HSNC 6: Proteins and Amino Acids

What compounds are proteins made up of?

C,H,O,N

Example of body’s working proteins

antibodies, hormones, oxygen carriers, enzymes,

example of structural proteins

tendons, ligaments, fibres of muscles, found in our bones, teeth, hair and nails.

What are proteins

strands of aa

How many aa does a protein have?

22

What is the structure of an aa?

Carbon atom with amine group and an acid group attached

How many make up most of the proteins of living tissues? how many can the body make aa itself? what are the essential aa what does that even mean

20

• 10 so half of 20

• some are essential so the body cant make aa itself or cant meet the body’s needs

• TV TILL PM

how does the body recycle aa? what does this allow? what does this sacrifice

break food and body proteins apart after digestion after the cellular work

• allows an emergency supply of aa for when we run out of glucose, protien, and fuel

• sacrifice the working muscle tissue – using the most dispensable muscles first and leaving the organs and heart protein until dire need.

what joins aa tgt to form proteins?

peptide bonds

How many aa join to form a protein? what does the electrical charges do to aa?

300 aa

• causes the protein strand to bend and coil as aa attract and repel one another, which forms globular shape or fibrous shape

What does the aa w electrically charged side chains intreact w water and how are they oriented?

attract water and orient outside of the protein

What does the neutral aa interact w water and oriented?

repel water and are attracted to one another, so orientate in the centre of the protein away from body fluids.

How many aa that can be combined in many diff ways? and how many proteins can a single human cell contain

20

10,000 diff proteins

What makes the protein so diff?

aa sequences of protein

What determines the aa in each finished protein?

genes

What can a wrong aa inserted in teh sequence cause?

disastrous health consequences

whats seickle cell disease

a condition where hemoglobin (the oxygen carrying protein of the red blood cells) is abnormally shaped, and therefore loses its function to carry and release oxygen

• due to one of the protein strands contain valine in the 6th aa instead of glutamic acid

what happens if too many crescent shaped cells in the blood?

abnormal blood clotting, strokes, susceptibility to infection, severe pain and early death can occur.

Where does protein digestion start? and what happens in there

• starts in stomach

• the gastric acid denatures the protein so it changes the shape of protein strand, opening it up to allow digestive enzymes to cleave/break the ppetide bonds

what can denature proteins

heat, acid, bases, alchocol, and salts of heavy metal like mercury

ex. cook egg, heat denatures protein to make egg more firm, whihc is benefiecla bc it ffrees bition, iorn, and aids in digestion

ex. poisions intake - poison denatures milk protein instead of protein tissues of mouth, esophagus, and stomach

• vommitting expels it then

What happens in digestion of small int + pancreas

most proteins enter as smaller pieces like a few aa, but majoirty polypeptides

• Protein digesting enzymes from the pancreas and the intestine split the polypeptides into di and tripeptides and single amino acids

• Enzymes on the surface of lining of the small intestine split the di and tripeptides, allowing the intestinal cells to absorb and transfer the amino acids to the bloodstream

What happens when aa are in the bloodstream

the amino acids are transported to all of the body’s cells.

what happens if larger molecules escape digestive process and enter bs intact?

Act as hormones to regulate body functions

• provide information to the body about the external environment

• stimulate an immune response, thus playing a role in food allergies.

why should we take caution when taking single aa as supplements?

• cells of sm int have seperate sites to absrob diff types of aa

• the same aa type compete for the same absorptive sites

• SO, consuming a lot of any aa may limit the absorption of other aa of the same general type

where do the aa goes after circulaitng in bs?

travel to the liver where they are used or released back into the blood to be taken up by other body cells

• The cells can then link the amino acids together to make proteins that they keep for their use or release into the lymph or blood for other uses.

Can the body use aa for E if necessary? T or F

TRUE

Functions of Proteins

1. support growht and maintenance - aa must be avaible to build proteins of new tissues like in muscles, embryo, or scar tissue needing to heal, rbc, cells lining dt)

2. builds enzymes, hormones, and other conmpounds - insuline and thyroxine

3. builds antibodies - attack foreign particles, recognizing proteins and leave them alone

4. maintains fluids and electrolyte balance - regulates the fluid to remain alive by mainting stores of internal protein (edema and transport proteins)

5. maintains acid-base balance - blood proteins acts as buffers to maintain blood’s normal pH, by picking up H when theres too many in bs, and release when too few

6. clots blood - Special blood proteins respond to injury by forming a stringy net that traps blood cells to form a clot

• clost acts as a plug to stop blood flow from the wound

1. provides E and glucose - protein can provide very little E

how long to rbc live for? what restores them>

3-4 months

• replaced by new cells produced by bone marrow

How long does the cells lining of the digestive tract live for?

2-3 days as they constantly shed and replace

what is thyroxine?

regulates the body’s metabolism

what is edema?

fluid buildup

• too much fluid collects in spaces between the cells of tissues

what do transport proteins do?

holds electrolytes in theri proper chambers

how are proteins invovled in wound heals?

protein collage replaces the clot with scar tissue

how can protein be used as glucose?

