Nutrition Exam #2: Chapter 6 Protein

What is formed when the amine group is removed from the amino acid?

Ammonia is formed

____________ removes the Amine group from Amino Acids.

Deamination

Peptides:

Fewer than 50 amino acids

Conditionally essential:

Nonessential amino acids that become essential because the body cannot make them examples: tyrosine and glycine

Enzymes involved in protein digestion:

Pepsinogen Trypsin Chymotrypsin Carboxypeptidase Aminopeptidase Tripeptidase Dipeptidase

________ and ________ are made of proteins.

hormones and enzymes

Peptide bonds break through:

hydrolysis

Three types of PEM:

kwashiorkor marasmus marasmic kwashiorkor

Deamination occurs in the:

liver

Collagen:

most abundant protein

Kwashiorkor:

severe protein deficiency (stomach protrusion)

Common blood disorder that involves abnormal or flawed protein formation:

sickle cell anemia

Primary structure:

simple linear chain

Protein digestion begins in the:

stomach

Some protein foods contain ________, which is not found in cards or lipids.

sulfur

Acts as pH buffers to balance hydrogen ions:

-acidosis = coma alkalosis = convulsions

Methods developed to determine the protein quality of foods:

-amino acid score -PDCAAS -Biological value

Complete proteins:

-contain all 9 essential amino acids -usually animal sources -higher quality

Carbon-containing remnants are:

-converted to glucose through gluconeogenesis -converted to fatty acids and stored as triglycerides in adipose tissue

In sickle cell anemia:

-gluatmine displaced by valine -occurs during periods of low oxygen -easily destroyed causing anemia -build up in arteries

Denaturation occurs in the presence of:

-heat -acids -bases -salts -mechanical agitation

Denaturation alters:

function

Shape of protein affects:

function

Amino acids can be converted to _________ for energy.

glucose

Too much protein:

-increase risk for heart disease -increase risk for kidney stones -increases risk for osteoporosis -cancer

High quality protein:

-is digestible -contains all essential amino acids -provides a sufficient protein to synthesize nonessential amino acids

Incomplete protein:

-low in 1 or more essential amino acids -usually plant sources

What are proteins?

-macronutrients found in each cell in the body

PEM:

-protein is used for energy rather than all other functions - other important nutrients are in short supply -prevalent in infants and children

A 3 ounce serving of cooked meat poultry or fish:

-provides 21 to 25 grams -7 g/ounce -deck of cards -one meal

In the liver, amino acids are:

-used to synthesize new proteins -converted to energy, glucose, or fat -released to bloodstream and cells

Quaternary structure:

2 or more polypeptide chains bond together

There are ___ amino acids that are used to make proteins.

20

Tertiary structure:

3D globular shape

Provide energy:

4 kcals/gram

Eleven nonessential/conditionally essential:

Alanine Asparagine Aspartic acid Glutamic acid Serine Conditionally: arginine Cysteine Glutamine Glycine Proline Tyrosine

Transcription:

DNA stores info DNA replicates itself by forming messenger RNA

Too little protein:

Protein energy malnutrition (PEM)

Regulate fluid balance:

albumin prevents edema (child with protruded stomach)

The proteins are classified by the numbr of:

amino acids in the chain

Protein is made up of chains of:

amino acids that are made based on an individuals DNA

Occasionally proteins are absorbed intact:

breast milk food allergies

Polypeptides enter the small intestine and are:

broken down into smaller peptides

Transamination:

builds nonessential amino acids

Most amino acids are sent into the blood to be:

picked up and used by the cells: maintenance growth healing

Pepsin breaks:

polypeptides into shorter chains

amino acids are transported to the liver from the intestines via the:

portal vein

Four levels of protein structure:

primary secondary tertiary quaternary

Cholecystokinin stimulates the release of:

proteases by the pancreas

Marasmus:

severe deficiency in kilocalories (emaciated child)

Amino acids are absorbed in:

small intestine

1. Bolus enters the

stomach

Improve satiety and appetite control:

suppresses ghrelin

3 steps of protein synthesis:

transcription translation elongation

Elongation:

transfer RNA collects amino acids from AA pool Ribosomes build a chain in the proper sequence, continuing until finished and new protein is released

Proteases break apart the polypeptides to:

tripeptides and dipeptides

Primary structure is _________ by denaturing.

unchanged

Denaturation =

unfolding

Ammonia is then converted into:

urea and excreted as urine in the liver

When does deamination occur?

when the amino acid pool reaches capacity

Protein synthesis is regulated by:

your genes

Actin & myosin:

muscle contractions

Anatomy of an Amino Acid:

-Amine group (NH2) -carboxylic Acid group (COOH) -Side Chain (R group) -peptide bonds

inadequate protein intake:

-Cells along GI tract are not replaced as they slough off -digestive function inhibited -absorption reduced -intestinal bacteria get into blood, causing septicemia -immune system compromised

There are _____ nonessential amino acids.

11

_________ stimulates the release of HCl.

Gastrin

______ denatures the protein and converts pepsinogen to pepsin

HCl

Nine essential amino acids:

Histidine Isoleucine Leucine Lysine Methionine Phenylalanine Threonine Tryptophan Valine

Proteins:

More than 50 amino acids (typically 100 to 10,000 amino acids linked together)

There are _____ essential amino acids.

Nine

Proteins contain ________, in addition to carbon, hydrogen, and oxygen.

Nitrogen

Transport substances throughout the body:

Oxygen, waszte, products, lipids, some vitamins and sodium and potassium through the blood and cell membranes

Protein intake recommendations:

RDA: 0.8 g/kg daily AMDR: 10 to 35 % total kcal/dl

Contribute to a healthy immune system:

atibodies are proteins that bind and neutralize pathogens that would harm the body

Excess dietary protein:

cannot be stored in the body

Marasmic Kwashiorkor:

chronic deficiency in kilocalories and protein (skin and bones)

A peptide bond forms by ______ when the acid group (COOH) and amine group of two different amino acids join and release a molecule of water.

condensation

Dipeptidases and tripeptidases break the:

dipeptidses and tripeptides into amino acids

Proteins act as a catalyst through:

enzymes speeding up reactions

Proteins act as a chemical messenger through:

hormones regulating cell actions

Translation:

mRNA translated the info from DNA to an amino acid sequence in the ribosomes

Secondary structure:

protein that is folded and twisted

Protein functions:

provide structural support and enable movement -collagen -Actin and myosin acts as a catalyst act as a chemical messenger regulate fluid balance acts as pH buffer