Amino Acids The Building Blocks of Proteins Flashcards Preview

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Flashcards in Amino Acids The Building Blocks of Proteins Deck (18):
1

Generic Amino Acid

- alpha-amino group bonded to a the alpha carbon
- alpha carbon covalently bonded
- alpha-carboxyl group bonded to alpha carbon
- N termini to C termini

2

In terms of epigenetics

- modify Lys and arg residues
- modifications of histones

3

Hydrophobic (neutral) R groups

- R groups are all hydrocarbons
- interact with each other, lipid surfaces, or other hydrophobic groups (bases in nucleic acids)
- do not react well with H2O

4

Hydrophilic (neutral) R groups

- partial charges

5

Acidic R groups

- have full negative charges

6

Basic R groups

- have full positive charges.

7

Acid and Basic R groups

- have full charges due to polar covalent bonds resulting in unequal sharing.

8

The distinction between hydrophobic and hydrophilic

- is not sharp.
- there is complete gradation between very hydrophobic and very hydrophilic.

9

hydropathy

- help predict structure of proteins using gradation

10

Aromatic Amino Acids

- 6 membered ring
- absorb near UV light
- conjugated, alternating double bonds.
- Phenylalanine, Tyrosine, Tryptophan

11

The aliphatic amino acids

- not aromatic.

12

Cysteine cross-linking proteins in reduced form

- The sulfhydryl groups are separate on each backbone

13

Cysteine cross-linking proteins in oxidized form

- involved in cross linking proteins
- crosslinks two separate proteins or different regions of the same protein.
- H2O is released
- stabilizes the 3D structure of proteins

14

Modification of amino acids with R groups that contain hydroxyl groups

- commonly modified by phosphorylation
- in post translational modification (after being incorporated into proteins)
- gives it a full negative charge
- how cells change the properties of proteins
- H2O is released.

15

Lysine post-translational modification

- acetylation
- methylation
- on epsilon amino group

16

Acetylation

- addition of an acetyl group on epsilon amino group
- charge lost

17

methylation

- addition of methyl group on epsilon amino group
- charge not lost.

18

Peptide bond

- link from N to C terminus
- water as a product
- between two amino acids