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HUN 1201 exam 3
HUN 1201 TCC
71
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10/21/2009

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Term
What do amino acids consist of and how are they structured?
Definition
  • Carbon, hydrogen, oxygen, and nitrogen

some basic structure for all amino acids

  • central carbon
  • hydrogen
  • an amino group (NH2)
  • an acid group (COOH)
Term
What is a conditionally essential amino acid? Give an example.
Definition

when a nonessential amino acid becomes esstial under certan circumstances

 

If you lack an essential vitamin that makes nonessential vitamin body cant make nonessential amino acids therefore making it conditionally essential

Term
what is the amino acid pool?
Definition
the supply of amino acids derived from either food proteins or body proteins that collect in the cells and circulate blood and stand ready to be incorporated in proteins another compounds used energy
Term
what is the amino acid sequence?
Definition
Vary within each protein variety of possible sequences for polypeptide chains is tremedous
Term
What is sickle cell anemia?
Definition

two of the hemoglobins four polypeptide chains have the normal sequence, but the other two do not.

 

alters ability to carry oxygen effectively.

Term

What is deamination?

 

Definition
when amino acids are broken down they are striped of their nitrogen containing group. it provides amonia and releases in blood. the liver picks it up and converts it into urea. urea returns to blood and kidney filters ureaout of blood, left over carbon used for energy ect.
Term
What is denaturation?
Definition
when proteins are subjected to heat, acid or other conditions that disturb their stability. they uncoil and lose their obility to function
Term
what are the enzymes involved in protein digestion?
Definition

stomach- hydrochloric acid uncoils each proteins tangled strands so that the digestive enzymes can attack the peptide bonds

 

acid converts pesinogen to pepsin

Pepsin breaks proteins into smaller polypeptide

peptidase enzyme splits dipeptides and tripeptides into amino acids

Term
waht is used to determine protein utilization and how are the protein requirements determined?
Definition

8 grams per kilogram of healthy body weight perday

 

weight / 2.2 lb/kg = x

 

xkg * .8 g/kg = grams of protein 

Term

what are complimentary proteins?

 

Definition
This strategy yields complimentary proteins that together contain the essential amino acids in quantities sufficient to support the body
Term
Why does fatty liver develop in children with protein malnutrition?
Definition
  • Sudden and recent deprivation of food
  • Fatty liver develops because protein carriers are not present to take fat out of the liver
Term
Why does adema develop in children with protein malnutrition?
Definition
  • The swelling of body tissue caused by excessive amounts of fluid in the interstitial spaces.
  • Inadequate dietary intake of protein
Term
What happens when an essential amino acid is not supplied in the diet?
Definition
The cell will dismantle it's own proteins to obtain it
Term
What is a high quality protein?
Definition
Dietary proteins containing all the essential amino acids in relatively the same amounts human beings require
Term
What is protein turnover?
Definition

The degredation and synthesis of protein

(within each cell, proteins are continually being made and broken down) 

Term
People associate ____ with ____ and protein with ____ so they eat meat to build ____.
Definition
People associate meat with protein and protein with strength so they eat meat to build muscles.
Term
To build strength, muscles need ____ ____ and ALL the nutrients.
Definition
To build strength, muscles need physical activity and ALL the nutrients.
Term
Protein is found not only in meat, but in eggs, legumes, milk, ____ and ____.
Definition
Protein is found not only in meat, but in eggs, legumes, milk, grains and vegetables.
Term
Protein's role in the body is not limited to ____ cells, it is a vital structural and working substance in ALL cells.
Definition
Protein's role in the body is not limited to muscle cells, it is a vital structural and working substance in ALL cells.
Term
Proteins contain ____, ____, ____, and ____.
Definition
Proteins contain carbon, hydrgen, oxygen, and nitrogen.
Term
The ____ atom gives the amino name to amino acids, the building ____ of proteins.
Definition
The nitrogen atom gives the amino name to amino acids, the building blocks of proteins.
Term
____= nitrogen containing
Definition
Amino= nitrogen containing
Term
All amino acids have what basic structure?
Definition
  • A central carbon
  • A hydrogen
  • An amino group (NH2)
  • An acid group (COOH)
  • The fourth bonding site on the carbon distinguishes each amino acid
Term
The ____ groups on amino acids vary from one amino acid to the next.
Definition
  • The side groups of amino acids vary from one amino acid to the next.
  • This makes amino acids more complex than either carbohydrates and lipids
  • A starch molecule would be several thousand units long, but each unit is a glucose molecule

 

