protein study guide exam 3

Excess dietary protein is stored in the liver.

False Extra protein that is eaten is not stored in the liver or anywhere else. Carbohydrates are stored, in limited quantities, as glycogen, and fat is stored, as triglyceride. But not protein.

Essential amino acids are those that the cells use to make proteins; nonessential amino acids are those that are burned as a fuel.

False Cells make proteins using ALL of the amino acids (essential and nonessential). All amino acids can be broken down and yield ATP. Essential amino acids are those that the body cannot make and therefore must be provided by the diet; Nonessential amino acids can be made. The correct answer is 'False'.

risks of too much dietary protein are

increased consumption of animal fats = increase risk of CVD heavy coffee, cigarette, alcohol consumption OR low intakes of Vit B1, B6 and folate = elevated homocysteine [ ] = increased risk of CVD increased consumption of animal proteins = increased risk of cancer of colon, breast, kidneys, pancreas and prostate

how protein is digested--where, how, end products

-Begins in stomach with release of pepsinogen, which is converted by HCl to pepsin -Pepsin secretion is caused by hormone gastrin, which is released when thinking about or chewing food -Once in SmInt, CCK is released which causes secretion of trypsin, chymotrypsin, and carboxypeptidase from pancreas -These enzymes break up protein into aa -SmInt cells absorb aa and small peptides, then move aa into portal vein to liver, where they can be converted to glucose or fat

protein turnover/recycling

-Proteins are constantly being synthesized and broken down in the body -Most aa are recycled to build new proteins -Some are eliminated in feces or urine -Some proteins broken down for energy -Hormones can alter protein synthesis -Insulin and growth hormone increase protein synthesis -Cortisol increases protein breakdown -AIDS causes increased rate of protein breakdown, but same rates of synthesis

amino acid in common

Composed of central C bonded to 4 groups Amino group: -NH2 Carboxyl group: -COOH Hydrogen: -H R group: completes amino acid, variable in structure

denaturation(when and what they yield)

-Treatment with acid or alkaline substances, heat, or agitation can denature proteins -Proteins in denatured state can no longer perform biological function -Denatured proteins are easier for us to chew and digest

deamination(when and what they yield)

-aa loses an amino group without transferring it to another molecule in liver and kidney -get rid of excess protein -convert amino acid to carbon and hydrogen and ammonia

health benefits of a vegetarian diet

-reduce heart disease, prevent cancer,

transamination (when and what they yield)

-synthesizing aa, one molecule accepts an amino group from another -essential aa convert to non essential aa -amino group is removed from the amino acid and donated to the a-keto acid converting that into an amino acid in liver and muscle

Non-essential AAs

AAs that can be synthesized from other AAs in humans

essential amino acids

AAs that cannot be synthesized from other AAs in humans, must be consumed

how many grams of protein are used in the body each day; why the RDA is so much less than this

Body degrades about 300g of protein per day, but we take in about 65-90g RDA is minimum .8g/kg

Function of protein?

Enzymes- one of the important functions of proteins is that they act as the catalyst for most of the chemical reactions in a cell Catalyst- alters the rate of the reaction without being changed in the reaction Substrate-is the compound which is altered in the enzymatic reaction -Provide materials for cell growth and mitosis -Maintain fluid balance in vasculature (albumins and globulins) -Maintain blood pH (hemoglobin) -Form hormones and enzymes -Contribute to immune function -Form glucose through gluconeogenesis -Provide energy

Taking a daily protein supplement (a protein powder that you add to water, juice or other beverage and then drink) is an inexpensive and ideal, health-wise, way to meet your RDA for protein.

False

what HCL is and what role it plays in the stomach for protein digestion

HCl uncoils protein, converts the inactive form of pepsinogen into pepsin (active form)

marasmus

PEM, results from severe deprivation of, or impaired absorption of energy, protein, vitamins, and minerals over LONG time; adaptaion to starvation -starvation, matchstick arms Symptoms: severe weight loss, muscle wasting, <60% weight-for-age

what kind of chemical bond holds amino acids together in a protein?

Peptide bonds-bond joining amino group of one aa to the carboxyl group of a 2nd aa

4 "destinies" are for amino acids in cells

The four destinies AA pool in the cell has 1)SYNTHESIS PROTEINS, NON ESSENTIAL AMINO ACIDS AND OTHER SUBSTANCES. - Most important destination -This decides the protein requirement -conceptual protein supply. For a limited amount of time we have limited amount of AA in the cell. ***REST THREE WILL ONLY TAKE PLACE AFTER DEAMINATION*** -Ammonia will be excreted in the urine - The left over carbon skeleton ( Keto acid) will have below mentioned 3 fates. 2) BURNED AS FUEL - Not required one. 3) GLUCOSE( LIVER, KIDNEY) - Only when body is deprived of CHOs. 4)FAT(LIVER) Over consumned calories. 2&4 both are over consumed proteins but 4th one is over consumed calories.

what kind of chemical reaction occurs to form protein from amino acids?

Translation Initiation- bring together all of the materials required for protein synthesis Elongation-- sequential addition of amino acids in the order specified by the mRNA Termination- release of completed protein from the ribosome

Nonessential amino acids are synthesized within cells through the process of transamination.

True

which foods contain protein; what high quality/complete and incomplete proteins are; what a limiting amino acid is; what foods are sources of complete/incomplete proteins

Tuna Milk Fish Red meat Poultry Beans and other legumes Nuts Dietary Considerations- animal and plant proteins vary widely in content of essential and non-essential aa Animal protein has all 9 essential aa, plants do not High-quality proteins- animal proteins contain all proteins we need in sufficient amounts Lower-quality proteins- plant proteins lack one or more aa we need If only lower-quality protein foods are consumed, enough essential aa may not be available for protein synthesis Essential aa in the smallest supply is said to be the limiting aa

Which of the following contains peptide bonds?

a. Cholesterol b. Lecithin c. Collagen Correct d. Amylose

Which of the following is an example of a denatured protein?

a. Lemonade b. Curdled milk (milk that has gone bad) CorrectWhen milk curdles from the milk "going bad", bacteria has multiplied significantly in the milk, produces acid and the acid denatures the protein in the milk, "curdling" the milk. c. Hydrogenated vegetable oil d. Coca Cola

Which of the following is an example of a complete protein?

a. Peanut Butter b. Pinto Beans c. Tuna Correct d. Brown Rice Complete proteins are those that contain all of the essential amino acids. These include animal proteins plus soybeans and quinoa. The correct answer is: Tuna

A vegan would eat ____(assuming he/she liked it!).

a. Tofu Correct b. Yogurt c. Eggs d. Salmon e. A vegan would eat all of these choices

Fill in the blank with one of the choices offered. _______ is the process by which proteins lose their 3 dimensional structure to become a chain of amino acids.

a. Transamination b. Denaturation Correct c. Enzymatic digestion d. Deamination e. Emulsification

protein

contains C, H, N, O in the form of amino acids, are essential to cell functions

protein-calorie malnutrition

deficiency of protein, energy, or both, incl kwashiorkor, marasmus, and overlapping conditions

what make amino acids unique

different R groups

how vegetarian diets might not be healthy

lack iron, B12, zinc, protein , omega 3,

amino acid and structure

organic acids containing an amino and a carboxyl group--subunits of proteins

kwashiorkor

sudden or recent inadequate protein intake, infections; adaptation fails -edema, ascites, enlarged liver -hair changes color skin lesions, flaky paint dermatitis

Deamination is the process by which amino acids lose their amino group.

true

what the RDA for protein is; how to calculate it given a body weight

weight in kg multiply weight (kg) x 0.8 g/kg