Ch 6: Protein Flashcards
Products of Protein
Muscles, bones, hormones, neurotransmitters
Process of communication between cells by biological messengers to govern cellular function
Cell Signaling
Chemical structures containing only carbon, hydrogen, oxygen, and/or nitrogen.
Organic Molecule
The organic building blocks of proteins containing both a carboxyl and an amino group.
Amino acids
Second-most abundant molecule in fat-free bodily tissues (water being the most abundant)
Protein
How many Amino Acids are there?
20
Five components of Amino Acids
- Central Carbon
- Carboxyl Group (Organic Acid -COOH)
- Hydrogen
- Amino Group (NH2)
- Side Group (R Group)
What makes an Amino Acid unique
Its Side Group
Types of Amino Acids
Essential, Conditionally Essential and Nonessential
Type of Amino Acid that must be consumed in the diet because they are necessary for bodily function and cannot be synthesized by the body
Essential Amino Acids
There are 9 including 3 Branched
Considered nonessential under normal circumstances and can be synthesized in the body; however, under certain physiological conditions, requirements can outweigh their availability or rate of synthesis, making them essential for some individuals
Conditionally Essential Amino Acids
There are 6
Instances for Conditional Amino Acids
Infancy, Injury, Disease or Trauma
Amino Acids Synthesized by the body
Nonessential Amino Acids
There are 5
The Essential Amino Acids
PVT TIM HALL
P - Phenylalanine
V - Valine
T - Threonine
T - Tryptophan
I - Isoleucine
M - Methionine
H - Histidine
A - Arginine*
L - Lysine
L - Leucine
Branched Amino Acids
Isoleucine
Leucine
Valine
Nonessential Amino Acids
Alanine
Asparagine
Aspartic acid
Glutamic acid
Serine
Conditionally Essential Amino Acids
Arginine
Cysteine
Glutamine
Glycine
Proline
Tyrosine
May become acetoacetate (a ketone body) or acetyl-CoA prior to entering the Krebs cycle for the generation of ATP
Ketogenic Amino Acids
Ketogenic Amino Acids
Leucine
Lysine
Amino Acids that have the potential to become glucose for use in energy metabolism
Glucogenic Amino Acids
Glucogenic Amino Acids
Alanine
Asparagine
Aspartic acid
Cysteine
Valine
Glutamic acid
Glutamine
Glycine
Proline
Serine
Arginine
Histidine
Methionine
Ketogenic or Glucogenic Amino Acids
Tyrosine
Isoleucine
Tryptophan
Phenylalanine
Threonine
Products of Protein Synthesis (Process of joining amino acids with peptide bonds to form proteins.)
Collagen, Myosin, Hemoglobin
The joining of two large molecules by removing one hydrogen from one molecule and a hydroxyl group (OH) from another molecule and then binding the two larger molecules together on the newly freed bonds.
Dehydration Synthesis
The bond between two amino acids, occurring between the carboxyl group of one and the amino group of the other.
Peptide Bond
Breakdown of one large molecule into two smaller molecules via the donation of one hydrogen and one hydroxyl group from water to the smaller molecules, respectively.
Hydrolysis
Two Peptides are joined
Three Peptides are joined
Four or more peptides are joined
10 or more peptides joined
- Dipeptide
- Tripeptide
- Oligopeptide
- Polypeptide
Bodily peptides are typically at least how many peptides
50 or more
Three major muscle proteins
Actin , Myosin (Uses ATP to grab Actin) and Titin (Elasticity)
Process of changing a protein’s shape, but not its primary structure
Denaturation
First step in Protein breakdown
Denaturation (temperature, pH, and enzymes)
Process of Protein breakdown
Chewing releases Gastrin (Hormone that release digestive fluids) from stomach, which causes release of Hydrochloric Acid (HCl) which releases Pepsin (Enzyme that breaks down peptide bonds in a Hydrolysis reaction). The smaller peptide chains move to the Small Intestine
Peptide chains to the Duodenum
Intestinal cells release Secretin (regulator of digestion–reduced pH) and Cholecystokinin (acts on pancreas to release the Proteases Enzymes: Trypsin, Chymotrypsin, Carboxylpeptidase and Elastase
reduce the size to single amino acids and dipeptides, which can then be absorbed from the small intestine into the hepatic portal vein, carrying them to the liver.
Peptidases and aminopeptidases
Amino Acids in the Liver
Amino acids may be used for protein synthesis, broken down into urea (urine waste), converted to carbohydrate or fat (gluconeogenesis or ketogenesis), metabolized for energy, or released into the peripheral blood stream for use throughout the body.
Protein Function
Protein and amino acids are primarily used to create bodily tissues; to form enzymes and cellular transporters, as cell signals; to maintain fluid balance; to buffer acids and bases (pH balance), in the production of hormones and neurotransmitters; and in the immune system.
Bones are made of?
Calcium and Collagen (also skin, tendons, ligaments, and joints)
Collagen composition
glycine, proline, and hydroxyproline
Protein found on the cell membrane that transports sodium and potassium to create an electrochemical gradient across the membrane
Sodium-Potassium Pump
Potassium into the Cell
Sodium out of the cell
Enzyme involved in the metabolism of glucose
Pyruvate dehydrogenase (converts the end product of anaerobic glycolysis, pyruvate, to acetyl-CoA for use in the Krebs cycle within the mitochondria)
Increase in the amino acid leucine
Signal muscle cells to begin synthesizing new proteins when the other necessary amino acids are present
Proteins and pH balance
Proteins and amino acids help regulate the body’s acid–base balance by binding to free hydroxyl groups or hydrogen ions in the blood to help maintain a neutral pH (Hemoglobin) prevents CO2 from forming Carbonic Acid
Peptide Hormones
Human Growth Hormone, Insulin, gastrin and leptin
Daily protein requirement
85 - 95 grams of protein per 2000 calories, 17 - 18% of total calories
Established by the Food and Nutrition Board of the Institute of Medicine, They establish the recommended dietary allowance (RDA) for protein, last revised in 2005
Dietary Reference Intake (DRI)
Dietary Reference Intake (DRI) for protein
46 grams per day for women, 56 grams for men
Based on 0.8 grams of protein per kilogram of body weight per day
Amount of nutrient needed to meet the needs of almost all individuals in an age–sex group.
Recommended Daily Allowance (RDA)
Factors for Daily Protein Requirement
Body size, activity level or sport, and body composition goals of the individual
Total Daily Protein Requirements average person
0.8 - 2.2 grams per kilogram
Quality of the amino acids found in, and the digestibility of, a protein
Protein Quality
A protein that contains sufficient quantities of all essential amino acids.
Complete Protein (animal products and Soy)
Two incomplete proteins that, when consumed together, mimic a complete protein by providing all essential amino acids.
Complementary Protein
Rice Proteins
Rice proteins are poor sources of lysine, but they are rich in cysteine and methionine
Bean Proteins
Beans have enough lysine, but they are poor sources of methionine and cysteine.
Examples of Complementary Proteins
wheat/peanut butter, pasta/peas, and lentils/almonds
Primary factor for increasing muscle protein synthesis to facilitate muscle recovery and growth
Leucine
Leucine is capable of enhancing muscle protein synthesis signaling for a period of about 3 hours after ingestion, and the optimal dose to maximize protein synthesis is 0.05 grams of leucine per kilogram of body weight
Protein timing
Therefore, 24-hour net muscle protein synthesis may be optimal if stimulated with dietary protein (containing leucine) every 3 hours
every meal should contain at least 0.4 grams of protein per kilogram of body weight and at least four meals should be consumed throughout the day
