Carbon<span> Dioxide is the by-product of </span>emissions<span> from our vehicles, heating our homes, using electricity and from other activities in our daily lives (explained more in the 6 steps to go green). It is also the leading greenhouse gas that contributes to climate change.</span>
<span><span><span>Release enzymes outside of the cell (exocytosis)</span>
which may serve the purpose of destroying materials around the cell.</span><span><span>Break-down 'digestion' of materials from inside the cell (autophagy)</span>
i.e. by fusing with vacuoles from inside the cell.
This could include digesting worn-out organelles so that useful chemicals locked-up in their structures can be re-used by the cell.</span><span><span>Break-down 'digestion' of materials from outside the cell (heterophagy)</span>
i.e. by fusing with vacuoles from outside the cell.
This could include breaking-down material taken-in by phagocytes, which include many types of white blood cells - also known as leucocytes. Specific mechanisms of heterophagy can be:<span><span>phagocytic - by which cells engulf extracellular debris, bacteria or other particles - only occurs in certain specialized cells</span><span>pinocytic - by which cells engulf extracellular fluid</span><span>endocytic - by which cells take-up particles such as molecules that have become attached to the outer-surface of the cell membrane.</span></span></span><span><span>Recycle the products of biochemical reactions that have taken place following materials being brought into the cell by endocytosis (general term for this 'recycling' function: biosynthesis) </span>
Different materials (chemicals) are processed in different ways, e.g. some structures may be processed/degraded within lysosomes and others are taken to the surface of the cell.</span><span>Completely break-down cells that have died (autolysis)</span></span>
In general, the functions of lysosomes involve breaking-down i.e. processing to 'make safe' or make use of, or removing from the cell e.g. by exocytosis, useless and potentially harmful materials such as old worn-out parts of the cell or potential threats such bacteria. Lysosomes can therefore be thought of as the rubbish disposal units within cel
Anaerobic exercise is one situation that would cause a buildup of lactic acid in human muscle cells. As the cells switched over from aerobic respiration to fermentation in order to produce ATP, lactic acid would be produced in relatively large quantities as a byproduct. This allows NADH and FADH2 electron carriers to be oxidized without the electron transport chain and would allow Glycolysis to continue.
