A1 Flashcards
how is water essential for life?(8)
- metabolism
- nutrition
- growth
- reproduction
- movement
- response to stimuli
- excretion
- homostasis
molecules
two atoms joined by covalent bonds (shared electrons)
polarity?
when the atoms in a molecule have both positive and negative charges
is water polar ?
yes
which atom is postive and wich is negative in water?
- oxygen negative
- hyrodgen positive
what bond forms between the atoms in a molecule?
intra molecular (in water its a covalent)
hyrogen bond
bonds between water molecules- the postive H and negative O
what happens between water modecules when they Cuddle
cohesion
what type of substance does water ahere to
hydrophillic
what does waters polarity make it?
- solvent
hyrophillic
attarcted to water
hydrophobic
not attracted to water
are hydrophobic molecules soluable in water? why?
no because they are none polar so theres nothing to attarct to the water
DNA are ____ made up of ______
- polymers
- nucleotides
each nucleotide is made up of what 3 parts ?
- phosphate group
- pentose sugar
- nitrogenous base
bases in dna
- adenine
- guanine
- cytocine
- thymine
bases in rna
- adenine
- guanine
- cytocine
- uracil
what is the backbone of DNA
strands of nucleotides joined together by carbon bonds on CARBON 3
how do these covalent bonds form in the strands?
condensation of the H on the phosphate group and the OH from the pentose sugar. this leaves a covalent bond and a production of water.
when the antiparallel spiral of DNA forms, what bonds form between bases?
hydorgen bonds
adenine and
thymine
adenine and (rna)
uracil
guanine
cytocine
when labelling the structure of DNA the one holding the base is carbon 1 and then u label left to right. what two ends to we have
5 - 3
3 - 5
3 differences DNA and RNA
- pentose sugar;
dna is deoxyribose
rna is ribose - bases
dna is thymine
rna is uracil - rna is usually one stand
dna is 2
what do triplets code for in DNA
Amino acids
the coding for similar ammino acids such gives evidence for what?
a common ansestor
what is the importance of these 64 codes
it is the conservation of the genetic code
how does condensation work
removing an OH from one molecule,and an O from anouther allowing a coavlent bond to form and release of water
