Biology Topic 2 Organisation, Temperature, pH, Leaf structure - Coggle…
Biology Topic 2 Organisation
The Human Digestive System
Organ system in which organs work together to digest food.
Enzymes in the digestive system
Enzymes catalyse specific reactions in living organisms.
Enzyme activity is affected by temperature and pH. If its too low or too high the enzyme denatures and won't fit it's active site anymore.
Lock and key Theory
Enzymes catalyse specific reactions because of the shape of their active site.
Digestive enzymes break large insoluble molecules (food) into smaller soluble molecules that can be absorbed in the bloodstream:
Carbohydrase e.g. amylase
Produced in the salivary glands, pancreas and small intestine. Breaks down carbohydrates into simple sugar. e.g. amylase breaks it down starch to glucose.
Made in stomach and pancreas. Breaks down proteins to amino acids.
Made in pancreas. Break down lipids(fats) to glycerol and fatty acids.
Bile NOT AN ENZYME
Made in the liver but stored in the gall bladder. Emulsifies lipids to increase the surface area to increase the rate of lipid break down by the lipases. Neutralises pH for lipase to work.
Benedict's Test. Orange to brick red precipitate.
Iodine test. Turns black.
Biuret reagent. Turns purple or mauve.
- Linked to increase rates of cardiovascular disease and development of Type 2 diabetes.
The result of changes to DNA that results in uncontrollable of growth and division.
Contained in one area of the body.
Invade tissues and spread to different parts of the body to form secondary tumours.
Principles of Organisation
e.g. muscle cells. the basic building blocks of living organisms.
e.g. muscle tissue. A group of cells with a similar structure and function.
e.g. the heart. Aggregations of tissues performing a specific function.
e.g. the circulatory system. Organs working together to form a organ system, which work together to form an organism.
Blood is tissue consisting of plasma which contains white and red blood cells, and platelets.
pale yellow fluid, Transports Carbon dioxide, hormones and waste.
Red blood cells
Carries oxygen. large surface area, full of haemoglobin, no nucleus.
White Blood Cells
Part of the immune system. Some produce antibodies and some engulf pathogens.
Fragments of cells. Clump together to form blood clots.
Lungs and Gas Exchange
Carries air to and from the lungs. Rings of cartilage protect the airway.
Carry air to and from the alveoli. Splits into multiple airways to get to all of the alveoli.
Site of gas exchange in the lungs. Large surface area.
Allow gas exchange in and out of the bloodstream. Oxygen diffuses into the blood and Carbon dioxide diffuses out of the blood.
Carry blood to the heart. Thin walls, large lumen, low pressure, have valves to stop backflow of blood, carry deoxygenated blood.
Carry blood away from the heart. Thick walls, small lumen, high pressure, carry oxygenated blood.
Connects arteries and veins. One cell thick to allow for diffusion, carry blood at a very low pressure.
Structures of the Heart and their Functions
Pumps blood to the lungs where gas exchange takes place.
Pumps blood around the rest of the body.
Pacemaker(in the right atrium)
Controls the natural resting heart rate. Artificial pacemakers can be fitted to fix any irregularities.
Carry oxygenated blood to cardiac muscles.
Prevent the backflow of blood.
Waxy cuticle top layer of leaf. Reduces water loss from leaf. Stomata and guard cells. Guard cells open and close stomata to control water loss and to allow for gas exchange.
Palisade cells. Cells near the top of the surface that is full with chloroplasts that contains chlorophyll. Adaptation maximises photosynthesis.
Air spaces in the leaf between cells. Increased surface area for gas exchange so that carbon dioxide can get in and out of photosynthesizing cells.
Hollow tubes strengthened by lignin adapted for the transportation of water in the transpiration stream.
Cell sap moves from one phloem cell to another through pores in the end cell.
New cells like roots are made here. This includes root hair cells which are adapted with a large surface area for the uptake of water in osmosis and mineral ions in active transport.
The rate at which water is lost from the leaves of a plant. The transpiration stream is a column of water that moves through the roots, stems and leaves. Temperature, humidity, air movement and light intensity all affect transpiration.
A potometer is used to measure the rate of transpiration.
Heart failure can be treated with a transplant or artificial heart
Coronary heart disease
A build up for fatty substances in the coronary arteries. Therefore oxygenated blood can't get to the cardiac muscles. This is treated with
which hold the arteries open. Or it can be treated with
which lower harmful cholesterol.
Faulty heart valves
When valves don't open or close properly. Blood can leak or flow in the wrong direction. A biological transplant can be made or a mechanical transplant.