Biochemistry: Proteins Flashcards Preview

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Flashcards in Biochemistry: Proteins Deck (19)
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1
Q

charges on functional groups

A

(1) help amino acids stay in solution  interact w/ other amino acids or solutes
(2) affect chemical reactivity

2
Q

peptide bond

A

C – N covalent bond after amino acid condensation

- chain composed of < 50 amino acids linked together

3
Q

peptide bond backbone

A

(1) R-group orientation
(2) directionality
(3) flexibility

4
Q

protein

A

polymers made up of amino acids

- many fcns (depends on size & shape)

5
Q

levels of organization (protein structure)

A

(1) primary structure
(2) secondary structure
(3) tertiary structure
(4) quaternary structure

6
Q

primary structure

A

unique sequence of amino acids in a protein
- limitless primary structures

fundamental to higher levels of protein structure

7
Q

secondary structure

A

distinctively shaped sections of proteins that are stabilized by H-bonding

  • possible structures
  • fcns
8
Q

possible structures of secondary structure

A

(1) α-helix (alpha-helix) – coiled backbone (spiral shape) stabilized by H-bonding
(2) β-pleated sheet (beta-pleated sheet) – segments of peptide chains bend 180˚ & fold into sheet-like shape by H-bonding
* type depends on primary structure

9
Q

secondary structure fcns

A

(1) increase stability of molecule

(2) help define shape

10
Q

tertiary structure

A

overall 3D shape of single polypeptide chain

- result from multiple interactions

11
Q

tertiary structure interactions

A

(1) H-bonding
(2) hydrophobic interactions
(3) van der Waals interactions
(4) covalent bonding
(5) ionic bonding

12
Q

quaternary structure

A

overall 3D shape formed from 2+ polypeptide chains (subunits)
- could be identical subunits or not

13
Q

groups of amino acids based on their side chains

A

(1) nonpolar side chain
(2) polar side chain
(3) uncharged side chain

interactions w/ otro amino acids predictable

14
Q

nonpolar side chain

A

(1) hydrophobic – lack charged or highly electronegative atoms -> no form H-bonds w/ water
(2) no dissolve -> tend to coalesce in aq. solution
(3) lost proton -> acidic
(4) interact w/ water

15
Q

polar side chain

A

(1) hydrophilic – readily dissolve in water
(2) took proton -> basic
(3) interact w/ lipids

16
Q

uncharged side chain

A

(1) highly electronegative oxygen -> polar covalent bond -> uncharged polar
(2) interact w/ lipids

17
Q

prion

A

(proteinaceous infectious particles) proteins that can be folded into infectious, disease-causing agents

(ie) mad cow disease

18
Q

protein folding characteristics

A

(1) mostly spontaneous
(2) some proteins require chaperones
(3) some misfolding

19
Q

protein fcns

A

(1) catalyst
(2) defense - antibiotics
(3) movement - dinein kinesin
(4) signaling - insulin
(5) structure - collagen & microtubules
(6) transport - hemoglobin