NUTR 280 Exam 3 JMU - Torisky

Protein is the _____ -containing energy nutrient

nitrogen

Protein is composed of any combination of ____ unique ____ ____

20, amino acids

What kind of protein chains have different "personalities"? What is this known as?

side chains, chemical behaviors

Where are the neutral side of the protein chains? What do they do?

stay on inside, associate with each other

Where are the charged side chains? What are they attracted to?

outgoing, attracted to water

Amino acid has ___ basic structures

3

What does amino acid also have

R group

What makes each amino acid unique

R group

Each amino acid has a central ____ atom

carbon

What is formed when the nitrogen containing group is removed?

carbon skeleton

R group is what kind of chain?

side

R group is responsible for?

way protein chain folds upon itself & determines final shape of protein

Essential

NEED FROM DIET

Nonessential

Body can make them if not gotten from food or enough

R group is part of an animo acid that determines what properties?

physical, chemical

What is the other portion of chemical structure?

Carboxylic acid group

The human body makes proteins by assembling the ___ amino acids in specific sequences

20

A healthy human body can make ___ or 20 amino acids that are in proteins

11

The information coded in protein synthesis is in what?

DNA

DNA

deoxyribonucleic acid

DNA is the ____ material that provides ____ for making proteins

hereditary, instructions

A ____ is a portion of DNA that ___ for a protein

gene, codes

How are amino acids linked?

chemically

Link of amino acid?

the acid group of one amino acid and the amino group of the next one

The link of an amino acid forms what?

peptide bond

A peptide bond is the?

chemical attraction that connects two amino acids together

When is a dipeptide formed?

when two amino acids bond, and a water molecule is released

What is the basic structure of a protein called?

primary structure

The primary structure:

a linear chain of amino acids linked by peptide bonds

The secondary structure of a protein is what?

the coiling of a polypeptide chain

The tertiary structure is: ___ dimensional, what kind of structure? What does it include?

three, twisted structure of a polypeptide chain, interactions between various amino acid groups on the chain

The quaternary structure is comprised of?

two or more polypeptide chains arranged together in a complex matter

What is hemoglobin?

arrangement of four polypeptide chains

Why is the shape of a protein is important?

because it determines its function

What can occasionally happen during protein synthesis?

an incorrect amino acid is introduced into the amino acid chain

What happens when DNA code is faulty?

the wrong amino acid will be inserted into the chain consistently

What does faulty amino acid insertion form?

abnormal polypeptide

What do abnormal peptides cause?

genetic defects that have devastating, even deadly, effects

Example of abnormal polypeptide?

Sickle Cell Anemia

What is sickle cell anemia?

an inherited form of anemia

What is sick cell anemia caused by?

genetic mutation in the hemoglobin gene

During sickle cell anemia, the wrong amino acid is added to ___ of the _____ chains in what?

two, polypeptide, hemoglobin

What is hemoglobin?

oxygen-carrying protein in red blood cells, altering their structure

What does the abnormal hemoglobin structure do? causes what?

impairs its oxygen-carrying function, causes red blood cells to take on a "sickled" appearance

Denaturation occurs when proteins are exposed to what? what happens during this process?

certain conditions, protein unfolds

What is altered during denaturation?

protein's natural shape and function

What conditions cause denaturation?

heat, acids, and physical agitation

____ ____ methods can cause protein in foods to denature

Food preparation

Examples of food cooking denaturation:

- cooking

- whipping

- addition of alcohol or acids

Denaturation in stomach:

hydrochloric acid denatures food proteins, making them easier to digest

Proteins roles: (3)

Growth, maintenance, & repair of tissue

Hormones are?

chemical messengers

Enzymes are ____ with ____?

catalysts, specificity

Antibodies are what?

immune system protectors

Antibodies have?

specific “mission”

Protein does what to substances?

transport key substances (active transport)

What substances does protein transport? (1)

fluid/electrolyte balance

What substances does protein transport? (2)

acid/base (pH) balance

What is the last resort (very costly) in protein substance transport?

source of fuel / glucose

____ is a precursor for serotonin

Tryptophan

______ is a precursor for epinephrine

Tyrosine

The sleepiness that often follows a turkey dinner can be in part attributed to the presence of the amino acid _____

Tryptophan

What is serotonin?

a neurotransmitter that enhances mood and promotes relaxation

What else is rich in tryptophan?

Other types of poultry: chicken

What are nonessential amino acids?

group of amino acids the body can make

What are essential amino acids?

body cannot make or cannot make enough of to meet its needs

All dietary animal protein contains?

all 9 EAAs

What are conditionally essential amino acids?

normally nonessential but became essential under a certain condition

First 4 amino acids: (H, I, L, L)

•Histidine

•Isoleucine

•Leucine

•Lysine

Next 5 amino acids: (M,P,T,T,V)

•Methionine

•Phenylalanine

•Threonine

•Tryptophan

•Valine

High-quality proteins are _____ proteins, how are they digested?

complete, well-digested, absorbed, and used by the body

Complete proteins are food sources of proteins that contain an adequate portion of?

each of the nine essential amino acids

Examples of complete proteins:

Meat, fish, poultry, eggs, dairy products

Low quality proteins are? What does it do to amino acids?

incomplete and generally less digestible, AA less bioavailable than high-quality proteins

Incomplete proteins contains ____ amounts of what?

inadequate, one or more of the essential amino acids

Limiting amino acid: the _____ amino acid found in the ____ concentration in an _____ protein

essential, lowest, incomplete

What happens if the body does not have an adequate amount of all the amino acids required to make a particular protein

that protein cannot be synthesized

What happens in the body when the protein cannot be synthesized? (3)

reduces the body's ability to support growth, repair, and maintenance of tissues

Most ___ food are not sources of complete proteins... except?(2)

plant, quinoa and soy protein

Complementary proteins example:

Cereal grains + legumes, Legumes + seeds, Eggs or milk product + vegetable protein food

What diets must be carefully planned to ensure all nutrient needs met

vegan (strict)

If vegan diet poorly planned may lack ____ proteins

complete

If vegan diet poorly planned may lack vitamin ____ . where is this found?

B12, found only in animal or fortified foods

If vegan diet poorly planned may lack ____ and _____. what is rich in this mineral?

iron, zinc, red meat

If vegan diet poorly planned may lack ____. what product is rich in this mineral?

calcium, dairy products

Some vegetarian diets are just as low in ___ ____ & ____ ___ as fast-food diets

nutrient density, high fat

First 11 amino acids

non essential (made by body)

Last 9 amino acids

essential (must be supplied by diet)

Nonessential amino acids often produced from essential amino acids in?

liver

Nonessential amino acid referred to as

dispensable

Essential amino acids referred to as

indispensable

Amines are compounds that include?

amino groups in their chemical structures

Derivatives of amino acids:

body uses amino acids to form nitrogen containing compounds that are not proteins

Positive nitrogen balance?

OKAY

- growing, pregnant, body-building

Zero nitrogen balance?

OKAY

- maintaining, most adults

Negative nitrogen balance?

NOT OKAY

- muscle atrophy, burn trauma, cancer, AIDS

Though the body conserves nitrogen by ____ amino acids, each day some protein and nitrogen are ___

recycling, lost

What accounts for most of the lost nitrogen

Urinary elimination of urea and creatinine

Daily nitrogen losses also occur? (2)

nails and hair grow

when the outermost layer of the skin and cells from the intestinal tract are shed

The body uses ___ ___ from ___ to replace the lost nitrogen

amino acids, foods