Chapter 5- Proteins Flashcards
What are amino acids?
The building blocks of proteins
How many amino acids are used by the human body?
20
What makes the amino acids differ in shape, size, composition, electrical charge, and pH?
The R group, specific to each individual amino acid
What does every amino acid have as part of their main structure?
Nitrogen and carboxylic acid groups
What are amino acids roles?
Oxidized by for energy (not preferred), incorporated into proteins in the body
How many non essential amino acids are there?
11, can be removed from diet and still made from other amino acids
How many essential amino acids are there?
9
If we don’t consume enough energy…
the body will sacrifice its own protein from enzymes, muscle, and protein in tissues to make glucose for our nervous system and vital organs
All protein gets broken down into what?
amino acids
What is an oligopeptide?
peptide bonds with 4-10 amino acids
What is a polypeptide?
peptide bond with more than 10 amino acids
How do you form a peptide bond?
carboxyl group of one amino acid bonds to the amino group of another
What do enzymes do?
work to speed up chemical reactions
What do hormones do?
serve as chemical messengers
What do antibodies do?
make up our immune system
what do cell transporters do?
allow substances to pass into intracellular space and excrete substances
What does collagen do?
most abundant type, protein serves as major constituent of bones and teeth
How many different carrier for amino acids are there?
6
What happens if you consume too much of 1 amino acid?
it can cause a deficiency in other amino acid that uses the same transport
Where does every single amino acid have to make a stop at first?
the liver
Where is about 90% of the proteins absorbed occur at?
the first 2/3 of the small intestine
How many free amino acids leave the stomach?
about 15 percent
What breaks down protein in the stomach?
hydrochloric acid and pepsin
What releases digestive enzymes for protein into the small intestine?
The pancreas
What are the metabolic fates of protein?
amino acids contribute to the liver and blood amino acid pool
What does an insufficient amount of one amino acid in protein synthesis do?
It may stop or slow the formation of the poly peptide
What happens if a nonessential amino acid is missing in protein synthesis?
The cell can make it or obtain it from the pool
What happens if an essential amino acid is missing for protein synthesis?
the body may break down some of its own protein to supply the amino acid or the synthesis of the protein will halt and be broken down to recycle amino acids
Side effect of athletes who consume little protein
More skeletal muscle protein is catabolized to contribute to amino acid pool
When the body breaks down amino acids to be recycled, what happens?
It leaves us with toxic by-products and unstable nitrogen groups are formed
What is the general recommendation for protein in the diet of average individuals?
.8 g/kg body weight
What is protein quality?
It refers to how well or poorly the protein is used in the body, specifically how well the essential amino acid profile of a protein matches with requirements of the body
What are complete proteins?
They have all of the essential amino acids and have at least 20% of their calories from protein
What is biological value?
a common method of measuring protein quality, how much protein is absorbed by the digestive tract and is retained in the body for growth and maintenance
What are the four primary roles of dietary protein in an athlete’s diet related to performance?
- maximizing gains in muscle mass and strength
- promoting adaptations in metabolic function
- preserving lean mass during rapid weight loss
- structural benefits to other protein-containing non muscle tissues such as tendon and bone
What are Branch Chain Amino Acids?
They have a specific structural shape and provide us with an alternative field source that carbs normally would
What is the daily protein needs for athletes?
An athlete’s needs generally range from 1.2-2 g/kg daily
Should there be protein periodization cycling with season timing?
Yes
What is muscle protein synthesis?
process of taking amino acids, getting them where they need to go, and building new muscle
What factors affect muscle protein synthesis?
Hormones play a role in signaling muscle building and dietary protein interacts with exercise to provide a trigger and substrate for synthesis
How much protein is recommended post workout?
about 15-25 g
Have higher doses of protein >40 g during exercise recovery show further benefits?
No
What are optimal protein sources for athletes?
milk-based protein are superior because they contain leucine and increase muscle strength
What types of foods are best before activity?
low-fat, low-fiber, and low to moderate protein
Vegetarian athletes have an increased risk of
lower bone mineral density and stress fractures
Protein should be eaten…
consistently in small amounts throughout the day
