Nutrition: Unit 2: Chapter 6:

Each amino acid contains a central carbon C surrounded by four parts. what are these 4 parts?

The 4 parts are carboxyl or acid group, amine group, and side chain.

What happens if amino acids in the amino acid pool aren't used for protein synthesis?

The amino acids that aren't used are broken down inot component parts. These component parts are used for other purposes, such as energy production, or stored in another form.

Describe what happens in the small intestine to digest proteins.

Trypsin, chymotrypsin, and carboxypeptidase are released. Trypsin and chymotrypsin continue to break down peptide bonds in the center of the polypeptide chain.

Calculate the nitrogen lost. It is lost in the urine as urea nitrogen.

A factor of 0.2 grams TIMES(x) UUN which is 8 grams in this example. 1.6 grams

Severe deficiency of protein is called_____ whereas a deficiency of kilocalories is____

Kwashiorkor/Marasmus

Different types of vegetarians and what they eat

Lacto-vegetarian ( grains, veggies, fruits, legumes, seeds, nuts, dairy) Lacto-ovo (grains, veggies, fruits, legumes, seeds, nuts, eggs.) Vegans ( grains, veggies, fruits, legumes, seeds, nuts.) Semivegetarian ( occasional meat, fish, and poultry.)

When amino acids are absorbed, they reach the liver first. What are possible ways the liver might metabolize these amino acids

Might be used to replace old proteins or synthesize new ones. or as an energy source.

What happens to digest protein mouth, stomach, and small intestine?

Mouth (Mechanical digestion chewing, tearing, mixing food with salivary juices to form bolus) Stomach (Hydrochloric acid denatures protein, activates pepsin which breaks the polypeptide chain into smaller polypeptides) Small intestine (Dipeptides result from peptide bonds. Digestion is finished to yield amino acids, which are absorbed into the bloodstream, travel through portal vein to the liver).

Some proteins are chemical messengers such as _____?

Hormones

Protein is the only food that provides

The nitrogen the body needs.

Most proteins are absorbed as single amino acids. Give some examples of proteins that are absorbed intact.

Whole proteins are absorbed intact, like antibodies from breast milk or in the case of food allergies.

Of the 20 amino acids, how many are considered unique?

nine

Protein is the only food component that provides the ____ the body needs for important processes, such as the synthesis of neurotransmitters.

nitrogen

What are the "building blocks" of proteins?

The proteins are made up of amino acids.

How does protein affect satiety?

The satiety when eating a high- protein meal comes from dietary protein suppressing the release of ghrelin.

What makes each amino acid (20 total) unique?

The side chain.

Proteins consist of a combination of

20 amino acids. A chain with more than 50 is a protein.

All proteins consist of some combinations of ____ unique amino acids and are classified according to the number of amino acids. A chain with more than 50 amino acids is called a ______?

20, protein.

Protein has 16 percent nitrogen, a common factor of ___ is used to calculate how it is in a given amount of food. A meal was found to contain 73 grams of protein What was its nitrogen content?

6.25 is the common factor. Nitrogen content of the meal is 11.68 grams. (73 divided by 6.25)

Define amino acid pools & protein turnover

AAP are limited supplies of amino acids that accumulate in the blood, protein turnover is the continual process of degrading and synthesizing protein. The body can use the amino acids in the pool to create proteins on demand.

Which 4 parts in the Amino acid surround the central Carbon?

Carboxyl or acid group, amine group, hydrogen atom, and distinctive side chain

What do catabolic enzymes do?

Catabolic enzymes break compounds apart.

Define a catalyst.

Catalysts are substances that aid and speed up reactions without being changed, damaged, or used up in the process.

_____ is the most abundant protein in the body and is found in all connective tissue, including the bones, tendons, and ligaments that support and connect joints and other body parts. This fibrous protein is also responsible for the skin's elasticity and forms the scar tissue necessary to repair injuries.

Collagen

Complete vs. incomplete protein

Complete provides all essential amino acids, along with non-essentials. An incomplete is low in one or more of the essential AA's. (Plant sources tend to be incomplete, soy protein and animal source proteins are complete)

What (of the protein) determines its function in the body

It's shape

Two ways to measure total protein intake in the diet.

Percentage of total calories, or grams of protein eaten per day.

Describe the four levels of structure of every protein.

Primary Structure: first stage after transcription. the amino acids have been linked together with a peptide bond to form a simple linear chain. Secondary structure: The hydrogen ions of amino acids linked together with the amine group, causing the straight chain to fold and twist. Tertiary structure: Side chains of the amino acids, most often containing sulfur, form bridges, causing the protein to form even stronger bonds than the second. These form loops, bends, and folds in the molecule. Quaternary structure: forms when two or more polypeptide chains cluster together, forming a final ball like structure.

Four levels of structure for every protein

Primary(length/sequence of chain of AA), Secondary(straight chain folds and twists because of hydrogen bonds), Teritiary (side chains react resulting in more bends and folding), Quaternary (Two or more polypeptide chains combine).

Proteins act as ____ and minimize the changes in acid-base levels by picking up or donating hydrogen ions in the blood.

buffers

Proteins act as what to minmize changes in acid-base levels by picking up or donating hydrogen ions

buffers

Define conditionally essential amino acids.

conditionally essential means the nonessentials like tyrosine and glycine, that become essential when the body cannot make them.

Most enzymes are made up of _____. Without enzymes, reactions would occur so slowly that you couldn't survive.

proteins

Latest reccomendation is to consume ____to ____percent of total calories from protein.

