Glycogen is a polysaccharide consisting of glucose. It is a branched polymer — that means it is not linear/straight but has long chains of glucose coming off the sides of another glucose chain. Animal cells store glucose in the form of glycogen. After eating, glucose levels in the blood increase, causing insulin to be released. [...]
Author Archives: chia
Glucose
Glucose is a simple sugar, a monosaccharide, that has the molecular formula C6 H12 O6. Other forms of monosaccharides are such as fructose and galactose. Glucose is used by our bodies as fuel for energy; they are the major starting points for cellular respiration which produces ATP. When glucose levels in the blood are high, [...]
Insulin
Insulin is a hormone that is secreted by the pancreas in response to in the blood. More specifically, they are produced by beta-cells which are found in an area of the pancreas called the Islets of Langerhans. When blood glucose levels go above a set point (90mg/100ml), for example after eating carbohydrates, the beta-cells detect [...]
Myelin
A myelin sheath is an insulating layer that is wrapped around an axon. In the peripheral nervous system, each myelin sheath is formed by an individual Schwann cell which wraps itself around the axon length. In the central nervous system, oligodendrocytes send out numerous processes (arms!) to wrap multiple axons. So myelin is actually just [...]
Neurotransmitters
Neurons communicate with each other by releasing chemical messengers called neurotransmitters. Neurotransmitters are found at the end of a neuron axon, called the presynaptic terminal. These chemicals are released in response to an electrical stimulation (the traveling action potential). Another neuron then detects the neurotransmitters by specific receptors at its postsynaptic membrane. Activation of these [...]
Amino acids
Amino acids are the building blocks of proteins. Our bodies need amino acids in order to make new cells and enzymes. Out of the 20 types of amino acids that exist, we can make 10. The other 10 must come from our diet. An amino acid has an amino group (NH2) and a carboxyl group [...]
Prokaryotes
Prokaryotes are the oldest living organisms on Earth, dating back to 3.5 billion years ago. They function as single cells; in other words, they are unicellular. Each cell is only about 1 micrometer (μm) in size! Prokaryotes are part of the kingdoms Archaea & Eubacteria. Prokaryotes have this basic structure: Prokaryotes have: a plasma membrane [...]