Week 7-Course1 Flashcards
What is the only substance that is found in the three states (gas/liquid/solid) under standard conditions?
Water
T or F : water is a nutrient
True
What are the functions of water in the human body? (3)
- helps control body temperature
- transports nutrients and waste products
- provides the solution for metabolic reactions
H2O has 2 hydrogen and one oxygen held together by ___ bonds that is ____ because of the partial charges
covalent
polar
Between the water molecules (intermolecular) there is ____ bonds resulting from the ____ charges of oxygen and ____ charges of hydrogen
hydrogen
Partial negative from oxygen
Partial positive of hydrogen
Why is water, a small molecule is not present in gaseous state
Because of the partial negativity of oxygen and partial positive of hydrogen that will results in intermolecular hydrogen bonds.
What properties the hydrogen bonding gives to the water? (4)
- cling to something else as well as itself
- have a higher melting and boiling point than other compounds
- freeze faster than it thaws
- form a crystalline structure in the solid state
Why is water a great solvent?
Because it can form hydrogen bonds so it can dissolve the polar substances
What are the two solutions that can be formed when dissolving in water
1- complete dissolution
2-incomplete dissolution
What is incomplete dissolution and what kind of nutrients are incompletely dissolved in water
protein and starches, their molecules remains intact but there is a small layer around the molecules that allow them to be dispersed in the water
What is complete dissolution and what kind of nutrients are completely dissolved in water
Sugars and salts, they dissolve completely in water because they form bonds with the hydrogen of water.
T or F : Atmospheric pressure doesn’t impacts the boiling and freezing points
false, water boils at higher temperature in low altitudes
T or F : it is nearly impossible to find water in it’s pure form
t
What changes in water can results if there is impurities?
1-physical and chemical characterisitics
2-flavor and color
3-boiling and freeezing points
4-hydrogen bonding
___ and ____ increase the boiling point and lower the freezing point
salt and sugar
Complete : the amount of H2O present in a food product is related to it’s _____
perishability
Why does water has an effect on the perishability? (2)
- because it is both a reactant and a reaction medium
2. because required by the microbes for growth
What are the two types or perishability?
1-deterioation
2-spoilage
What is deterioation?
chemical reactions that happens naturally in that product over
time. Every product that is left overtime will have continued chemical reactions and these will lead
to the deterioaration of the quality and the sensories properties of the product.
What is spoilage?
dammage that is indued by microorganisms wether they are bacteria, yeast or fungi.
This also leads to the deterioaration of the quality and the sensories properties of the product
T or F : spoilage and deterioation are synonyms
false, they contribute to the perishability but are not due to the same factors
What are the three form of water?
1-Free water
2-hydrate water
3-bound water
Give the characteristics of free water
- is easily separated from food tissue
- often contains dissolved compounds
- boils and freezes easily
- readily evaporates when foods are dried
Give the characteristics of hydrate water
- is any compound loosely bound with water
- must be boiled to be free of water, known as anhydrous
Give the characteristics of bound water
- is tied to the structure of larger molecules
- does not easily freeze or boil
- chemically reacts as part of the larger molecule
- can’t be extracted
T or F : the type of water affect the perishability
true
T or F : if two foods product have 88% water content, they will have the same perishability
False, it depends on the free water content
The high surface tension of water is explained by its high level
of ……
hydrogen bonds
Reduced water holding capacity of meat proteins
makes the meat ……
chewy
