Nucleic Acids, Derivatives, Ions and Water Flashcards
Describe Semi-Conservative Replication
Dna Helicase unwinds and Unzips Breaking H bonds
Strands Separate and expose each strand to act as a template.
Complementary Base pairing (state base -> base)
Dna polymerase condensation reaction phosphodiester bonds.
Each new DNA molecule contains one original and one new strand.
Can you evaluate the work of scientists in validating the Watson-Crick model of DNA replication?
Each strand acts as a template
1 DNA molecule is composed of one new and one original strand.
Meselson and Stahl Experiment:
N15 bacteria placed on normal agar
1N14 1N15 1st gen
1 Completely N14 1 mixed 2nd gen
Increasing conc of N14 strands and same N15 strands present.
Can you describe how a single molecule of adenosine
triphosphate (ATP) is a nucleotide derivative?
Pentose sugar
Nitrogenous Base
Phosphates
What three ways is ATP resynthesised?
Respiration, Photosynthesis, Phosphorylation of ADP+Pi.
Can you explain how ATP is converted to ADP? Include the type of reaction that it is and the enzyme that catalyses it.
ATP to ADP and Pi is catalysed by ATP hydrolase in a hydrolysis reaction adding water.
Can you explain how ATP is resynthesised from ADP? Include the type of reaction that
it is and the enzyme that catalyses it.
ADP and Pi to ATP is catalysed by ATP Synthase in a condensation/phorylsation reaction
What are the roles of ATP
Active Tranport
Muscle Contraction
Protein Synthesis
Secretion
Activation of molecules
Why is ATP suitable for its function?
Releases small controlled bursts of Energy, Little lost as heat.
Releases energy spontaneously.
Phosphorylates other compounds, making them more reactive.
Rapidly resynthesises.
Not lost from cells.
Explain how water Hydrogen bonds.
Separation of weak delta + and delta - charges allows for weak H bonds.
Role of Hydrogen ions and ph
acidity of solutions
H+ ions used in respiration and photosynthesis.
Role of iron ions.
Structural component of Haemoglobin binds to Oxygen.
Role of sodium ions
Co transport of glucose and amino acids.
Nervous conduction.
Role of phosphate ions
Components of DNA, ATP, RNA and phospholipids.
Properties of Water and significance.
Universal solvent- reaction rate faster when aq
High latent heat vapor- evap –> cooling
High c - temp buffer for enzymes
High cohesion - surface tension and transpiration
Metabolite - water required in hydrolysis, photosynthesis and reactions tend to take place aq
Transparent- sunlight through for aquatic plants (food chain)
Not easily compressed - support for hydrostatic skeleton of worms.
What are DNA and RNA and what are their functions?
DNA: polynucleotide double stranded form the instructions for the synthesis of proteins found within organisms.
RNA: mRNA, tRNA, rRNA play a part in protein synthesis
Explain Complementary Base pairing.
Purines: Guanine and Adenine
Pyrimidines: Cytosine and Thymine
Purine to Pyrimidine
Adenine – Thymine/Uracil
Cytosine — Guanine
Compare and contrast components of RNA and DNA.
DNA: Deoxyribose sugar ATCG
RNA: Ribose sugar AUCG
Compare and contrast structure of DNA and RNA.
Both pentose sugars
Both contain phosphate
Both have 4 Nitrogenous Bases
Dna has 2 strands/ rna 1
dna is helical/ rna is linear
dna has thymine/ rna has uracil
dna has deoxyribose/rna has ribose
Structure relates to function of DNA
Sugar-phosphate backbone and double helix - strength, stability, protects info coded in bases.
Long- stores a lot of info
Helix- Compact lot in little space
Base sequence- Codes for AA/Proteins
Double stranded- allows for semi conservative replication each strand acts as a template.
Complementary base pairing- allows for accurate replication
H bonds - strong and stable but easily broken for SCR
Explain how the relative simplicity of DNA led to many scientists doubting it carried the genetic code?
Nucleotides which carry information are only made up of a Phosphate a pentose sugar and a nitrogenous base.
