河南师范大学：《生物化学》课程PPT教学课件（英文版）Section B Amino acids and protein

B Amino acids and protein Amino acids and collagen structure Protein purification acids and bases Chromatography of ● Protein structure proteins myoglobin an Electrophoresis of proteins hemoglobin Protein sequencing

• Amino acids and structure • acids and bases • Protein structure • myoglobin and hemoglobin • collagen • Protein purification • Chromatography of proteins • Electrophoresis of proteins • Protein sequencing B Amino acids and protein

B1Amino acids Amino acid Stereoisomers(stereo-isomer) x The 20 standard amino acids Ionization

Amino Acid Stereoisomers (stereo-isomer) The 20 standard amino acids Ionization B1 Amino acids

Basic structure of an amino acid side chain R H OH N H H amo group carboxyl group

Basic Structure of an amino acid

TThe two enantiomers COo COO NH3+-C-HH一CNH3 R R L-Amino acid D-Amino acid

COO￾NH3 + C H R COO￾H C NH3 + R L-Amino acid D-Amino acid The two enantiomers

Enantiomers Enantiomers are molecules that have opposite spatial configuration are said to be optically active One enantiomer will rotate polarized light a set number of degrees to the right. This is called the dextrorotatory isomer or(+)isomer. The other enantiomer will rotate the plane polarized ight the same number of set degrees in the opposite left direction. This isomer is said to be a levorotatory isomer or(-)isomer

Enantiomers • Enantiomers are molecules that have opposite spatial configuration are said to be optically active. • One enantiomer will rotate polarized light a set number of degrees to the right. This is called the dextrorotatory isomer or (+) isomer. • The other enantiomer will rotate the plane polarized light the same number of set degrees in the opposite left direction. This isomer is said to be a levorotatory isomer or (-) isomer

The two enantiomers D-Alanine L-Alanine c○oH COOH Mirror CH3 CH3 NH2 NH H

The two enantiomers

TThe 20 standard amino acids >Hydrophobic aliphatic amino acids >Hydrophobic aromatic amino acids >Polar charged amino acids >Polar uncharged amino acids

The 20 standard amino acids ➢Hydrophobic aliphatic amino acids ➢Hydrophobic aromatic amino acids ➢Polar charged amino acids ➢Polar uncharged amino acids

Hydrophobic aliphatic amino acids H2N—C—coOH H glycine Gy:甘氨酸

Hydrophobic aliphatic amino acids Gly :甘氨酸 H H2N COOH H C glycine

Hydrophobic aliphatic amino acids CH3 HN一C—coOH alanine Aa:丙氨酸

Hydrophobic aliphatic amino acids Ala:丙氨酸 CH3 H2N COOH H C alanine

Hydrophobic aliphatic amino acids H3CC二CH3 HaN COOH valine va:缬氨酸

Hydrophobic aliphatic amino acids Val:缬氨酸 H H3C C CH3 H2N C COOH H valine