Protein is broken down into energy and nitrogen, which is either used or sent to the liver where it is converted to urea and then sent to the kidneys for excretion in the urine. The fragments that remain are carbon, hydrogen and oxygen, which can be used to build glucose or fatty acids.

Because amino acids can be converted to glucose, protein can help to maintain a steady blood glucose level and serve the glucose needs of the brain as need arises. There is no specialized protein storage area in the body. When body amino acids are required for energy, the body must dismantle its tissue proteins, leading to lean body tissue wasting.

If the body takes in excess amino acids, the body cannot store them. It will remove and excrete the amine group, and use the remaining fragments to support the body’s energy needs, convert to glucose for storage as glycogen, or convert to fat for storage

What can protein be used for or when aa arrives at a cell…

1) It can be used to build part of a growing protein

2) It can be altered to make another needed compound (e.g., the amino acid tryptophan can be converted to make niacin ( B vitamin)

3)The cell can dismantle the amino acid in order to use the amine group to build a different amino acid. After the amine group is removed, the remainder can be used for energy or converted to glucose or fat for storage. If the body is not using the amine group to create a different amino acid, it will be excreted from the cell, and then from the body as urine.

Amino acids are considered waste when they are not used to build protein or other nitrogen ocntaining compounds. When does this occur?

1. When the body does not have enough energy from other sources

2. When the diet provides more protein then the body needs

3. When the diet has too much of any single amino acid (such as from supplements)

4. When the diet supplies protein of low quality, with too few essential amino acids.

how To prevent the wasting of dietary protein and allow for the synthesis of needed body protein, dietary protein must be

1. Adequate in quantity

2. Supply all essential amino acids in the proper amounts

3. And must be accompanied by adequate energy from CHO and fat.

where are large and small proteins found in the food group?

meat and alternatives, milk and alternative food group

• veggies and fruits, grain products food groups

how many people in developed countries eat protein

most

DRI of body weight (g/kg) and ave. women and men (g/day)

0.8 g/kg body weight

women 46 g/day

men 56 g/day

DRI Acceptable Macronutrient Distribution Range for protein (AMDR)

10-35r% total energy

what factors does the body respond to when it comes to dietary proteins

1. body’s state of health

2. nutrient and E consumed at the same time

   1. protein’s quality

how does malnutrition affect protien digestion and absorption

digestive enzymes secretion slows as the digestive tract lining degenerates, impairing protein digestion and absorption

What is required for immune infection ?

additional protein to enahnce immune function

how to get the most effcient use of proteins

accompanied by the full array of vitamins and minerals.

What does protein quality determine

determine how well a diet supports the growth of children and the health of adults

What infleunces protein quality

1. digestibility - most aa from animal proteins are MOSt easily digested and absorbed (>90% absorbed), then legumes (80-90%), grain and plant proteins (70-90%)

2. aa composition - High quality proteins are ones with ample amounts of all essential amino acids, low doesnt

whats a cooking metho that imporves protein diges? what impairs it

Cooking with moist heat (e.g., steaming or poaching) improves protein digestibility,

where as dry heat methods (e.g., broiling) can impair it.

what happes if the body restricts essential aa intake?

the body starts to limit the break down of working proteins and reduce amino acid use for fuel to conserve the essential amino acids it currently has.

COMPOIMETRY PROTEINS AUDO

what is protein reccomendations based on?

nitrogen balance studies, which compare nitrogen lost through excretion with the nitrogen eaten in food.

what is nitrogen equilibrium

they have roughly the same amount of protein in body all the timew

whats positive nitrogen balance (ex?)

Nitrogen in exceeds nitrogen out. Somewhere in their bodies, more protein is being built than are being broken down (e.g., growing children, pregnant women).

What is negative nitrogen balance? ex?

Nitrogen out exceeds nitrogen in. Muscle or other protein tissue is being broken down and lost (e.g., illness, injury. Also astronauts: stress of space flight and no need to support body’s weight against gravity causes muscles to weaken and waste).

What is protein energy malnutrition know for? what is it? where is prevalent? when does it strike? and what does it cause

• the worlds most widespread form on malnutrition

• combo of protein deficiency and energy deficiency

• more prevalent in Africa, Central America, South America, the Middle East, and East and West Asia

• early in childhood often causing stunted growth, however affects adults as well (leading to weight loss and wasting).

how many children face starvation, mlanutrtion, and hunger? How many die everyday bc theyre malnoursihed

r 500 million children

33,000 children die every day

what are the forms of Protien energy malnutrition

Marasmus and Kwashiorkor

what is marasmus

• chronic inadequate food intake, a total diet deficiency

• slow chronic form of PEM

• seen in children 6-18 months who live in overpopulated cityies

• Malabsorption occurs because digestive enzymes are in short supply and digestive tract lining deteriorates.

what does a child with marasmus suffers from

1. weight loss, like muscle and fat loss

2. very thin in appearance (one characteristic seen is “matchstick thin” arms

3. Muscles (including heart muscles) weaken

4. brain development is stunted and learning impaired.

