B2 Flashcards
What is a cell?
The basic building block of a living organism
What is a tissue?
A group of cells with similar structure and function working together. For example, muscular tissue contracts to bring about movement.
What is an organ?
A collection of tissues working together to perform a specific function, For example, the Stomach contains glandular, muscular and epithelial tissues
What is an organ system?
A group of organs working together to perform a specific function. For example, the digestive system contains organs, such as the stomach, the small intestine and the large intestine.
What do enzymes do?
Enzymes catalyse chemical reactions
What is the lock and key theory?
Enzymes are specific, the substrate must fit perfectly into the active site.
What enzyme are proteins broken down by?
Proteases, These are found in the stomach, the pancreas and the small intestine
what does a double pump mean in the heart
-the heart works as a double pump system for two circulatory systems;the pulmonary circulation and systemic circulation.
-blood passes through the heart twice per circuit
What is the effect of temperature on the rate of reaction?
-As we increase the temperature, the activity of enzyme increases
-However, if we pass the optimum temperature, the rate of reaction decreases to zero
How are arteries adapted to their functions?
-Thick muscular walls,this allows them to withstand the very high pressure of blood
-elastic
-thin lumen
How are capillaries adapted to their function?
-Capillaries have very thin walls so the diffusion path is very short
-This allows substances to diffuse rapidly between the blood and body cells
How are veins adapted to their function?
-Veins have a thin wall. The blood pressure is low so does not need to be thick
-Veins contain valves to stop blood flowing backwards
-wider diameter then arteries
-large lumen
What does it mean for an enzyme to denature?
Where the substrate no longer fits perfectly into the active site
This can happen due to too high temperatures
what is a benign tumor
-a tumor contained in one location,usually in cell membrane
-not cancerous and do not invade other parts of the body
-can grow very largely may cause damage to other organs
what is a malignant tumor
-cancerous
-tumor that can be spread via blood
-can invade other tissues
-cells divide more rapidly and have longer lifespan
-disrupts healthy tissue and could lead to death
what is cancer
development of a tumor due to uncontrolled cell division
how does smoking and alcohol affect pregnancy
-carbon monoxide from smoking effects the amount of oxygen the baby gets
-alcohol passes across the placenta and damages the foetus