10 to 35 percent

The body is made up of over _____ different proteins. At birth, the exact code for each of these proteins is stored in ____ and filed away in DNA.

100,000, genes.

Calculate your individual protein needs. (p. 231)

160/2.2 =72. kg 72 x 0.8=58 g protein

DRI for grams of protein need to consume daily is based on...

A persons need to maintain protein dependent tissues and to perform protein-dependent body functions.

Define the terms amino acid pools and protein turnover. How do amino acid pools contribute to protein turnover?

Amino acid pool: its an accumulation of amino acids in the blood and cells. Amino acids are pulled from the pools and used to build new proteins. Protein turnover: is the process of degrading and synthesizing protein.

3 methods for determining protein quality.

Amino acid score, biological value, and PDCAA combines chemical score with digestibility of a food protein for an accurate indication.

After a protein is digested and the amino acids are absorbed, what can the cells use those amino acids for?

Amino acids can be used to synthesize new proteins, or can be converted to ATP, glucose, or fat.

When amino acids are absorbed, they reach the liver first. What are some possible ways the liver might metabolize these amino acids?

Amino acids might be used as an energy source or if the individual doesn't get an adequate diet the amino acids can be converted to glucose through the process called gluconeogenesis.

Most proteins are absorbed as single amino acids. What are examples of proteins absorbed intact

Antibodies from breast milk, or in case of food allergies.

Hows much nitrogen is usually lost through hair, skin, feces?

Approx 2 grams per day.

Why do we call them essential amino acids?

Because the body cannot synthesize them, they must be obtained through dietary sources.

What two factors determine the quality of protein

Digestibility, types and amounts of amino acids it contains.

Why might a lack of protein cause edema?

Edema occurs because the interstitial spaces between the cells becomes bloated and the body tissue swells.

Soruces highest in protein

Eggs, lean meats, low fat or fat free dairy products.

What are reasons a person may choose a vegetarian diet?

Ethical, religious, environmental reasons or health reasons.

Describe what happens in the stomach to digest proteins.

HCI and pepsinogen are released. once the bolus enters the stomach HCI converts the pepsinogen to an active enzyme called pepsin. the strands are propelled into the small intestines as part of the chyme.

Proteins can be unfolded or denatured by ____, _____, ______,_____, or _______.

Heat, acids, bases, salts, or mechanical agitation.

Proteins can be unfolded or denatured by what?

Heat, acids, bases, salts, or mechanical agitation.

Why would an individual have a negative nitrogen balance

Immediately following surgery, fighting an infection, experiencing severe emotional trauma. This increases the need for calories and protein.

How do proteins play a role in fluid balance

Moves fluids and keeps water dispersed evenly inside and outside of cells.

Of the 20 amino acids the body combines to make proteins, _____ of them are classified as essential amino acids. Why do we call them essential amino acids?

Nine, They are called essential because they cant be made by the body or cannot be made in sufficient quantities to sustain the body's needs.

Can proteins provide energy to the body? Are they the primary source? Why or why not?

Proteins can be used as an energy source, but you don't want to use proteins as a primary energy source. Proteins have so many more important roles that the proteins need to be used for.

Explain how proteins play a role in fluid balance.

Proteins help with moving fluids and keeping water dispersed evenly inside and outside of cells, which helps maintain a state of fluid balance.

Discuss some of the essential roles proteins play in the human body.

Proteins play a role in every cellular activity, from building, repairing and maintaining cells to storage, transport, and utilization of the nutrients.

Risks and benefits of vegetarian diet

Reduces risk of heart disease, high blood pressure, diabetes, stroke, obesity, prostate and colon cancer. Risk is underconsuming nutrients prtwin and vitamin b12.

It is the _____ of the protein that determines its function in the body. Anything that alters the bonds between the side chains will alter the protein's ______ and thus its function.

Shape, shape.

Describe what happens in the mouth to digest proteins.

The teeth tear and shred the food, breaking it into smaller pieces.

What are the three steps of protein synthesis?

The three steps of protein synthesis are; transcription, translation, and elongation.

Can proteins provide energy, are they primary source, why?

They can provide energy, not a primary source because carbs and fays are far better suited for energy.

What happens if AA in the pool arent used for protein synthesis?

Theyre broken down into their component parts. Used for other purposes such as energy production, or stored in another form.

After a protein is digested, amino acids are absorbed, what can cells use those amino acids for?

To synthesize new proteins, converted to ATP, glucose, or fat. When other cells need to be replenished, AA are relased into bloodstream & transported thru the body

Risks from eating too much or too little protein.

Too much heart unhealthy fat, weaker bones, heart disease, kidney stones, osteoporosis, cancer. Too little can lead to protein energy malnutrition.

Essential roles proteins play in the body

Virtually all cellular activity from building, repairing, & maintaining cells to storage, transport, and use of nutrients you eat. hormones/enzymes are made of protein and direct how fast calories are burned, heart beat, and attraction to someone.

Three examples of how proteins transport substances

Vitamin A attaches to the protein for transport to liver and other cells. Specialized transport proteins sole function is to escort them across the enterocytes to their inteded locations.

Proteins can alter the ____ of the body fluids.

pH

All of the 20 amino acids that the body uses to make proteins contain the same four parts. what makes each amino acid unique?

the side chain is what makes each amino acid unique.

Define nonessential amino acids.

they are called nonessentials because they can be made by the body, therefore they don't need to be consumed in the diet.

Define conditionally essential amino acids

those nonessential amino acids that become essential (and must be consumed in the diet) when the body cannot take them.