topic 1b more biological molecules Flashcards
DNA and RNA are both?
types of nucleic acid, and both carry info
DNA (deoxyribonucleic acid) function?
store genetic info
RNA (ribonucleic acid) function?
transfer genetic info from DNA to ribosomes. Ribosomes read the RNA to make polypeptides (translation)
Nucleotide structure?
phosphate group- pentose sugaer (sugar with 5 carbon atoms) and then a nitrogen base
what are the monomers of DNA and RNA?
nucleotides
polynucleotide structure?
many nucleotides join together. nucleotides join up between the phosphate group of one nucleotide to the sugar of another. bond is called a phosphodiester bond- formed by a condensation reaction
polynucleotide—- whats the chain of phosphates and sugars i known as the?
sugar phosphate backbone
DNA structure?
double helix, polynucleotide 2 strands wind round eachother
DNA nucleotide structure?
phosphate group, pentose sugar (deoxyrobise0 and a base either thymine,guanine, cytosine or adenine.
complementary base pairing?
2 DNA polynucleotide strands join together by hydrogen bonds between the bases.
RNA structure?
ribose sugar instead of deoxyribose . Uracil replaces thymine , 2 nucleotides form a single polynucleotide strand not a double —- differences to DNA
why does DNA replicate?
DNA copies itself before cell division so that each new cell has a full amount of DNA - called semi-conservative replication because half of the strands in each new DNA molecule are from the original DNA molecule
how is DNA replicated?
- DNA helicase breaks hydrogen bonds between 2 polynucleotide strand= helix unwind.
- each original strand acts as a template for a new one, complementary base pairing means free floating DNA are attracted to their exposed bases.
- condensation reaction joins the nucleotide of the new strand together catalysed by the enzyme DNA polymerase- hydrogen bonds form between the bases of the new and original strands
- each new DNA molecule contains one strand from the original DNA and one new strand
why is energy important?
plants and animals need energy for biological processes to occur
Example of how plants and animals use energy?
Plants= active transport- solutes to their leaves- DNA replication, cell division and protein synthesis Animals= active transport, DNA replication, cell division and protein synthesis
ATP stands for?
adenosine triphosphate
Respiration?
release of energy from glucose, cell cant get its energy directly from glucose, so In respiration it is released as ATP.
ATP structure?
nucleotide base (adenine), ribose sugar and 3 phosphate groups. Known as a nucleotide derivative because its a modified form of a nucleotide
Making and using ATP?
when energy needed by a cell, ATP is broken into ADP+P. = hydrolysis reaction, a phosphate bond is broken, the reaction is catalysed by the enzyme ATP hydrolase
how is ATP resynthesized?
condensation reaction between ADP and P - catalysed by enzyme ATP synthase
Structure of water?
H2O.
Why is water a polar molecule?
unshared negative electrons on the oxygen atom give it a slight negative charge , this makes it polar because it has a slight partial negative and positive side on the other.
Hydrogen bonding?
weak bonds between a slightly positively charged hydrogen atom and a slightly negatively charged atom in another molecule.
properties of water?
- important metabolite- hydrolysis and condensation reactions
- good solvent, ions get totally surrounded by water molecules (dissolve)
- high latent heat of vaporisation- water evaporates when hydrogen bonds holding water together are broken, this allows water molecules on the surface to escape as a gas- needs lots of energy to do this
- can resist changes in temp- hydrogen bonds= high specific heat capacity
- very cohesive- cause its polar- they stick together- helps water flow
whats an ion?
atom/ group of atoms with an electrical charge
ion with a positive charge is called?
cation
ion with a negative charge is called an?
anion
whats an inorganic ion?
ion which doesn’t contain carbon.
