Biology B3 Further Biology- EXCHANGE OF MATERIALS

ACTIVE TRANSPORT

- Diffusion and osmosis(semi-permeable membrane)

- HOWEVER, the body needs substances that have to be moved against a concentration gradient (from low to high)

- This allows cells to absorb ions from very dilute solutions. 

- Also allows them to move substances like sugars and ions from one place to       another through the cell membranes.

THIS ALL REQUIRES ENERGY FROM RESPIRATION

Root hair cells and the gut lining of your cells have lots of mitochondria to provide the energy they need to carry out lots of active transport.

THE IMPORTANCE OF ACTIVE TRANSPORT

- Glucose can be moved out of the gut and kidney into the blood even though its from a high to low concentration gradient.

-Mineral ions in the soil are usually found in very dilute solutions, more dilute than inside the cell of the plant, by active transport the cell can absorb the ions from the soil through active transport. (against the concentration gradient)

EXCHANGE OF GASES IN THE LUNGS

The Breathing System

- Oxygen takes the waste carbon dioxide that the cells produce in respiration. 

- Your whole chest area (containing your lungs, heart, ribs, alveoli (air sacs in lungs), and everything else up there) is called your THORAX!

- Your upper body is separated by your lower body by the diaphragm which is a strong sheet of muscle.

- Your ribcage and diaphragm change shape as you breathe in and out.

EXCHANGE OF GASES IN THE THE LUNGS

- Your alveoli are what makes up your lungs, they are tiny air sacs but have a very large surface area (better diffusion) area which is always moist (gases can dissolve) with a rich blood supply (maintains concentration gradient) 

- Alveoli have very thin walls to make diffusion as effective as poss.

EXCHANGE IN THE GUT

- V. Important to the body- Forms simple sugars such as GLUCOSE, AMINO ACIDS, FATTY ACIDS AND GLYCEROL. 

Absorption in the Small Intestine

- The food you eat is the building blocks of respiration and the tissues your body is made out of.

- The food molecules must move from your small intestine to your bloodstream for this to happen.

- THIS HAPPENS BY DIFFUSION AND ACTIVE TRANSPORT

- Food needs to be broken down into a soluble form as digestion takes place, only when the food molecules are dissolved in water can diffusion take place!

- When the molecules are broken down they can pass into the blood vessels through the gut lining because there is a high concentration of food molecules in the gut and a…