CARBON
What is it...and WHY is it important?
Carbon ­the building block of life, basis for most molecules that make up living things.
­atomic structure gives it unique bonding properties
­has 6 electrons (4 in outer energy level)
­can form up to four covalent bonds in order to be stable (single, double, and triple bonds are all possible)
O
C
O
H
O
H
C
H
H
C
H
H
Carbon chains can bond with carbon rings to form larger more complex molecules
**All organisms are made of four types of carbon based molecules: Carbohydrates, Lipids, Proteins, and nucleic acids. ­All have different structures and functions but all form around carbon chains or rings.
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Carbohydrates
­a biomolecule composed of carbon, oxygen, and hydrogen
­fruits and grains are high in carbohydrates
­3 types: monosaccharides, disaccharides, and polysaccharides ­monosaccharides and disaccharide sugars require less effort in order to be used by the body
WHY are they important?
­used by our cells to provide energy to our bodies and structure to plant cells
a) Monosaccharides­ simple sugar, composed of one ring
­Examples: fructose (found in fruits) & glucose (a sugar made by plant cells during photosynthesis
b) Disaccharides­ two sugar carbohydrate
(monosaccharide + monosaccharide= disaccharide) ­Examples: glucose and fructose combine to make sucrose (table sugar)
c) Polysaccharides­ polymers composed of many monosaccharide subunits
­ polysaccharides are the hardest ones for our bodies to digest
­Examples: Starch, Glycogen, and Cellulose
­Starch­ made and stored by plants, used for energy by plant cells and as food reservoirs in seeds and bulbs.
­Glycogen­ made and stored in animals (example: mammals store energy in the liver this way)
­Cellulose­ forms all cell walls of plants/gives plants structural support and makes up the exoskeleton of insects. (It’s the stringy fibers in celery)
­Foods loaded with Carbs include: pasta, white flour, white rice, bananas, potatoes, French fries, soft drinks, corn
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­Carbohydrate Loading: when runners or other athletes eat tons of carbs the day before the race or a game to store up extra energy to be burned later
­What happens when we eat them???
­Once they are eaten and digested, or broken down, they can be taken up by the blood stream, becoming blood glucose. Insulin usually transports these simple sugars across the walls of body cells where it can then be used for energy. However, diabetics insulin does not work properly and so the carbohydrates start to build up in the blood stream which causes sugar levels to rise.
Lipids
-insoluble (cannot dissolve) in water because their molecules
are non-polar and are not attracted to water molecules.
-Examples: fats, oils, cholesterol
-Made of chains of carbon, oxygen, and hydrogen
WHY ARE THEY IMPORTANT???
-Some lipids are broken down as a source of usable
energy for cells, others are part of a cell's structure.
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The fat/oils in plants and animals is very similar in structure
-both have glycerol bonded to molecules called fatty
acids
Fatty acids- chains of carbon atoms bonded to hydrogen
atoms
-two types: saturated and unsaturated
-saturated fatty acids: bad for you, contain
only single bonds, they are solid at room
temperature, examples: butter, lard
-unsaturated fatty acids: better for you, contain
double bonds, liquid at room temperature, examples:
canola oil, olive oil
Lipids' Importance
-very important for the proper
functioning of organisms
-cells use lipids for energy storage,
insulation, and protective coverings
-they are the major components of
the membranes that surround all
living cells
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Trans fats
-chemically altered vegetable oils
-produced artificially in a process called hydrogenation
(turns liquid oil into solid fat)
-found in thousands of processed foods (sweets, to
ready-made meals)
-used because they are cheap, add bulk to products, have
a neutral flavor and give the product a longer shelf life
-no nutritional value
-have been linked to high cholesterol
All cell membranes are made up of a lipid called a
phospholipid.
-made up of a glycerol, two fatty acids, and
phosphate group.
-they have a polar head and a nonpolar tail
-this helps move things in and out of the cell
Cholesterol
-lipid with a ring structure
-your body needs some cholesterol in order to
function correctly
-examples: it is part of the cell membrane, body
uses it to make steroid hormones which are
important to body's response to stress, sexual
development, reproductive system, etc.
BUT too much will accumulate in blood vessel walls and
begin to narrow them -could lead to heart attacks and
strokes.
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