chem / food.texon commit [methods] piecewise funciton definition on CAS (aa95ebe)
   1\documentclass[a4paper]{article}
   2\usepackage[a4paper,margin=2cm]{geometry}
   3\usepackage{multicol}
   4\usepackage{amsmath}
   5\usepackage{amssymb}
   6\usepackage{tcolorbox}
   7\usepackage{fancyhdr}
   8\usepackage{carbohydrates}
   9\usepackage{tabularx}
  10\usepackage{mhchem}
  11
  12\pagestyle{fancy}
  13\fancyhead[LO,LE]{Food Chemistry}
  14\fancyhead[CO,CE]{Andrew Lorimer}
  15
  16\setlength\parindent{0pt}
  17
  18\begin{document}
  19
  20  \title{Food chemistry}
  21  \author{Andrew Lorimer}
  22  \date{}
  23  \maketitle
  24
  25  \section{Vitamins}
  26
  27  \subsection*{Fat-soluble vitamins}
  28
  29  \begin{itemize}
  30    \item Carbon and hydrogen
  31    \item Non-polar (few or no polar groups)
  32    \item Soluble in other non-polar solvents e.g. fats, oils
  33    \item Can be synthesised endogenously
  34  \end{itemize}
  35
  36  \subsection*{Water-soluble vitamins}
  37  
  38  \begin{itemize}
  39    \item Absorbed directly into bloodstream
  40    \item Catalyse cellular reactions
  41    \item Excreted through kidneys in urine
  42    \item Must be obtained from food
  43  \end{itemize}
  44
  45  \section{Proteins}
  46
  47  \begin{itemize}
  48    \item All proteins contain C, H, O, N
  49    \item Plants make proteins from inorganic compounds, animals cannot
  50    \item Built from monomers called \textbf{amino acids}
  51  \end{itemize}
  52
  53  \subsection*{Aminio acids}
  54
  55  \begin{itemize}
  56    \item Contains amino (\ce{-NH2}) and carboxyl (\ce{-COOH})
  57    \item Most have four groups bonded to central atom
  58    \item May be polar or non-polar (amphoteric), acidic or basic
  59    \item \textbf{Essential amino acids} - cannot be synthesised, must be supplied in diet
  60    \item Amino acids (except glycine) are enantiomers due to chiral centres
  61    \item Must be correct chirality to act as a biological catalyst
  62  \end{itemize}
  63
  64  % amino acid general structure (see Jacaranda p.328)
  65
  66  \chemfig{{\color{red}N}(-[:135,,,,red]{\color{red}H})(-[:225,,,,red]{\color{red}H})-[:-45]C(-[:-90]\color{orange}\textit{R})(-H)-[:45]{\color{blue}C}(=[:90,,,,blue]{\color{blue}O})-[,,,,blue]{\color{blue}OH}}
  67
  68  \subsection*{Zwitterions}
  69
  70  \begin{itemize}
  71    \item Zwitterion = \textit{dipolar ion}
  72    \item Behaves as a base in acidic environments: \ce{-COOH- + H+ -> -COOH}
  73    \item Behaves as an acid in basic environments: ammonium group loses \ce{H+} \(\implies\) anionic form
  74  \end{itemize}
  75
  76  % Zwitterion structural equation (Jacaranda p.330)
  77
  78  \[ \ce{$\underset{\text{acid form}}{\ce{^+H3N-CH2-COOH}}$ <=>[+H+] $\underset{\text{zwitterion form}}{\ce{^+H3N-CH2-COO-}}$ <=>[-H+] $\underset{\text{basic form}}{\ce{H2N-CH2-COO-}}$} \]
  79  \[ \text{cationic} \hspace{12cm} \text{anionic} \]
  80
  81  \subsection*{Formation of proteins}
  82
  83  \[ \text{Amino acid} \rightarrow \text{peptide} \tag{polymerisation} \]
  84
  85  Peptide group (amide): \ce{-C=ONH} (condensation reaction produces \ce{H2O})
  86
  87  Amino acid \textit{residue} - product of peptide formation reaction
  88
  89  Large polypeptides are called \textit{proteins}
  90
  91  \subsection*{Protein structure}
  92
  93  \begin{enumerate}
  94    \item \textbf{Primary structure} - order of amino acids in peptide chain
  95    \item \textbf{Secondary structure} - coils/pleats/folds in polymer
  96    \item \textbf{Tertiary structure} - three-dimensional structure, e.g. H-bonding, ionic bonding
  97    \item \textbf{Quaternary structure} - arrangement of multiple protein molecules
  98  \end{enumerate}
  99
 100  % diagram of structural levels (Jacaranda p.332)
 101
 102  \subsection*{Enzymes}
 103
 104  \begin{itemize}
 105    \item Biological catalysts (lowers \(E_A\))
 106    \item Names usually end in \textit{-ase}
 107    \item Every enzyme has a unique 3D shape
 108    \item Rate of reaction \(\propto\) concentration up to \textit{saturation point}
 109    \item \textbf{Substrate} - reactant molecule
 110    \item \textbf{Active site} - destination of substrate
 111  \end{itemize}
 112
 113  % enzyme catalyst diagram (Jacaranda p.334)
 114
 115  \subsubsection*{Lock and key model}
 116
 117  Reactants and enzymes must have complementary shapes
 118
 119  \subsubsection*{Indicued fit model}
 120
 121  Active site may change to fit subtrate
 122
 123  \subsection*{Coenzymes}
 124
 125  "Helper" molecules to enzymes. Non-protein molecules. Temporarily forms a loose bond with protein molecule to form active enzyme. Coenzymes are not specific to the substrate (different to enzymes).
 126
 127  \section*{Digestion of protein}
 128
 129  Proteins are hydrolysed by the \textit{pepsin} enzyme (\(\implies\) addition of \ce{H2O}).
 130
 131  \begin{description}
 132    \item [Hydrolysis:] breaking of strong covalent (peptide) bonds
 133    \item [Denaturation:] breaking of weak bonds (dispersion, H-bonds)
 134  \end{description}
 135
 136  \section{Carbohydrates}
 137
 138  \subsubsection*{Monosaccharides}
 139
 140  The smallest carbohydrates.
 141
 142  \chemname{\glucose[model=haworth, ring]}{\(\alpha\) glucose \\ \ce{C6H12O6}}
 143  \chemname{\glucose[anomer=beta, model=haworth, ring]}{\(\beta\) glucose \\ \ce{C6H12O6}}
 144  \chemname{\galactose[model=haworth, ring]}{galactose \\ \ce{C6H12O6}}
 145  \chemname{\mannose[model=haworth, ring]}{mannose \\ \ce{C6H12O6}}
 146  \chemname{\xylose[model=haworth, ring]}{xylose\\ \ce{C5H10O5}}
 147  \setchemfig{cram width=2pt}
 148  \chemname{\chemfig{(-[:90]HO)(-[:270]HOCH2)-[:-45](-[:270, 0.5]HO)-(-[:90, 0.5]OH)-[:45]D-[:135]E}}{fructose \\ \ce{C6H12O6}}
 149  
 150\end{document}