Term
Protein can be made up of ____ different kinds of amino acids, each with a different ____.
Definition
Protein can be made up of 20 different kinds of amino acids, each with a different side chain.
Term
More than half of the amino acids are ____- our bodies can make them on their own.
Definition
More than half of the amino acids are nonessential- our bodies can make them on their own. 
Term
The body can make all nonessential amino acids given ____ to form the amino group and fragments from ____ and ____ to form the rest. 
Definition
The body can make all nonessential amino acids given nitrogen to form the amino group and fragments from CHO and fat t form the rest.
Term
There are ____ amino acids that the body cannot make or cannot make in sufficient amounts. These include:
Definition

There are 9 amino acids that the body cannot make or cannot make in sufficient amounts. These include:

 

  1. Histidine
  2. Isoleucine
  3. Leucine
  4. Lysine
  5. Methionine
  6. Phenylalanine
  7. Threonine
  8. Tryptophan
  9. Valine

Term
What is a conditionally essential amino acid?
Definition

 

  • When a nonessential amino acid becomes essential under certain circumstances, it is known as conditionally essential

 

  • For example: the body uses phenylalanine (essential) to make tyrosine (nonessential)
  • But if the diet fails to provide phenylalanine, or the person has phenylketonurea (PKU), then tyrosine becomes conditionally essential

 

Term
What is a peptide bond?
Definition

  • Cells link amino acids end-to-end in a variety of sequences to form thousands of different proteins
  • A peptide bond is the bond that unites one amino acid to the next
  • Condensation bonds amino acids

Term
Two amino acids bonded together form a ____.
Definition
Two amino acids bonded together form a dipeptide.
Term
____= 3 amino acids
Definition
Tripeptide= 3 amino acids
Term
____= many amino acids linked together
Definition

  • Polypeptide= many amino acids linked together
  • Most proteins are a few dozen to several amino acids long

Term
Amino Acid sequences vary within each ____.
Definition

  • Amino Acid sequences vary within each protein.
  • The variety of possible sequences for polypeptide chains is tremendous 

Term
Describe how the shape of a protein is determined.
Definition

  • Polypeptide chains twist into a variety of complex, tangled shapes, depending on their amino acid sequence
  • The unique side group of each amino acid gives it characteristics that attract it to, or repel it from the surrounding fluids and other amino acids.
  • Some amino acid side groups carry electrical charges that are attracted to water molecules, they are hydrophilic
  • Others are neutral and are repelled by water, they are hydrophobic
  • As amino acids are strung together to make a polypeptide, the chain folds so that its charged hydrophilic side groups are on the outer surface near water
  • The neutral hydrophobic groups tuck themselves inside, away from the water
  • This intricate coiled shape gives the protein maximum stability

Term

  1. The ____ of proteins enable them to perform their various tasks in the body.
  2. Some proteins form _____ that can carry and store materials within them.
  3. Some, such as those of ____, are more than ten times as long as they are wide, forming strong, rodlike structures.
  4. While some polypeptide chains function just as they are, some need to associate with other polypeptides to form large working ____.

Definition

  1. The unique shape of proteins enable them to perform their various tasks in the body.
  2. Some proteins form hallow balls that can carry and store materials for them.
  3. Some, such as those of tendons, are more than ten times as long as they are wide, forming strong, rodlike structures.
  4. While some polypeptide chains functino just as they are, some need to associate with other polypeptides to form large working complexes.

Term
Some proteins require ____ to activate them, like hemoglobin.
Definition
Some proteins require minerals to activate them, like hemoglobin
Term
Hemoglobin is the globular protein of the red blood cells that _____, each polypeptide holds a(n)____ molecule. 
Definition
Hemoglobin is the globular protein of the red blood cells that carries oxygen, each polypeptide holds a(n) iron molecule.
Term
When proteins are subjected to ____, ____, ____, ____, ____, ____, or other conditions that disturb their stability, they undergo denaturation- they uncoil, lose their shape, and lose their function.
Definition
When proteins are subjected to heat, agitation, base, alcohol, heavy metals, or other conditions that disturb their stability, they undergo denaturation- they uncoil, lose their shape, and lose their function.
Term
What are some examples of denaturation?
Definition

Some examples of denaturation include:

  1. Hardening of an egg when it is cooked
  2. The curdling of milk when acid is added
  3. The stiffening of egg whites when they are whipped

Term

Digestion and absorption

  • Proteins in foods do not become ____ proteins directly
  • The foods supply the amino acids from which the body ____ its own proteins
  • When we eat protein, enzymes break the peptide bonds and the polypeptides become shorter and shorter until only ____ are left. 

