CHEMSHEETS BIOCHEMISTRY www chemsheets co uk A 2

CHEMSHEETS BIOCHEMISTRY © www. chemsheets. co. uk A 2 1103 22 -July-2016

AMINO ACIDS amine group carboxylic acid group © www. chemsheets. co. uk A 2 1103 22 -July-2016

AMINO ACIDS From Dept Bio Pemn State

Joining amino acids together to make polypeptides and proteins: Condensation reaction: molecules join and water is eliminated © www. chemsheets. co. uk A 2 1103 22 -July-2016

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Breaking down polypeptides and proteins into amino acids: Needs: acid or enzyme Hydrolysis reaction: reaction with water in which O-H bond breaks © www. chemsheets. co. uk A 2 1103 22 -July-2016

Amino acids be analysed by TLC (can be stained using ninhydrin)

or view results under UV light

solvent front Rf values can identify amino a 5 cm 4 cm For substance R Rf = 3 = 0. 6 5 For substance S Rf = 4 = 0. 8 5 3 cm starting line R S © www. chemsheets. co. uk A 2 1095 17 -Jul-16

PROTEINS Public domain image from wikipedia

Public domain image from wikipedia Helix held in shape by hydrogen bonds

α-helix β-sheet

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1 y structure held by: covalent bonds between amino acids 2 y structure held by: hydrogen bonds 3 y structure held by: hydrogen bonds disulfide bonds ionic attractions (e. g. COO– and NH 3+) etc Public domain image from wikipedia

DNA

DNA phosphate group This is a NUCELOTIDE P 2 -deoxyribose. SUGAR BASE one of 4 bases: • adenine • guanine • cytosine • thymine

DNA P BASE SUGAR DNA is a polymer made of: -sugar-phosphate-sugar-pho P BASE SUGAR

DNA part of a chain 2 -deoxyribose phosphate

DNA adenine bonding site to deoxyribose H bonding site to base partner

DNA thymine bonding site to deoxyribose H bonding site to base partner

DNA guanine bonding site to deoxyribose H bonding site to base partner

DNA cytosine bonding site to deoxyribose H bonding site to base partner

DNA

BASE PAIRS IN DNA hydrogen bonding between base pairs holds DNA strands to thymine cytosine 0 0 guanine adenine

BASE PAIRS IN DNA

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CIS-PLATIN Very effective drug to fight cancer (e. g. testicular) Pt binds to N in guanine in DNA (substitutes for Cl- ligands) Stops DNA replication

ENZYMES • are proteins that act as catalysts in biological systems • they bind to a substrate but are very stereospecific Public domain image from wikipedia

ENZYMES • Drug action – blocks active sites to inhibit enzymes Public domain image from wikipedia