*The Molecules of Life

*I didn’t take 11 chemistry so watch this!!!!*Water*Biological Molecules – Hank strikes again!

*Basic Elements of LifeRemember: CHNOPS

C = Carbon H = Hydrogen N = Nitrogen

O = Oxygen P = Phosphorus S = Sulfur

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*CHNOPS

*CHNOPS elements usually form covalent bonds.*Electrons shared stability

* How to “read” molecular structures

Bond

DoubleBond

*How to “read” molecular structure

Bond

Carbon

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*Examples of covalent bonding

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*Carbon

*Carbon atoms form covalent bonds to carbon atoms.*Carbon chains form "backbones" of organic

molecules.*Various lengths*"Functional groups" may be attached to carbon chains.*determine properties of molecules

* cause diversity of organic molecules

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*"Functional groups:"4 to know

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*"Functional groups"

*Any or all functional groups may be attached to a carbon backbone to make*alcohols,*acetic acid,*fatty acids,*sugars,*amino acids, *etc.

*Crucial to the carbon-based life on the Earth are several types of biologically-essential molecules. *The basic types of molecules are carbohydrates, lipids, proteins and nucleic acids.

Carbohydrates

*The carbohydrates are the compounds which provide energy to living cells. They are compounds of carbon, hydrogen and oxygen with a ratio of two hydrogens for every oxygen atom. The carbohydrates we use as foods have their origin in the photosynthesis of plants. They take the form of sugars, starches, and cellulose.*The name carbohydrate means "watered carbon" or

carbon with attached water molecules. Many carbohydrates have empirical formuli which would imply about equal numbers of carbon and water molecules. For example, the formula for glucose C6H12O6 suggests 6 carbon atoms and 6 water molecules.

Four Macromolecules: Carbohydrates

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*CARBOHYDRATES

*Monosaccharides = "Simple sugars"*glucose, fructose, etc.

*Disaccharides*Polysaccharides

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*CARBOHYDRATES*"Simple sugars" = monosaccharides*Used as cellular "fuel," source of energy *(as gasoline for engine)

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*Disaccharides:Monosaccharide molecules react to form

disaccharides.

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*Synthesis = dehydration synthesis*Removal of OH + H forms water, H2O

*Leaves bonding sites that join monosaccharide units.

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*Disassembly = hydrolysis*Break bond between monosaccharide units.*Add OH + H to fill bonding sites.

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*Polysaccharides*Built up of monosaccharide units by dehydration

synthesis.*Disassembly by hydrolysis.

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*Polysaccharides*Examples:*Glycogen - stored fuel in liver, muscle cells*Starch - stored energy in plants, digestible (hydrolysis)*Cellulose - plant cell walls, indigestible (dietary fiber)*Chitin - arthropod exoskeletons, indigestible

Carbohydrates

Lipids

*Fats, oils, waxes, and sterols are collectively known as lipids. *Like the carbohydrates, the true fats

contain only carbon, hydrogen, and oxygen. The molecules of such a lipid are made up of a glycerol molecule with three fatty acid molecules attached to it. This kind of lipid is also called a triglyceride.

*Four Macromolecules: Lipids

* An important class of lipids is composed of the phospholipids that make up cell

membranes. The class of compounds called steroids are also lipids and cholesterol is one of the steroids

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*LIPIDS

*Steroids*unlike other lipids,

4-ring structure

Proteins

*Proteins are the "workhorse" molecules of life, taking part in essentially every structure and activity of life. They are building materials for living cells, appearing in the structures inside the cell and within the cell membrane.*While many of the proteins are structural proteins,

many are regulatory proteins called enzymes.*They contain carbon, hydrogen, and oxygen like

the carbohydrates and lipids but they also contain nitrogen and often sulfur and phosphorus.

*Four Macromolecules: Proteins

*Protein molecules are often very large and are made up of hundreds to thousands of amino acid units.*Amino acids are organic compounds which

contain both an amino group and a carboxyl group.

*The 20 amino acids are combined in different ways to make up the 100,000 or so different proteins in the human body. Some of these proteins are in solution in the blood and other fluids of the body, and some are in solid form as the framework of tissue, bone and hair.

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*Amino acids

*Examples:*20 “R” groups 20 kinds of amino acids in all biological

chemistry.

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*PROTEINS

*Globular*hemoglobin*myoglobin*hormones

* insulin, glucagon, growth hormone

*antibodies*receptors*ENZYMES

*Structural/Fibrous*keratin* epidermis, hair, nails

*collagen* tendons, ligaments

*silks

*Protein Monomers and Polymers

*Proteins fold and fold and fold….

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*PROTEINS: ENZYMES

*Biological polymers (carbohydrates, lipids, proteins, nucleic acids) must be assembled precisely!!*Chemical processes must occur in proper sequence.*Chemical processes require energy (heat) for

activation.*Reactions occur very slowly at body temperature.*Add heat to speed up reaction undesirable reactions

*How to control reactions at moderate temperature?*Answer = . . .

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*ENZYMES*Enzymes = biological

catalysts*Properties*SPECIFICITY: *1 enzyme 1 reaction

*LOWER ACTIVATION ENERGY:

* increased reaction rate

*CONTROL (regulation):

*Enzymes can be “switched on” or “off.”

Nucleic Acids

*Nuclei acids control the processes of heredity by which cells and organisms reproduce proteins.*The key nucleic acids are DNA

(deoxyribonucleic acid) and RNA (ribonucleic acid).*A molecule of a nuclei acid consists of a

long chain of units called nucleotides.

* Four Macromolecules: Nucleic Acids

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*Nucleic acids*Polymers of

nucleotides*3 parts of

nucleotide*5-C sugar (ribose,

deoxyribose)

*Base (A, C, G, T or U)

*Phosphate

*Nucleotides

*Nucleotides are the basic structural units of nucleic acids which control the production of proteins in living organisms.*The nucleotides are made up of a

phosphate group, a pentose sugar, and a nitrogen base.