Nitrogen is an essential element for living organisms. It is needed to make proteins, nucleic acids and ATP. The nitrogen cycle shows how this element is transferred between different parts of an ecosystem. In this article we will look at the four major steps and the microorganisms involved in the processes. The nitrogen cycle The... Continue Reading →
Limiting Factors – Photosynthesis Ep 3
The environmental conditions must be just right for photosynthesis to take place at the fastest possible rate. Today we're going to take a look at how light intensity, temperature and carbon dioxide (CO2) concentration can affect and limit the rate of photosynthesis. They will also affect plant growth, because photosynthesis produces glucose. Plants require glucose... Continue Reading →
Light-Independent Reaction – Photosynthesis Ep 2
In the last article we left photosynthesis at a point where ATP, reduced NADP, and oxygen had been produced in the light-dependent reaction. Oxygen is a waste product of photosynthesis, however the ATP and reduced NADP are used for the light-independent reaction. So although light energy isn't specifically needed for any reaction in this next... Continue Reading →
Light-Dependent Reaction – Photosynthesis Ep 1
Photosynthesis is the process used by plants and other photosynthetic organisms to produce glucose. The glucose can then go on to be used in respiration, stored as starch, or used for other purposes. Photosynthesis requires light energy, but it is actually only the first stage which is directly light-dependent. We will focus on the light-dependent... Continue Reading →
Translocation in Plants – Exchange and Transport Ep 16
Translocation is the movement of dissolved solutes (also called 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. A source... 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 →
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 →
Chloroplasts – Cell Organelles Ep 4
So far, all the organelles we have looked at (the nucleus, mitochondria, ribosomes and RER) are found in both animal and plant cells. Today's organelle, the chloroplasts, are only found in plant cells and some eukaryotic algae. The main function of chloroplasts is to carry out photosynthesis - the reaction that uses light energy to... Continue Reading →
