Exam 3 Study Guide

PROTEIN

...

what the 4 "destinies" are for amino acids in cells; under what conditions do destiny #2, #3 and #4 occur?

1. Synthesis of Proteins, NEAAs and other substances 2. Burned as fuel 3. Glucose (Liver,Kidneys) 4. Fat (Liver) Under what conditions do destiny #2, #3 and #4 occur? Burned as fuel (amino acids) when there is scarce of glucose and fatty acids. Glucose (liver,kindey) comes from deamination from amino acid which removes amino hroup (NH2) leaving it as carbon structure with only acid group becomes keto acid. Keto acid is used for energy or production of glucose, ketones, cholesterol or fat. Amino acids may be converted to fat when energy and protein intakes exceed needs and carbohydrate intake is adequate. In this way, protein-rich foods can contribute to weight gain.

which nutrients vegetarians need to pay special attention to when selecting foods to make up their meals and snacks

B12, calcium, vitamin d, iron, zinc and omega-3 fatty acid. •FYI: Protein is not the most challenging nutrient to get on a vegetarian diets!

what happens to dietary protein that is in excess of the body's requirement

Converted to Fat p.184

what happens to the amino group when an amino acid is deaminated; how it is excreted from the body

Deaminating Amino Acid causes 2 products: Ammonia (NH3) and Keto Acid (with acid group) Ammonia is combines with carbon dioxide by the Liver to make a less toxic compound. To balance out the acid-base in blood. then kidney filters out the urea form the blood. Urea = CO + NH3.

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

High Quality Proteins • They have all of the EAAs (they are "complete") • Animal products • Soy • Quinoa, Buckwheat • Some other seeds Incomplete proteins • Low in 1 or more EAA • Limiting amino acid • Most plant-based proteins • Grains, beans other than soy, veggies Limiting amino acid: the essential amino acid found in the shortest supply relative to the amounts needed for protein synthesis in the body. Four amino acids are most likely to be limiting: ● Lysine ● Methionine ● Threonine ● Tryptophan High Quality Proteins: Animals (meat, seafood, poultry, eggs, and milk and milk products). Although gelatin is an exception. Gelatin lacks tryptophan and cannot support growth and health as a diet's sole protein. A few others are high quality (for example, soy protein Incomplete Proteins: Plants (vegetables, nuts, seeds, grains, and legumes) have more diverse amino acid patterns and tend to be limiting in one or more essential amino acids. Some plant proteins are notoriously low quality (for example, corn protein).

how a vegetarian diet might lead to better health.

High in fiber and low in calories. Better weight control.

what HCL is and what role it plays in protein digestion

Hydrochloric acid uncoils (denatures) each protein's tangled strands so that digestive enzymes can attack the peptide bonds. The hydrochloric acid also converts the inactive form of the enzyme pepsinogen to its active form, pepsin.*

who needs a protein supplement and why

People who can't eat enough protein. Environmentally ill or surgery in mouth leads to lose of appetite.

what does "protein sparing action of carbohydrates" mean?

Protein sparing is the process by which the body derives energy from sources other than protein. Such sources can include fatty tissues, dietary fats and carbohydrates. Protein sparing conserves muscle tissue. The balance between digestible protein and digestible energy in the diet is a key factor.

what protein turnover/recycling is; what its significance is regarding dietary protein requirement

Protein turnover: the degradation and synthesis of protein. (Our dietary protein requirement is <50 grams of protein/day)

what protein is? what an amino acid is? their basic chemical structures; what all amino acids have in common; what makes each amino acid unique

Proteins: compounds composed of carbon, hydrogen, oxygen, and nitrogen atoms, arranged into amino acids linked in a chain. Some amino acids also contain sulfur atoms. Amino Acids: building blocks of proteins. Each contains an amino group, an acid group, a hydrogen atom, and a distinctive side group, all attached to a central carbon atom. - amino 5 containing nitrogen Amino acids --> Protein Their basic chemical structures: Central carbon w Hydrogen, Amino Group (NH2) and Acid group (COOH). What all amino acids have in common? Central Carbon with hydrogen and NH2( Amino group). what makes each amino acid unique? The Acid Group Thus, although all amino acids share a common structure, they differ in size, shape, electrical charge, and other characteristics because of differences in these side groups.

what the RDA for protein is; how to calculate it given a body weight; why an obese person should use a "healthy weight" rather than their actual weight to calculate their RDA

RDA for protein: 0.8g of Protein per kg. 0.8g/kg 1kg/2.2lb ex: 91.5lb/2.2lb= 41.4kg 41.5kg x 0.8g/kg= 33.2g of Protein Obese person should use healthy weight to calculate RDA because it is not as accurate as someone with more muscles same weight as an obese person.

how the side chains of amino acids affect the structure of proteins

RNA collect AA from cell fluid to messenger RNA. 20 AA has a specific transfer RNA. Messenger RNA calls for Transfer RNA to unload the AA then Messenger RNA repeats next and next. AA are lined up are genetically determined, enzymes bind them together and completed protein strand is released.

