Outline six structures in an animal cell.

Discuss the relative contributions of the three energy systems for a runner during a 100 m sprint and a 10 000 m race.

Discuss the oxygen debt process which occurs during recovery after a 10 000 m race.

Using sporting examples, distinguish between peripheral and central fatigue.

nucleus:
contains the DNA ✔

has the instructions for the functioning of the cell ✔

cytoplasm:
the matrix or fluid that is inside a cell ✔

allows for chemical reactions to occur as well as transport of various substances/anaerobic glycolysis ✔

cell membrane:
outer wall of the cell ✔

controls the movement of substances in and out of the cell ✔

many cells have 2 membranes ✔

mitochondrion:
involved in the aerobic production of ATP ✔

ribosomes:
involved in protein synthesis (production) ✔

commonly bound to a membrane forming rough endoplasmic reticulum ✔

rough endoplasmic reticulum:
involved in protein synthesis ✔

smooth endoplasmic reticulum:
produces vesicles (sacs) for transporting proteins around the cell ✔

Golgi apparatus:
involved in the processing and packaging of proteins and fats ✔

centriole:
involved in organizing the cell during cell division ✔

lysosome:
involved in the digestion and breakdown of food particles, worn out organelles and bacteria✔

Award [2 max] for a list.

Award marks for a correctly annotated diagram.

both runners will use ATP-PC ✔

100 m sprint will be throughout / to near the end ✔

10 000 m race will be at the start and then at any time when a rapid change in pace occurs ✔

lactic acid will start to be used by the 100 m sprinter near the end ✔

lactic acid will be used at the start of the 10000 m race and then when pace goes above 85/90 % maxHR ✔

aerobic system has a limited/insignificant contribution during the 100 m race
OR
anaerobic system will be the main energy provider for the 100 m race ✔

aerobic system will be the main energy provider for 10000 m race as the runner settles into a pace ✔

Accept a suitably annotated diagram.

at the end of the race, the athlete’s breathing rate <and heart rate> remains elevated
OR
excess post-exercise oxygen consumption occurs during recovery ✔

the greater the intensity of the race the greater the EPOC/oxygen debt ✔

ATP/ PC stores are replenished <in the muscles>✔

myoglobin / hemoglobin are reoxygenated ✔

phosphagen stores and myoglobin stores can be replenished within a few minutes of recovery <alactacid/fast component> ✔

aerobically metabolize lactic acid
OR
resynthesize lactate to glycogen ✔

replacement of muscle / liver glycogen stores ✔

the recycling/removal of lactate and replenishment of glycogen stores may take several hours after exercise <lactacid/slow component> ✔

Accept a suitably annotated diagram.

peripheral fatigue occurs rapidly whereas central fatigue is developed over a prolonged period of exercise ✔

e.g. 100 m sprint vs end of marathon

peripheral can recover more rapidly than central ✔

peripheral is commonly linked to high-intensity activities whereas central is more linked to endurance activities ✔

peripheral can be due to a muscle/muscles contracting repeatedly without resting whereas central refers to impaired function of CNS
OR
peripheral can be due to a depletion in PC stores/accumulation of fatiguing by-products whereas central could be due to overheating, dehydration or lack of glucose stores ✔

peripheral can be seen in the reduced muscular force being generated whereas central may be impaired reactions and decision making ✔

peripheral can be localized whereas central affects whole body ✔

Award [3 max] if no examples given.

Many candidates were able to state at least four structures of an animal cell. However, there were few candidates who were able to outline the structures with suitable depth.

Many candidates demonstrated good knowledge but were unable to apply their responses in full to the question. Candidates needed to consider the duration and intensity of the events and the changes that might occur during the events. In general, candidates were able to refer to the use of ATP-PC by both events and the role of the aerobic system within the 10 000m race and its absence within a 100m race. However, there was little accurate reference to the lactic acid system.

Many candidates understood the question but struggled to provide sufficient points to achieve full marks. Further review of this topic is required.

Poorly answered, many candidates struggled to access marks. Many candidates struggled with the command term 'distinguish' which required candidates to focus on the differences between the two types of fatigue.