Phosphocreatine and ATP – Muscles Ep 3

Muscle contraction requires a large amount of energy, meaning that a constant source of ATP is needed. In this article we will look at the three sources of ATP which muscle fibre cells can use. Phosphocreatine ATP has to be made by adding a phosphate group (Pi) to ADP. In the ATP-phosphocreatine system, the phosphate... Continue Reading →

Muscle Fibre Cells – Muscles Ep 1

Muscle fibre cells are a great example of how animal cells can be highly specialised for their function. In this article we will look at the structure of muscle fibre cells and how it relates to their function. Muscle fibres cells - structure and function The below diagram shows a cross-section of a muscle fibre... Continue Reading →

Cardiovascular Disease – Diseases Ep 1

Cardiovascular disease is a non-communicable disease; it is not caused by a pathogen and cannot be passed from person to person. Most cardiovascular disease begins with atherosclerosis developing in an artery due to factors such as high blood pressure. In this article we will look at how atheromas develop, cardiovascular disease risk factors, and treatments.... Continue Reading →

Coenzymes and Cofactors – Enzymes Ep 4

So far in this series we have looked at how enzymes work, what can affect the rate at which they work, and how their action can be inhibited. Today we are looking at coenzymes and cofactors: non-proteins that are needed in order for some enzymes to be able to catalyse their reaction. Coenzymes Coenzymes are... Continue Reading →

Anaerobic Respiration and RQs – Respiration Ep 4

Anaerobic respiration happens when there isn't enough oxygen present for aerobic respiration to continue. Different types of organism use different pathways - lactate fermentation or alcoholic fermentation. For both pathways, the amount of ATP produced is much lower than in aerobic respiration because the only ATP produced comes from glycolysis (2ATP per glucose molecule). You... Continue Reading →

Oxidative Phosphorylation – Respiration Ep 3

We've reached the final stage of aerobic respiration - oxidative phosphorylation. This step takes place using proteins in the inner mitochondrial membrane. Now we will find out what all the reduced NAD and reduced FAD produced in glycolysis, the link reaction, and the Krebs cycle is used for. Oxidative phosphorylation The coenzymes NAD and FAD... Continue Reading →

The Krebs Cycle – Respiration Ep 2

The Krebs cycle has many names. Sometimes it is called the tricarboxylic acid (TCA) cycle or the citric acid cycle. But whatever name you give it, it's an important part of aerobic respiration. In the last article we covered the first two stages of aerobic respiration (glycolysis and the link reaction). We ended the link... Continue Reading →

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