Proteins I: Structure/Function Flashcards
1
Q
how do proteins vary?
A
- In size, shape, function, structural, enzymes, signaling, channels/pumps
- Single chain
- Multi-chain
2
Q
how do you indicate the sizes of polypeptides?
A
- # of amino acids
- Microns - measurement
- Molecular weight (kilodalton, kDa)
3
Q
how do you indicate the shape of polypeptides?
A
- globular
- fibrous
4
Q
what is the beadle and tatum concept?
A
- 1 gene = 1 enzyme
- Linked DNA to enzymatic activity
- They missed the following
- 1 gene = 1 protein
- 1 gene = 1 polypeptide
- Not all proteins are enzymes
5
Q
what is the monomeric unit of proteins?
A
amino acids
6
Q
What does it mean for an amino acid to have polarity?
A
they have two sides: N and C terminus
7
Q
What are polar charged amino side groups?
A
8
Q
what are polar unchared amino side groups?
A
9
Q
what are nonpolar amino side groups?
A
10
Q
what are the side chains with unique properties?
A
11
Q
what bond do two amino acids form?
A
peptide bond
12
Q
why is a backbone in a polypeptide called that?
A
- The backbone is the same in all polypeptides
- Same can be applied to the phosphate backbone in DNA
13
Q
what are some characteristics of the polypeptide?
A
- The side chains flip
- The backbone is hydrophilic
- A new amino acid is added to the C-terminus
14
Q
what are the levels of organization of a polypeptide?
A
- primary structure: sequence of amino acids
- secondary structure: hydrogen bonding to create alpha helices and beta sheets
- tertiary structure: interactions between R groups
- quaternary structure: interactions between multiple polypeptide subunits
15
Q
How does an alpha helix interact with a plasma membrane?
A
- The alpha helix is amphipathic, so is the membrane
- The alpha helix inverts inward (hydrophilic on the inside, on the outside) to create a channel