Definition

  • Proteins in foods do not become body proteins directly
  • The foods supply the amino acids from which the body makes its own proteins
  • When we eat protein, enzymes break the peptide bonds and the polypeptides become shorter and shorter until only amino acids are left

Term
Describe what happens to proteins in the stomach
Definition

 

  • The major event in the stomach is partial breakdown of proteins
  • Hydrochloric acid uncoils (denatures) each protein's tangled strands so that the digestive enzymes can attack the peptide bonds
    • Hydrochloric acid converts the enzyme pepsinogen (inactive) to pepsin (active)
    • Pepsin cleaves proteins into smaller polypeptides

 

Term
Describe what happens to proteins in the small intestine
Definition

 

  • When polypeptides enter the small intestine, several pancreatic and intestinal proteases hydrolyze them even further to small peptides
  • The peptidase enzymes on the membrane surfaces of the intestinal cells split most of the di-peptides and tri-peptides into amino acids
  • Only a few di-peptides enter the circulation intact

 

Term
Discuss the process of protein absorption in the intestines
Definition

  • A number of specific carriers transport amino acids ( and di-peptides and tri-peptides) into the intestinal wall
  • Once inside, the amino acids may be used for energy or to make needed compounds
  • Amino acids not used by the intestinal cells are carried in the blood to the liver
  • Enzymes are proteins and they get digested as well and are broken down to amino acids

Term
Each human being is unique because of small differences in the body's ____.
Definition

  • Each human being is unique because of small differences in the body's proteins.

  • These differences are determined by the amino acid sequences of proteins, which in turn, are determined by genes.

 

Term
The instruction for making every protein in a person's body are transmitted by way of the genetic information received at ____.
Definition

  • The instruction for making every protein in a person's body are transmitted by way of the genetic information received at conception.

  • These instructions are filed in the DNA (deoxyribonucleic acid) in the nucleus of cells

Term
Transforming the information in DNA into the appropriate sequence of amino acids needed to make a specific protein requires what 2 major steps?
Definition

 

  1. Transcription- A stretch of DNA is used as a template to make a strand of RNA (ribonucleic acid) known as messenger RNA (mRNA). mRNA then takes the code across the nuclear membrane into the body of the cell. It attaches itself to one of the ribosomes (protein making machine)
  2. Translation- mRNA specifies the sequence in which the amino acids line up for synthesis of a protein

 

Term
Describe how amino acids Line up
Definition

  • Transfer RNA (tRNA) collects amino acids from the cell fluid and brings them to the mRNA
  • Each of the 20 amino acids has a specific tRNA
  • Thousands of tRNA each carrying its amino acids wait to unload its amino acid
  • When the mRNA's list calls for a specific amino acid, the tRNA moves into position, then the next and so on
  • Enzymes bind the amino acids together'
  • The protein strand is released and the tRNA are freed to return for other loads of amino acids

Term
The sequence of amino acids in each protein determines its ____ which supports a specific ____.
Definition
The sequence of amino acids in each protein determines its shape which supports a specific function.
Term
If a genetic ____ alters the amino acid sequence of a protein, or if a mistake is made in copying the sequences, ____ will result.
Definition
If a genetic error alters the amino acid sequence of a protein, or if a mistake is made in copying the sequences,  an altered protein will result.
Term
Describe sickle cell anemia
Definition

  • In a person with sickle cell anemia, two of hemoglobin's four polypeptide chains have the normal sequence, but the other two do not
  • Valine takes the place of glutamic acid
  • This alterations alters hemoglobin's ability to carry oxygen effectively
  • Sickle cell anemia raises energy needs, causes many medical problems, and can be fatal

Term
What are some of the roles of proteins?
Definition

  • Proteins are very versatile
  • They have many roles in the body:
    • Building materials 
    • Enzymes
    • Hormones
    • REgulators of fluid balance
    • Acid-base regulators
    • Transporters
    • Antibodies
    • Source of energy and glucose
    • other roles

Term
Within each cell, proteins are continually being made and broken down, a process known as ____.
Definition
Within each cell, proteins are continually being made and broken down, a process known as protein turnover.
Term
When proteins break down, they free amino acids and mix with amino acids from dietary proteins to form the ____.
Definition
When proteins break down, they free amino acids and mix with amino acids from dietary proteins to form the amino acids pool.
Term
The amino acid pool remains constant regardless of rate of ____ and ____.
Definition

  • The amino acid pool remains constant regardless of rate of degradation and intake.
  • These amino acids can be used to make other proteins, or their nitrogen will get stripped and they will be stored as fat

Term

Nitrogen balance

  • In healthy adults, protein ____ balances ____
  • Protein ____ balances with nitrogen ____ in the urine, feces, and sweat.
  • When nitrogen intake = nitrogen output a person is in nitrogen equilibrium or ____.

Definition

 

  • In healthy adults, protein synthesis balances degradation
  • Protein intake balances with nitrogen excretionin the urine, feces, and sweat.
  • When nitrogen intake = nitrogen output a person is in nitrogen equilibrium or zero nitrogen balance.

