This document provides an overview of human biochemistry, covering topics like energy metabolism, proteins, carbohydrates, lipids, and micronutrients. It discusses how humans derive energy primarily from the oxidation of fats, carbohydrates, and proteins. Proteins are natural polymers made of amino acids, with essential amino acids that must be obtained through diet. The structure of proteins is described from primary to quaternary levels. Proteins serve important roles in the body such as structural functions, catalysis as enzymes, and transport. Electrophoresis techniques can separate amino acids based on differences in their isoelectric points.

1. Introduction

2.  Energy
 Proteins
 Carbohydrates
 Lipids
 Micronutrients and Macronutrients
 Hormones
 Enzymes (AHL)
 Nucleic Acids (AHL)
 Respiration (AHL)

3.  We derive our energy from the oxidation of
food
 Fats (37 kJ g-1)
 Carbohydrates  CO2 + H2O + energy
 Proteins (17 kJ g-1)
 Males have a RDI of 10500 kJ, females 8000 kJ
 Lipids have a greater ratio of H:O than
carbohydrates (16:1 compared to 2:1)

4.  Use calorimeter

9.  Natural polymers made by amino acids.
 Proteins important to humans are made of
20 α-amino acids (in data booklet)
 Essential amino acids: amino acids our
body cannot synthesize (10)
 Complete protein: a protein made of
essential amino acids, e.g. casein (milk,
eggs, soybeans)
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14. >At isoelectric point
>identical ionizations
>only zwitterion
>H3N+-CHR-COO- form
>no net charge
H++ H2N-CHR-COO-← H3N+-CHR-COO- → H3N+-CHR-COOH + OH-
>At high pH >At low pH
>Extra OH- reacts with H+ >Extra H+ reacts with OH-
>[H+] drops >[OH- ] drops
>Equilibrium shifts to the left >Equilibrium shifts to the
>H2N-CHR-COO- form right
>negative charge >H3N+-CHR-COOH form
>positive charge
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15. >when H+ is added H3N+-CHR-COO- + H+→ H3N+-CHR-COOH +
>equilibrium shifts to right H O
2
>[H+] drops
>pH remains the same
>buffer action
>when OH- is added H2O + H2N-CHR-COO-← OH- + H3N+-CHR-COO
>equilibrium shifts to left
>[OH-] drops
>pH remains the same
>buffer action
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17. Amino Acid
Left Right
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18. Primary structure
>sequence of amino acids
>characteristic of protein function
Secondary structure
>folding of polypeptide chain
>by Hydrogen bonds
α-helix: between atoms of the same chain, e.g. hair,
wool
pleated sheet: between parallel chains, e.g. silk
random coil: no repeating pattern
Tertiary structure
>3D shape of secondary structure
> several types of interaction
Quaternary structure
>3D shape of tertiary structures of different
polypeptide chains
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20. Tertiary structure
Myoglobin
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21. Quaternary structure
Haemoglobin
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24.  Structural (collagen, keratin)
 Catalysts (enzymes)
 Hormones (insulin)
 Antibodies (interferons)
 Transport (haemoglobin)
 Energy (from muscles)
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26. distance traveled by compound
Rf = distance traveled by solvent
Rf is specific for each amino acid
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27. >At isoelectric point (pH of buffer)
>identical ionizations
>only zwitterion
>H3N+-CHR-COO- form
>no net charge
>not affected by electric field
H++ H2N-CHR-COO-← H3N+-CHR-COO- → H3N+-CHR-COOH + OH-
Different amino acids have different isoelectric points
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28. Electrophoresis
(constant pH)
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