Translocation is the movement of dissolved substances (also called solutes or assimilates) through the phloem vessels. If you haven't already, make sure to read about the structure of the phloem vessels here first so you've got a good grounding to take this topic further. Source to Sink Solutes move from a source to a sink.... Continue Reading →
Water Transport in Plants – Exchange and Transport Ep 15
In the last post we looked at the structure of the xylem vessels, so now we're going to take a look at their function. Water transport in plants happens up the xylem vessels in a transpiration stream from roots to leaves due to the properties of water and transpiration at the leaves. Let's break the... Continue Reading →
Xylem and Phloem Structure – Exchange and Transport Ep 14
Today we're starting on transport in plants. Plants don't have hearts or blood, but they still need to transport substances around because their surface area to volume ratio is too high to rely on diffusion alone. The tissues involved in transport are the xylem vessels and the phloem vessels. In this article we will focus... Continue Reading →
Digestion – Exchange and Transport Ep 13
So far in the exchange and transport series we have mainly been looking at exchange and transport of gases. However, organisms also need to absorb nutrients such as glucose and amino acids so they can carry out processes like respiration and protein synthesis. In this article we will cover how large food molecules are broken... Continue Reading →
Blood Vessels – Exchange and Transport Ep 10
Getting blood around the body requires a network of blood vessels. These come in different shapes and sizes depending on their location and function. In this article we will look at the structure of arteries, veins, capillaries. Arteries Arteries carry oxygenated blood away from the heart to the tissues of the body (except the pulmonary... Continue Reading →
The Cardiac Cycle – Exchange and Transport Ep 9
The cardiac cycle is the sequence of contraction and relaxation that the heart goes through continuously to keep blood pumping around the body. It's fairly complicated, but broken down into steps it makes sense if you think about the direction blood travels through the heart. Two important words you need to know before we start... Continue Reading →
The Human Heart – Exchange and Transport Ep 8
So far in this series we've looked at how substances are exchanged across membranes, particularly oxygen and carbon dioxide in gas exchange systems. Today, we're going to start looking at how substances get transported around organisms, starting off by looking at the structure of the human heart. The Human Heart The heart is the key... Continue Reading →
Gas Exchange in Plants – Exchange and Transport Ep 7
Sometimes it's easy to forget that plants exchange gases too because you can't see evidence of ventilation. As well as needing oxygen for respiration, plants also need carbon dioxide for photosynthesis. In addition, oxygen is a waste product of photosynthesis and carbon dioxide is a waste product of respiration. Dicotyledonous Plants First of all, what... Continue Reading →
Gas Exchange in Fish and Insects – Exchange and Transport Ep 6
Fish and insects don't have lungs like humans and other mammals do. Instead, they have clever alternative gas exchange systems in order to deliver oxygen to their cells and remove carbon dioxide. Let's look at each organism individually. Gas Exchange in Fish I'm sure it's fairly obvious that fish don't breath air because they live... Continue Reading →
Gas Exchange in Humans – Exchange and Transport Ep 5
We've now looked at three ways in which substances can be transported across cell membranes: diffusion, osmosis, and active transport. Today's topic is example of where diffusion takes place in the human body, all with the purpose of taking in oxygen for respiration and removing carbon dioxide. There's quite a lot of information today so... Continue Reading →
