Match the following sentences:
1) Substances transported against a concentration gradient, requiring the energy made from respiration
2) The diffusion of molecules through a partially permeable membrane from a place of higher concentration to a place of lower concentration
3)The net movement of particles from an area of higher concentraion to an area of low concentration
Name TWO substances that use active transport
Name the TWO organ systems that are specialised to aid the exchange of materials and their location in the body
- Villi in the small intestine
- Alveoli in the lungs
How are villi adapted to suit their job?
They have a large surface area and an extensive network of capillaries
How are alveoli adapted for their job?
It improves the efficiency of the exchange of oxygen and carbon dioxide.
- The alveoli are very close to the capillaries
- They have a large, moist surface area
- They have an excellent blood supply
How are leaves adapted to improve the rate of photosynthesis?
- They are broad, thin and flat with lots of internal air spaces providing a large surface area
- Stomata on the undersurface
What is the job of stomata?
It allows carbon dioxide in and oxygen out (by diffusion)
What is transpiration?
The loss of water vapour by a plant through the stoma
Name THREE conditions that make transpiration happen faster
- Hot conditions
- Dry conditions
- Windy conditions
What controls the opening and closing of stomata?
What is the difference between oxygenated blood and deoxygenated blood?
Oxygenated blood contains food and oxygen to transport to he body's cells
Deoxygenated blood contains waste products, including carbon dioxide, away from the cells
Name the THREE things that make up the circulation system
- The heart
- Blood vessels
Name the heart vessels and valves and their location
Which type of blood does the right side of the circulatory system carry?
Which type of blood does the left side of the circulatory system carry?
Right: Deoxygenated blood
Left: Oxygenated blood
Name the TWO seperate circulation systems
- One carries blood to the lungs and then back to the heart
- The other carries blood to the rest of the body's organs then back to the heart
Do veins carry blood to or away from the heart?
Do arteries carry blood to or away from the heart?
Veins: To the heart (Visit)
Arteries: Away from the heart (Away)
What are the FOUR components that make up blood?
- Red blood cells
- White blood cells
What is the role of plasma in the blood?
- It transports carbon dioxide from the organs to the lungs
- It transports glucose (soluble products of digestion) from the small intestine to the organs
- It transports other waste (eg. urea) from the liver to the kidneys
What is the role of red blood cells in the blood?
How are they adapted to this role?
They transport oxygen
from the lungs to the organs
- They are adapted as they have no nucleus so they can contain lots of haemoglobin (a red pigment which can carry oxygen)
- In the lungs, haemoglobin combines with oxygen to form oxyhaemoglobin. In the organs oxyhaemoglobin splits up into haemoglobin and oxygen
What happens in aerobic respiration?
When glucose is combined with oxygen inside living cells it breaks down and releases energy. This is aerobic respiration.
What is the point in aerobic respiration?
The energy created helps muscles to contract
What is the equation of respiration?
Glucose + Oxygen ---> Carbon Dioxide + Water + Energy
Define anaerobic respiration
When there is no oxygen present, glucose cannot break down completely in living cells. This incomplete breakdown of glucose releases a little bit of energy very quickly.
What happens when lactic acid builds up?
Muscles become fatigued
Define oxygen debt
The oxygen that is needed to break down the build up of lactic acid
What is the equation for anaerobic respiration?
Glucose ---> Energy + Lactic acid
Name FOUR things that happen to the body during exercise?
- Heart rate increses (eg. around 70 bpm to around 100 bpm)
- The arteries supplying the muscles dilate (widen)
- The rate and depth of breathing increases
- The changes increase the blood flow to muscles
- The supply of oxygen and sugar is increased which speeds up removal of carbon dioxide
- Animal starch (glycogen) stored in muscles is broken down to glucose used in respiration
What are the main TWO functions of the kidneys?
- Maintain the concentrations of dissolved substances in the blood
- Remove urea
What TWO tissues are kidneys made up of?
- Blood vessels
- Tubules (small tubes)
What TWO organs does the ureter connect?
The kidneys and the bladder
What is ultrafiltration?
It is where the body moves all substances from the blood into the tubule and then selectivly reabsorbs the substances we need back into the blood. The unwanted substances are excreted through urine.
What THREE substances are excreated in urine in ultrafiltration?
Excess water, ions and all urea
What THREE substances are reabsorbed into the blood in ultrafiltration?
Most of the water, ions and all sugar
In a dialysis machine, what does the blood flow between?
A partially permeable membrane
What is the role of a partially permeable membrane in a dialysis machine?
It allows the urea and all excess substances to pass from the blood into the dialysis fluid
What does the dialysis contain to ensure substances such as glucose or mineral ions are not lost from the blood through diffusion during dialysis?
The same concentration of useful substances as the blood.
What is the main issue with kidney transplants?
Rejection by the immune system
What can the risk of rejection by the immune system in organ donation be limited?
- Use a donor kidney with a tissue type as close as possible to that of the recipient (close relative)
- The bone marrow of the recipient is irradiated to stop the production of white blood cells
- Recipient is given drugs that supresses immune system (immunosuppressant drugs)
- Recipient kept in sterile conditions for some time after the operation to reduce the risk of infection.
What is fermentation?
Where yeast respires with oxygen (anaerobic respiration) to produce ethanol (alcohol) and carbon dioxide, all from glucose
What is the equation for fermentation?
Glucose ---> Ethanol + Carbon Dioxide + Energy
When yeast respires with oxygen (aerobic respiration) what are the two things that are produced?
Water and carbon dioxide
What is the difference between aerobic respiration and anaerobic respiration?
- Aerobic is respiring with oxygen
- Anaerobic is respiring without oxygen
What are the FOUR main foods yeast is used in the production of?
Bread, beer, wine and yoghurt
What is the equipment used to grow microorganisms?
Name TWO products that are made in fermenters?
Penicillin and mycoprotein
What gas is mainy biogas?
How is biogas made?
- In a biogas generator
- It is made from organic waste products
- Microorganisms break down waste, produce the gas and excrete 'digested sludge'
- Made through anaerobic respiration
Name THREE nutrients used in a culture medium
- Carbohydrates (energy source)
- Mineral ions
What jelly-like substance is most commonly used as a growth medium?
What are the THREE procedures to ensuring a uncontaminated culture of microorgansisms?
- Sterilisation of perti dishes and culture medium
- Sterilisation of inoculating loops
- Sealing the petri dish
What is the best way of killing unwanted microorganisms?
Heating the surface to a very high temperature