Unity and diversity: Molecules Flashcards
(22 cards)
DNA
Deoxyribonucleic acid
RNA
Ribonucleic acid
Nitrogenous bases
Adenine (purines- double rings) links with
Thymine (Pyrimidines- single rings)
Cytosine (Pyrimidines- single rings) links with Guanine (purines- double rings)
DNA Condensation reactions
Reaction between a phosphate and a pentose sugar to form a phosphodiester bond and water
5’ end
End with phosphate
3’ end
End with pentose sugar
What is the function of Nucleic acids?
to pass informationinformation between gnerations and to code for protein production
What is the sugarphosphate back bone?
it is the chain of pentose sugars(ribose or deoxyiribose) and phosphate groups that run anti parallel to each other in DNA
Cohesion
The ability of like molecules to stick together
(Water forms hydrogen bonds)
Adhesion
the ability of dissimilar molecules to stick together. Water can do this with polar and charged molecules in/on solid surfaces
Solvent
Water can disslove ions or polar atoms. Slightly charged regions of the water molecule surround atoms of opposing charge
Water(Ice):
Buoyancy
Ice is less dense than water so some ecosystems can survive under ice. Organism also have similar densities to water so that they can float
Viscosity
the ability to flow easily
increases the drag on organisms passing through the water compared to the air
Thermal Conductivity
The rate at which heat passes through it is high
Specific heat
How much heat can something absorb without changing it’s temperature significantly
Latent heat of vaporisation
It makes water a very good coolant as it has a high specific heat capacity
Intermolecular forces
Give an example
Inbetween molecules and break during state changes
Hydrogen bonds
Intramolecular bonds
within the molecule and don’t break during state changes
Intermolecular forces in water and why?
Hydrogen bonds
Oxygen is electronegative so pulls electrons closer to it. This gives the hydrogen atoms partial positivity and the oxygen partial negativity. So hydrogens are attratced to other molecules oxygens and oxygens are attratced to other molecules hydrogens. This causes the water molecule to be dipolar
What effect does having hydrogen bonds have on Water?
It makes water have a high boiling point becuase they they require more energy to be broken
compare DNA and RNA
4 points each
DNA
* Deoxyribose
* Double stranded
* Base pairs Guanine, Cytosine, Adanine and Thymine
* Confined to the nucleus
RNA
* Ribose
* Single stranded
* Base pairs Guanine, Cytosine, Adanine and Uracil
* Can leave nucleus
3 different types of RNA
+ what they do
mRNA - encodes for proteins
tRNA - acts as an adaptor between mRNA and amino acids
rRNA - forms ribosomes
