Biology - Organisation Flashcards
What is a group of organs working together called?
An organ system
True or false? A tissue is only made up of one type of cell?
False. A tissue can be made of more than one type of cell working together.
What is an organ?
A group of different tissues that work together to perform a certain function
Put the following components in order of size from smallest to largest:
Lungs, epithelial cell, respiratory system, epithelial tissue
Epithelial cell, epithelial tissue, lungs, respiratory system
What is the role of the digestive system?
The digestive system breaks down and absorbs food
What is the names of the glands that secrete enzymes to a) the mouth and b) the duodenum (just before the intestines)?
a) salivary gland, b) pancreas
What is an enzyme?
A biological catalyst
What is a substrate?
A chemical an enzyme acts on
What is an active site of an enzyme?
The part of the enzyme that the substrate fits into
What is the ‘lock and key’ model of enzyme action?
The ‘lock and key’ model states that a reaction will only be catalysed if the shape of the substrate fits exactly into the active site
What does denatured mean?
Denatured means the enzyme’s active site has changed shape so it no longer fits the substrate
Give two variables that affect the rate of an enzyme-controlled reaction.
Temperature, pH
Explain why the rate of an enzyme catalysed reaction decreases if the temperature is too low or too high?
If too low, particle collisions are infrequent and there is not enough energy to react. If too high the enzyme gets denatured.
If 45cm3 of product is formed in 100 seconds, what is the rate of reaction in cm3/s?
Rate of reaction = amount of product formed / time = 45/100 = 0.45 cm3/s
Which type of molecule is broken down into amino acids?
Proteins
What are the products of lipid (fat) digestion?
Fatty acids and glycerol
In which organs are proteases produced?
The stomach, pancreas and small intestines
Which organ produces bile and where is bile stored?
Produced in the liver and stored in the gall bladder.
Which enzyme breaks down starch, and where is this enzyme produced in the body?
Amylase. It is produced in the salivary glands, pancreas and small intestine.
What does the body use the products of digestion for?
To build new chemicals like carbohydrates, proteins and lipids, or use some of the glucose for respiration.
Give two functions of bile
To neutralise stomach acid and to emulsify fats
What does emulsify mean?
To break down fat into tiny droplets to increase surface area
What is the chemical test for starch? (Include colour change)
Iodine test: brown to blue/black
What is the chemical test for simple sugars? (Include colour change)
Benedict’s test: blue to red (heating required)
What is the chemical test for proteins? (Include colour change)
Biuret test: blue to purple (careful corrosive)
What is the chemical test for lipids? (Include colour change)
Ethanol test: cloudy white layer (careful flammable)
Where in the lungs does gas exchange take place?
Alveoli
What is the difference between the trachea and the oesophagus?
Inhaled air passes down the trachea to the lungs, food passes down the oesophagus to the stomach.
What are the bronchi?
The first branches off the trachea that pass into each lung.
What are the bronchioles?
The branches off the bronchi in the lungs that lead to the alveoli.
What are the alveoli?
The air sacs in the lungs where gas exchange takes place.
Why do lungs have alveoli?
By having a large number of alveoli, the lungs increase the surface area for gas exchange.
How are alveoli adapted to their function?
Large surface area, thin moist walls, good blood supply. These all increase the rate of diffusion of gases.
Breathing rate = number of breaths / time in minutes, so if I take 200 breaths in 5 minutes, what is my breathing rate?
200/5 = 40 breaths per minute
How is gas exchanged between the blood and the alveoli?
Diffusion across the walls of the capillaries and alveoli
What gases enter the blood and which gases leave the blood at the lungs?
Oxygen diffuses in, Carbon Dioxide diffuses out the blood
Which side of the heart pumps deoxygenated blood to the lungs?
Right (remember, when we look at a diagram the ‘Right side’ is actually on the left)
Name the blood vessel which carries blood into the right atrium of the heart.
Vena Cava
Why does the heart have valves?
To stop blood flowing backwards
Describe the route blood takes through the heart
Body -> Vena Carva -> Right Atrium -> Right Ventrical -> Pulmonary Artery -> Lungs -> Left Atrium -> Left Ventrical -> Aorta -> Body
What vessels supply blood to the heart muscle?
Coronary arteries
What part of the heart maintains a regular heartbeat
The pacemaker
What type of vessel carries blood away from the heart?
Artery
What type of vessel carries blood back to the heart?
Vein
What type of vessel carries blood between cells in tissues?
Capillaries
What is the function of white blood cells?
To defend the body against infection
What is blood plasma?
The liquid that carries everything in blood.
Why are capillary walls one cell thick?
To give a short diffusion distance for chemicals like Oxygen
Rate of blood flow (ml/min) = volume of blood (ml) / time (min). So if 1500 ml of blood flows through an artery in 5 minutes what is the rate of blood flow?
1500 / 5 = 300 ml/min
Why is an artery wall thicker than a vein wall?
Because the artery wall has to withstand high pressure.
How are red blood cells adapted to their function?
- Biconcave (doughnut) shape to increase surface area to absorb Oxygen.
- Haemoglobin to bind to Oxygen.
- No nucleus to give more room to carry Oxygen.
What is a stent? (Treating cardiovascular disease)
A stent is a tube that is inserted inside an artery to keep it open.
What is one disadvantage of using stents? (Treating cardiovascular disease)
Risk of operation complications, infection or blood clotting.
What is coronary heart disease?
When the coronary arteries get blocked by layers of fat, restricting blood flow to the heart muscles.
What are the advantages and disadvantages of an artificial heart over a real donor heart?
Advantages: less likely to get rejected by body.
Disadvantages: blood doesn’t flow through smoothly. Need to take blood thinning drugs. Risk the electrical motor could fail.
That is good or very very good?
Very very very good!
