can this be made up?
- lacks B12
- take them as a supplement
what is another nutrient that vegans lack? how can this be avoided?
- loss of calcium
- consume lots of dark green & leafy veggies
list 4 deficiencies often associated w vegans?
- B12
- calcium
- EPA
- DHA
how can vegans avoid EPA and DHA deficiencies
fortify with:
- supplements or marine algae
what is celiac disease
- an immune disorder characterized by an abnormal immune response to a protein fraction in gluten
what does the reaction to gluten in celiac disease cause?
- causes severe damage to the intestinal mucosa & subsequent malabsorption
what is dermatitis herpetiformis (DH)
- a gluten sensitive disorder characterized by severe skin rash
- a condition that is separate from celiac disease
how is DH similar to celiac disease? how are they different?
- both involve gluten
- both treated by avoiding gluten
- a person w celiac disease will not necessarily develop DH when gluten is consumed
what is non-celiac gluten sensitivity
- this is basically when people are sensitive to gluten & experience symptoms found in celiac disease, but do not test positive for it
what specific effect does celiac disease have on the intestinal tissue? what does this cause?
- causes the villi to be shortened or absent
= reduced mucosal surface area
= reduced # of cells to digest & absorb nutrients
what is a common symptoms of celiac disease (3)
GI disturbances:
- diarrhea
- steatorrhea
- flatulence
what can result from mucosal damage? what does this cause?
- lactase deficiency can results
- which can cause milk products to axacerbate GI sympoms
due to nutrient malabsorption, children w celiac disease often exhibit… (4)
- poor growth
- low body weight
- muscle wasting
- anemia
adults w celiac disease may develop… (4)
- anemia
- bone disorders
- neurological symptoms
- fertility problems
individuals with celiac disease are at a risk of developing other diseases such as… (4)
- type 1 diabetes
- autoimmune thyroid diseases
- inflammatory bowel diseases
- intestinal cancers
what are 3 types of screening tests done for celiac
- IgA-human tissue transglutaminase (TTG)
- IgA endomysial antibody test (EMA)
- serume IgA test
when can you begin a gluten-free diet? why?
after a blood test AND an upper endoscopy with intestinal biopsy
- the diet would interfere w the results
what is the only definitive means of diagnosing celiac disease
- an intestinal biopsy
what kind of anemia can occur with celiac disease?
- iron deficiency anemia
what is the treatment for iron deficiency anemia
- strict gluten-free diet with special attention to iron rich foods
what causes lactose intolerance in people w celiac disease
due to:
- damaged villi
- decreased lactase production
what is treatment for lactose intlerance with celiac disease
- gluten-free diet and a temporary restriction of dietary lactose
- once a client is asymptomatic, reintroduct lactose slowly
what nutritional complication can occur in people w celiac disease r/t bones? why?
- osteopenia
- osteoporosis
- due to malabsorption
what is treatment of osteopenia/osteoporosis for celiac
- gluten-free diet with special sttention to calcium & vitamin D rich foods
list 3 other deficiencies occurring with celiac disease
- folate
- B12
- other vitamin deficiencies
what 2 GI symptoms are common with celiac disease
- diarrhea
- constipation
what causes diarrhea r/t celiac
- damaged villi
- malabsorption
- lactose intolerance
what causes constipation r/t celiac disease
- the gluten free diet tends to be low in fiber
what effect can celiac disease have on calories?
either:
- calorie deficiency
- calorie excess & obesity
how can celiac disease cause calorie/protein deficiency
- poor intake due to GI symptoms
- malabsorption
how can celiac disease cause calorie excess or obesity
- gluten-free prepared foods tend to be higher in fat, carbs, and calories
what are some symptoms of celiac disease (6)
- GI symptoms
- weight loss
- chronic fatigue/weakness
- low iron levels
- muscle cramps
- bone & joint pain
what does the gluten-free diet eliminate?
eliminates food that contain:
- wheat
- barley
- rye
what are gluten sources that may be overlooked
- beer
- coffee substitutes
- meds
- salad dressings
- soy sauce
- makeup
