| State one property of water that makes it useful to animals and plants. | it is a solvent. |
| Substances that are absorbed from the alimentary canal may enter cells and become part of
the cells.
State the storage carbohydrate made from glucose in liver cells. | glycogen |
| State the type of protein used in the immune system that is produced from amino acids by lymphocytes. | antibodies |
| Fat is produced from fatty acids and glycerol by cells in the fatty tissue beneath the skin.
State one function of this layer of fat | thermal insulation ; |
| Amino acids are an example of a type of nutrient transported in the blood.
State two examples of larger molecules found in cells that are made from amino acids. | protein ;
named proteins ;; |
| Fat is a necessary component of the human diet.
State three ways in which the human body uses fat | 1 (for) energy / energy source / respiration ;
2 storage / stored ; (fat or vitamins or energy)
3 insulation / reduce heat loss / maintains temperature / ref to myelin ;
4 protection (against mechanical damage) / cushions organs / shock
absorber ;
5 AVP ;
6 AVP ;e.g. buoyancy
making (some) hormones
making (cell) membranes
provide heat
absorption of vitamins
waterproofing |
| State the name for the structure of a DNA molecule | double helix |
| Describe the structure of a DNA molecule. | double helix;
(strands) contain, bases /A and T and C and G;
A joins with T/C joins with G;
strands /bases, join/ pair up, by crosslinks /hydrogen bonds;
AVP; |
| Explain these results. | iodine solution diffused, into the bag/through the (Visking) tubing ;
iodine molecules small (enough to pass through the membrane) ;
iodine solution stains starch ora ;
no starch diffused, out of the bag/ through the (Visking) tubing ;
starch molecules too large (to pass through the membrane) ;
ref to pore /AW, size ; |
| State three factors that influence the movement of molecules through membranes | temperature ;
(surface) area ;
concentration (gradient)/water potential ;
size/ type, of molecule ;
thickness /distance, across membrane/ permeability (of membrane) ;
pressure ;
(number of) protein, channels / pumps /AW ;
energy / number of mitochondria ; |
| Describe and explain the results shown in Table 3.1. | blue at time 0 indicates no glucose present ;
ensures that no glucose on outer surface of dialysis tubing / in water, as a result of an error ;
green / yellow / red, indicates presence of glucose ;
glucose, diffuses / moves, out of dialysis tubing / into water ;
(movement is) down the concentration gradient / high to low concentration ;
dialysis tubing is permeable to glucose ;
AVP ; |
| The student repeated the investigation with a higher concentration of glucose in the dialysis tubing.
Predict the results that the student would observe. | idea that (Benedict’s solution) changes colour quicker / gives more intense colour / AW ; |
