nucleic acid

• what makes up a nucleotide?

  diagram

  A) phosphate group

  B) nitrogenous group

  C) pentose sugar

  
• what are the nitrogenous bases?

  Adenine (A)

  Guanine (G)

  Cytosine (C)

  Thymine (T)
• what links the phosphate group of one nucleotide to the pentose sugar?

  condensation reactions
• what is a polymer of nucleotides called? 


  a strand
• what is the difference between DNA and RNA?

  RNA is single-stranded

  RNA has uracil instead of thymine
• what are the types of RNA?

  messenger RNA

  transfer RNA

  ribosomal RNA
• when does hydrogen bonding occur in DNA?


  between the same pairs of bases (known as complementary base pairing)
• Section of DNA

  diagram

  A) hydrogen bond

  B) hydrogen bond

  C) single nucleotide

  D) hydrogen bond

  E) base pair

  F) sugar-phosphate backbone

  
• how many hydrogen bonds form between A and T?

  2
• how many hydrogen bonds form between G and C?

  3
• how much genetic information can DNA hold?

  almost infinite
• template strand 


  one strand of the 'parent' DNA is kept in the 'daughter' molecule
• what does the helicase do in replication

  unwinds the double helix and separates the two strands by breaking hydrogen bonds
• semi-conservative replication

  when half of the original DNA molecule is kept in each of the two new DNA molecules
• why is it important to keep one original DNA strand

  genetic continuity, regular body cell replacement to ensure new cells perform the same jobs as old cells
• what is one issue that could arise if DNA consisted of two parallel sides rather than antiparallel

  no hydrogen bonding between pairs
• what does messenger RNA do

  carry genetic information from DNA to ribosome
• what does transfer RNA do

  carry amino acids to ribosomes
• what does ribosomal RNA do

  facilitates binding of mRNA and tRNA
• what bond do adjacent RNA molecules form after a condensation reaction

  phosphodiester bond
• the formation of an RNA polymer

  diagram

  A) phosphodiester bond

  
• what do each DNA polynucleotide strands have

  3' end and a 5' end
• what does the number 3' and 5' relate to

  which carbon atom on the pentose sugar could be bonded with another nucleotide
• a single DNA polynucleotide strand

  diagram

  A) phosphate

  B) 1

  C) 2

  D) 3

  E) 4

  F) 5

  G) C5

  H) 1

  I) 2

  J) 3

  K) 4

  L) 1

  M) 2

  N) 3

  O) 4

  P) 3'

  Q) pentose sugar

  R) nucleotide

  
• what bond joins the nucleotides in the sugar-phosphate backbone

  covalent bonds
• what bonds join the bases of the two complementary strands

  hydrogen bonds
• what is the name of the strand that will carry the base sequence which is read by enzymes

  coding strand
• why is genetic engineering possible 


  genetic code is universal
• what are conserved sequences 


  coding and non-coding sequences that have remained unchanged in all organisms
• why does complementary pairing allow

  the DNA to be copied is very precisely during DMA replication which ensures that the genetic code is accurately copied and expressed in new cells
• how can DNA storage capacity be measured

  by the number of genes in the DNA
• how else can the storage capacity be measured

  the number of base pairs in the genome