Flashcards in Lecture 6 - Protein: Amino Acids Deck (67)
What is a protein?
Large complex molecules composed of amino acids
What do all amino acids have in common?
Unique side group
Where does our body main source of Nitrogen come from?
What are the 2 groups of amino acids?
Essential/indispensable and Nonessential/dispensable
What is an essential amino acid?
One that we have to consume in our diet because our body cant make it or cant make it in high enough quantities that our body needs
What is the process in which Amino acids are formed?
Where are proteins stored?
Our bodies don't have storage for protein
-they are all being used and have some type of function
What is he process in which proteins are made?
An mRNA is made from DNA. mana comes out of the nucleus and ribosomes bind at many different places on the mRNA and tRNA comes and brings the appropriate amino acid that is next in the protein sequence
How many structures are there for proteins?
What is the primary structure of proteins?
Simply the sequence of amino acids
-not a functional protein
What is the secondary structure of proteins?
Twisting/folding in the chain determined by weak electrical attractions within the chain
-provides strength and rigidity
What is tertiary structure of proteins?
Complex structures due to side chain properties
-3D shape either fibrous (structural) or globular (transportation)
What is Quaternary Structure of proteins?
Interaction between polypeptide chains. 2 or more chains being stuck together
What is protein denaturation?
When a proteins stability is disturbed, which causes the protein to lose its shape and function
What are some forms of denaturation?
Acids and Bases
Other damaging substances
Which proteins are dented from which substance?
Every protein will be susceptible to different forms of denaturation in different ranges
Ultimately what does denaturation result in?
An irreversible loss in protein function
-primary structure usually still there
Is there digestion of proteins in the mouth?
What happens to protein digestion in the stomach?
HCl denatures proteins and activates pepsin which is a non specific protease cutting peptide chains into smaller ones
What happens to protein digestion in the small intestine?
Pancreas and cells in the intestines release enzymes to further breakdown the protein
What are the 2 important enzymes that are important for protein digestion in the small intestine?
Tripsin: cleaves peptide chain only at lysine and arginines
-inhibits its own production
Chymotripsin: Also cleaves at certain amino acids
How are proteins absorbed?
Amino acids must be transferred into intestinal cells via specific carriers for amino acids and small peptides
-one carrier for a couple specific amino acids
What are the 2 things that can happen to amino acids after they are in the intestinal cells?
1. Used for energy
2. Used for synthesis of other compounds
When proteins are absorbed and not used where do they go?
Sent to the liver via the blood stream
Why do we need proteins?
Cell growth, repair and maintenance
Why are proteins and fluid balance important?
Proteins attract waster and are found in cells and in plasma. Don't normally cross the cell membranes and therefore fluid accumulates in the tissues
Why are proteins important in acid-base balance?
Low proteins lead the environment to be more acidic or basic which disturbed protein function by altering blood pH.
Why are proteins important in antibodies?
Antigens are destroyed by antibodies. Molecular memory is called immunity. If there is a low intake in protein then you have a weakened immune system
-each antigen has a specific antibody to protect the body from being sick
Why are proteins important in energy?
Proteins can be sacrificed when needed for energy (4kcal/g of protein)
-protein needs to go through deamination, creating ammonia and is excreted through the kidneys