DLISC1 - EXTRA QUESTIONS Flashcards
(33 cards)
what is the definition of an atom?
smallest amount of unit that retains the prperties of an element
three most abundant elemetns in the earths crust?
1 - oxygen
2 - silicon
3 - aluminium
four most abundant elements in our body?
1 - oxygen
2 - carbon
3 - hydrogen
4 - nitrogen
why is hydrogen bonding important to DNA?
- because it hold the two strands of DNA double helix
- it stabilises the structure of protein and DNA
- critical properties of water
what is the difference between mass and weight?
mass is the quantity of matter in a physical body
weight is the force by which the earth attrracts towards its centre
physical changes vs chemical changes
physiccal is change in a substance usch as solid to liquid, but chemical changes alter the chemcial composition so a new substance is formed
how do DNA store genetic information?
in the form of nucleotide sequences
what is a codon?
it is 3 nucelotdie sequences that codes for a specific amino acid which is building blocks of protein.
Pros of green chemistry
Pros:
* Prevents the generation of pollution
* Reduces the negative impacts of chemical products and processes on human health and the environment
* Lessens and sometimes eliminates hazard from existing products and processes
cons of green chemistry
Cons:
* High implementing costs
* Lack of information
* No known alternative chemical or raw material inputs yet
examples of green chemistry
biodegradable plastics
solar power
green pharmaceutical preparations
lipase is responsible for breaking down?
fats
what bond links monodaccharides in disaccharides and polysaccharides?
glycosidic bond
which class of RNA carries amino acids?
tRNA
which class of RNA carries the code from DNA?
mRNA
which group of elements would you predict should fomr a positively chared ion? provde exmaples for each
metal elements form positive ions
e.g. H, Li, Na, K, Rb, Cs, Fr
non-metal elements form negative ions
e.g. Be, Mg, Ca, Sr, Ba, Ra
which elements would form ionic compunds?
calcium and oxygen
what defines the acidity of solutions?
the concentration of hydrogen ions
what is an exothermic reaction?
reations that release energy (e.g. in the form of light)
what is an endothermic reaction?
reactions that absorb energy (e.g. in the form of light?
what is the difference between endothermic and exothermic reactions?
one makes the surroundings cooler and one warmer
ethanol is soluble in water because…
the hydroxyl group in ethanol participates in hydrogen bonding with water
the carbon 14 isotopes contains:
6 protons, 8 neutrons, 6 electrons
which element is not considered a greenhouse gas?
argon
