Lecture 5 - 3-D Structure of Proteins Flashcards Preview

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Flashcards in Lecture 5 - 3-D Structure of Proteins Deck (27):
1

What is responsible for hydrogen bonding within proteins?

-Amino groups (NH3) -Carbonyl groups (COOH)

2

The carbons of an AA that lie on either side of the chiral carbon

alpha-Carbon

3

Alpha-carbons are on same side of the amino acid

Cis

4

Alpha-carbons on opposite side of the amino acid

Trans

5

Bond between Nitrogen and chiral carbon 

phi

A image thumb
6

Bond between chiral carbon and carboxylic acid group

psi

A image thumb
7

Linear arrangement of AA residues

primary structure

8

Coiling and/or pleating of amino acid chain

secondary structure

9

Alpha helices work to stabilize proteins by _____

Hydrogen bonds

10

Number of amino acids per turn in alpha helix

3.6

11

In beta strands, when one AA hydrogen bonds with only one other AA, it is a (parallel/anti-parallel).

Anti-parallel

12

In beta strands, when one AA residue hydrogen bonds to two other AA residues, it is (parallel/anti-parallel)

parallel

13

Specific 3-D configuration of a peptide chain

Tertiary structure

14

Bonding between cystiene residues, works to stabilize proteins by covalent linkage

Di-sulfide bonds

15

The structure of most "structural proteins"

Filamentous (F-proteins)

16

The structure of most enzymes

Globular (G-proteins)

17

Multiple subunit proteins coming together, often after post-translational modification

Quaternary structure

18

How are subunits held together in quaternary structure???

NON-covalent linkages!!!!

19

What is the repeating motif in collagen?

-Gly-X-Y-Gly-X-Y-

20

Why is repeating Gly in collagen important?

Allow for small, tight protein turns; it can be compacted

21

Clinical correlation: what is the mechanism behind "scurvy?"

A defective Proline hydroxylase prevents -OH from being added to Proline, this produces the inability to form collagen, which results in poor wound healing/destroyed connective tissue

22

Breaking of disulfide bonds

protein denaturation

23

What are the steps of protein denaturation?

Increased heat produces most of the denaturation; chemical denaturation breaks di-sulfide bonds

24

What are the three main denaturing agents?

- Urea - Beta-mercaptoethanol - Guanidinium chloride

25

The ____ of a protein is formed by the amino/carbonyl connection, with side chains projecting off.

backbone

26

2* structure bonding

α−helix and β−turn/β−sheets

27

3* structure bonding

-S-S- bonding

H-bonding

metal binding

hydrophobic interaction