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}