Topic 1 Flashcards
(45 cards)
Define genome
entire set of DNA/genes in a cell
state and explain the 5 major components of water
metabolite
-required for hydrolysis and released in condensation
solvent
-polar so ions get surrounded by water molecules
high heat capacity
-acts as buffer (due to H bonds between water molecules can ABSORB a lot of energy)
large latent heat of vaporisation
-cooling effect and little loss of water through evaporation
cohesion
-between water molecules produces surface tension
what are the monosaccharides of maltose
glucose + glucose
monosaccharides of sucrose?
glucose + fructose
monosaccharides of lactose?
glucose + galactose
monosaccharides of glycogen?
a-glucose
monosaccharides of starch?
a-glucose
monosaccharides of cellulose?
B-glucose
similarities and differences between triglycerides and phospholipids
similarities: -formed by condensation reactions -1 molecule of glycerol -ester bond -release of 1 water molecule differences: -triglycerides has 3 molecules of fatty acids; phospholipids has 2 molecules of fatty acid and 1 phosphate containing group
how do you test for lipids / oil?
emulsion test:
-{grind seeds}
-dissolve/mix/shake with ethanol
-in test tube
-add water
results - white emulsion/cloudy if lipids presenthow to test for proteins/peptide bonds?
biuret test:
-test tube
-add equal volume of NaOH solution [so its alkaline]
-few drops of dilute copper (II) sulfate solution
positive result: blue to purple
how to test for starch?
iodine / potassium iodide:
-test tube
-add iodine dissolved in potassium iodide solution
positive result: browny-orange to blue-black
describe how you could make a temporary mount of a piece of plant tissue to observe the position of starch grains in the cells when using an optical light microscope
[4]
{6}
- add drop of water to glass slide
- obtain thin section of plant tissue
- place on drop of water
- stain with iodine dissolved in potassium iodide
- lower cover slip at an angle
- using mounted needle
define monomer and give an example
small, basic molecular unit from which large molecules are made
- glucose
- monosaccharide
- amino acid
- nucleotide
define polymer and give examples
molecule made from large number of monomers joined together by polymerisation
- polysaccharide, polynucleotide, polypeptide
- DNA
- starch
- protein
- cellulose
describe how phospholipids are arranged in a plasma membrane
- bilayer
- where hydrophobic tails are to the inside
- hydrophobic head are to outside
give three properties and their functions of triglycerides
large and non polar so INSOLUBLE in water
->storage does not affect water potential of cells
low mass:energy
- > good for storage
- > animals have less mass to move around
high ratio of H-O atoms so triglycerides release water when oxidised
- > provide important source of water
- > organisms adapted to live in dry environments
give 3 properties and its function of phospholipids
polar as phosphate heads are hydrophilic and tails are hydrophobic
->form BILAYER in aqueous
hydrophobic head
->hold at surface of cell membrane
forms glycolipids with carbohydrates
->important on cell surface membrane for cell recognition
how to test for reducing sugars/glucose/monosaccharides/maltose/lactose?
benedict’s reagent: -add benedict’s reagent in excess (to make sure all the sugar reacts) -heat in water bath results: blue [no sugar or non-reducing sugar] green [little] yellow [some] orange [fair amount] red [high concentration of sugar present
NOTE: to compare different concentration of different solutions
- > filter solution
- > weigh precipitate
- > compare weighings
how to test non reducing sugars / sucrose
break down to monosaccharides => benedict’s test: -dilute HCL -water bath -sodium hydrogen carbonate -benedict’s reagent -heat in water bath results: Blue [no sugar] green [little] yellow [some] orange [fair amount] red [high concentration]
Note: to compare different concentrations of different solutions
->filter solutions ->weigh precipitate
define glycosidic bond
- covalent bond
- between 2 adjacent sugars (monosaccharides)
- between C-O and C
- releasing 1 water molecule
- via condensation reaction
define ester bond
- covalent bond
- between glycerol and fatty acid
- between -OH group and -COOH group
- releasing 1 water molecule
- via condensation reaction
define peptide bond
- covalent bond
- between 2 adjacent amino acids
- between C of carboxyl group and N of amino group
- releasing 1 water molecule
- via condensation reaction
note:
dipeptide = 2 amino acids
polypeptide = many amino acids
define saturated
no double or triple bonds
