Chapter 3: Protein structure and function Flashcards
These proteins are involved in the response of a cell to a chemical stimulus
receptor proteins
These are responsible for almost everything an organism does and they are structurally diverse and have a wide range of functions as a result
Proteins
What is a prion?
Infectious proteins that can also cause normal proteins to misfold. They can’t be treated and can be acquired through ingestion.
How important is one amino acid in a protein?
If one amino acid is changed in a protein it depends if it will have an effect or not
What is a polymer constructed from amino acids that haven’t been folded called?
Polypeptide
What occurs in the backbone in the secondary protein structure?
Hydrogen bonding
These proteins are responsible for movement
contractile and motor proteins
What are the amino acids with electrically charged side chains?
Aspartate, glutamate, lysine, arginine, histidine
What is the core structure to all amino acids?
Amino group, carboxyl group, C-H, and an R-group
What is the name of a polypeptide that has folded?
Protein
The fourth level of protein structure in which multiple polypeptides come together. It is not found in all proteins
Quaternary
These proteins accelerate chemical rxns necessary to sustain life
enzymatic proteins
What are the beginning and ends of a polypeptide called in the residue numbering system?
N-terminus = beginning
C-terminus = end
How are peptide bonds formed?
Dehydration/condensation reaction
These proteins store amino acids
storage proteins
What do some proteins require to fold properly?
Molecular chaperones
What are amyloid diseases?
A build up of misfolded proteins
These proteins transport substances
transport protein
What types of things can alter protein folding?
Environment. Temperature, pH, etc.
These proteins help with support
structural proteins
Where do peptide bonds form?
Between a carboxyl group and an amino group, thus linking the carbon from the carboxyl to the nitrogen of the amino group
The third level of protein structure in which there are interactions between R groups. Most proteins stop here
Tertiary
These can only occur at certain points in protein folds and can’t just occur anywhere on the polypeptide
Alpha helix and Beta pleated sheets
The second level of protein structure where hydrogen bonds between amino and carbonyl groups in backbone. Forms alpha helicies and beta pleated sheets
secondary
Can a protein function in its primary structure?
No, it’s also technically still a polypeptide as no folding has occurred
What is the bond called that links amino acids together?
Peptide bond
Eight different protein types
Enzymatic, defensive, storage, transport, hormonal, receptor, contractile and motor, and structural
What diseases are associated with misfolded proteins?
Amyloid diseases like Alzheimer’s, Parkinson’s, ALS, Type II Diabetes, and Bovine Spongiform Encephalopathy (Mad cow disease)
These proteins protect against disease
defensive proteins
What are the monomers of proteins?
amino acids
These account for more than 50% of the dry weight of our bodies
Proteins
What determines the primary structure of a polypeptide and why?
The DNA sequence of that gene because DNA has directions for making proteins
What is the sequence of central atoms a polypeptide that hasn’t folded follows?
N-C-C-N-C-C-N-C-C-N…
These proteins help in coordination of an organisms activities
hormonal proteins
What are the two types of folds a polypetide/protein can make that we need to know?
Alpha helix and Beta pleated sheets
Amino acid. Amino group on left side. Carboxyl group on ride side.
In this structure, side chains start interacting with each other
Tertiary structure
The first level of protein structure in which there is a chain of amino acids
primary
What are the amino acids with polar side chains?
Serine, threonine, tyrosine, asparagine, and glutamine
How does sickle-cell anemia form?
In the primary structure of the protien, Glu-6 changes to Val-6. This one change in amino acids causes the difference in red blood cells
What are the amino acids with nonpolar side chains?
Glycine, alanine, valine, leucine, isoleucine, methionine, cysteine, phenylalinine, tryptophan, and proline
What is the longest protein and how long is it?
Titin (connectin) and it is 34350 amino acid residues long
In this structure, two or more polypeptides come together
Quanternary structure
What are the 4 levels of protein structure?
Primary, secondary, tertiary, and quaternary
