1 - Biological molecules

-condensation joins two molecules together with a chemical bond and the elimination of a water molecule -hydrolysis breaks a chemical bond between two molecules using a water molecule

-2 molecules with the same chemical formula but different structural formula -alpha and beta glucose alpha has the -OH on the bottom

-starch (alpha glucose) -glycogen (alpha glucose) -cellulose (beta glucose)

-perform Benedict’s test -filter and dry the precipitate -use mass balance to get the mass

-made of 2 polysaccharides (amylose + amylopectin) -amylose has α 1-4 GS bonds and forms a straight chain (can coil into a helix) -amylopectin has frequent α 1-6 GS bonds that make it branch off

-insoluble, so it won’t affect water potential -helical structure, so it is very compact and good for storage -large molecule, so it can’t leave the plant cell

-has long straight chains which are linked together via H-bonds to form fibrils -very strong + can resist osmotic pressure (good for making cell walls) -can resist enzymatic action so it doesn’t get digested

-helical structure, so it is compact -insoluble, so it won’t affect water potentials -branched, higher SA, so enzymes can hydrolyse it faster into a-glucose for it to be used in the mitochondria for AR (good energy store)

double bond between 2 carbons

-can be used to make phospholipids, which are used in cell membranes -can respire fatty acids to release energy, which can be used towards forming new cells and the processes involved (eg protein synthesis)

-high number of carbon-hydrogen bonds compared to the number of carbons, stores lots of energy -insoluble in water, won’t affect water potentials by osmosis -low in mass, won’t affect movement of the organism

-structure is always determined by the relative position of the AAs -primary is their sequencing -secondary due to H-bonds between different peptide bonds -tertiary is 3D structure due to R-group interactions, which is directly linked to function -quaternary formed with multiple PP chains If asked about function, always mention tertiary with specific R-group interactions

-the weakly -ve charged oxygen from C=O is attracted to the weakly +ve charged hydrogen on N-H on different peptide bonds, forming hydrogen bonds -forms α-helixes (H-bond between every 4th) or β-pleated sheets (parallel parts of the same PP chain form H-bonds) Secondary structure only refers to these types of hydrogen bonds

covalent bond formed between 2 cysteine amino acids, found in tertiary structure

-hydrophobic molecules tend to stay near each other to minimise contact with water -this leads to a weak interaction being formed between different non-polar R groups on different amino acids in tertiary structures Like how fat forms globules in water rather than spreading out

-fibrous proteins (eg collagen, keratin) have secondary -globular proteins (eg the 4 subunits that make up haemoglobin) have tertiary Haemoglobin itself is quaternary though

-proteins are found in blood (eg haemoglobin) and are sensitive to changes in pH -it would result in a change in tertiary structure -less oxygen would bind to the haemoglobin Saying “denature” isn’t enough, mention the protein structure

-as [substrate] increases, R increases for both lines -however, using a CI reduces the likelihood of ESCs forming, and reduces R for a given [substrate] -as [substrate] increases for the CI curve, the likelihood that a substrate will collide with the active site compared to the CI increases, and so R increases

-with CIs, the effect of the inhibitor can be overcome by simply increasing [substrate] to increase likelihood of ESCs forming -with NCIs, the active site’s shape is no longer complementary to the substrate, so its effects cannot be overcome, and the rate of reaction has a lower maximum

increasing the substrate concentration does not overcome the inhibition, and does not affect rate of reaction after a certain point

rRNA and proteins

-some regions of the gene are non-coding and act as start/stop codes (eg introns) -may be an addition mutation

DNA may sometimes be single stranded in viruses, so no complementary base pairing is seen

-joins free nucleotides by forming phosphodiester bonds between them -only joins in 5’-3’ direction (has a specific active site shape that is complementary only to the 3’ end, since the shape of the 3’ end and the 5’ end is different)