UNIT 7 Flashcards
Proteins and Amino Acids
Proteins
compounds composed of carbon, hydrogen, oxygen, and nitrogen and arranged as strands of amino acids. Some of these acids contain sulfur
What are working proteins?
These are the proteins that include the body’s enzymes, antibodies, transport vehicles, some hormones, and oxygen carriers.
What are structural proteins
These are the proteins in tendons and ligaments, scars, the fibres of muscles, the cores of bones and teeth, etc.
Amino acids
Amino = Nitrogen containing
these acids are the building blocks of proteins. each has an amine group at one end, an acid group at the other, and a distinctive side chain
amine group
the nitrogen-containing portion of an amino acid.
side chain
the unique chemical structure attached to the backbone of each amino acid that differentiates one amino acid from another.
Dispensable/ nonessential amino acids
amino acids that the body can synthesize in sufficient amounts to meet its need
indispensable/ essential amino acids
amino acids that either cannot be synthesize at all by the body or cannot be synthesize in amounts sufficient to meet physiological need.
conditionally indispensable/ essential amino acid
an amino acid that is normally nonessential but must be supplied by the diet in special circumstances when the need for it exceeds the body’s ability to produce it.
How does the body’s priority system work when choose which tissue protein to break down in times of emergency?
It starts with the most dispensable tissues first. Examples being the small proteins found in the blood and muscles.
It guards the structural proteins of the heart and other organs until there is no other options available.
How many amino acids can compose a protein?
A maximum of 20
Peptide Bond
a bond that connects one amino acid with another, forming a link in a protein chain.
collagen
a type of body protein from which connective tissues such as tendons, ligaments, scars, and the foundation of bones and teeth are made
enzymes
protein catalysts. A catalyst is a compound that facilitates a chemical reaction without itself being altered in the process.
Hemoglobin
the globular protein of red blood cells, whose iron atoms carry oxygen around the body via the bloodstream
What is meant by “ Inherited Amino Acid Sequences”
For each protein within the body, there exists a standard amino acid sequence that is specified by heredity
If a wrong amino acid is inserted into this standardized chain, there can be disastrous consequences on health
EX: Sickle Cell anemia
Describe the process of coiling and folding of a protein molecule
- A chain is a shape taken by a strand of amino acids
- This chain becomes coiled and spring shaped as their side chains variously attract and repel one another
- Due to this attraction and repulsion, the coil will fold over itself and adopt its functional shape
- At this point a protein may become functional, or may need to join with other proteins, or even add a carbohydrate, vitamin, or mineral to become functional
ex: Hemoglobin must bond with iron to become functional.
Denaturation
The irreversible change in a proteins shape, brought about by heat, acids, bases, alcohol, salts of heavy metals, or other agents.
Generally speaking
How does the body begin to process dietary protein?
The body first alters the protein by breaking it down into its constituent amino acids
The stomachs acid helps to uncoil the protein so that the stomachs protein digesting enzymes can attack the peptide bonds.
Doing this allows to body to rearrange them into specific human body proteins later.
polypeptides
Protein fragments of many (more than 10) amino acids bonded together
oligopeptide
A strand of amino acids that is between 4-10 acids long
dipeptides
protein fragments that are two amino acids long
tripeptides
protein fragments that are three amino acids long
What happens to the polypeptides and amino acids that fragmented off digested proteins as they enter the small intestine?
Enzymes from the pancreas and the intestine split this peptide strands into tripeptides, dipeptides, and amino acids
After this, absorptive cells split them further into their constituent elements. These amino acids are then absorbed into the blood stream.
What are the main organs in protein digestion?
Stomach: Starts the initial breakdown of protein into mostly polypeptides. This breakdown process is denaturation
Small Intestine Alkaline juice from the pancreas neutralizes the acid digesta released by the stomach. Once neutralized, protein digesting enzymes from the pancreas and intestine break down proteins into di and tripeptides, or single amino acids.
Enzymes on the surface of the small intestine split the di and tripeptides for absorption.
Protein turnover
The continuous breakdown and synthesis of body proteins involving the recycling of 300-400g of amino acids each day.