Lecture 3.0: Macromolecules 1 Flashcards
What are the two theories for the origin of life?
1) Molecules of life came from extraterrestrial sources
2) Molecules of life resulted from chemical evolution on Earth
What evidence supports the theory of extraterrestrial sources for the origin of life?
The composition of meteorites suggests that some of life’s complex molecules could have come from space.
What evidence supports the theory of chemical evolution?
Conditions on the primitive Earth led to the formation of large molecules unique to life.
What are the four major types of biological macromolecules?
1) Proteins
2) Carbohydrates
3) Lipids
4) Nucleic acids
What are macromolecules?
Giant polymers made from smaller units called monomers
What type of reaction links monomers to form macromolecules?
Condensation (or dehydration) reaction.
What is the reverse reaction of polymer formation called?
Hydrolysis reaction
What are proteins composed of?
Polymers of amino acids
How does the amino acid sequence influence protein function?
Tells the protein how to fold.
What are the four groups attached to a central carbon atom in an amino acid?
1) Amino group
2) Carboxyl group
3) Hydrogen atom
4) R group
How are amino acids classified based on their R groups?
-5 have Charged hydrophilic side chains
-5 have Uncharged hydrophilic (polar) side chains
-7 have Hydrophobic (nonpolar) side chains
What is a peptide linkage?
The bond formed between the amino group of one amino acid and the carboxyl group of another
What is a polypetide?
A molecule consisting of two or more amino acids. Also another name for proteins.
What are the four levels of protein structure?
1) Primary
2) Secondary
3) Tertiary
4) Quaternary
What defines a protein’s primary structure?
The precise sequence of amino acids.
What are the two common secondary structures in proteins?
- Alpha-helix
- Beta-pleated sheet
What is the tertiary structure of a protein?
The specific three-dimensional shape resulting from bending and folding.
What is quaternary structure in proteins?
The arrangement of multiple polypeptide subunits.
What is denaturation in proteins?
The loss of a protein’s normal 3D structure and function.
What role do chaperonins play in protein folding?
They help keep other proteins from interacting inappropriately and assist in proper folding. Can also reassemble denatured proteins. Some are irreversible, ex: fried egg, or protein in brain of Alzheimer’s patient.
When can we consider something to be alive?
If it has at least one cell.
Which macromolecule makes up more than 50% of all organisms?
Protein
What is an advantage of the biochemical unity that is macromolecules?
Organisms acquire needed biochemicals by eating other organisms.
What are the bonds that connect amino acids in proteins called?
Peptide bonds
What is another word for the condensation of proteins?
Polarization
What is another word for the Hydrolysis of proteins?
Depolarization
What is the characteristic of theCysteine amino group?
Has a termnanal disulfide (—S—S—).
What is the characteristic of the Glycine amino group?
Has a hydrogen atom as the R group.
What is the characteristic of the Proline amino group?
Has a modified amino group that forms a covalent bond with the R group, forming a ring.
What are the R groups that interacts with the primary determinant of the tertiary structure?
-Disulfide bonds
-Aggregation of hydrophobic side chains
-van der Waals forces
-Ionic bonds
-Hydrogen bonds
