Biological Molecules Flashcards
Starch structure to function
Insoluble so no effect on water potential so water isn’t drawn in by osmosis
Large and insoluble so doesn’t diffuse out of cells
Compact so a high energy to mass ratio
When hydrolysed it forms a glucose so is easily transported
Branched so many ends for enzymes to simultaneously hydrolyse
What is the branched part of starch
Amylopectin
What are the straight parts of starch
Amylose
Glycogen structure to function
Insoluble so no effect on water potential so water isn’t drawn in by osmosis
Insoluble so doesn’t diffuse out of cells
Compact so high energy to mass ratio
Highly branched so enzymes can hydrolyse simultaneously which is important for animals with a higher metabolic rate
Cellulose structure to function
Made up of b glucose so form long straight unbranched chains
Cellulose chains run parallel linked by hydrogen bonds to increase collective strength
Molecules are grouped to form microfibrills which are grouped to form macrofibrils which increases strength
Structure of triglycerides to function
High ratio of energy storing c-h bonds
Low mass to energy ratio good for storage
Insoluble so no effect on water potential
High ratio of hydrogen to oxygen atoms so when oxidised form water as a source for desert animals
Main roles of lipids
Energy
Waterproofing
Insulation
Protection
Structure of phospholipids to function
Polar- hydrophilic phosphate head and hydrophobic fatty acid tail
So form a bilayer in cell membranes
Form glycolipids important in cell recognition
Steps of cell fractionation
Cold, isotonic buffer solution
Homogenation where it is blended and then filtered
Ultracentrifugation where it is spun slow where heaviest organelle forms first pellet
Then spun faster to get next pellet
Why use cold isotonic buffer solution
Cold- reduce enzyme activity that might break down organelles
Isotonic - same water potential to prevent shrink or bursting
Buffer- maintain ph
Order of pellets in ultracentrifugation
Nuclei
Chloroplast
Mitochondria
Lysosomes
How do reducing sugars react with Benedict’s test
They donate electrons to reduce blue copper sulphate into orange copper oxide
How to calculate ph
-log(moles)
