2-3: Carbon Compounds

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• California content standards 1h: carbs, lipids, proteins, nucleic acids are important in living things and are synthesized from simple precursors.

The Chemistry of Carbon

• 6 protons, 6 electrons (e-)• Room for 4 e- in outer shell. (4 unpaired

e-)• So, it can form 4 covalent bonds with

other atoms.• Carbon has the ability to form millions

of different large and complex structures.

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Carbon

• Wood, paper, cotton• Diamond• Charcoal• Pencil lead, graphite• Oil• What else?

CarbonCarbon

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+ +

+++

+--

-

-

-

-

-

-

--

These 4 These 4 unpaired unpaired valence shell valence shell electrons electrons can be can be shared.shared.

Bonds Between CarbonBonds Between Carbon

Ethylene

Acetylene 2-32-3

?

Macromolecules

• Macromolecules are formed by a process known as polymerization.

• The smaller units, or monomers, join together to form polymers.

•Monomers in a polymer may be identical, or the monomers may be different.

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Four groups of organic compounds found in living things are:

• LipidsLipids• CarbohydratesCarbohydrates• Nucleic acidsNucleic acids• proteinsproteins

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Lipids

• Made mostly of C, HMade mostly of C, H• Part of cell structurePart of cell structure• Reserve energy supply in Reserve energy supply in

organisms (twice as much E organisms (twice as much E as CHas CH22Os.)Os.)

• Generally not soluble in water.Generally not soluble in water.• Fats, oils, waxes, steroidsFats, oils, waxes, steroids

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Fats and OilsFats and Oils

• Fats and oils are chemically Fats and oils are chemically similar, but oils are liquid at similar, but oils are liquid at room temp. Fats tend to be solid.room temp. Fats tend to be solid.

• Plant oils: peanut oil, corn oil, Plant oils: peanut oil, corn oil, canola oil, castor oilcanola oil, castor oil

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Oils

Fats

• Serve as cushion under skin in animals, stops heat loss

• Not stored for long, but constantly being replaced.

• Whale blubber

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Fat (whale blubber)

Wax

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Saturated vs. UnsaturatedSaturated vs. Unsaturated

• Fats with single C-C bonds are Fats with single C-C bonds are saturatedsaturated. (tend to be solid at . (tend to be solid at room T).room T).

• Fats with one or more double or Fats with one or more double or triple bonds between C atoms are triple bonds between C atoms are unsaturatedunsaturated. (tend to be liquid at . (tend to be liquid at room T).room T).

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Saturated fat

Unsaturated fat

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There is evidence that saturated fats tend to increase the amount

of cholesterol produced in the body. Some cholesterol can lead

to narrowing of the arteries.

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It is not that we are eating too much fat per se, or that any particular type of fat is bad for us, but more that the balance of the types of fat that we consume has become upset.

http://www.feap.info/consumer/nutrition/fat_en.asp

http://www.rropl.com/healthline1.html#top

http://news.bbc.co.uk/cbbcnews/hi/newsid_3600000/newsid_3601300/3601398.stm

2. Carbohydrates2. Carbohydrates

• Compounds of carbon (C), Compounds of carbon (C), hydrogen (H), and oxygen (O) hydrogen (H), and oxygen (O) usually in a ratio of 1 : 2 : 1.

Can beAbbreviated

CH2O

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Carbohydrates (Carbs)

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Living things use carbs as their main source of energy.

The breakdown of sugars, such as glucose, supplies immediate,

quick energy for all cell activities.

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Extra sugar is stored as complex carbohydrates known as starches (plants)

and

glycogen (animals).

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Plants and some animals also use carbs for structural

purposes.

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Structural carb in plants = cellulose.

Structural carb in crabs, insects, and fungi = chitin.

• Examples of Examples of starchstarch:: Corn, Corn,

potatoes, tortillaspotatoes, tortillas

• In humans, In humans, glycogen is stored in the liver, musclesglycogen is stored in the liver, muscles..

• Examples ofExamples of cellulosecellulose:: paper, cotton, wood paper, cotton, wood

• Examples of Examples of chitinchitin:: crab, crab,

shrimp, insect shellsshrimp, insect shells

Single sugar molecules are called monosaccharides.

Monosaccharides include glucose, galactose (a component of milk), and fructose (found in many fruits).

The large macromolecules formed from monosaccharides are called polysaccharides. 2-32-3

Starch and cellulose are both polymers made from glucose monomers.Humans can digest starch, but not cellulose. (Cows and termites have an organism living within their digestive tracts which can digest cellulose). In the human diet, cellulose is termed “insoluble fiber” and is important for good digestive health. 2-32-3

3. Nucleic Acids

-Nucleic acids are macromolecules containing hydrogen, oxygen, nitrogen, carbon, and phosphorus.

-Nucleic acids are polymers assembled from individual monomers known as nucleotides.

Nucleotides consist of three parts:

1. a 5-carbon sugar2. a phosphate group3. a nitrogenous base

Individual nucleotides can be joined by covalent bonds to form a polynucleotide, or nucleic acid.

C

CC

C C

C ?

What is their function?

Nucleic acids store and transmit hereditary, or genetic, information.

-There are 2 kinds of nucleic acids:RNA: contains the sugar

ribose.DNA: contains the sugar

deoxyribose.

4. Proteins

Proteins are macromolecules that contain nitrogen, carbon, hydrogen, and oxygen.

Proteins are polymers of molecules called amino acids.

Amino acids are compounds with an amino group (-NH2) on one end and a carboxyl group (-COOH) on the other end.

The portion of each amino acid that is different is a side chain called an R-group.

The instructions for arranging amino acids into many different proteins are stored in DNA.

AminoAcids

Protein Molecule

What do proteins

do?

Some proteins control the rate of reactions and regulate cell processes. Some proteins are used to form bones and muscles. Other proteins transport substances into or out of cells or help to fight disease.

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–Large carbohydrate molecules such as starch are known as

• lipids.

• monosaccharides.

• proteins.

• polysaccharides.

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Many lipids are formed from glycerol and

• fatty acids.

• monosaccharides.

• amino acids.

• nucleic acids.

2–3Proteins are among the most diverse macromolecules because• they contain both amino groups and

carboxyl groups.• they can twist and fold into many

different and complex structures.• they contain nitrogen as well as

carbon, hydrogen, and oxygen.• their R groups can be either acidic or

basic.

2–3Which of the following statements about cellulose is true?• Animals make it and use it to store

energy.• Plants make it and use it to store

energy.• Animals make it and use it as part of

the skeleton.• Plants make it and use it to give

structural support to cells.

–A major difference between polysaccharides and proteins is that• plants make polysaccharides, while

animals make proteins.• proteins are made of monomers, while

polysaccharides are not.• polysaccharides are made of

monosaccharides, while proteins are made of amino acids.

• proteins carry genetic information, while polysaccharides do not.