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A fatty acid molecule will yield more energy than a single glucose molecule both if oxidised by the body to produce ATP, or when burnt in oxygen to give heat.
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In general this first answer looks right, and in most cases it can be applied very well.
However the amount of energy basically depends on the molecule's structure and bonding properties of C-O, C=O, C-H and O-H bonds plus the number of those bonds, which have to be 'broken down' by O2 to form CO2 and H2O.
Also the (mean) molecular weight should be accounted for when comparing energy per 100 GRAM, as is usually done in food science.
It is mainly proportional to the amount of oxygen needed to 'burn' or oxidise 100 gram of fatty acid or glucose biologically.
Some table values:
Glucose (monosaccharide) 1563 kJ / 100 g
Saccharose (disaccharide) 1650 kJ / 100 g
Starch, (polysaccharide)... 1748 kJ / 100 g
Acetic acid , C2H4O2 about 1.6 MJ / 100 g
Butyric acid, C4H8O2 about 1.9 MJ / 100 g
Stearic acid, C18H36O2 about 4.0 MJ / 100 g
Fat, in general, mean value: 3.7-3.8 MJ / 100 g
Fats and ethanol have the greatest amount of food energy per mass: 38 and 30 kJ/g respectively.
Proteins and most carbohydrates have about 17 kJ/g. Carbohydrates that are not easily absorbed, such as fiber or lactose in lactose-intolerant individuals, contribute less food energy.
Polyols (including sugar alcohols) and organic acids have less than 16 kcal/g.
The Energy Content of Foods
The food we eat can be divided up into several classes; fats or lipids, sugars and starch, proteins and alcohols. These can give us energy, usually measured in calories per gram. It may be surprising for some of you, but these
different foods contain varying amounts of energy. While fats yield 9 kilocalories / gram, sugars and starch give us a little less than half of this, that is, 4 kilocalories / gram. Proteins also give about 4 kilocalories / gram. Alcohol yields 7,5 kilocalories / gram. That means that a glass of wine gives us as much energy as double as much cola! Beer and wine are major contributors to the current global obesity epidemic.
What is the basis for these differences? Remember, the energy content of the food we eat is directly related to "electron-hopping" from hydrogen-carbon complexes to oxygen atoms. Food with many carbon-oxygen links can be said to be partially burned or oxidized before we eat it. It contains fewer high-energy electrons and, therefore, less energy.
Now, just look at the figure. You will quickly see that fats contain mostly carbon-hydrogen bonds and little oxygen. Fats or lipids are almost fully reduced and excellent donors of high-energy electrons. The sugar (glucose) at the bottom of the figure contains many oxygen atoms and is partially oxidized before being eaten. That means that it has fewer electrons to donate to oxygen during metabolism and, therefore, gives us less energy than fats. Alcohol (ethanol) lies between these in oxidation state and "energy content". It contains fewer hydrogen atoms and high-energy electrons per molecule than fats, but more than sugars.
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Why do human cells rely far more on glucose and fat for energy than on protein?
More energy is available to us aerobically (fat can only be metabolized aerobically), the high energy needs of endurance MORE
What are the four sources of energy for muscle cells?
fat, calories, sugar, and energy or glucose
How do animals store glucose?
Most animals store glucose as glycogen in liver and muscles .
Is glucose and fat-soluble?
Fat or more widely known as lipids is not soluble to water glucose is soluble in water.you need to be more specific as to what you think they migth be soluble in.
Glucose may be used in the body to?
Glucose is used by the body as a primary source of energy. Red blood cells and neurones rely entirely on glucose for energy. Excess amounts of glucose in the body is converted to glucogon or fat and stored for later use.
Why will cell choose to use glucose over fat when fat yields more energy?
cell use glucose instead of fat because glucose is easy to burn into energy but it takes a lot of workout ot burn fat..
Does unit of fat take more oxygen to be converted to energy than glucose?
yes
Why do human cells rely far more on glucose and fat for energy than on protein?
More energy is available to us aerobically (fat can only be metabolized aerobically), the high energy needs of endurance MORE
What is a property of conditioned muscles?
they rely less on fat breakdown and more on glucose oxidation for energy
Does glucose build muscles?
no, because glucose is a form of sugar, and sugar is energy, and energy is pretty much fat.
What are the production of glucose and protein or fat?
The process of glucose being made from protein or fat is called gluconeogenesis. The glucose is then used to provide energy to the brain and nervous system.
What does glucose produce for the body?
Your body uses glucose to produce energy. In fact, glucose serves as your body's primary source of energy because it can be broken down more efficiently than either fat or protein. Read more: What Does Glucose Produce? | eHow.com http://www.ehow.com/facts_5868649_glucose-produce_.html#ixzz2LNJTobrZ
Which substance is used by the body to store energy?
Answer: Glucose is one. Answer: Glucose, fat, and carbohydrates.
What are the four sources of energy for muscle cells?
fat, calories, sugar, and energy or glucose
What Is a cell's main source of energy.?
A cell's main souce of energy is glucose.
What is stored by the body as energy reserves?
Energy is stored for later use by converting it to a compound that can be stored. These are glycogen and humans and starch in plants. In humans, insulin is produced by the pancreas which converts glucose (which can't be stored) into glycogen (which can be stored) which is stored in the liver. to convert the glycogen back to glucose when energy is needed the pancreas produces glucagon, this then converts the glycogen to glucose which is ready to be used by the body for energy.
Resting skeletal muscles use glucose as a preferred energy source?
Resting skeletal muscles burn glucose for energy. Although fat can also be used as an energy source, if glucose is present, muscles will use glucose first.
