Chemistry II (organic chemistry and molecules of life)

organic chemistry

the chemistry of carbon

the molecules of life

carbohydrates, lipids, proteins, nucleic acids

binding properties of carbon

can covalently bind up to 4 different atoms, can form single, double, and triple bonds

carbon can bind itself

creates infinite varity of carbon skeletons with energy rich covalent bonds

result of carbon binding

infinite diversity and complexity of organic molecules

hydrocarbons

composed entirely of hydrogen and carbon, very strong, forms stable portions of most biological molecules

dehydration reaction

monomer to polymer, cells join monomers into chains called polymers

dehydration reaction results

covalent linkage of the monomer to the chain through loss of a hydrogen molecule

hydrolysis reaction

cells break polymers down into monomers

carbohydrates function

energy-yielding fuel stores, extracellular structural elements and signals, bulk in fecesc

carbohydrates composition

building blocks of monosaccharides

monosaccharides examples

glucose, fructose, ribose, deoxyribose

disaccharides

2 monosaccharides covalently linked

disaccharides examples

sucrose, lactose, maltose

polysaccharides (complex carbohydrates)

many sugar units (same or different) covalently linked

polysaccharides examples

starch, glycogen, cellulose

starch

energy storage in plants, polymer of glucose subunits

amylase

an enzyme that breaks starch into monosaccharides usable by humans

glycogen

energy storage in animal cells, polymer of glucose subunits

cellulose

polymer of glucose, humans do not have cellulase so linkages cannot be hydrolyzed (fiber or bulk in feces)

lipids characterization

inability to dissolve water (hydrophobic)

lipids functions

protection, insulation, regulation, vitamins, structure, energy

lipid types

fats (triglyceride), phospholipids, steroids

fats (triglyceride)

building blocks, glycerol + 3 fatty acids, unsaturated fatty acids, saturated fatty acids, stored in adipose cells

unsaturated fatty acids

liquid at room temp, contain double bonds

saturated fatty acids

solid at room temp, no double bonds

phospholipids

phosphate replaces one of the fatty acids, form lipid bilayer with hydrophobic and hydrophilic molecular ends

steroids composition

carbon skeleton forms 4 fused rings, different steroids arise from different functional groups, cholesterol

cholesterol

serves as base steroid or building block

examples of steroids

cholesterol, bile salts, estrogen, progesterone, testosterone

proteins

polymer of amino acid monomers, each protein has a unique 3D structure that corresponds to a specific function

proteins function

regulation, transport, protection, contraction, structure, energy

monomers (amino acids) aa

all proteins are constructed from the same 20 amino acids

amino acids aa

only differ in the R group, gives each aa its special chemical behavior, aas are grouped together according to their side chain properties (hydrophobic/hydrophilic, etc.)

proteins as polymers

amino acids are linked together by dehydration reactions, forming a peptide bond

protein shape

a functional protein is 1 or more polypeptides precisely folded into a unique 3D shape, final 3D conformation facilitates its specific function

primary structure

sequence of amino acids held together by a peptide bond, sequence is determined by inherited genetic info, even a slight change in primary structure may affect structure and function of the protein

primary structure clinical

sickle-cell anemia

secondary structure

hydrogen bonds between the backbone of the primary structure, result is helical coil (alpha helix) or sheet-like array (beta pleated sheet)

tertiary structure

final 3 dimensional conformation of a protein that results from weak interactions between the R groups

chemical bonding between different parts of the polypeptide _____

reinforces the shape

quaternary structure

complexing of 2 or more polypeptide chains through weak interactions (hemoglobin)

fibrous (structural) proteins

extended and strandlike, insoluble in water and very stable, ideal for mechanical support and tensile strength

fibrous proteins examples

collagen, keratin, etc.

globular (functional) proteins

compact and spherical, water soluble and chemically active, play crucial roles in virtually all biological processes

globular proteins examples

antibodies, peptide hormones, enzymes, chaperones

protein denaturation

fibrous proteins with secondary final conformation are highly dependent on weak bonds to maintain shape and function, easily broken by chemicals and physical factors, thus causes protein to unravel and lose its normal 3D conformation → normal functioning is lost

enzymes

globular proteins that speed up chemical reactions (catalysts), usually end in -ase

enzymes clinical

lactose intolerance

nucleotides composition

5 carbon sugar (DNA and RNA), a base (A, T, C, G), and a phosphate group

nucleic acids

provide instructions for building proteins (blueprints for life)

DNA

double stranded, forms double helix, genetic messages are encoded in base sequence

DNA - in a gene….

the sequence of nucleotide bases is translated into amino acid sequence to make a specific protein

RNA

single stranded, function is assembly of proteins

adenosine triphosphate (ATP)

chemical energy used by all cells

ATP/ADP cycle

energy is released by breaking high-energy phosphate bond, then restoration of energy bonds for future use

how atp drives cellular work

transport work, mechanical work, chemical work