Slides in this set
Homeostasis is the process used by the body to maintain a stable internal environment.
These conditions include water content, ion content, body temperature and blood glucose
The thermoregulatory centre is the part of the brain that monitors and controls body
The pancreas monitors and controls blood glucose concentration. It produces a hormone
called insulin the reduces blood glucose levels. Diabetes is a disease which can be caused
by insufficient insulin.…read more
Removing Waste Products
Waste products must be removed from the body. If they are not, they will increase in
concentration and may interfere with chemical reactions or damage cells. Waste products
that must be removed include carbon dioxide and urea.
Waste product Why is it How is it
carbon dioxide it is a product of through the lungs
aerobic respiration when we breathe
urea it is produced in the the kidneys remove
liver when excess it from the blood
amino acids are and make urine,
broken down which is stored in
Controlling Body Temperature
Enzymes work best at 37° so the body temperature is controlled. A part of the
brain called the thermoregulatory centre monitors and controls body
It collects information as nerve impulses from temperature receptors in the :
·Brain These are sensitive to the temperature of the blood flowing there
·Skin These are sensitive to skin temperature
Sweating is one way that helps the body to cool down. We sweat more in
hot conditions , so more water is lost from the body. The water we lose
must be replaced by food or drink.
Ions such as sodium and chloride are also lost when we sweat, they should
be replaced through food or drink . If the body's ion content is wrong, cells
can be damaged.…read more
The process where water particles move from a dilute solution to a more
concentrated solution through a semi-permeable membrane.
Plants gain water by osmosis through their roots. Water moves into plant cells by
osmosis , making them turgid or stiff so that they are able to hold the plant upright.
Dilute Solution Concentrated Solution
The process by which green plants and some other organisms use sunlight to
synthesize foods from carbon dioxide and water.
The Equation : Light energy
Carbon Dioxide + Water Glucose + Oxygen
Green plants absorb light using chlorophyll in their
leaves. They use it to react carbon dioxide with
water to make a sugar called glucose. The glucose is
used in respiration, or converted into starch and
stored. Oxygen is produced as a by-product.
Temperature, carbon dioxide concentration and
light intensity are factors that can limit the rate of