Protein Structure- Function Flashcards
What is the 1. Monomer 2. Polymer 3. Covalent Bond of a protein?
- Amino Acid
- Polypeptide
- Peptide Bonds
What causes the difference properties in amino acids?
R Groups
What does the molecule of an amino acid consist of?
Amino group (N-H2) and Carboxyl group (OH-C=O)
How many different amino acids are there?
20
The composition of an amino acid determines the _____ of a protein.
Structure
What does it mean if an amino acid has a positive charge?
Basic
What does it mean if an amino acid has a negative charge?
Acidic
If a protein is hydrophilic, it is most likely what? (Polar or Nonpolar)
Polar
If a protein is hydrophobic, it is most likely what? (Polar or Nonpolar)
Nonpolar
What does a nonpolar amino acid consist of?
Hydrocarbon chains
What does a polar amino acid consist of?
OH or polar molecule from R group
What is another name for Cysteine (polar molecule)
Sulfidral
Amino acids linked by covalent bonds are called _______ _________.
Peptide bonds
Where does the bond form between amino acids?
The backbone between the amino and carboxyl group
Polypeptides consist of what?
Sequence of amino acids
A function protein consists of ____ polypeptides precisely twisted and folded in to a unique shape.
1+
The specific activities of proteins result from what?
Their 3D architecture
What are the four levels of protein structure? Define each
- Primary- unique sequence of amino acids (polypeptide chain)
- Secondary- coils and folds in the polypeptide chain (consists of H-bonds)
- Tertiary- Determined by interactions among various side chains
- Quaternary- consists of multiple polypeptide chains
What is Transthyretin?
A protein that in serum and CSF that transports the thyroid hormone thyroxine and vitamin A
What is the primary structure of a protein?
Amino acid sequence dictated by covalent bonding through the backbone
What is the secondary structure of a protein? Name the two types
Twists and folds of structure.
- Alpha helix
- Beta pleated sheet
What kind of bonding is found in secondary structures?
H-Bonding
How often are H-bonds in alpha helices?
Every 4th peptide bond
What is the most common type of secondary structure to across membranes?
Alpha Helix
What are the two types of beta sheets?
Parallel ->,->
Anti-parallel ->,
How often are H-bonds in beta sheets?
Typically 3-10 amino acids
How many strands are needed to form a beta sheet?
2 or more
What determines the tertiary structure?
The primary and secondary structures
What does a tertiary structure depend on ?
The R group and how they interact
Which R groups have ionic bonds?
Acidic/basic
What R groups are hydrophobic?
Nonpolar R groups
What is the strongest bond formed between amino acids?
Disulfide Bridge
What is a quaternary structure?
More than one polypeptide subunit
What impacts protein structure? (4)
- Temperature
- Solvent
- pH
- Salt concentration
What is denaturation?
The unraveling of proteins in the tertiary and secondary structures
What is a disease linked to a change in primary structure?
Sickle Cell disease