 

Term
Nitrogen balance studies are used to estimate ____.
Definition
Nitrogen balance studies are used to estimate protein requirements
Term
If the body makes more protein than it breaks down, the body is in ____.
Definition

  • If the body makes more protein than it breaks down, the body is in positive nitrogen balance.
    • Growing infants
    • Children
    • Adolescents
    • Pregnant women
    • People recovering from protein deficiency or illness
  • These people retain the protein to make new tissues (blood, bone, skin, and muscle cells) so they do not excrete as much nitrogen as they take in

Term
If the body degrades more than it synthesizes and loses proteins, nitrogen status becomes ____.
Definition

  • If the body degrades more than it synthesizes and loses proteins, nitrogen status becomes negative.
    • People who are starving
    • Burn victims
    • Severe injuries
    • Fever
  • Their output exceeds their intake because muscle and other body proteins are being broken down for energy

Term
When amino acids are broken down, they are ____.
Definition
When amino acids are broken down, they are deaminated- stripped of their nitrogen containing group
Term
Describe deamination 
Definition

  • Deamination produces amonia and is released into the blood
  • The liver picks up the ammonia and converts it to urea (less toxic than ammonia). Urea is the principle nitrogen excretion product of protein metabolism (2 ammonia fragments and a CO2)
  • The urea returns to the blood
  • The production of urea increases as dietary protein increases
  • Urea reaches its maximum production rate when a person consumes ~250 grams per day
  • The kidneys filter urea out of the blood
  • The remaining carbon fragments (after deamination) can enter a number of pathways
    • Used for energy
    • Used for production of glucose, ketones, cholesterol, or fat

Term
____ dietary proteins containing all the essential amino acids in relatively the same amounts that human beings require.
Definition
High quality protein dietary proteins containing all the essential amino acids in relatively the same amounts that human beings require.
Term
How is the quality of a protein determined?
Definition

  • Quality is determined by
    • Protein digestibility (animal proteins: 90-99%) (plant proteins: 70-90%) (soy and legumes: >90%)
    • Amino acid composition (if the diet does not supply an essential amino acid, a cell will dismantle its own proteins to obtain it)-not good!

Term

Complimentary Proteins

  • In general plant proteins are ____ quality than animal proteins and plants also offer ____ protein (per weight or measure of food).
  • For this reason ____ improve the quality of proteins in their diets by combining plant-protein foods that have different but complementary amino acid patterns
  • This strategy yields ____ that together contain the essential amino acids in quantities sufficient to support the body

Definition

  • In general plant proteins are lower quality than animal proteins and plants also offer less protein (per weight or measure of food).
  • For this reason vegetarians improve the quality of proteins in their diets by combining plant-protein foods that have different but complementary amino acid patterns
  • This strategy yields complimentary proteins that together contain the essential amino acids in quantities sufficient to support the body

Term
Describe Protein-energy malnutrition
Definition

  • When people are deprived of protein, energy, or both, the result in protein-energy malnutrition (PEM)
  • Most often strikes in childhood
  • Most prevalent form o malnutrition in the world
  • PEM occurs in 2 forms
    • Marasmus
    • Kwashiorkor

Term
Describe Marasmus
Definition

  • Named after the Greek word meaning "dying away"
  • Severe deprivation of food over a long period of time
  • Most common in children 6-12 in overpopulated, impoverished areas

Term
Describe Kwashiorkor
Definition

  • Sudden and recent deprivation of food
  • Typically occurs in children between 18 months and 2 years
  • Weight loss is not as severe as marasmus
  • Proteins and hormones that previously maintained fluid balance diminish and fluid leaks causing the abdomen and limbs to become swollen with edema
  • Fatty liver develops because protein carriers are not present to take fat out of the liver
  • After several severe problems, the child can die

Term
Describe infections
Definition

  • Antibodies can be broken down to provide the body with amino acids it needs 
  • This causes the immune system to weaken
  • This can cause an infection of the immune system known as dysentery
  • Dysentery causes diarrhea which causes dehydration
  • If anemia kicks in (body not producing hemoglobin) then further weakness occurs
  • All this leads to heart failure and death

Term
What are the health effects of protein?
Definition

  • In developed countries we see an excess of protein intake
  • Overconsumption of proteins offers no benefits and may even pose health risks
  • High-protein diets have been associated with:
    • Heart disease
    • Cancer
    • Osteoporosis
    • Obesity
    • Kidney stones

Term

Heart Disease

  • A high protein diet may contribute to the progression of ____ due to the consumption of animal products which have high levels of ____ fats.

Definition

  • A high protein diet may contribute to the progression of heart disease due to the consumption of animal products which have high levels of saturated fats.

Term
The amino acid homocysteine may be an independent risk factor for heart disease- not known if heart disease causes an elevated level of homocysteine in the blood or if elevated levels of
Definition