Amino acids, proteins and DNA

• What is an amino acid composed of?

  An amine group and a carboxylic acid group
• Why are amino acids named '2-amino acids'?

  The amine group is on the second carbon
• What are amino acids also known as due to their structure?

  Alpha-amino acids
• What characteristic does the second carbon in amino acids often have?

  It is often chiral
• What do optical isomers refer to in amino acids?

  Amino acids exist as different enantiomers
• What enantiomer do nearly all amino acids exist as in nature?

  A single negative enantiomer
• How do amino acids behave in terms of acids and bases?

  They can react as both acids and bases
• What happens to amino acids in acidic conditions?

  The molecule gains a positive end
• What occurs in basic conditions for amino acids?

  The molecule gains a negative end
• What is the isoelectric point of an amino acid?

  When the overall pH of the molecule is zero
• What technique can be used to identify unknown amino acids?

  Thin-layer chromatography
• What are proteins made of?

  Sequences of amino acids
• What links amino acids together in proteins?

  Peptide links
• What process can reverse the formation of proteins?

  Hydrolysis in 6.0 moldm^-3 HCl
• How do enzymes typically carry out hydrolysis?

  By using enzymes instead of harsh conditions
• What types of bonds hold protein structures together?

  Hydrogen bonds, van der Waals forces, and sulfur-sulfur bonds
• What is the primary structure of proteins?

  A single polypeptide chain of amino acids
• What is the secondary structure of proteins?

  An alpha-helix or beta-pleated sheet

  
• What defines the tertiary structure of proteins?

  Chains folded into a 3D coil
• What is a disulfide bridge in proteins?

  A sulfur-sulfur bond that stabilizes structure

  
• What are enzymes classified as?

  Biological catalysts
• What is the active site of an enzyme?

  Specific to a certain substrate molecule
• What does it mean for enzymes to be stereospecific?

  They can only break down a single enantiomer
• What is DNA short for?

  Deoxyribonucleic acid
• What is DNA classified as?

  A condensation polymer
• What three components make up a nucleotide?

  A sugar, a phosphate, and a base

  
• What sugar is present in DNA nucleotides?

  2-deoxyribose
• What forms the sugar-phosphate backbone of DNA?

  Sugar-phosphate bonds between nucleotides

  
• What are the four possible bases in DNA nucleotides?

  Adenine, Cytosine, Thymine, Guanine

  
• How do bases pair in DNA?

  Through hydrogen bonding

  
• What is the structure of DNA?

  A double helix structure

  
• What are complementary bases in DNA?

  Specific pairs that bond together
• How many hydrogen bonds do Guanine and Cytosine form?

  Three hydrogen bonds

  
• How many hydrogen bonds do Thymine and Adenine form?

  Two hydrogen bonds

  
• What is Cisplatin used for?

  As an anticancer drug
• What is the structure of Cisplatin?

  The cis isomer of a square planar complex
• Why is only the Z-isomer of Cisplatin effective?

  Cells in nature are chiral
• How does Cisplatin bond to DNA?

  By bonding to two adjacent Guanine bases

  
• How does Cisplatin prevent cancer from spreading?

  By preventing mutated DNA from replicating
• What side effects can Cisplatin cause?

  Hair loss and other serious side effects