BIOL1000 Chapter 3

Organic compound

Compounds that contain carbon. Typically contain H.

Carbon skeletons

Vary in length, double bond position, branching, and rings

Isomers

Same chemical formula, different arrangement

Hydrocarbons

Molecules consisting of only C and H. Found in regions of some much larger more complex compounds

Types of chemical groups

Hydroxyl, carboxyl, carbonyl, amino group, phosphate group, methyl group

Hydroxyl

Typically considered alcohols

Carbonyl

Carboxyl

donates H to solution making it acidic

Amino group

Amine

Nitrogen bonded to Carbon. picks up H+ to form amino group

Phosphate group

Methyl group

Polar group

Hydrophilic (water loving) group. Hydroxyl, carboxyl, carbonyl, amino, phosphate

Non-polar group

Hydrophobic, methyl group, not reactive, affects shape of molecule

Macromolecules

A very large organic molecule composed of many smaller molecules. Made up of large polymers

Polymer

small molecules made from identical or similar building blocks in chain.

Monomers

Building blocks of polymers

Dehydration reaction

A chemical reaction in which molecules combine by removing water. OH from one and H from another

Hydrolysis

Breaking down complex molecules by the chemical addition of water. OH attaches to one and H attaches to the other.

Enzymes

Macromolecules that speed up chemical reactions in cells (catalysts)

Carbohydrates

Typically hydrophilic, many hydroxyl groups

Monosaccharides

Simplest of sugars, multiple of CH2O, form rings of carbon, main fuel of cells

Sugars

carbohydrates found both in food and in the body

Dissccharide

2 monosaccharides

Polysaccharides

Lots of monosaccharides linked in dehydration reaction, storage molecules and structural functions, four types (starch, glucose, cellulose, chitin)

Starch

A storage polysaccharide in plants consisting entirely of glucose, used as carb bank, coil into helical shape (branched or unbranched), most animals have enzymes that hydrolyze starch

Glycogen

Glucose storage in animals (mostly in liver and muscle cells), highly branched, hydrolyze glycogen to release glucose when needed

Cellulose

Polymer of glucose, cable like, component of tough walls that enclose plant cells, some microorganisms can hydrolyze but animals cannot break it down

Chitin

A structural polysaccharide found in exoskeleton of insects and crustaceans and found in cell walls of fungi

Lipids

Hydrophobic, smallest macro, made up of monomers, includes fats, phospholide, and steroids

Fat

3 fatty acids linked to glycerol, aka triglyceride

Fatty acid

Carboxyl group bonded to hydrocarbon chain (non polar)

Glycerol

small sugar

unsaturated fatty acid

Hydrocarbon chain with only single and double bonds, liquid at room temperature, causes bends in chain, fats of plants and fish

saturated fatty acid

Only single bonds, solid at room temp, most animal fats

Partly hydrogenated oils

Unsaturated fats converted to saturated fats

Function of fats

Energy storage, plants store energy as carbs but animals store energy as fats (adipose tissue)

Phospholid

Main component of cell membrane, glycerol, two fatty acid chains, 1 phosphate, fatty acid tails in middle and glycerol heads on outside

What part of a phospholid is polar?

Phosphate/glycerol portion (water loving)

Steroids

Carbon skeleton with four fused rings, vary in chemical groups attached

Cholesterol

Common component of animal cell, precursor for production of steroids

Proteins

Polymer of amino acids, function depends on structure, proteins recognize and bond to other molecules, fold spontaneously into shape, bad folds cause diseases

Roles of proteins

Enzymes, transport molecule, defense protein, signaling protein, receptor protein, contractile protein, structural protein, storage protein

Shapes of proteins

Globular (most enzymes), fibrous (hair, tendons, ligaments)

Denaturation

loss of normal shape of a protein due to heat or other factor

Amino acids

Building blocks of protein, all have amino, carboxyl, and R group

Peptide bond

Dehydration reaction between carboxyl and amino group of amino acid

Dipeptide

Molecule or peptide with 2 amino acids

Polypeptide

Chain of amino acids, must be folded to make protein, R groups affect folding

Hydrophobic amino acids

have non polar R groups, R groups will cluster in centre if golbular

Hydrophilic amino acids

have polar or charged R groups, R groups on outside

Primary structure

sequence of amino acids in a polypeptide chain

Secondary structure

Segments of polypeptides chain coil into regional patterns

Tertiary structure

Overall shape of folded polypeptide

quaternary structure

Results from two or more polypeptide subunits, subunits interact to form proteins

Nucleic acid

a complex organic substance present in living cells, especially DNA or RNA, whose molecules consist of many nucleotides linked in a long chain.

Gene

Inheritance that determines the amino acid sequence of polypeptide

DNA

nucleic acid that a gene is made of, two polynucleotide strands with double helix bond, pairs held with hydrogen bonds, strands complementary

RNA

nucleic acid that assembles polypeptide according to steps from DNA, one polynucleotide strand

Nucleotides

Monomers that make up nucleic acid, 5 carbon sugar, have nitrogenous base, bound by dehydration reactions (sugar bonds to phosphate group)

Nitrogenous base

Structure that contains N and C

Polynucleotides

Polymer built from nucleotide monomers, have sugar phosphate backbone

DNA nucleotides

adenine, thymine, guanine, and cytosine

RNA nucleotides

adenine, guanine, cytosine, and uracil

Gene expression

Production of proteins with instructions from DNA, gene to RNA to protein, RNA interacts with protein building cell