Unit 3 Flashcards
Define osmosis.
Diffusion of water from an area of high concentration to a low concentration through a partially permeable membrane.
What does membrane allow through?
Water molecules
What happens if we place a cell into pure water?
Water moves into the cell by osmosis.
What would happen if we placed a cell into a concentrated sugar solution?
Water would move out of the cell by osmosis
What do sports drinks contain? Why?
Water and ions to replace those lost in swear
Sugars to Roland those used in respiration for energy
What is a solvent?
Liquid like water
What is the solute?
Solid that dissolves in solvent (sugar)
What is active transport?
When substances are absorbed against the concentration gradient from low to high concentration.
What does active transport require? From what?
Energy from respiration
How is active transport different from diffusion?
Particles move against conc gradient
Requires energy
What are respiration inhibitors?
Poisons stop mitochondria from carrying out aerobic respiration
What does a respiration inhibitor do?
Reduces energy available to Cells causing active transport to slow and stop
Name some specialised exchange systems.
Small intestine
Lungs
What is found in the small intestine?
Villi
How does villi increase the rate of diffusion of food molecules in the small intestine?
Large surface area
Good blood supply = steep concentration gradient
Thin surface =faster diffusion
What happens in the lungs?
Gas exchange
What are the air sacs called in the lungs?
Alveoli
What happens inside the alveoli in the lungs?
- oxygen diffuses from air into blood stream
- oxygen into blood cells
- carbon dioxide diffused out of blood stream into air
How are alveoli adapted to increase diffusion?
Large surface area
Good blood supply = steep concentration gradient
Thin surface = faster diffusion
What is another word for breathing?
Ventilation
In what part of the body are the lungs found? What is this part called?
Upper body
Thorax
What is the lower part of the body called?
Abdomen
What muscle separates the thorax and abdomen?
Diaphragm
What are the lungs surrounded by?
Ribs
What is found in between the ribs?
Intercostal muscles
What happens during breathing?
Diaphragm and intercostal muscles work together to change the volume of the lungs
What happens when you inhale?
Diaphragm and intercostal muscles contract increasing lung volume
Pressure in Lungs decrease
Aid drawn into the lungs
What happens when we exhale?
Diaphragm and intercostal muscles relax decreasing lung volume
Pressure in lungs increase
Air is pushed out of the lungs
How to breathing aid the lungs ?
Keeps concentration gradient as high as possible -oxygen diffusion fast
Concentration gradient of co2 high as possible too
How does an iron lung work?
Forms an air tight seal around patients body (only head exposed)
Machine reduces air pressure in chamber and the lungs expand allowing air to rush in
Machine then increases pressure the lungs become smaller and air rushes out
Advantages and disadvantages of an iron lung?
Good-
Patient is conscious and can communicate
Not damadge airways
Bad-
Bulky and patient must be still
Patient breaths in normal air not extra oxygen
How does a bag ventilator work? What are they used for?
Face mask over mouth
Squeeze bag forces air into patients lungs
Emergencies
What are the advantages and disadvantages of modern artificial ventilators?
Good-
We use a high percentage of oxygen than normal air
It’s automatic and can change frequency of breathing
Bad-
Patient can’t communicate
Damage patients trachea
What does blood contain?
Plasma
Platelets
Red blood cells
White blood cells
What is the function of plasma?
Liquid which transports molecules round the body:
Soluble digestion products from small intestine to other organs
Carbon dioxide from organs to lungs after aerobic respiration
Waste urea from liver to kidneys to be passed out in urine
What do red blood cells do?
Transport oxygen from the lungs to the organs fro aerobic respiration. They contain oxygen carrying molecules called haemoglobin
How do red blood cells pass round oxygen?
In the lungs there’s a high concentration of oxygen
Oxygen diffuses into the red blood cells and combines with haemoglobin to form oxyhemoglobin.
Red blood cells now move out of the lungs to other organs (e.g. Liver) where concentration of oxygen is low
Oxyhemoglobin releases its oxygen
Oxygen diffuses into cells of organs
Used in aerobic respiration
What doe red blood cells not contain? Why?
No nucleus
Increase amount of haemoglobin meaning they can carry a lot of oxygen
What do white blood cells do?
Form part of the immune system
Defend body against microorganism (e.g. Bacteria)
What are platelets? What do they do?
Small fragments of cells with no nucleus
Help blog clot at site of a wound