5. hair becomes sparse, thin, dry and pulls out easily.

6. skin becomes dry, thin and wrinkled (like an elderly person).

7. n infection of the intestinal tract which causes diarrhea (dysentery) can occur, causing further depletion of nutrients

8. The rate of infections increases and Kwashiorkor often follows because the body is using more protein to try to fight infection.

What is Kwashiorkor result in? seen in how old? name from? how does it work

• results from severe, acute malnutrition with too little protein to support body function

• seen in children 1-3 years of age.

• The name Kwashiorkor is the Ghanaian name for “the evil spirit that infects the first child when the second child is born”

The first baby is weaned from breast milk as soon as the second is born. Therefore, the child loses out on high-quality protein source (breast milk) and are often given watery cereal instead (poor protein source).

Symptoms of Kwashiorkor

1. The hair becomes dry and brittle, easily pulls out, can change colour (because of insufficient tyrosine), and will straighten

2. skin becomes scaly and patchy with lesions that fail to heal.

3. severe wasting of body fat or muscle is not seen, so the child does not look wasted in appearance (DOESNT LOOK MALNOURISHED)

4. Proteins and hormones responsible for maintaining fluid balance are diminished, resulting in edema

5. belly often protrudes because of fatty liver, caused by lack of transport proteins to move fat out of liver

What can high intake of animal protien cause?

1. increased saturated fat intake - Animal protein sources can be high in saturated fat – a known contributor to atherosclerosis and heart disease

2. kidney problems - high-protein diet worsens pre-existing kidney problems and can accelerate the decline in function in kidneys only mildly impaired.

3. bone mineral loss - high protein = low cal and low veg/fruit intake

When u have kdiney problems, whats an effective way to slow progression of disease?

reduce dietary protein

w=what did World Cancer reserach fund reccomend?

we limit our intake of red meat (beef, pork, lamb) to 500 grams per week and avoid processed meats (e.g., ham, bacon, some sausage, etc

Why do vegeterians beocme them LOl

healthy eating, culture, ethics,

What is vegetarian

include plant based foods and eliminate some or all animal-derived foods.

what are vegans

include only foods from plant sources: vegetables, fruit, grains, legumes, nuts and seeds. Also called strict vegetarian

what are lacto-ovo-vegetarians

ncludes dairy products, eggs and all other foods in vegan diet.

what are lacto vegetarians

includes dairy products and all other foods in vegan diet.

what are ovo vegetarians

includes eggs, and all other foods in vegan diet.

partial vvegetarian

includes seafood, poultry, eggs, dairy products, vegetables, fruits, grains, legumes, nuts and seeds. Excludes or strictly limits certain meats, such as red meats.wha

what are pesco vegetarian

same as partial vegetarian, but also eliminates poultry.

what is fruitarian

includes only raw or dried fruits, seeds and nuts in the diet.

what is macrobiotic diet

a vegan diet composed mostly of whole grains, beans/legumes, fermented soy and certain vegetables, with smaller amounts of nuts, seeds and fruit

• combines zen buddhism w vegetarina diet

what does macrobiotic mean in greek ? how does it connect to philosphy? what happens when extreme macrobiotic diets occur

long life or great life

• macrobiotic diet supports the philosophy of balancing foods to attain a balance of yin and yang.

• a person may progressively eliminate foods until only brown rice, herbal teas and water remain.

  • These extreme macrobiotic diets have resulted in malnutrition and even death.

Benefits of vegetarians?

1. weight control

2. heart disease - People who eat plant-based diets die less often from heart disease and related illnesses then people who eat meat.

• ower in saturated fat and cholesterol and higher in fibre

1. BPresure - low bp and low hypertension

2. Cancer - due to higher veg/fruit intake

examples of plant based proteins? and what do they help w

soy - may help to lower LDL cholesterol, triglyceride levels and blood pressure when consumed in place of animal protein.

Pros of omnivorous diet (veggies and meat)

1. optimal growth

2. easier to achieve needs during preg - women who eat meat, milk, eggs can adequately achieve vit B12, D, cal, Fe, Zn, and protein

3. increases resistanct to illness

how come vegans are shorter than omniobore diet

have a difficult time achieving adequate Vitamin B12, iron, zinc, calcium, Vitamin D and may have higher protein requirements that the general population (because protein sources are all from plants).

POORLY PLANNED AUDIO

What can poorly planned vegetarians diets lack in?

Protein, iron, zinc, calcium, vitamin B12, vitamin D, omega-3 fatty acids.

what can poorly planned omnivorous diets lack

Vitamin A, vitamin C, folate and fibre (especially if intake of vegetables and fruit is low).