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
Public domain image from wikipedia
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
α-helix β-sheet
Public domain image from wikipedia
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
Public domain image from wikipedia
Public domain image from wikipedia
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
- Slides: 31