A1 Unity and diversity: Molecules Flashcards
Cohesion
Xylem, surface tension
Adhesion
Capilary action in soil, plant cell walls
Other water properties
Buoyancy, viscosity, thermal conductivity, specific heat capacity
DNA drawing
pentose dugar, phosphates, nitrogenous base, C///G, T//A
Is 3’ or 5’ on phosphate
5’
Hershey-Chase
Radioactive phosphate (RNA) and sulfur (proteins) in viruses to see what gets injected
Four main types of biological molecules found in all living things?
Carbohydrates, proteins, lipids, and nucleic acids.
What’s the monomer of a carbohydrate?
A monosaccharide, like glucose.
What do you call a chain of amino acids?
A polypeptide, which folds into a protein.
What kind of reaction links monomers together?
Condensation reaction – water comes out, bonds go in.
What kind of reaction breaks polymers apart?
Hydrolysis – water goes in, bonds break.
What’s the bond called between two monosaccharides?
A glycosidic bond.
DNA vs RNA
A/U, deoxyribose sugar vs ribose sugar
What role does purine-to-pyrimidine pairing play in the DNA helix’s stability?
Purines (adenine and guanine) always pair with pyrimidines (thymine and cytosine), maintaining uniform width and enabling stable hydrogen bonding in the DNA double helix.
(Too many purines = too wide; too many pyrimidines = too narrow. It’s molecular feng shui.)
What did Chargaff’s data reveal about purine and pyrimidine ratios?
In all organisms, the amount of adenine = thymine and guanine = cytosine, but the overall A+T to G+C ratio varies across species.
(This was the first big hint that base-pairing rules were universal—but with some flair.)
