Nucleic Acid Word Stimulants Flashcards
DNA
Double Helix Replicated by parent DNA Thousands of bases Carries genetic info from parents Phosphodiester bond
DNA pairs
Adenine - Thymine
Guanine - Cytosine
1:1 ratio
Thousands of bases
Phosphodiester Bond
Condensation reactions
Phosphate C3 - Sugar C5 of another
DNA location
Mainly Nucleus; some Mitochondria / chloroplast
Nucleotide Structure
Pentose Sugar (deoxyribose/ribose)
Phosphate group
Nitrogen-containing organic group
Complementary Base Pairs
Adenine - Thymine/Uracil
Guanine - Cytosine
Hydrogen bonds (3 GC) (2 AT/U)
RNA
Single Sranded (phsophodiester strand) Transcribed against DNA template
RNA Pairs
Adenine - Uracil
Guanine - Cytosine
No base ratio
RNA Location
Made in nucleus
Found in cytoplasm
tRNA Structure
Transfer RNA
70-90 bases
Clover shaped strand
tRNA Role
Binds to amino acids
Carriers to mRNA/ribose complex
mRNA Structure
Few hundred>thousands of bases
mRNA Role
Genetic material
Nucleus>Ribosome (polypeptide synthesised)
DNA replication location
Nucleus
S phase of Interphase
DNA Replication Steps
DNA double strand ‘unzips’ - h bonds break
DNA helicase
Free nucleotides in nucleus joins to complementary bases on tRNA
DNA polymerase (condensation reaction)
Two new separate strands
DNA Helicase
‘Unzips’ DNA double strand
Breaks hydrogen bonds
Hydrolysis Reactions
DNA polymerase
Joins complementary nucleotides
Condensation Reaction
Semi-Conservative Model
Old strand (parent - genetic continuity) Two new strands (1 new strand, 1 old)
Watson-Crick Model
Isotopes
N14 - light, top of tube
N15 - heavy, bottom of tube
Centrifuged 1st (mixed) & 2nd generation (1 light, 1 mixed)
ATP
Adenosine Triophosphate
ADP
Adenine Diphophate
Inorganic Phophate
Pi
Phosphorylates other compounds - more reactive
Energy
Some heat (ATP>ADP) Light dependent photosynthesis, sugars oxidised by cellular respiration (ADP>ATP)
ATP Structure
Adenine
Ribose
3 Phsophate groups
ATP properties
Soluble in H2O
Universal energy currency
ATP > ADP
ATP + H2O > ADP + Pi + Energy ADP Hydrolase (hyrdolysis) Endothermic
ADP Hydrolase
ATP to ADP
Hydrolysis reaction
ADP > ATP
ADP + Pi + E > ATP + H2O
ATP Synthase (condensation)
Phsophorylation
Exothermic
ATP uses
Energy for biological processes (immediate source) Anabolic processes (Monomers>polymers) Active transport (Glucose blood>Liver) (Na+, K+ axons) Muscle contraction (fibre shortens)
Water structure
H2O Delta negative/positive No net charge lone pairs on O (x2) Hydrogen bond (very strong)
Water Uses
Major component of cells
Solvent properties
Metabolite in many metabollic reactions (condensation/hydrolysis)
Solubilty
In solvents - ions,polar molecules
Insoluble - non polar
Water properties
High surface tension
Large latent heat of vaporisation
High relative heat capacity
High surface tension
Strong cohesion (H bonds)
Support columns of H2O
Transport cells of plants (xylem vessels)
Large Latent Heat of Vaporisation
Energy to evaporate 1 g of H2O
Cooling effect :
Little water lost in evaporation (lots of heat energy to break h bonds)
Carry away heat energy
High Relative Heat Capacity
Higher melting and boiling points than expected
Hydrogen bonds
Buffers changes in temperature
