Chapter 5 – Carbon Compounds in Cells

Mr. MartinoCollege Prep Biology

5.1 Carbon is the main ingredient of organic molecules

Other than water, carbon-containing compounds are the most common in cells

Organic compounds: carbon-containing compounds synthesized by cells (> 2 million known)

Inorganic compounds: non-carbon based molecules such as water, oxygen, ammonia

Properties of Org. Comps. – con’tCarbon skeleton: (backbone)

chain of C atoms in organic moleculesProperties of Carbon:

Can form 4 single covalent bondsC- skeletons may vary in lengthSkeletons may be branchedSkeletons may form ringsSkeletons may have double bondsHydrocarbon: organic molecules only composed of carbon and hydrogen

Properties of organic compounds also depend upon functional groups which are groups of atoms attached to C skeletons

Functional groups are usually involved in rxns.All are polar (O or N present)Polarity makes them Hydrophilic: “water loving” which is important for lifeMany molecules have more than one functional group

Monomer: single molecular units that build larger units

Polymer: many monomers linked together making a large molecule

Dehydration Synthesis: the process of linking monomers to form polymers

All unlinked monomers have -H and -OHWater is released

Ex. Building of all macromolecules

Hydrolysis: breaking down of large molecules into smaller molecules

Add waterReverse of dehydration synthesis

Ex. digestion

5.2 Carbohydrates

Carbohydrates: “watered carbon” – large class of polymers including sugars and starches

Contain C, H and O in a 1:2:1 ratio (CH2O)

Monosaccharide: carbohydrate monomer

Most are sweet

Polar

Have 5 or 6 carbon skeleton

Carbohydrates – con’tOligosaccharide: short chain of 2 or more monosaccharides

Disaccharide: 2 monosaccharides

Ex: lactose, sucrose, maltose

Sucrose is the main carbohydrate of plant sap – used to nourish plant parts (we use for table sugar)Maltose is grain sugar – used to nourish germinating seeds (we use to make beer)

Polysaccharides: polymers

of hundreds to thousands

of monosaccharides

Starch: a storage

molecule in plant parts

All glucose

Coils (helix) and

may or may not

be branched

Used for E

Potatoes, corn, grains

Cellulose: polysaccharide that serves to protect cells and support organisms

Most abundant organic compound on Earth

polymer of glucose

Unbranched rods

Joined by H-bonds

Cannot be hydrolyzed by most animals

Fiber is necessary but not as a nutrient

Glycogen: storage polysaccharide found in liver and muscle cells of animals

Polymer of glucoseHelical shapeIdentical to starch except more extensively branchedContains more E than starchToo much is converted to fat

5.3 LipidsLipids: Diverse compounds consisting of mostly C and H linked by nonpolar, covalent bonds

All are greasy or oily to the touchNonpolar = hydrophobic

“water fearing”Include fats, phospholipids, waxes, and steroids

Fat: large lipid made of a glycerol and three fatty acids – triglyceride

Glycerol – an alcohol with 3 C’s that have OH’sFatty acid – carboxyl with a hydrocarbon chainStores more than twice as much E than starch Unsaturated: double bonds

Kinky – can’t pack tightOils (from plants)

Saturated: maximum # H’s Solids (from animals)

Phospholipids: major component of cell membranes, protect surfaces, regulate functions

Similar to fatsHave P group & 2 fatty acids attached to glycerol

Waxes: protect, lubricate and cover fruits, animals and insects

A fatty acid + alcoholMore hydrophobic than fats Prevents desiccation

Sterols: lipids whose C skeleton is bent to form 4 fused rings

3 6-sided rings & 1 5-sided ringCholesterol is present in animal cell membranes, form vitamin D, bile salts for digestion of fats & makes sex hormonesAlso known as steroids

Nope, not them , HIM !!!

5.4 Amino Acids and Protein StructureProteins: macromolecules essential to the structure and function of cells

Polymers of amino acidsMost diverse of all organic compoundsSeven major classes:

Structural – spider silk, hair, and fibers of tendons & ligaments, feathers and cartilageContractile – control muscle movement Storage – (nutritious) stores amino acids such as albumin, milk, many seedsDefensive – antibodies of blood that fight infectionTransport – move molecules & ions across cell membranes - includes hemoglobin which carries oxygen in bloodSignal (hormones)– certain hormones that carry messagesEnzymes – chemical catalysts that promote and regulate most all chemical reactions

Amino Acids and Protein Structure – con’t

Amino acids: monomers of proteins

20 different kinds that make all the proteins possibleHave four parts bonded to a central carbon atom:

Amino groupCarboxyl group (acid)Single hydrogen ionR group – the one group that varies between them all

Determines the properties of the amino acid

Amino Acids and Protein Structure – con’t

Peptide bond: covalent bond that forms by dehydration synthesis & is only found in proteins

Occurs between the carboxyl group of one A. A. and the amino group of anotherForms polypeptides which can range from a few A. A.’s to thousands

5.5 Protein’s 3-D StructureThere are 4 levels of protein structureProteins are one or more polypeptide chains folded in a unique shapeShape is extremely important for the enzyme to recognize and attach to its target

Denaturation: the process of changing a protein’s shape so it can no longer function properly

Ex. Cooking egg whites or meatsCaused by heat, pH change, salt concentration change, or chemical balance change

5.7 Nucleotides and Nucleic AcidsNucleotides: monomers

that make up nucleic acids and ATP (adenosine triphosphate)

Consist of a 5-C sugar (deoxyribose in DNA, ribose in RNA and ATP), phosphate group, and a nitrogenous base5 nitrogenous bases: adenine (A), thymine (T – only in DNA), guanine (G), cytosine (C), and uracil (U – only in RNA)

5.7 Nucleotides and Nucleic Acids

Nucleic Acids: blueprints for proteins (and life)

Two types: deoxyribonucleic acid (DNA) & ribonucleic acid (RNA)

DNA – the genetic information inherited from parents that controls the life of the cell and organism

Happy Halloween!!!!!!!

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