u1: proteins Flashcards
1
Q
what is a protein
A
macromolecule made up of amino acid monomers
2
Q
amino acid structure
A
- central carbon bonded to carboxyl (COOH), amino group (NH2), R group, and H atom
3
Q
how are proteins defined?
A
by the R group that they possess
4
Q
are amino acids/proteins hydrophillic/hydrophobic? how is it determined?
A
- nonpolar R group = hydrophobic
- polar R group = hydrophillic
- proteins: contain many amino acids and thus amphiphillic
5
Q
peptides + how r they made
A
- polymer of 2 or more amino acids
- formed by dehydration synthesis that forms peptide bond between amino acids
6
Q
how r peptides named?
A
- based on number of amino acids
- dipeptide, tripeptide
- oligopeptides: less than 10 to 15
- polypeptides 15+
- proteins have more than 100
7
Q
amino acids in solution
A
- amino group (NH2) bonds to H
- carboxyl group (COOH) releases an H
8
Q
levels of protein organization
A
- primary structure
- secondary structure
- tertiary structure
- quaternary structure
9
Q
protein primary structure
A
linear sequence of amino acids
10
Q
protein secondary structure
A
- amino acids in primary structure interact via hydrogen bonds
- linear chain coils into alpha helix OR folds into fan shape (beta pleated sheet)
11
Q
protein tertiary structure
A
- 3D structure
- happens when interactions occur between R groups and btwn R groups and water
12
Q
protein quaternary structure
A
when multiple polypeptides interact
13
Q
protein conformation
A
- overall 3D shape is important for protein to function
- proteins can change conformation
- opening/closing cell membrane pores
14
Q
protein denaturation
A
- drastic conformational change that destroys the function of a protein
- occurs w/ extreme heat/pH
- often permanent
15
Q
protein functions
A
- structure
- communication
- membrane transport
- catalysis
16
Q
protein functions: structure
A
- collagen
- keratin (hair, nails, skin)
17
Q
protein functions: communication
A
- some hormones
- cell receptors
18
Q
protein functions: membrane transport
A
- form channels
- carriers (solute across membranes)
19
Q
protein functions: catalysis
A
- enzymes are catalysts
