Chapter 6 Flashcards
proteins
- definition
- play a role in
- 2 functions
- contain what
- made up of
- the predominant structural and functional material in every cell
- every cellular activity
- building, repairing and maintaining cells
- storage, transport and utilization of nutrients that you eat
- building, repairing and maintaining cells
- C H O N
- amino acids
amino acids
- each AA has what 3 things
- what determines proteins function
- how many AA in a chain
- acid group (COOH)
- amine group (NH2)
- side chain (unique)
- 20 unique AA
peptide dipeptide tripeptide polypeptide protein
- <50 AA
- 2 AA
- 3 AA
- > or equal to 10 AA
- > 50 AA
how many essential AA
- can it be made by the body
- where do you get them
- 9
- no
- obtain through diet
how many nonessential AA
-can it be made by the body
- 11
- yes from other AA or by adding N to C - containing structures
conditionally essential AA
under certain conditions, some nonessential AA cannot be synthesized and must be consumed in diet
peptide bond
connects the COOH group of one AA to the NH3 group of another AA
what determines how a protein will fold
AA, their side chains and their interaction with the environment
denaturation
- definition
- what does it do
- ex
- the alteration (unfolding) of protein shapes
- changes structure and function of the protein
- heating egg whites, acidic environment of stomach, mechanical agitation, salt
where are dietary proteins digested and absorbed
in stomach and sm intestine
stomach acids
-2 functions
denature protein and activates pepsin
-breaks down protein into shorter polypeptides
what happens to polypeptides in the sm. intestine
broken down into tripeptides, dipeptides and AA
where are AA absorbed through
sm intestine and enter the blood and travel to liver. proteins are broken down further
AA
-where do they come from (3)
- diet
- breakdown of proteins in body
- a limited supply is stored in AA pools in blood and cells for needed protein synthesis
protein turnover
-process of continuous breakdown and synthesis of protein from its AA
can protein be stored?
no however AA can
AA can be used to make
- 2
- ex
body proteins and non protein substances
-thyroid hormones and melanin
after amine groups are removed what happens to them
-4
- converted to urea and excreted in urine
- burned for energy
- stored as fat
- made into glucose
DNA
- contains what
- component
- instructions for protein synthesis
- gene
gene
DNA segment that codes for specific protein
RNA molecules
- definition
- ex
- carry out instructions for protein synthesis
- mRNA, tRNA
mRNA and tRNA function
perform very specific roles during protein synthesis
sickle cell anemia
- results from
- definition
- what does mutation cause
- from abnormal formation of hemoglobin
- mutation in a gene changes AA sequence in hemoglobin molecule (glutamine to valine)
- causes sickle cell shaped RBCs that are not efficient at carrying O2 and are prone to blood clotting
Phenoketonuria (PKU)
-caused by
abnormal synthesis of phenylalanine hydroxylase
phenylalanine hydroxylase
enzyme needed to metabolize phenylaline
proteins
- 8 functions
- used where
- provide structural and mechanical support and help maintain body tissues
- build enzymes and many hormones
- help maintain fluid balances by attracting water
- help maintain acid-base balance
- transport substances
- contribute to healthy immune system
- provide energy
- improve satiety and appetite control
- provide structural and mechanical support and help maintain body tissues
- in muscle contraction (actin and myosin)
collagen
a ropelike, fibrous protein that is the most abundant protein in body
connective tissue
- definition
- ex
the most abundant tissue type in body
-bones, tendons, ligaments
transport proteins
-function
shuttle O2, waste products, lipids, some vitamins and sodium and potassium through your blood and into and out of cells through cell membranes
antibodies
- definition
- what creates antibodies
- provides what
- proteins that eliminate potentially harmful substances
- the body creates antibodies against pathogens and stores that info
- immunity against subsequent exposure
what proteins improve satiety and appetite control
ghrelin, leptin and cholecystokinin
what should healthy adults be in
nitrogen balance
nitrogen balance
amount of N consumed in dietary protein = amount excreted in urine
nitrogen imbalances
-2 types
- positive nitrogen balance
- negative nitrogen balance
positive nitrogen balance
- definition
- what do bodies do
- ex
- more N is retained (for protein synthesis) than is excreted
- Bodies need to hold onto N to build new tissues
- infants, children, pregnant women
negative nitrogen balance
- definition
- what do bodies do
- ex
- more N is excreted than consumed (body proteins are broken down)
- bodies are breaking down more protein than is consumed
- starvation, serious injury or illness
complete proteins
- contains what
- low or high quality protein
- sources
contains all essential AA plus some non essential AA
- high quality
- soy, quinoa, and animal protein
incomplete proteins
- definition
- low or high quality
- sources
- low in 1 or more essential AA
- low
- plant foods, gelatin
limiting AA
AA found in shortest supply is an incomplete protein
what are plant proteins upgraded to ____ by 2 things
- consuming modest amounts of soy or animal protein
2. protein complementation
protein complementation
- definition
- ex
- being complemented with other plant proteins that provide enough of the limiting AA
- rice and beans
protein digestibility corrected amino acid score (PDCAAS)
- definition
- basis of what
- ex.
