Ch. 7: Microbial Biochemistry Flashcards
biochemistry
- the discipline that studies the chemistry of life
- its objective is to explain form & function based on chemical principles
organic chemistry
the discipline devoted to the study of carbon-based chemistry, which is the foundation for the study of biomolecules & the discipline of biochemistry
macronutrients
most abundant elements in cells
- hydrogen (H), oxygen (O), nitrogen (N), phosphorous (P), sulfur (S)
- CHONPS
- account for 99% weight of cell
the four most abundant elements
- hydrogen
- carbon
- oxygen
- nitrogen
micronutrients
- trace elements
- required by some cells; essential to many biochemical reactions
examples of trace elements
- sodium (Na)
- potassium (K)
- zinc (Zc)
organic molecules
typically contain chains of carbon & hydrogen atoms
inorganic compounds
- don’t contain carbon
- make up 1-1.5% of cell weight
biomolecules
part of living matter & contain carbon
carbon skeleton
carbon atoms bind together in large #s producing this chain
- can be branched, straight, or ring shaped
isomers
molecules w/the same atomic makeup but different structural arrangement of atoms
structural formulas
serve as graphic representation of molecular structure, showing how the atom is arranged
structural isomers
compounds that have identical molecular formulas but differ in bonding sequence of the atoms
example of structural isomers
glucose, galactose, fructose
functional groups
groups of atoms w/in molecules that are categorized by their specific chemical composition & chemical reactions they perofmr
symbol R
stands for residue or remainder in chemical formula
hydrogen bonds
involving a hydrogen atom located between a pair of other atoms having a high affinity for electrons; such a bond is weaker than an ionic bond or covalent bond
hydroxyl functional group
-OH
methyl functional group
C-CH3
carboxyl functional group
Carbonyl
amino
phosphatw
sulfhydryl
macromolecules
large molecules formed by linking together a great # of identical, or very similar, smaller organic molecules
monomers
smaller molecules that act as building blocks
polymers
macromolecules that result from linking monomers together
what are the main groups of carbon containing molecules
- proteins
- carbohydrates
- lipids
- nucleic acids
carbohydrates
energy storage, receptors, food, structural role in plants, fungal cell walls, exoskeleton of insects
lipids
energy storage, membrane structure, insulation, hormones, pigments
- composed of hydrogen & carbon
nucleic acids
storage & transfer of genetic information
proteins
enzymes, structure, receptors, transport, structural role in cytoskeleton of a cell & extracellular matrix
- when # of amino acids becomes very large or when multiple polypeptides are used as building subunits these result
dehydration synthesis
monomer molecules bind end to end in process that results in formation of water molecules as byproduct
covalent bond
a water molecule is removed as 2 monosaccharides are linked
monosaccharides
- simple sugars
- simplest carbohydrate
- 4 or more are stable in cyclic or ring structure
disaccharide
2 monosaccharides chemically bonded
glycosidic bond
name given to covalent bond between 2 monosaccharides
polysaccharide (glycans)
large polymers composed of hundreds of monosaccharide monomers
what are the most important polysaccharides
starch, glycogen, cellulose
- cellulose = linear, structural component
- glycogen = branched, energy storage in animals & bacteria
- starch = branched; energy storage in plants
peptidoglycan composed of what
alternating NAG & NAM units
NAG stands for
N-acetylglucosamine
NAM stands for
N-acetylmuramic acid
chitin composed of what
polymers of NAG
fatty acids
lipids that contain long-chain hydrocarbons terminated w/carboxylic acid functional group
hydrophobic
water fearing; water repelling
hydrophilic
water loving
saturated fatty acids
- fatty acids w/ hydrocarbon chains that contain single bonds
- have greatest # of hydrogen atoms possible & are therefor saturated
- solid at room temp
- example: stearic acid
unsaturated fatty acids
- fatty acids w/hydrocarbon chains containing at least one double bond
- liquid at room temp
- example: oleic acid
unsaturated fatty acids
- trfatty acids w/hydrocarbon chains containing at least one double bond
- liquid at room temp
- example: oleic acid
triglyceride (triacylglycerol)
formed when 3 fatty acids are chemically linked to a glycerol molecule
- primary components of adipose & sebum
ester linkage (bond)
a compound derived from an acid in which at least one acidic hydrogen atom of that acid is replaced by an organyl group.
complex lipids
contain at least 1 additional component, such as phosphate group (phospholipid) or carbohydrate moiety (glycolipid)
phospholipid
glycolipid
amphipathic
molecule presenting w/a hydrophobic portion & a hydrophilic portion
steroids
complex ring structures found in cell membranes
most common type of steroid
cholesterol
amino acid
organic molecule that has a central carbon atom referred to as a alpha carbon bonded to H atom side chain, -COOH, NH3; 4th group bonded to carbon varies and is called side chain and is represented by R
oligopeptide
formed by joining up to approx. 20 amino acids
polypeptide
formed from up to 50 amino acids
4 levels of protein structure
- primary
- secondary
- tertiary
- quaternary
primary protein structure
simply the sequence of amino acids that make up the polypeptide chain
secondary protein structure
- long chains where hydrogen bonding may occur between amino & carbonyl groups w/in peptide backbone
- results in localized folding of polypeptide chain into helices and sheets
tertiary
large scale 3D shape of a single polypeptide chain
- these interactions can result in this: disulfide bridges, hydrogen bonds, ionic bonds, hydrophobic reactions
disulfide bridges
bond between SH functional groups
quaternary structure
interactions that hold together protein subunits
native structure
folded proteins that are fully functional in their normal biological role
denature
when proteins lose 3D shape & are longer functioning
conjugated proteins
have a nonprotein portion
glycoprotein
carbohydrate w/protein
lipoprotein
carbohydrate w/lipid