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

Stomach: Hydrolysis, Hydrochloric acid uncoils (denatures) each protein's tangled strands so that digestive enzymes can attack the peptide bonds. The hydrochloric acid converts the inactive form of the enzyme pepsinogen to its active form, pepsin. Pepsin cleaves proteins—large polypeptides—into smaller polypeptides and some amino acids. Small Intestine: Polypeptides are hydroluzed by pancreatuc and intestinal proteases to short peptide chains. tri, dipeptides then amino acids. Peptidase enzymes on the membrane surfaces of the intestinal cells split most of the dipeptides and tripeptides into single amino acids. Only a few peptides escape digestion and enter the blood intact

what the amino acid pool is

These amino acids mix with amino acids from dietary protein to form an "amino acid pool" within the cells and cir

who needs to be particularly aware of the challenges of getting enough nutrients on a vegetarian diet

Vegans

where and how proteins are synthesized; the role of the ribosome, DNA, mRNA and tRNA

Where: body of cell How: info. in DNA, transcription (a template from DNA) process of making mRNA, mRNA carries cods and attaches into the ribosomes. Translation: the process of messenger RNA directing the sequence of amino acids and synthesis of proteins.

what the term "complementary proteins" refers to; for what purpose it can be applied to food choices

complementary proteins: two or more dietary proteins whose amino acid assortments complement each other in such a way that the essential amino acids missing from one are supplied by the other. Eating a variety of whole grains, legumes, seeds, nuts, and vegetables. Protein deficiency will develop, however, when fruits and certain vegetables make up the core of the diet, severely limiting both the quantity and quality of protein. Highlight 2 describes how to plan a nutritious vegetarian diet.

what denaturation is; where it occurs; what leads to it; foods that are examples of denatured protein

denaturation: the change in a protein's shape and consequent loss of its function brought about by heat, agitation, acid, base, alcohol, heavy metals, or other agents Where: Stomach What leads to it: Happens when protein is exposed to acid, heat, is agitated plus other conditions. foods that are examples of denatured protein: Eggs, milk when acid is added, foods containing protein are denatured when exposed to stomach acid.

how vegetarian diets might not be healthy.

eating only saturated fats: chips, cookies and french fries.

what essential amino acids are (the definition--don't memorize specific ones)

essential amino acids: amino acids that the body requires but cannot make, and so must be obtained from the diet (see Table 6-1); also called indispensable amino acid.

what marasmus and kwashiorkor are

kwashiorkor was attributed to protein deficiency and marasmus was attributed to energy deficiency. Together, they were named protein-energy malnutrition.

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

peptide bond

what transamination are deamination; what they yield

transamination: The transfer of an amino group from one amino acid to a keto acid, producing a new nonessential amino acid and a new keto acid. Deamination •The removal of the amino group (NH2) from an amino acid. What remains is the corresponding keto acid (carbon skeleton) what they yield? Transfer the Amino group. Removes the Amino Group from Amino Acid and remains as a Keto Acid.

what functions proteins perform in the body (at least the ones covered in BIO45!)

• Structure - structural proteins (ex.collagen) • Enzymes • Antibodies • Some Hormones • Fluid Balance (ex. albumin/globulin) • Transport proteins • Fuel - 4 calories/gram • Under specific circumstances: converted to glucose • Blood clotting factors • Visual pigments • Many more

what the risks of too much dietary protein are

•Can lead to inadequate CHO intake •Can put a stress on the kidneys •Can lead to dehydration •May risk of heart disease •May risk of cancer •May risk of osteoporosis •Aggravates gout

the different types of vegetarian diets

•Different Types • Lacto-Ovo -eat what animals produce •Vegan •Others •Motivations •Health •Ethical •Environment

the potential health benefits of a vegetarian diet;

•Vegetarians tend to experience: •Better weight control • Lower blood pressure • Less heart disease • Less of some types of cancer •Plus more •From epidemiological studies (correlations only)