Bio Flashcards
I can discuss why complex multicellular organisms require specialised breathing systems with
reference to diffusion.
Complex multicellular organisms need specialised breathing systems because as they get larger simple diffusion is no longer efficient. The surface area to volume ratio decreases so the oxygen will take longer to reach all the cells. Complex multicellular organisms have specialised breathing systems to be able to breathe faster
I can describe the structure of the thorax to show the ribs, intercostal muscles, diaphragm, trachea, bronchi, bronchioles, alveoli and pleural membranes.
See photos
I can describe and explain the difference in composition between inhaled and exhaled air.
Inhaled air:
Nitrogen 78%
Oxygen 21%
Other gasses 1%
Carbon dioxide 0.04%
Exhaled air
Nitrogen 78%
Oxygen 17%
Other gasses 1%
Carbon dioxide 4%
I can describe the mechanism of breathing in and out with correct reference to the role of the intercostal muscles and the diaphragm in ventilation, and the terms lung volume and pressure.
When you inhale, the diaphragm contracts and the external intercostal muscles contract. As the volume of the increases in the chest cavities the pressure decreases. The air pressure is higher outside the chest . Air goes from high to low pressure and therefore the air flows into the lungs
When you exhale the diagram relaxes and the internal intercostal muscles contract. The volume of air in the chest cavities decreases. This means that the pressure increases. The pressure is higher inside the chest than out. The air goes from high to low pressure so flows put of the lungs
I know that the alveoli are the site of gas exchange.
Gas exchange is when air is inhaled, oxygen diffuses from the alveoli into the blood to be used for respiration by the body’s cells.
Carbon dioxide is a waste product made by the body’s cells during respiration.
It diffuses from the blood into the alveoli and is exhaled.
I can explain how the alveoli are adapted to perform the function of gas exchange.
The alveoli have a rich blood supply so the oxygen can be taken away quickly
A big difference in gas concentration means that gas exchange happens faster due to a steeper concentration gradient
They have thin walls so that the gases don’t need to travel far
A short distance to travel
Large surface area
Moist walls allow these the gasses to dissolve
Permeable walls a,low gasses to pass through
Nicotine
Nicotine is addictive it causes a smoker to want more cigarettes. Can increases the heart rate and blood pressure.
Makes blood vessels narrower than normal which can lead to
heart disease
I can recall the effect of exercise on breathing rate.
More breaths per minute
More volume deeper breaths
I can explain, with reference to cellular respiration, why breathing rate changes with and after exercise.
So when we are exercising we need to increase the rate of respiration to release more energy for muscle contraction. This means more oxygen in order for respiration to take place in cells,more glucose arriving at the cell this mean breathing rate and volume increases. This means glucose and oxygen arrive at the cells more quickly. Hearth rate increases to pump the blood around the body faster . Resulting of respiration increases, more atp,
I can describe an experiment to investigate the effect of exercise on breathing rate.
Take resting breathing and heart rate by counting number of breaths and heart rate over 2 mins, do this twice, record it in your table and obtain an average
1 person should march on the spot for 1 min (timed using the iPad stopwatch)
Allow person to sit for 10 s, then start stopwatch to count number of breaths and heart rate over 2 mins, do this twice, record the data and obtain an average.
Allow person to rest until breathing rate comes back to resting rate
Repeat steps 3 and 4 but this time do the marching for 2 min
7 components of a balanced diet.
Carbohydrates. …
Proteins. …
Fats. …
Vitamins. …
Minerals. …
Dietary fibre. …
Water.
I can give three examples of good sources of carbohydrates, lipids (fats and oils) and proteins.
Carbs:
bread, noodles, pasta, crackers, cereals, and rice.
Lipids:
Oils and spreads
Proteins:
Meat, fish, eggs, beans
I can describe the functions of carbohydrates, lipids (fats and oils) and proteins in living organisms.
Nutrient Major function
Carbohydrates Source of energy, glucose is the main respiratory substrate
Proteins Growth and repair
Lipids Energy, make up part of cell membranes so essential for normal growth
I can describe the chemical tests for glucose, starch, protein and lipid.
Starch:
Introduce three drops of starch solution to a dimple on the spotting tile
● Add several drops of iodine. The iodine solution turns blue black in the presence of starch.
Glucose:
● Introduce 2cm3 glucose solution to a test tube.
● Add 2cm3 Benedict’s solution.
● Place the test tube in a beaker of boiling water from the kettle and leave for 5 minutes. The
blue solution turns orange or red if glucose is present.
Protein:
● Introduce 2cm3 protein solution into a test tube.
● Add 2cm3 sodium hydroxide solution.
● Add two drops of copper sulphate solution, shake and observe. The pale blue colour turns
to violet.
Lipids:
● Introduce 2cm3 oil into a test tube.
● Add 2cm3 ethanol and shake well. The solution becomes cloudy as an emulsion is formed.
I can explain how energy requirements vary with age, level of activity and pregnancy.
In general, the greater a persons mass, the more energy they need.
People who are active tend to need more energy than sedentary people.
When adults get older, they tend to need less energy.
Equation on slides of needed
