Exchange of materials Flashcards
Osmosis: What is Osmosis?
Osmosis is the movement of water through a partially permeable membrane (just for Lucy)
Osmosis: How is it similar to diffusion?
It moves water molecules randomly and does not need energy from the cell
Osmosis: What is another way of saying High water concentration?
a dilute solution
Osmosis: What is another way of saying low water concentration?
a more concentrated solution
Osmosis: Is the cell membrane permeable?
the cell membrane is partially permeable
Active Transport: What do cells use active transport for?
Active transport is used to absorb substances across partially permeable membranes against the concentration gradient
Active Transport: What is needed for active transport?
Energy from repiration
Active Transport: What do cells absorb from dilute solutions?
ions
Active Transports: What can be reabsorbed in the kidney tubules by active transport?
Glucose
The sports drink dilemma: What happens when you exercise?
You muscles respire energy. Glucose is used in respiration
The sports drink dilemma: When you get hot you sweat what is in sweat ? What happens if you sweat too much?
Sweat contains water and mineral ions. If you sweat too much you can become dehydrated
The sports drink dilemma: What should you do after exercise? Why?
You should drink water or energy drinks to replace sugars, mineral ions and water to replace what you have lost during exercise.
The sports drink dilemma: What is in sports drinks?
Sports drinks are solutions of sugar and mineral ions
The sports drink dilemma: What does the water in sports drink do?
It helps to rehydrate your body cells
Exchanging materials: What are efficient exchange surfaces like?
Have large surface areas, thin walls, or a short diffusion path, also an effcient transport system
Exchanging materials: What increases the surface are of the lungs?
The alveoli (air sacs)
Exchanging materials: What has a special exchange surface?
Large, complex, organisms, to obtain all food and oxygen they need.
Exchanging materials: Where does the oxygen diffuses into?
Diffuses back into the many capillaries surrounding the alveoli
The sports drink dilemma: What are the benefits to sports drinks ?
Some sports scientists this it is just as good as drinking water for a short period of exercise. The drinks may be better to help athletes who need to replace mineral ions and sugers as well as water.
Exchanging materials: What has a special exchange surface?
Large, complex, organisms, to obtain all food and oxygen they need.
Ventilating the lungs: The lungs contain exchange surface of the breathing system, what is exchanged?
Oxygen is exchanged for carbon dioxide
Ventilating the lungs: Where the lungs situated?
In the thorax, inside the rib cage above the diaphragm (which separates the lungs from the abdomen)
Ventilating the lungs: What happens when we breath in?
-The intercostal muscles, between the ribs and the diaphragm contract -The ribcage moves up and out and the diaphragm flattens -The volume of the thorax increases -The pressure in the thorax decreases and the air is dawn in
Ventilating the lungs: What happens when we breath out?
-The intercostal muscles of the ribcage and diaphragm relax -The ribcage moves down and in and the diaphragm becomes domed -The volume of the thorax decreases -The pressure increases and air is forced out
Ventilating the lungs: What is the movement of the air in and out of the lungs called?
Ventilation.
Artificial breathing aids: What are some of the reasons why someone cannot get oxygen into their bloodstream?
-If the alveoli are damaged, the surface area for gas exchanged is reduced -If the tubes leading to the lungs are narrowed, less air can be moved through them -If the person is paralysed, their muscles will not work to pull the ribcage up and out.
Artificial breathing aids: Name three breathing aids and explain them
- The ‘iron lung’ was used for people with polio who were paralysed. The person lay with their chest sealed in a large metal cylinder. When air was drawn out of cylinder the person’s chest moved out and they breathed in. The vaccum which was formed inside the cylinder created a negative pressure. When air was pumped back in to the cylinder it created pressure on the chest and forced air out of the person’s lungs. -Breathing aids which force measured amounts of air into the lungs use positive pressure. Bags of air linked to masks can force air down the trachea. -Positive pressure aids are often smaller, easier to manage in the home can be linked to computers for control.
What are used for active transport?
Transport Proteins
How can active transport work?
The cells can absorb ions and release them
Give an example of a process in the human body which uses active transport
Reabsorption of glucose in the kidney tubules
Why are the lungs ventilated?
To maintain a steep diffusion gradient
Which muscles control breathing and where are they?
Intercostal muscles between the ribcage and diaphragm
Who was the iron lung used for?
People with polio who were paralysed
What are the names of the upper and lower parts if the body? what separates them?
Thorax and abdomen separated by the diaphragm
What do positive pressure aids force air down?
the trachea
Benefits of positive pressure aids?
Small, easy to manage in the home, can be connected to a computer device for control.
Exchange in the gut: The food we eat is digested in the gut into?
Small soluble molecules
Exchange in the gut: Which part of the gut are small soluble molecules absorbed into the blood?
small intestine
Exchange in the gut: What line the inner surface of the small intestine?
Villi
Exchange in the gut: Name three things that make the villi an efficient exchange surface?
-Thousands of finger like projections which in increase the surface area where absorbtion takes place -The villi walls are thin and have many capillaries close to the wall providing a good blood supply -Soluble products of digestion can be absorbed into the villi by either diffusion or active transport
Exchange in the gut: What similarities do villi and alveoli have?
They both have thin walls, large surface area and good blood supply
Exchange in plants: Gases diffuse in and out of leaves through thiny holes called ____?_____
Stomata
Name the gases and what they do?
-Oxygen ~ needed for respiration and waste products of photosynthesis -Carbon Dioxide ~ needed for photosynthesis and waste product of respiration
The plants loose water vapour through the stomata due to?
evaporation
How do leaves diffuse the gases?
The leaves are thin and flat. Internal air spaces which help to increase the rate of diffusion
What do root hair cells do?
Increase the surface area of roots for the absorbtion of water and mineral ions
If the plant is dry what will the stomata do?
It will close to prevent wilting
Transpiration:
Explain how water is lost from the leaves
Water goes up the roots passes through plant to leaves. In the leaves water evaportes from the leaf cells and water diffuses out through the stomata.
The movement of water through the plant is ?
transpritation stream
what causes the plant to dehydrate and dry up ?
Evaparation - more rapid in hot wind bringht places
What happens to prevent excessive water loss?
guard cell can close
The leaves wilt - leaves hang down and shrivel reducing the surface area
By what proces does water vapour move out of the leaves?
Diffusion
