organisation Flashcards
what are cells used to make?
example: cell -> tissue
cell -> tissue -> organ -> organ system -> organism
how to calculate rate of reaction?
rate of reaction = 1000/time
what are enzymes:
- enzymes are catalysts produced by living things.
- a catalyst is a substance which increases the speed of a reaction, without being changed or used up in the reaction
how do enzymes work?
- each enzyme has an active site with a unique shape that fits onto the substance involved in a reaction
- each substrate then fits with the enzyme (Lock and key)
- the reaction causes the substrate to break down quicker
describe carbohydrases (with an example)
Enzymes called carbohydrases convert carbohydrates into simple sugars.
E.g. amylase is used to break down starch
what do enzymes need?
Enzymes need the right temperature and pH level (optimum levels) otherwise they will denature and not work
describe proteases:
Proteases convert proteins into amino acids.
describe lipases:
Lipases break down lipids (fats) to glycerol and fatty acids.
what are the products of digestion used for?
to build new carbohydrates, lipids and proteins. Some glucose is used in respiration.
what are the digestive organs?
- Salivary glands
- Liver
- Gall bladder
- Stomach
- Pancreas
- Large intestine
- Small intestine
- Rectum
What is the role of the mouth?
Begins the digestion of carbohydrates
What is the role of the stomach?
- Begins the digestion of protein; small molecules such as alcohol absorbed
- Pummels the food with its muscular walls
- Produces the protease enzyme (pepsin)
What is the role of the small intestine - Duodenum?
- Continues the digestion of carbohydrate and protein; begins the digestion of lipids
- Absorbs nutrients
What is the role of the small intestine - Ileum?
- Completes the digestion of carbohydrates and proteins into single sugars and amino acids
- absorption of single sugars, amino acids and fatty acids and glycerol
What is the role of the Large intestine?
- Absorption of excess water
- egestion of undigested food
What is the role of the salivary glands?
Produce amylase enzyme in saliva
What is the role of the liver?
- Bile is produced
- Bile neutralizes stomach acid
- Bile emulsifies fats
What is the role of the gall bladder?
Bile is stored before released into the small intestine
What is the role of the pancreas?
Produces protease, amylase and lipase enzymes
Food test: how to test for sugars and what is a positive result?
Use Benedict’s solution - it changes from blue to red/yellow/green depending on how much sugar is present
Food test: how to test for starch and what is a positive result?
Use Iodine solution - changes from orange to black or blue
Food test - how to test for proteins?
Use Biuret solution - changes from blue to purple
Food test - how to test for lipids?
Use Sudan III - a top layer will form and become bright red
What is the lung structure?
Alveoli, Bronchioles, Bronchi, Trachea
What is the features of the alveoli?
1- Thin lining: the lining of the alveoli is very thin so that gases can quickly diffuse through it.
2- Good blood supply: the alveoli have a dense capillary network so that large volumes of gases can be exchanged.
3- Large surface area: human lungs contain about 500 million alveoli - This speeds up diffusion because gases have more area over which to diffuse.
What is on the left side of the heart?
Aorta, pulmonary vein, left atrium, heart valve, left ventricle
What is on the right side of the heart?
Pulmonary artery, vena cava, right atrium, heart valve, right ventricle
How does the deoxygenated blood reach the lungs?
- the deoxygenated blood enters the heart through the vena cava
- It travels through the right atrium into the right ventricle, the the tricuspid valve
- It leaves through the pulmonary artery to the lungs
How does the oxygenated blood reach the body?
- After the blood is oxygenated, it enters the lungs through the pulmonary vein
- It flows through the left atrium, into the left ventricle
- It leaves the heart through the aorta, ready to circulate the body and heart
Describe the arteries:
Carry oxygenated blood from the heart to the body’s tissues
Describe the veins:
Carry deoxygenated blood from the body back to the heart
Describe the capillaries:
Tiny blood vessels with walls one-cell thick where exchange of materials occurs.
What is the lumen?
The lumen is the hollow opening or the space inside the blood vessel.
What are the key features of the arteries?
- Always carry blood away from the heart
- Carry oxygenated blood, except for the pulmonary artery
- Carry blood under high pressure
- Have thick muscular and elastic walls to pump and accommodate blood
- haws a narrow lumen
What are the key features of the arteries?
- always carry blood to the heart
- Always carry deoxygenated blood, except for the pulmonary vein
- Carry blood under low or negative pressure
- Have thin walls - have less muscular tissue than arteries
- Have less connective tissue than arteries
- Have a wide lumen
How do arteries control blood flow?
In order to control blood flow through the vessels, the smooth muscle surrounding the arteries can constrict which causes vasoconstriction (narrow lumen) or they can relax which causes vasodilation (wide lumen).
