Lecture 10 Protein Flashcards
Is protein an essential marconutrient?
YES - 10 essential (amino acids) proteins
Protein is an Important Nutrient
(if not the most important)
Protein= of primary importance
Why are proteins so important?
because if we loose 40% of our lean body mass you will die, you need to eat protein to ensure that you will not die and make sure that you maintain muscle
Whats “True Protein”
Nitrogen found only in a protein.
Amino acids linked by peptide bond
Whats “Crude Protein”
All nitrogen compounds in a
feedstuff. Even if the nitrogen isn’t part of a
protein (non protein nitrogen; NPN).
– True + NPN
List non-protein nitrogen:
urea, ammonia, nitrites,
nitrates
Name major animal feeds rich in protein
Sunflower meal
Canola meal
Cotton seed meal
Soybean meal (one we use most for animals)
A cow daily consumes 20kg of dry matter (DM), about 16% of
which is protein. Calculate daily protein intake (kg) of the
cow .
Daily protein intake= 20 x 16/100 = 3.2kg
In poultry what % of their diet is protein?
20-25% of DM
In pigs what % of their diet is protein?
14-20% of DM
In cows what % of their diet is protein?
14-18% of DM
What % of DM in the body is protein?
50% (1/3 is in muscles)
How much does the average human male have in his body of protein?
11kg
-45-50% of this protein is in skeletal muscle
-The rest is in skin, blood, kidney, liver, brain and other organs.
What is protein composted of?
C, H, O, N (S, P)
-Its a component of every body tissue.
-Vary widely in chemical composition ,physical properties, size, shape, solubility and biological function.
Whats the common unit of protein?
Amino Acid
-20 commonly found in animals diets
-10 required in animals diets
In whos body is there an exception to the 50% of DM in the body?
Adipocytes
What is the sequence of amino acids determined by?
The function of the particular protein in the body.
Whats the biological function of protein?
Principal organic chemical constituent of body organs and soft tissues. A lot of functional diversity
What is some of the functional diversity of protein?
– Cell membrane structure and function
– Enzymes
– Hormones and other chemical messengers
– Immune factors (antibodies)
– Fluid balance
– Acid-base balance
– Transport
– Source of energy and glucose
What are digestive enzymes?
Proteins
Proteins are broken down into by enzymes like **,* and ***
1-Amino acids
2-Pepsin
3-Trypepsin
4-Peptidase
Name two structural and mechanical proteins
1- Fibrous Proteins
– Elastin * Tendons
– Collagen * Bone and skin
– Keratin * Hair and nails
2- Motor proteins (contractile proteins)
– Actin and myocin * Make muscles work
What do protein hormones do?
- Chemical messengers that are made in one part of the body but act on cells in other parts of the body
- Examples
– Insulin
– CCK
– Some reproductive
hormones
– Growth Hormone
Are steroid hormones protein hormones?
- Steroid hormones are not
proteins
List examples of protein hormones:
- Examples
– Insulin
– CCK
– Some reproductive
hormones
– Growth Hormone
What are the protein receptors and carriers?
1- Active transport
2- Facilitated diffusion
What are protein receptors, carriers outside the cell?
-Hormone, hormone receptor
What are transport proteins?
They transport substances in the blood:
– Lipoproteins (transport lipids)
– Hemoglobin (transports oxygen and carbon
dioxide)
– Albumin (transports calcium, FFA, Zn)
Whats the immune functions of proteins ?
Antibodies are proteins that attach to and inactive bacteria and viruses that cause infection
What are the last dietary ingredient or tissue to be used for energy?
Proteins
– Efficiency of capturing ATP from AA oxidation is low
– Occurs in starvation and dieting
What are the biological functions and prosperities of proteins?
Need continuous dietary protein
supply because of metabolic turnover,
rates vary widely with biological
activity
What is protein trunover?
The protein in animals is continually being
synthesized and degraded
This is continuous process is called protein turnover
Different organs have different “protein turnover”
rates (% per day)
What’s the % of nitrogen is in protein?
15.5-18.0 % (16%)
What is SGLT1?
A protein
Proteins are *** of amino acids
Polymers
How do protein and carbohydrates differ?
Protein contains nitrogen (about 16% of total weight)
Synthesising muscle and breaking it down-what’s it called
-Metabolic turnover.
When does hypertrophy occur?
muscle synthesis > muscle breakdown
What are the different protein structures:
-Primary (1)
-Secondary(2)
-Tertiary(3)
-Quaternary(4)
What is primary protein structure :
Sequence of amino acids (covalent bonds)
What is secondary protein structure:
Occurs when the sequence of amino acids are linked by hydrogen bonds.
Twisting of chains into coiled structures
-a helix
-b sheet
H bonding
Every amino acid has…
-amino group
-carbolic acid group
Whats the tertiary structure of protein :
Occurs when certain attractions are present between alpha helicase and pleated sheets
Grouping of secondary structures
-Coiled and fold into layers
-H and disulfide bonds
-Globular
Whats the quaternary structure of protein:
A protein consisting of more than 1 amino acid chain
– Several tertiary structures
linked
– Large complex proteins
Primary structures of protein:
- Linear (unbranched) sequence of several (more
than 50) amino acids - The primary structure is held together by peptide bonds
Needs atleast 4-5 ATP to make a peptide bond
Secondary Structure of protein:
– Twisting of the chains (primary structure) into a helix
– The helix is stabilized by H bonds
-Heating in water breaks the hydrogen bonds
Tertiary structure of protein:
– Represents higher level of folding
* Secondary structures fold into layers
* Stabilized by Hydrogen and disulfide bonds
(In life we are consuming proteins in the tertiary structure)
Quaternary structure of Protein:
– Several tertiary structures are linked together to form
quaternary structures
– Large complex proteins
What does every amino acid have a different one of?
