Cell Theory states that cells come from pre-existing cells. What does this mean? Our body is made up of billions of cells, and all of them originate from only TWO basic cells – the sperm and egg. To get from 2 cells to a billion, these 2 cells divide many many MANY times. A lot [...]
Author Archives: chia
Lab Tests for Gases
Test for oxygen : Gas collected is able to relight a glowing splint (light a wooden splint, blow it out and then insert it quickly into the gas chamber) Test for carbon dioxide : Bubbling carbon dioxide through lime water (calcium hydroxide) makes it cloudy due to solid precipitates of calcium carbonate. Ca(OH)2 (aq) + [...]
Fatty Acids
In food, fats are in the form of triglycerides (1 glycerol + 3 fatty acid chains). There are a few types of fatty acids: Saturated , where the fatty acid chain has no double bonds (think of the hydrocarbon chain being saturated with hydrogens. Animal products such as lard, butter, whole milk, eggs and meat [...]
Electron Transport Chain
(or Oxidative Phosphorylation) The final part of cellular respiration is called the electron transport chain, where oxidative phosphorylation occurs. Oxidative phosphorylation refers to phosphorylation of ADP to ATP using energy released by oxidation of NADH + H+. The electron transport chain takes place on the inner mitrochondrial membrane, using NADH + H+ made by glycolysis [...]
Anaerobic respiration
The first phase of cellular respiration, glycolysis, is said to be anaerobic. Anaerobic means it doesn’t need oxygen (the opposite is aerobic – requiring oxygen). During intense exercise, oxygen in the blood gets used up quickly and sometimes there isn’t enough. The lack of oxygen blocks oxidative phosphorylation (see electron transport chain). NADH + H+ [...]
Electron carriers
Electron carriers in cells accept and give away electrons to facilitate reduction (gain of electrons) and oxidation (loss of electrons). They are crucial in cell respiration and are found on the inner membrane of mitochondria and chloroplasts (the energy producing organelles of animals and plant cells respectively). NAD (Nicotinamide Adenine Dinucleotide) is the main electron [...]
Cellular Respiration
In order for a cell to carry out its functions, it requires energy in the form of ATP. Cellular respiration is the way cells make this ATP, using food as its fuel. is the most common starting point for cellular respiration (although other sugars, fats and proteins can also be used). The overall equation for [...]
Glycolysis
Glycolysis is the breaking down (lysis) of glucose (glyco) into pyruvate (also known as pyruvic acid). It is the first part of cellular respiration, where cells use glucose as fuel for energy (making ATP). Glycolysis takes place in the cytoplasm of the cell, and some energy is made in the process. This part of respiration [...]
Disaccharides
Disaccharides are formed when 2 monosaccharides are linked together by a glycosidic linkage. Maltose used for beer brewing is glucose + glucose. Lactose, found in milk, is glucose + galactose. Sucrose, table sugar, is actually glucose + fructose. Plants (including fruits and vegetables) usually carry carbohydrates from their leaves to other parts in the form [...]
Polysaccharides
Polysaccharides are polymers of sugars, where hundreds or thousands of monosaccharides are joined together by glycosidic linkages. A glycosidic linkage is a covalent bond that is formed between two monosaccharides by a dehydration reaction — the removal of a water molecule (H + OH). Polysaccharides are used for: 1. Storage In plant cells, excess glucose [...]