What are the key features of the capillaries?
- the walls are one cell thick
- they allow the exchange of molecules between the blood and body cells
- molecules diffuse across their walls
Give an example (up to 4) of exchange of molecules:
1- Oxygen diffuses through the capillary wall, into the tissue fluid, and the cells
2- Carbon dioxide diffuses from the cells into the capillary walls
3- Glucose diffuses from the blood plasma, across the capillary walls and into the cells
4- The waste product urea diffuses from the cells of the liver, across the capillary walls and into blood plasma
What is vein thickening?
A combination of medial and adventitial thickening to withstand higher pressure and blood volume
What are the valves in veins?
One-way valves that prevent backflow and ensure blood flows towards the heart
Why do the arteries have elastic properties?
Stretched and recoiled to regulate blood flow and pressure
What are the red blood cells for?
Carry oxygen, contain hemoglobin, and have a life span of 120 days
what are the white blood cells for?
Fight infection, foreign substances, and have a life span varying by type
what are platelets in the cell?
Platelets are responsible for triggering blood clotting at the sites of wounds. Platelets are small cell fragments that do not have a nucleus
What is the hemoglobin function?
Binds oxygen in lungs, carries it to tissues, and releases it for energy production
What is coronary heart disease?
In coronary heart disease layers of fatty material build up inside the coronary arteries, narrowing them. This reduces the flow of blood through the coronary arteries, resulting in a lack of oxygen for the heart muscle
What are stents used for?
Stents are used to keep the coronary arteries open.
What are statins used for?
Statins are widely used to reduce blood cholesterol levels which slows down the rate of fatty material deposit.
What are the advantages and disadvantages of a heart transplant?
Advantages: Their body can continue functioning, the person stays alive
Disadvantages: the heart may be rejected, have to take drugs for the rest of their life, have an increased risk of infection
What are the consequences of faulty valves?
- Reduced heart efficiency due to blood flowing in the wrong direction.
- Serious complications if left untreated
- Increased workload on the heart, leading to complications
- Valves not opening wide enough or failing to close properly can restrict blood flow and cause fluid buildup in the lungs
describe mechanical and biological valves:
mechanical - man made valves
biological - taken from other humans or mammals (like pigs)
What is the difference between communicable and non-communicable diseases?
communicable - spread person to person or between animals and people. They can be caused by things like bacteria
Non communicable - these cannot be spread between people and can last a long time. For example: cancer and asthma
Can diseases interact and cause other problems?
Yes - sometimes a disease can cause other physical or mental health issues. For example:
- being infected with HPV can cause cervical cancer (in women)
- Depression can be triggered if a person has a physical illness that affects their life expectancy
What other factors can affect your health?
- your diet
- the stress you experience
- your life situation (quality of life)
What are risk factors?
things that are linked to the likelihood of you developing a disease
Give some examples of risk factors linked to non communicable diseases:
1) smoking - damages the walls of arteries and the lining of the lungs
2) Drinking alcohol - damages the nerve cells in the brain
3) Obesity - makes the body less sensitive to insulin
4) Smoking or drinking when pregnant - damages the unborn baby
5) exposure to certain substances or radiation - can cause cancerous cells
6) inheriting faulty genes - this can increase the risk of cancer
What is cancer caused by?
Uncontrolled, rapid cell growth and division which forms tumors.
What are the different types of tumors?
Benign - the tumor grows in one place, and doesn’t invade other cells. They are not normally dangerous or cancerous
Malignant - the tumor grows and spreads to other healthy cells. It can spread throughout the body. These are dangerous and are cancers.
What are the layers of the leaf?
1) upper epidermis - outermost layer, provides protection and prevents water loss
2) palisade mesophyll - photosynthesis
3) spongey mesophyll - Allows gas exchange
4) lower epidermis - reduce water loss
5) guard cells - control water loss and gas exchange
6) stomata - tiny holes that control water loss and gas exchange
Describe the phloem:
Transports sugars and organic compounds, composed of living cells, moves in both directions - carries out translocation
Describe the xylem:
Transports water and minerals, composed of dead cells, only moves upwards - carries out transpiration stream
what is transpiration?
The process by which water is transported from roots to leaves and evaporates into the air
what are the steps of transpiration?
Root absorption, xylem transport, evaporation, and transpiration stream
Factors Affecting Transpiration:
Temperature, humidity, light, stomatal aperture, and other environmental factors
What is Translocation?
The movement of organic compounds from the site of production to other parts of the plant
Steps of Phloem Translocation?
Photosynthesis, loading, transport, and unloading
Factors Affecting Translocation:
Water potential, temperature, humidity, light, and other environmental factors