Every single amino acids is gonna have a different “R”
whats the difference between a peptide bond and a glyosidic bond
Dipeptide has how many amino acids?
2 amino acids
Tripeptide how many amino acids?
3 amino acids
Oligopeptides how many amino acids
4-10 amino acids
Polypeptide how many amino acids
10 or more amino acids
What are proteins in the body and diet like?
long polypeptide (100’s of amino acids)
Know neutral, basic and acidic amino structures:
Whats the amino acids structures:
- Consist of a central carbon atom bonded to:
a hydrogen, a carboxylic acid, an amino
group, and an additional side group that is
unique to each amino acid - The first amino acid was chemically
described in 1806
What are general prosperities of amino acids:
- 20 - 25 found in common dietary
proteins - In reality, there are hundreds of
amino acids, but ~20 are used
most commonly in protein
synthesis, and form the ‘major
amino acids found in the diet’. - Chemically diverse, but have
common general formula
What are the classifications of amino acids:
-Neutral
-Acidic
-Basic
-Heterocyclic
Name 8 of the 10 essential amino acids:
What 3 amino acids do you need to know the structure of:
-Basic
-Acidic
-Neutral
What is the definition of nonessential amino acids:
also called dispensable amino
acids, are ones the body can create.
* Nonessential amino acids include alanine, asparagines, aspartic
acid, cysteine, glutamic acid, glutamine, glycine, proline,
serine, and tyrosine.
List essential amino acids:
also called indispensable amino acids,
must be supplied by the foods people consume.
* Essential amino acids include histidine, arginine, isoleucine, leucine, lysine,
methionine, phenyalanine, threonine, tryptophan, and valine.
List conditionally essential amino acids:
refer to amino acids that are
normally nonessential but essential under certain conditions
Essential amino acids you NEED TO KNOW
PVT. TIM HALL
Phenylalanine
Valine
Threonine
Tryptophan
Isoleucine
Methionine
Histidine
Arginine
Leucine
Lysine
What are conditionally essential Amino Acids:
- Amino acids that can become essential in certain
physiologic conditions
– Examples: - taurine in cats
- proline in young pigs
- tyrosine becomes essential in people with “phenylketonuria (PKU)”
– PKU; 1 in 15,000 babies
– Hydroxylation of phenylalanine normally forms tyrosine
» Tyrosine important in adrenaline, noradrenaline, thyroxine
and melanin synthesis
A limiting amino acid is always gonna be an …
essential amino acid
Examples of cats:
Cats are unable to convert other amino acids into taurine, unlike other species
Taurine is not a meaningful component of plant protein
Symptoms of Taurine Deficiency in Cats:
*Retinal degeneration.
*Irreversible blindness if retinal degeneration is not addressed.
*Weakening of the muscles of the heart leading dilated cardiomyopathy.
*Death if cardiomyopathy is not addressed.
*Digestive issues.
*Fetal abnormalities.
*Small litter sizes.
*Low birth weights
Limiting AA- def
– Limiting AA is any essential AA present in a
lower amount than needed to support protein
synthesis
What can stop protein synthesis?
– A shortage of just one essential AA will stop
protein synthesis…..no matter if there is an
excess of other essential AA
Example of a limiting amino acids:
Lysine is a limiting amino acid for dairy
cows eating corn (e.g., corn silage and corn grain)
– Corn contains less lysine compared to the
amount required for milk protein production
(Concentration (2%) of lysine in corn is quite lower than the concentration (8%) in casein (milk protein)
List another limiting amino acid:
Methionine is a limiting amino acid for dairy
cows eating soybean (whole seed or meal)
– Soybean contains less methionine compared to the amount required for milk protein production
(Concentration (1%) of methionine in soy protein is lower than the concentration (2%) in casein (milk protein)
Whats the def of High Biological protein: and whats it influenced by?
-Ability of a specific dietary protein to supply amino acids in the relative amounts required for
protein synthesis by body tissues
-Biological value is influenced mainly
by essential amino acid composition
Whats important to know about biological value?
Biological value is not fixed, but varies
with the varying needs of different
species, and physiological and
nutritional states
What is complete proteins?
Foods containing all the essential amino acids
– Examples: fish, meat, eggs, milk, cheese
Whats incomplete proteins?
- Foods that are contain insufficient amounts of some
essential amino acids
– Examples: Legumes, nuts, whole grains
Whats important to know about human nutritional protein?
Doesn’t mean vegetarian meals are less nutritious. Just
means that food stuffs need to be carefully considered
and balanced.
What do high quality proteins contain?
- Contains all the essential amino acids
- Animal foods contain all the essential amino acids.
- Plant foods are diverse in content and tend to be missing
one or more essential amino acids
What do complementary proteins contain?
- Combining plant foods that together contain all the
essential amino acids - Strategy used by vegetarians to avoid amino acid
defeciency
What’s the typical recommendations for adults to consume?
60g of protein a day (0.8g/kg of BW)
