Please enable JavaScript.
Coggle requires JavaScript to display documents.
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.
Protease
Made in stomach and pancreas. Breaks down proteins to amino acids.
Lipases
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.
Non-communicable diseases
Food Tests
Sugar (glucose)
Benedict's Test. Orange to brick red precipitate.
Starch
Iodine test. Turns black.
Biuret
Biuret reagent. Turns purple or mauve.
Obesity
- Linked to increase rates of cardiovascular disease and development of Type 2 diabetes.
Cancer
The result of changes to DNA that results in uncontrollable of growth and division.
Benign tumour
Contained in one area of the body.
Malignant Tumour
Invade tissues and spread to different parts of the body to form secondary tumours.
Principles of Organisation
Cells
e.g. muscle cells. the basic building blocks of living organisms.
Tissue
e.g. muscle tissue. A group of cells with a similar structure and function.
Organs
e.g. the heart. Aggregations of tissues performing a specific function.
Organ Systems
e.g. the circulatory system. Organs working together to form a organ system, which work together to form an organism.
Blood
Blood is tissue consisting of plasma which contains white and red blood cells, and platelets.
Plasma
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.
Platelets
Fragments of cells. Clump together to form blood clots.
Lungs and Gas Exchange
Trachea
Carries air to and from the lungs. Rings of cartilage protect the airway.
Bronchioles
Carry air to and from the alveoli. Splits into multiple airways to get to all of the alveoli.
Alveoli
Site of gas exchange in the lungs. Large surface area.
Capillaries
Allow gas exchange in and out of the bloodstream. Oxygen diffuses into the blood and Carbon dioxide diffuses out of the blood.
Heart
Blood Vessels
Veins
Carry blood to the heart. Thin walls, large lumen, low pressure, have valves to stop backflow of blood, carry deoxygenated blood.
Arteries
Carry blood away from the heart. Thick walls, small lumen, high pressure, carry oxygenated blood.
Capillaries
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
Right Ventricle
Pumps blood to the lungs where gas exchange takes place.
Left Ventricle
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.
Coronary Arteries
Carry oxygenated blood to cardiac muscles.
Heart Valves
Prevent the backflow of blood.
IN PLANTS
Plant Tissues
Epidermal Tissues
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 mesophyll
Palisade cells. Cells near the top of the surface that is full with chloroplasts that contains chlorophyll. Adaptation maximises photosynthesis.
Spongy Mesophyll
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.
Xylem
Hollow tubes strengthened by lignin adapted for the transportation of water in the transpiration stream.
Phloem
Cell sap moves from one phloem cell to another through pores in the end cell.
Meristem Tissue
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.
Transpiration
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
stents
which hold the arteries open. Or it can be treated with
statins
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.
Temperature
pH