1A Biological Molecules Flashcards
Proteins
Polymers made up of the monomers amino acids.
Structural levels of proteins
Primary
Secondary
Tertiary
Quaternary
What is the primary structure determined by?
The order of bases in a gene determine the sequencing of amino acids in a polypeptide chain.
Where do the hydrogen bonds in the secondary structure of a protein form?
Between the negatively charged C=O of the carboxyl group of one amino acid and the positively charged H of the amino group of another amino acid.
Tertiary structure
- the further folding of the secondary structure
- to form a unique 3D shape
- held in place by ionic, hydrogen and disulfide bonds
Where do the bonds in the tertiary structure form?
Between the R groups of different amino acids.
Disulfide bonds only occur between two sulfur atoms in the R group (cystein)
Quaternary structure
A proteins made up of more than one polypeptide chain.
e.g. Hb
What happens if a protein is denatured?
The bonds which hold the tertiary and secondary structure in shape break, and therefore the unique 3D shape is lost.
This 3D shape is critical to a proteins function.
What can cause a protein to denature?
• too high temperature
• changes in pH
ionic - changes in pH
hydrogen - heat, acidity
Prosthetic group
The molecule incorporated in a conjugated protein
Conjugated protein
Protein molecules joined with another molecule called a prosthetic group
Lipoproteins
Conjugated proteins with a lipid prosthetic group
Glycoprotein
Conjugated proteins with a carbohydrate prosthetic group
Proteases
protein-digesting enzymes
Peptide bond
The bond formed by condensation reactions between amino acids
Compare the energy storage capabilities of lipids and carbohydrates
Lipids (especially triglycerides) can store about 3x as much energy as the same mass of carbohydrates
What type of protein is collagen?
Fibrous protein
Where in the human body is collagen found?
• skin
• matrix of bones
• tendons
In what body structures is keratin found?
Hair
Nails
anion
a negative ion
cation
a positive ion
ionic bonds
bonds formed when atoms give or receive electrons; they result in charged particles called ions
covalent bond
bonds formed when atoms share electrons; covalent molecules may be polar if the electrons are not shared equally
dipole
the separation of charge in a molecule when the electrons in covalent bonds are not evenly shared
polar molecule
a molecule containing a dipole
dissociation
splitting of a molecule into smaller molecules, atoms, or ions, especially by a reversible process
hydrogen bonds
weak electrostatic intermolecular bonds formed between polar molecules containing at least one hydrogen atom
monomer
a small molecule that is a single unit of a larger molecule called a polymer
polymer
a long-chain molecule made up of many smaller, repeating monomer units joined together by chemical bonds
macromolecule
a very large molecule often formed by polymerisation