Chapter 4 Flashcards
Foods are made of _____ which is composed of ___ ___, as either _____ or _____.
matter
pure substances
elements
compounds
Elements are the ____ form of matter - ____ be broken down further.
simplest
cannot
Compounds are made of ___ or ___ ____, _____ bonded in definite proportions by ____.
two more elements chemically weight
Compounds are represented as _____ that depict their _____ _____.
formulas
element
composition
Important compounds in food science are _____ compounds.
-All contain _____ (___), _____ (__), ____ (__) and sometimes ___ (__), ____ (__)or ____ (__).
organic carbon (C) Hydrogen (H) Oxygen (O) sulfur (S) Nitrogen (N) Phosphorus (P)
Matter can also exist as ____ in which two or more _____ are combined ____.
-___, ____, _____
mixtures
substances
physically
Solutions, dispersions, emulsions
_____ – one or two letter designations for elements depicted in the periodic table.
Symbols
Formulas – depicts all of the ____ in a ____, including ____ as ____ numbers.
elements
compound
proportions
subscribed
Equations– a ____ description of a ____ ___ using ___ ___ and ____.
Example:
C6H12O6 + 6 O2 6 CO2 + 6 H20 (breakdown of ____)
written chemical chemical symbols formulas glucose
Chemical reactions - ___/___ interact with each other through ___ ___.
-Results in a ___ ___ with different ___ from the ____.
atoms/molecules chemical bonding new substance properties reactants
Elements interact with one another via ___ ___, which requires ____.
-Only ____ are involved in chemical bonds.
chemical
bonds
energy
electrons
Electrons are ____ charged and are attracted to ____ charged ___.
___ can be seen as having a series of electron orbits.
negatively
positively
nucleus
atom
To determine maximum number of electrons in each energy level, use \_\_\_\_. 1st level – \_\_\_ 2nd level – \_\_ 3rd level – \_\_\_ 4th level – \_\_\_
X=2n^2 2 8 18 32
Most atoms become chemically stable when they have ___ electrons in their ____ shell (____ shell ).
Valence shell is the ____ electron ___.
8 outermost valence outer orbital
During chemical bonding, ____ elements are ____ according to the ___ given in their ___.
-____ Acid – C3H6O2
-Can be written as a ____ formula in order to ___ the bonding that takes place.
Exmaple: CH3 – CH2 – COOH
reacting combined proportions formula Propionic structural visualize
Covalent Bonds– occur when ____ are ___.
___, ___, or ___ pairs of elections can be shared resulting in ___, ___, ___ bonds.
electrons
shared
One, two or three
single, double, triple
__, ___, ___, and ___ have covalently bonded carbon atoms.
-Form the ____ of these molecules
Fats, proteins, carbs, vitamins
backbone
Ionic Bonds– the ___ of ___ between ___.
- Resulting in a ___ ____ shell of both ___.
- Elements that ____ electrons become ___ charged and are called ____ (____)
- Elements that ___ electrons are ___ charged and called ____ (___).
____ (NaCl) is an example of a compound with ionic bonding.
transfer electrons reactants full valence elements donate positively cations (sodium) receive negatively anions (chlorine) salt
- Hydrogen Bonds– a type of ____ bond with ___ rather than ___ sharing of ___, resulting in a ___ ___.
- Intermolecular bonds– ___ between ___ ___ molecules.
covalent unequal equal electrons weak force bonds two different
___ ___ (H bonding) They don’t ___, they just ___ with each other.
Static clinging
share
interact
Chemical reactions in foods: Generally classified as either ____ or ____ reactions.
-Either type may be either ____ or _____.
composition
decomposition
enzymatic
nonenzymatic
Composition reactions– __ or ___ substances combine resulting in a ____ ____ (____).
-Synthesis of ____ from ___ ___.
two more single product (A+B=AB) protein amino acids
Decomposition reactions– ___ substance becomes ___ ____ (____).
-____ of ____ yields two ____ molecules.
One substance two products (AB=A+B) hydrolysis maltose glucose
In food the effect of enzymes can be either:
- Positive- _____ of ____.
- Negative- ____ of ___ ___ and ____.
tenderization meat browning cut fruits vegetables
Enzymes are _____ ____ and serve as ____ ____ (cause ____ to speed ___) of chemical reactions.
specialized proteins biological catalyst reactions speed up
Active site–location where the ____ joins with the ____ to form the ____ ___ ___.
-____ ___ region that contains __ ___ that bind, __-____, to the substrate.
substrate enzyme enzyme substrate complex Three dimensional amino acids non-covalently