- if you ate only milkwould you meet all of your AA needs?
- measure of protein quality taking into account digestibility and AA profile
- basis of protein as % DV on food labels
- milk protein, chickpeas, and wheat
- yes
milk protein PDCAAS of..
- chickpeas
- wheat
- 100%
- 87% is digestible
- 44%
protein recommedations
- average intake in the US; why?
- ____ of body weight needed daily (>18 yo)
- 10-35% of total daily calories
- 15%, because we are consuming more calories as fat and carbs
- 0.8g of protein/kg
calculating your daily protein needs
-ex
convert weight from lbs to kg by dividing by 2.2 then multiplying by .8
-130lb divided by 2.2 = 59; 59 x .8 = 47
how much more protein do ___ need?
- pregnant women
- infants
- infants (1-3 yo)
- infants (4-13)
- 1.1 g/kg
- 1.5 g/kg
- 1.1 g/kg
- 0.9 g/kg
protein shakes and powder
- made of what
- contain
- whey, soy or rice protein
- unwanted additives
amino acid supplements
- sold as
- may have what type of effects
- remedies for various health issues
- negative effects
protein and energy bars
convienient, but expensive and high in calories
eating to much protein
- risks
- generates what
- what should you consume
- can displace what
- associated with what
- increase risk of heart disease, kidney stones, calcium loss from bones
- acid: body responds by releasing calcium from bones
- foods rich in potassium or calcium
- other nutrient and fiber rich foods
- a reduced risk of chronic disease
eating to little protein
- may lead to what
- risks
- -reduction of lean body mass, especially in older adults
- increased risk of fratility, impaired healing, and decreased immune function
protein -energy malnutrition (PEM)
- definition
- more common in
- factors
- inadequate calories and/or protein
- children because they are growing
- poverty, stopping lactation
kwashiorkor
- definition
- signs
- seen in where
- translated to
- severe deficiency of dietary protein
- edema, muscle loss, skin rashes, hair changes, water and electrolyte imbalances
- children weaned to low-protein cereals
- the sickness the baby gets when the new baby is born
marasmus
- definition
- signs
- severe deficiency of calories
- emanciation, lack of growth, loss of fat stores
marasmic - kwashiorkor
-definition
worst of both conditions
how to treat protein deficiency diseases
medical treatment, food and water (3 step approach)
vegetarians meet protein needs by consuming
-2
- variety of plant foods
2. protein rich meat alternatives
protein rich meat alternatives
-5
- soy
- quinoa
- dried beans and other legumes
- nuts
- eggs, dairy (lacto-ovo-vegetarians)
vegetarian
- 2 benefits
- risk
- may reduce risk of heart disease, high BP, diabetes, cancer, stroke and obesity
- food staples are rich in fiber and low in saturated fat and cholesterol
- may reduce risk of heart disease, high BP, diabetes, cancer, stroke and obesity
- potential deficiencies of nutrients found in animal foods
benefits of soy
- high quality protein source
- low in saturated fat and 0 cholesterol
- contains isoflavones (phytoestrogen)
- lowers blood cholesterol levels
- may reduce risk of heart disease and certain cancers
